# Petroleum Office
> Petroleum engineering calculation platform — Excel add-in for PVT, DCA, VFP, IPR, SCAL, and more

## Pages
- [Home](/home.md): Product overview, Excel functions, tools, and pricing
- [Pricing](/pricing.md): Subscription plans and FAQ
- [Tools](/tools.md): Productivity tools — Unit Converter, LAS Import, Eclipse Import, Case Generation
- [Academic Program](/academics.md): Free access for students and faculty at participating universities

## Functions
- [PO.DCA.AKB.D](/function/po.dca.akb.d.md): Calculates instantaneous decline rate D(t) for Ansah-Knowles-Buba (2000) decline, [1/T]. Computed numerically.
- [PO.DCA.AKB.EUR](/function/po.dca.akb.eur.md): Estimated Ultimate Recovery (EUR) to an economic rate limit for Ansah-Knowles-Buba (2000) decline, [L3]. Returns cumulative production up to the time the rate reaches the economic limit.
- [PO.DCA.AKB.Fit](/function/po.dca.akb.fit.md): Fit Ansah-Knowles-Buba (2000) decline to rate-time data and return parameters as a row array [Qi, Alpha, Beta].
- [PO.DCA.AKB.Prod](/function/po.dca.akb.prod.md): Calculates cumulative production using Ansah-Knowles-Buba (2000) semi-analytical decline model for bounded reservoirs. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.AKB.Rate](/function/po.dca.akb.rate.md): Calculates production rate using Ansah-Knowles-Buba (2000) semi-analytical decline model for bounded reservoirs. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.AKB.Time](/function/po.dca.akb.time.md): Time to reach an economic rate limit for Ansah-Knowles-Buba (2000) decline, [T]. Returns the time when the production rate falls to the specified economic limit.
- [PO.DCA.AKB.WFit](/function/po.dca.akb.wfit.md): Weighted fit of Ansah-Knowles-Buba (2000) decline to rate-time data and return parameters as a row array [Qi, Alpha, Beta].
- [PO.DCA.Arps.D](/function/po.dca.arps.d.md): Calculates instantaneous decline rate D(t) for Arps decline, [1/T]. D(t) = Di/(1+b×Di×t). Computed numerically.
- [PO.DCA.Arps.EUR](/function/po.dca.arps.eur.md): Estimated Ultimate Recovery (EUR) to an economic rate limit for Arps decline, [L3]. Returns cumulative production up to the time the rate reaches the economic limit.
- [PO.DCA.Arps.Fit](/function/po.dca.arps.fit.md): Fit Arps decline to rate-time data and return parameters as a row array [Qi, Di, b].
- [PO.DCA.Arps.Prod](/function/po.dca.arps.prod.md): Calculates cumulative production using Arps (1945) decline curve, [L3]. Units of volume [L3] and time [T] must be consistent. Use b=0 for exponential, 0<b<1 for hyperbolic, b=1 for harmonic.
- [PO.DCA.Arps.Rate](/function/po.dca.arps.rate.md): Calculates rate using Arps (1945) decline curve, [L3/T]. Units of volume [L3] and time [T] must be consistent. Use b=0 for exponential, 0<b<1 for hyperbolic, b=1 for harmonic.
- [PO.DCA.Arps.Time](/function/po.dca.arps.time.md): Time to reach an economic rate limit for Arps decline, [T]. Returns the time when the production rate falls to the specified economic limit.
- [PO.DCA.Arps.WFit](/function/po.dca.arps.wfit.md): Fit Arps decline to rate-time data with weights and return parameters as a row array [Qi, Di, b].
- [PO.DCA.Convert.AnnualToMonthly](/function/po.dca.convert.annualtomonthly.md): Converts annual effective decline rate to monthly effective decline rate using compound conversion.
- [PO.DCA.Convert.DailyToAnnual](/function/po.dca.convert.dailytoannual.md): Converts daily effective decline rate to annual effective decline rate using compound conversion.
- [PO.DCA.Convert.EffectiveToNominal](/function/po.dca.convert.effectivetonominal.md): Converts effective (periodic) decline rate to nominal (continuous) decline rate. Dn = -ln(1 - De).
- [PO.DCA.Convert.MonthlyToAnnual](/function/po.dca.convert.monthlytoannual.md): Converts monthly effective decline rate to annual effective decline rate using compound conversion.
- [PO.DCA.Convert.NominalToEffective](/function/po.dca.convert.nominaltoeffective.md): Converts nominal (continuous) decline rate to effective (periodic) decline rate. De = 1 - exp(-Dn).
- [PO.DCA.Data.Clean](/function/po.dca.data.clean.md): Cleans production data by interpolating over outlier points. Returns cleaned rate array with outliers replaced by interpolated values.
- [PO.DCA.Data.OutlierFlag](/function/po.dca.data.outlierflag.md): Flags outliers using rolling window Z-score analysis. Returns TRUE for data points that are outliers based on local statistics.
- [PO.DCA.Diag.Beta](/function/po.dca.diag.beta.md): Computes the beta diagnostic β = t×D(t) for flow regime identification. β≈0.5: linear flow, β≈0.25: bilinear, β≈1.0: boundary-dominated.
- [PO.DCA.Diag.Bourdet](/function/po.dca.diag.bourdet.md): Calculates the Bourdet (smoothed) derivative at point t. Used for flow regime identification and production diagnostics.
- [PO.DCA.Diag.bParam](/function/po.dca.diag.bparam.md): Computes the time-varying Arps b-parameter. b=0: exponential, 0<b<1: hyperbolic, b=1: harmonic, b>1: transient (unconventional).
- [PO.DCA.Duong.D](/function/po.dca.duong.d.md): Calculates instantaneous decline rate D(t) for Duong model, [1/T]. Computed numerically.
- [PO.DCA.Duong.EUR](/function/po.dca.duong.eur.md): Estimated Ultimate Recovery (EUR) to an economic rate limit for Duong decline, [L3].
- [PO.DCA.Duong.Fit](/function/po.dca.duong.fit.md): Fit Duong decline to rate-time data and return parameters as a row array [q1, qInf, a, m].
- [PO.DCA.Duong.Prod](/function/po.dca.duong.prod.md): Calculates cumulative production using Duong decline model, [L3]. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.Duong.Rate](/function/po.dca.duong.rate.md): Calculates rate using Duong decline model, [L3/T]. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.Duong.Time](/function/po.dca.duong.time.md): Time to reach an economic rate limit for Duong decline, [T]. Returns the time when the rate falls to the specified limit.
- [PO.DCA.Duong.WFit](/function/po.dca.duong.wfit.md): Weighted fit of Duong decline to rate-time data and return parameters as a row array [q1, qInf, a, m].
- [PO.DCA.EEDM.D](/function/po.dca.eedm.d.md): Calculates instantaneous decline rate D(t) for Extended Exponential Decline Model (EEDM), [1/T]. Computed analytically.
- [PO.DCA.EEDM.EUR](/function/po.dca.eedm.eur.md): Estimated Ultimate Recovery (EUR) for Extended Exponential Decline Model (EEDM). Returns Q0/BetaL (approximate EUR based on terminal decline), [L3].
- [PO.DCA.EEDM.Fit](/function/po.dca.eedm.fit.md): Fit Extended Exponential Decline Model (EEDM) to rate-time data and return parameters as a row array [Q0, BetaL, BetaE, n].
- [PO.DCA.EEDM.Prod](/function/po.dca.eedm.prod.md): Calculates cumulative production using Extended Exponential Decline Model (EEDM). Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.EEDM.Rate](/function/po.dca.eedm.rate.md): Calculates production rate using Extended Exponential Decline Model (EEDM). Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.EEDM.Time](/function/po.dca.eedm.time.md): Time to reach an economic rate limit for Extended Exponential Decline Model (EEDM), [T].
- [PO.DCA.EEDM.WFit](/function/po.dca.eedm.wfit.md): Weighted fit of Extended Exponential Decline Model (EEDM) to rate-time data and return parameters as a row array [Q0, BetaL, BetaE, n].
- [PO.DCA.LGM.D](/function/po.dca.lgm.d.md): Calculates instantaneous decline rate D(t) for Logistic Growth Model (LGM), [1/T]. Computed analytically.
- [PO.DCA.LGM.EUR](/function/po.dca.lgm.eur.md): Estimated Ultimate Recovery (EUR) for Logistic Growth Model (LGM). Returns K (carrying capacity), [L3].
- [PO.DCA.LGM.Fit](/function/po.dca.lgm.fit.md): Fit Logistic Growth Model (LGM) to rate-time data and return parameters as a row array [K, a, n].
- [PO.DCA.LGM.Prod](/function/po.dca.lgm.prod.md): Calculates cumulative production using Logistic Growth Model (LGM). Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.LGM.Rate](/function/po.dca.lgm.rate.md): Calculates production rate using Logistic Growth Model (LGM). Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.LGM.Time](/function/po.dca.lgm.time.md): Time to reach an economic rate limit for Logistic Growth Model (LGM), [T].
- [PO.DCA.LGM.WFit](/function/po.dca.lgm.wfit.md): Weighted fit of Logistic Growth Model (LGM) to rate-time data and return parameters as a row array [K, a, n].
- [PO.DCA.ModHyp.D](/function/po.dca.modhyp.d.md): Calculates instantaneous decline rate D(t) for Modified Hyperbolic decline, [1/T]. Computed numerically.
- [PO.DCA.ModHyp.EUR](/function/po.dca.modhyp.eur.md): Estimated Ultimate Recovery (EUR) to an economic rate limit for modified hyperbolic decline, [L3]. Returns cumulative production up to the time the rate reaches the economic limit.
- [PO.DCA.ModHyp.Fit](/function/po.dca.modhyp.fit.md): Fit Modified Hyperbolic decline to rate-time data and return parameters as a row array [Qi, Di, Dlim, b].
- [PO.DCA.ModHyp.Prod](/function/po.dca.modhyp.prod.md): Calculates cumulative production using modified hyperbolic production decline curve. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.ModHyp.Rate](/function/po.dca.modhyp.rate.md): Calculates rate using modified hyperbolic production decline curve. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.ModHyp.Time](/function/po.dca.modhyp.time.md): Time to reach an economic rate limit for modified hyperbolic decline, [T]. Returns the time when the production rate falls to the specified economic limit.
- [PO.DCA.ModHyp.WFit](/function/po.dca.modhyp.wfit.md): Weighted fit of Modified Hyperbolic decline to rate-time data and return parameters as a row array [Qi, Di, Dlim, b].
- [PO.DCA.PLE.D](/function/po.dca.ple.d.md): Calculates instantaneous decline rate D(t) for Power Law Exponential (PLE) model, [1/T]. D(t) = D∞ + n×Di0×t^(n-1). Computed numerically.
- [PO.DCA.PLE.EUR](/function/po.dca.ple.eur.md): Estimated Ultimate Recovery (EUR) to an economic rate limit for Power Law Exponential (PLE) decline, [L3]. Returns cumulative production up to the time the rate reaches the economic limit.
- [PO.DCA.PLE.Fit](/function/po.dca.ple.fit.md): Fit Power Law Exponential (PLE) decline to rate-time data and return parameters as a row array [Qi_intercept, Di_intercept, D_inf, n].
- [PO.DCA.PLE.Prod](/function/po.dca.ple.prod.md): Calculates cumulative production using Power Law Exponential (PLE) rate decline model. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.PLE.Rate](/function/po.dca.ple.rate.md): Calculates production rate using Power Law Exponential (PLE) rate decline model. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.PLE.Time](/function/po.dca.ple.time.md): Time to reach an economic rate limit for Power Law Exponential (PLE) decline, [T]. Returns the time when the production rate falls to the specified economic limit.
- [PO.DCA.PLE.WFit](/function/po.dca.ple.wfit.md): Weighted fit of Power Law Exponential (PLE) decline to rate-time data and return parameters as a row array [Qi_intercept, Di_intercept, D_inf, n].
- [PO.DCA.SEDM.D](/function/po.dca.sedm.d.md): Calculates instantaneous decline rate D(t) for Stretched Exponential model, [1/T]. D(t) = (n/τ)×(t/τ)^(n-1). Computed numerically.
- [PO.DCA.SEDM.EUR](/function/po.dca.sedm.eur.md): Estimated Ultimate Recovery (EUR) to an economic rate limit for Stretched Exponential decline, [L3].
- [PO.DCA.SEDM.Fit](/function/po.dca.sedm.fit.md): Fit Stretched Exponential decline to rate-time data and return parameters as a row array [Qi, Tau, N].
- [PO.DCA.SEDM.Prod](/function/po.dca.sedm.prod.md): Calculates cumulative production using Stretched Exponential decline model. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.SEDM.Rate](/function/po.dca.sedm.rate.md): Calculates production rate using Stretched Exponential decline model. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.SEDM.Time](/function/po.dca.sedm.time.md): Time to reach an economic rate limit for Stretched Exponential decline, [T].
- [PO.DCA.SEDM.WFit](/function/po.dca.sedm.wfit.md): Weighted fit of Stretched Exponential decline to rate-time data and return parameters as a row array [Qi, Tau, N].
- [PO.DCA.THM.D](/function/po.dca.thm.d.md): Calculates instantaneous decline rate D(t) for Transient Hyperbolic Model, [1/T]. Computed analytically.
- [PO.DCA.THM.EUR](/function/po.dca.thm.eur.md): Estimated Ultimate Recovery (EUR) to an economic rate limit for Transient Hyperbolic Model, [L3].
- [PO.DCA.THM.Fit](/function/po.dca.thm.fit.md): Fit Transient Hyperbolic Model to rate-time data and return parameters as a row array [Qi, Di, bi, bf, telf].
- [PO.DCA.THM.Prod](/function/po.dca.thm.prod.md): Calculates cumulative production using Transient Hyperbolic Model. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.THM.Rate](/function/po.dca.thm.rate.md): Calculates production rate using Transient Hyperbolic Model. Units of volume [L3] and time [T] must be consistent.
- [PO.DCA.THM.Time](/function/po.dca.thm.time.md): Time to reach an economic rate limit for Transient Hyperbolic Model, [T].
- [PO.DCA.THM.WFit](/function/po.dca.thm.wfit.md): Weighted fit of Transient Hyperbolic Model to rate-time data and return parameters as a row array [Qi, Di, bi, bf, telf].
- [PO.EoS.Component.Exists](/function/po.eos.component.exists.md): Checks if a component exists in the database. Returns TRUE or FALSE.
- [PO.EoS.Component.List](/function/po.eos.component.list.md): Returns a list of all available component names in the database.
- [PO.EoS.Component.Props](/function/po.eos.component.props.md): Returns component properties [Tc, Pc, omega, Mw] as a row array from the database. Spills horizontally into 4 cells.
- [PO.EoS.Envelope.PR](/function/po.eos.envelope.pr.md): Phase envelope using Peng-Robinson EoS. Output: 'bubble_T', 'bubble_P', 'dew_T', 'dew_P' (arrays), or 'cricondenbar_P/T', 'cricondentherm_P/T', 'critical_P/T' (scalars).
- [PO.EoS.Envelope.SRK](/function/po.eos.envelope.srk.md): Phase envelope using SRK EoS. Output: 'bubble_T', 'bubble_P', 'dew_T', 'dew_P' (arrays), or 'cricondenbar_P/T', 'cricondentherm_P/T', 'critical_P/T' (scalars).
- [PO.EoS.Flash.PR](/function/po.eos.flash.pr.md): PT Flash calculation using Peng-Robinson EoS. Returns V (vapor fraction), L (liquid fraction), x (liquid composition), y (vapor composition), or K (K-values) based on output parameter.
- [PO.EoS.Flash.SRK](/function/po.eos.flash.srk.md): PT Flash calculation using SRK EoS. Returns V (vapor fraction), L (liquid fraction), x (liquid composition), y (vapor composition), or K (K-values) based on output parameter.
- [PO.EoS.Fug.PR](/function/po.eos.fug.pr.md): Calculates fugacity for all components using Peng-Robinson EoS, [Pa]. Returns array.
- [PO.EoS.Fug.SRK](/function/po.eos.fug.srk.md): Calculates fugacity for all components using SRK EoS, [Pa]. Returns array.
- [PO.EoS.Ki.PR](/function/po.eos.ki.pr.md): Calculates K-values (equilibrium ratios Ki = φL/φV) using Peng-Robinson EoS, [-]. Returns array.
- [PO.EoS.Ki.SRK](/function/po.eos.ki.srk.md): Calculates K-values (equilibrium ratios Ki = φL/φV) using SRK EoS, [-]. Returns array.
- [PO.EoS.Kij.ChuehPrausnitz](/function/po.eos.kij.chuehprausnitz.md): Estimates binary interaction parameter kij from critical volumes using Chueh-Prausnitz correlation, [-].
- [PO.EoS.Kij.Matrix](/function/po.eos.kij.matrix.md): Generates N×N binary interaction parameter matrix using correlation. Methods: 'Nikos' (PR, T-dependent), 'Elliot-Daubert' (SRK), 'Chueh-Prausnitz'. Returns N×N array.
- [PO.EoS.Mixture.Mw](/function/po.eos.mixture.mw.md): Calculates mixture molecular weight from mole fractions and property table, [kg/mol].
- [PO.EoS.Pb.PR](/function/po.eos.pb.pr.md): Calculates bubble point pressure using Peng-Robinson EoS, [Pa].
- [PO.EoS.Pb.SRK](/function/po.eos.pb.srk.md): Calculates bubble point pressure using SRK EoS, [Pa].
- [PO.EoS.Pdew.PR](/function/po.eos.pdew.pr.md): Calculates dew point pressure using Peng-Robinson EoS, [Pa].
- [PO.EoS.Pdew.SRK](/function/po.eos.pdew.srk.md): Calculates dew point pressure using SRK EoS, [Pa].
- [PO.EoS.Phi.PR](/function/po.eos.phi.pr.md): Calculates fugacity coefficients for all components using Peng-Robinson EoS, [-]. Returns array.
- [PO.EoS.Phi.SRK](/function/po.eos.phi.srk.md): Calculates fugacity coefficients for all components using SRK EoS, [-]. Returns array.
- [PO.EoS.Rho.PR](/function/po.eos.rho.pr.md): Calculates density using Peng-Robinson EoS, [kg/m³].
- [PO.EoS.Rho.SRK](/function/po.eos.rho.srk.md): Calculates density using SRK EoS, [kg/m³].
- [PO.EoS.SCN.Props](/function/po.eos.scn.props.md): Returns Katz-Firoozabadi SCN properties [Tc, Pc, omega, Mw] as a row array. Carbon number range: 6-45.
- [PO.EoS.Tb.PR](/function/po.eos.tb.pr.md): Calculates bubble point temperature using Peng-Robinson EoS, [K].
- [PO.EoS.Tb.SRK](/function/po.eos.tb.srk.md): Calculates bubble point temperature using SRK EoS, [K].
- [PO.EoS.Tdew.PR](/function/po.eos.tdew.pr.md): Calculates dew point temperature using Peng-Robinson EoS, [K].
- [PO.EoS.Tdew.SRK](/function/po.eos.tdew.srk.md): Calculates dew point temperature using SRK EoS, [K].
- [PO.EoS.Vm.PR](/function/po.eos.vm.pr.md): Calculates molar volume using Peng-Robinson EoS, [m³/mol].
- [PO.EoS.Vm.SRK](/function/po.eos.vm.srk.md): Calculates molar volume using SRK EoS, [m³/mol].
- [PO.EoS.Z.PR](/function/po.eos.z.pr.md): Calculates compressibility factor using Peng-Robinson EoS, [-]. Returns Z for specified phase.
- [PO.EoS.Z.SRK](/function/po.eos.z.srk.md): Calculates compressibility factor using SRK EoS, [-]. Returns Z for specified phase.
- [PO.ESP.BrakeHP](/function/po.esp.brakehp.md): Calculates brake horsepower accounting for pump efficiency, [HP].
- [PO.ESP.BrakeHP.FromRate](/function/po.esp.brakehp.fromrate.md): Calculates brake horsepower directly from rate and head, [HP].
- [PO.ESP.Cable.CrossSection](/function/po.esp.cable.crosssection.md): Returns cable cross-sectional area, [kcmil].
- [PO.ESP.Cable.MinSize](/function/po.esp.cable.minsize.md): Determines minimum cable size for voltage drop limit, [AWG].
- [PO.ESP.Cable.PowerLoss](/function/po.esp.cable.powerloss.md): Calculates power loss in cable, [kW].
- [PO.ESP.Cable.PowerLoss.Pct](/function/po.esp.cable.powerloss.pct.md): Calculates power loss as percentage of motor power, [%].
- [PO.ESP.Cable.Resistance](/function/po.esp.cable.resistance.md): Returns cable resistance at temperature, [ohm/1000ft].
- [PO.ESP.Cable.Temperature](/function/po.esp.cable.temperature.md): Estimates cable temperature with current, [degF].
- [PO.ESP.Cable.Vdrop](/function/po.esp.cable.vdrop.md): Calculates voltage drop in ESP cable (3-phase), [V].
- [PO.ESP.Cable.Vdrop.Full](/function/po.esp.cable.vdrop.full.md): Complete voltage drop calculation, [V].
- [PO.ESP.Cable.Vdrop.Pct](/function/po.esp.cable.vdrop.pct.md): Calculates voltage drop as percentage, [%].
- [PO.ESP.Cable.Vdrop.Status](/function/po.esp.cable.vdrop.status.md): Returns voltage drop status.
- [PO.ESP.Cable.Vmotor](/function/po.esp.cable.vmotor.md): Calculates voltage at motor terminals, [V].
- [PO.ESP.Cable.Vsurface](/function/po.esp.cable.vsurface.md): Calculates required surface voltage, [V].
- [PO.ESP.Curve.BEP](/function/po.esp.curve.bep.md): Returns Best Efficiency Point flow rate from pump curve, [bbl/d].
- [PO.ESP.Curve.BEP.Eff](/function/po.esp.curve.bep.eff.md): Returns maximum efficiency value from pump curve, [fraction].
- [PO.ESP.Curve.Efficiency](/function/po.esp.curve.efficiency.md): Interpolates efficiency from pump performance curve, [fraction].
- [PO.ESP.Curve.Head](/function/po.esp.curve.head.md): Interpolates head from pump performance curve, [ft/stage].
- [PO.ESP.Curve.InRange](/function/po.esp.curve.inrange.md): Checks if operating point is within recommended range.
- [PO.ESP.Curve.Power](/function/po.esp.curve.power.md): Interpolates power per stage from pump curve, [HP/stage].
- [PO.ESP.Curve.Range.Status](/function/po.esp.curve.range.status.md): Returns descriptive operating range status.
- [PO.ESP.Gas.Dunbar.Factor](/function/po.esp.gas.dunbar.factor.md): Calculates Dunbar gas correction factor, [dimensionless].
- [PO.ESP.Gas.Qg.Free](/function/po.esp.gas.qg.free.md): Calculates free gas rate at pump intake conditions, [rcf/d].
- [PO.ESP.Gas.Ql.Total](/function/po.esp.gas.ql.total.md): Calculates total liquid rate at pump intake, [bbl/d].
- [PO.ESP.Gas.Recommendation](/function/po.esp.gas.recommendation.md): Returns gas handling recommendation based on void fraction.
- [PO.ESP.Gas.RhoMix](/function/po.esp.gas.rhomix.md): Calculates gas-liquid mixture density, [lb/ft3].
- [PO.ESP.Gas.Sep.Eff](/function/po.esp.gas.sep.eff.md): Estimates rotary gas separator efficiency, [fraction].
- [PO.ESP.Gas.Turpin.Factor](/function/po.esp.gas.turpin.factor.md): Calculates Turpin gas handling factor, [dimensionless].
- [PO.ESP.Gas.Void](/function/po.esp.gas.void.md): Calculates gas void fraction at pump intake, [fraction].
- [PO.ESP.Gas.Void.Full](/function/po.esp.gas.void.full.md): Complete gas void fraction calculation from field data, [fraction].
- [PO.ESP.Gas.Void.PostSep](/function/po.esp.gas.void.postsep.md): Calculates void fraction after gas separator, [fraction].
- [PO.ESP.Head.FromPressure](/function/po.esp.head.frompressure.md): Converts pressure to head using fluid specific gravity, [ft].
- [PO.ESP.Head.PressureAtDepth](/function/po.esp.head.pressureatdepth.md): Calculates pressure at depth given surface pressure, [psi].
- [PO.ESP.Head.Static](/function/po.esp.head.static.md): Calculates static head from vertical depth, [ft].
- [PO.ESP.Head.ToPressure](/function/po.esp.head.topressure.md): Converts head to pressure using fluid specific gravity, [psi].
- [PO.ESP.HydraulicHP](/function/po.esp.hydraulichp.md): Calculates theoretical hydraulic horsepower (bbl/d basis), [HP].
- [PO.ESP.HydraulicHP.GPM](/function/po.esp.hydraulichp.gpm.md): Calculates theoretical hydraulic horsepower (gpm basis), [HP].
- [PO.ESP.Motor.Amps](/function/po.esp.motor.amps.md): Calculates motor current draw (3-phase), [A].
- [PO.ESP.Motor.Amps.FromNameplate](/function/po.esp.motor.amps.fromnameplate.md): Calculates current from motor nameplate data, [A].
- [PO.ESP.Motor.Eff.AtLoad](/function/po.esp.motor.eff.atload.md): Estimates motor efficiency at partial load, [fraction].
- [PO.ESP.Motor.Load.Status](/function/po.esp.motor.load.status.md): Returns motor load status description.
- [PO.ESP.Motor.LoadFactor](/function/po.esp.motor.loadfactor.md): Calculates motor load as fraction of rating, [fraction].
- [PO.ESP.Motor.PowerKW](/function/po.esp.motor.powerkw.md): Calculates motor power consumption (3-phase), [kW].
- [PO.ESP.Motor.Qcool](/function/po.esp.motor.qcool.md): Calculates minimum flow rate for motor cooling, [bbl/d].
- [PO.ESP.Motor.RequiredHP](/function/po.esp.motor.requiredhp.md): Calculates minimum motor horsepower with safety factor, [HP].
- [PO.ESP.Motor.Temp.Rise](/function/po.esp.motor.temp.rise.md): Estimates motor temperature at operating conditions, [degF].
- [PO.ESP.Motor.V.Nearest](/function/po.esp.motor.v.nearest.md): Returns nearest standard ESP motor voltage, [V].
- [PO.ESP.Nodal.AOF](/function/po.esp.nodal.aof.md): Calculates Absolute Open Flow potential, [STB/d].
- [PO.ESP.Nodal.Drawdown](/function/po.esp.nodal.drawdown.md): Calculates drawdown at given production rate, [psi].
- [PO.ESP.Nodal.Submergence](/function/po.esp.nodal.submergence.md): Calculates submergence above pump intake, [ft].
- [PO.ESP.Pump.Efficiency](/function/po.esp.pump.efficiency.md): Calculates pump efficiency from hydraulic and brake HP, [fraction].
- [PO.ESP.Pump.Pdis](/function/po.esp.pump.pdis.md): Calculates pump discharge pressure, [psi].
- [PO.ESP.Pump.SG.Mix](/function/po.esp.pump.sg.mix.md): Calculates composite SG for oil-water mixture, [dimensionless].
- [PO.ESP.Pump.TotalHead](/function/po.esp.pump.totalhead.md): Calculates total head from number of stages, [ft].
- [PO.ESP.Pump.TotalPower](/function/po.esp.pump.totalpower.md): Calculates total power from number of stages, [HP].
- [PO.ESP.Stages](/function/po.esp.stages.md): Calculates required number of pump stages (rounded up), [stages].
- [PO.ESP.Stages.Actual](/function/po.esp.stages.actual.md): Returns exact (non-rounded) stage count for sensitivity analysis, [stages].
- [PO.ESP.System.Hfric](/function/po.esp.system.hfric.md): Simplified friction head calculation, [ft].
- [PO.ESP.TDH](/function/po.esp.tdh.md): Calculates Total Dynamic Head for ESP sizing, [ft].
- [PO.ESP.TDH.Full](/function/po.esp.tdh.full.md): Extended TDH calculation with IPR-based PIP, [ft].
- [PO.ESP.TDH.NetLift](/function/po.esp.tdh.netlift.md): Calculates net vertical lift (pump depth minus fluid level), [ft].
- [PO.ESP.Viscosity.Eff.Corr](/function/po.esp.viscosity.eff.corr.md): Applies viscosity correction to efficiency, [fraction].
- [PO.ESP.Viscosity.Head.Corr](/function/po.esp.viscosity.head.corr.md): Applies viscosity correction to head, [ft].
- [PO.ESP.Viscosity.Quick.Factor](/function/po.esp.viscosity.quick.factor.md): Simplified viscosity correction for screening, [dimensionless].
- [PO.ESP.Viscosity.Rate.Corr](/function/po.esp.viscosity.rate.corr.md): Applies viscosity correction to flow rate, [gpm].
- [PO.ESP.Viscosity.Recommendation](/function/po.esp.viscosity.recommendation.md): Returns viscosity-based ESP recommendation.
- [PO.FA.Corrosion.CA](/function/po.fa.corrosion.ca.md): Calculates required corrosion allowance, [mm].
- [PO.FA.Corrosion.CR.CO2](/function/po.fa.corrosion.cr.co2.md): Calculates CO2 corrosion rate using de Waard-Milliams correlation, [mm/yr].
- [PO.FA.Corrosion.CR.Inh](/function/po.fa.corrosion.cr.inh.md): Calculates inhibited corrosion rate, [mm/yr].
- [PO.FA.Corrosion.Fug.CO2](/function/po.fa.corrosion.fug.co2.md): Calculates CO2 fugacity for accurate corrosion predictions, [psi].
- [PO.FA.Corrosion.Pp.CO2](/function/po.fa.corrosion.pp.co2.md): Calculates CO2 partial pressure from total pressure and mole fraction, [psi].
- [PO.FA.Corrosion.Severity](/function/po.fa.corrosion.severity.md): Returns corrosion severity classification (Low/Medium/High/Severe).
- [PO.FA.Erosion.CFactor](/function/po.fa.erosion.cfactor.md): Returns recommended C factor based on service conditions, [dimensionless].
- [PO.FA.Erosion.Dmin](/function/po.fa.erosion.dmin.md): Calculates minimum pipe diameter to avoid erosion, [in].
- [PO.FA.Erosion.Ratio](/function/po.fa.erosion.ratio.md): Calculates erosion ratio (V/Ve). Values >1.0 indicate erosion risk, [dimensionless].
- [PO.FA.Erosion.RhoMix](/function/po.fa.erosion.rhomix.md): Calculates gas-liquid mixture density, [lb/ft³].
- [PO.FA.Erosion.Risk](/function/po.fa.erosion.risk.md): Returns erosion risk classification (Low/Medium/High/Critical).
- [PO.FA.Erosion.Ve](/function/po.fa.erosion.ve.md): Calculates erosional velocity limit using API RP 14E, [ft/s].
- [PO.FA.Erosion.Vmix](/function/po.fa.erosion.vmix.md): Calculates mixture velocity in pipe, [ft/s].
- [PO.FA.Hydrate.Conc](/function/po.fa.hydrate.conc.md): Calculates required inhibitor concentration for target temperature depression, [wt%].
- [PO.FA.Hydrate.Conc.MEG](/function/po.fa.hydrate.conc.meg.md): Calculates required MEG concentration for target temperature depression, [wt%].
- [PO.FA.Hydrate.Conc.MeOH](/function/po.fa.hydrate.conc.meoh.md): Calculates required methanol concentration for target temperature depression, [wt%].
- [PO.FA.Hydrate.dT](/function/po.fa.hydrate.dt.md): Calculates temperature depression from inhibitor using Hammerschmidt equation, [°F].
- [PO.FA.Hydrate.dT.MEG](/function/po.fa.hydrate.dt.meg.md): Calculates temperature depression from MEG using Hammerschmidt equation, [°F].
- [PO.FA.Hydrate.dT.MeOH](/function/po.fa.hydrate.dt.meoh.md): Calculates temperature depression from methanol using Hammerschmidt equation, [°F].
- [PO.FA.Hydrate.dTsub](/function/po.fa.hydrate.dtsub.md): Calculates subcooling (hydrate formation temp minus operating temp), [°F].
- [PO.FA.Hydrate.Qinj.MEG](/function/po.fa.hydrate.qinj.meg.md): Calculates MEG injection rate required, [gal/day].
- [PO.FA.Hydrate.Qinj.MeOH](/function/po.fa.hydrate.qinj.meoh.md): Calculates methanol injection rate required, [gal/day].
- [PO.FPP.Field.Prod](/function/po.fpp.field.prod.md): Calculates cumulative field production at time t using buildup-plateau-decline model. Integrates rate over buildup, plateau, and decline phases. Supports exponential (b=0), hyperbolic (0<b<1), and harmonic (b=1) decline.
- [PO.FPP.Field.Rate](/function/po.fpp.field.rate.md): Calculates field production rate at time t using buildup-plateau-decline model. Linear ramp during buildup, constant rate during plateau, Arps decline after. Supports exponential (b=0), hyperbolic (0<b<1), and harmonic (b=1) decline.
- [PO.FPP.Sched.Prod](/function/po.fpp.sched.prod.md): Calculates cumulative field production from drilling schedule. Uses trapezoidal integration of aggregated rate profile.
- [PO.FPP.Sched.Rate](/function/po.fpp.sched.rate.md): Calculates aggregated field rate from drilling schedule. Uses convolution of well profile with drilling schedule.
- [PO.FRAC.KGD.Length.Leakoff](/function/po.frac.kgd.length.leakoff.md): Khristianovic-Geertsma-de Klerk (KGD) fracture half-length with Carter leakoff, [ft].
- [PO.FRAC.KGD.Length.NoLoss](/function/po.frac.kgd.length.noloss.md): Khristianovic-Geertsma-de Klerk (KGD) fracture half-length without fluid loss, [ft].
- [PO.FRAC.KGD.Pnet](/function/po.frac.kgd.pnet.md): Khristianovic-Geertsma-de Klerk (KGD) net fracturing pressure, [psi].
- [PO.FRAC.KGD.Volume](/function/po.frac.kgd.volume.md): Khristianovic-Geertsma-de Klerk (KGD) fracture volume (both wings), [bbl].
- [PO.FRAC.KGD.Wavg](/function/po.frac.kgd.wavg.md): Khristianovic-Geertsma-de Klerk (KGD) average fracture width, [inches].
- [PO.FRAC.KGD.Width](/function/po.frac.kgd.width.md): Khristianovic-Geertsma-de Klerk (KGD) fracture width at wellbore, [inches].
- [PO.FRAC.KGD.Width.General](/function/po.frac.kgd.width.general.md): Khristianovic-Geertsma-de Klerk (KGD) fracture width (generalized with Poisson's ratio), [inches].
- [PO.FRAC.Leakoff.Cc](/function/po.frac.leakoff.cc.md): Compressibility-controlled leakoff coefficient (Cc), [ft/sqrt(min)].
- [PO.FRAC.Leakoff.CL](/function/po.frac.leakoff.cl.md): Total leakoff coefficient from components (series combination), [ft/sqrt(min)].
- [PO.FRAC.Leakoff.Cumulative](/function/po.frac.leakoff.cumulative.md): Cumulative fluid volume lost per unit area, [ft].
- [PO.FRAC.Leakoff.Cv](/function/po.frac.leakoff.cv.md): Viscosity-controlled leakoff coefficient (Cv), [ft/sqrt(min)].
- [PO.FRAC.Leakoff.Eff](/function/po.frac.leakoff.eff.md): Fracturing fluid efficiency, [fraction].
- [PO.FRAC.Leakoff.Velocity](/function/po.frac.leakoff.velocity.md): Carter leakoff velocity at given time, [ft/min].
- [PO.FRAC.Leakoff.Vol](/function/po.frac.leakoff.vol.md): Total leakoff volume from fracture, [bbl].
- [PO.FRAC.PKN.Length.Leakoff](/function/po.frac.pkn.length.leakoff.md): Perkins-Kern-Nordgren (PKN) fracture half-length with Carter leakoff, [ft].
- [PO.FRAC.PKN.Length.NoLoss](/function/po.frac.pkn.length.noloss.md): Perkins-Kern-Nordgren (PKN) fracture half-length without fluid loss, [ft].
- [PO.FRAC.PKN.Pnet](/function/po.frac.pkn.pnet.md): Perkins-Kern-Nordgren (PKN) net fracturing pressure, [psi].
- [PO.FRAC.PKN.Volume](/function/po.frac.pkn.volume.md): Perkins-Kern-Nordgren (PKN) fracture volume (one wing), [bbl].
- [PO.FRAC.PKN.Wavg](/function/po.frac.pkn.wavg.md): Perkins-Kern-Nordgren (PKN) average fracture width, [inches].
- [PO.FRAC.PKN.Width](/function/po.frac.pkn.width.md): Perkins-Kern-Nordgren (PKN) fracture width at wellbore, [inches].
- [PO.FRAC.PKN.Width.Leakoff](/function/po.frac.pkn.width.leakoff.md): Perkins-Kern-Nordgren (PKN) fracture width with Carter leakoff (large time), [inches].
- [PO.FRAC.PKN.Width.NoLoss](/function/po.frac.pkn.width.noloss.md): Perkins-Kern-Nordgren (PKN) fracture width without fluid loss, [inches].
- [PO.FRAC.Proppant.Ds](/function/po.frac.proppant.ds.md): Proppant settling distance during transport, [ft].
- [PO.FRAC.Proppant.Re](/function/po.frac.proppant.re.md): Particle Reynolds number for settling, [dimensionless].
- [PO.FRAC.Proppant.TR](/function/po.frac.proppant.tr.md): Proppant transport ratio (horizontal/settling velocity), [dimensionless].
- [PO.FRAC.Proppant.Vs.Hindered](/function/po.frac.proppant.vs.hindered.md): Hindered settling velocity (Richardson-Zaki), [ft/min].
- [PO.FRAC.Proppant.Vs.Stokes](/function/po.frac.proppant.vs.stokes.md): Stokes settling velocity (infinite dilution), [ft/min].
- [PO.FRAC.Proppant.Vs.StokesField](/function/po.frac.proppant.vs.stokesfield.md): Stokes settling velocity using specific gravity (field units), [ft/min].
- [PO.FRAC.Proppant.WallFactor](/function/po.frac.proppant.wallfactor.md): Wall correction factor for settling in narrow fracture (Faxen), [dimensionless].
- [PO.FRAC.Radial.Pnet](/function/po.frac.radial.pnet.md): Radial (Penny-shaped) fracture net pressure, [psi].
- [PO.FRAC.Radial.Radius.Leakoff](/function/po.frac.radial.radius.leakoff.md): Radial (Penny-shaped) fracture radius with Carter leakoff, [ft].
- [PO.FRAC.Radial.Radius.NoLoss](/function/po.frac.radial.radius.noloss.md): Radial (Penny-shaped) fracture radius without fluid loss, [ft].
- [PO.FRAC.Radial.Volume](/function/po.frac.radial.volume.md): Radial (Penny-shaped) fracture volume, [bbl].
- [PO.FRAC.Radial.Wavg](/function/po.frac.radial.wavg.md): Radial (Penny-shaped) fracture average width, [inches].
- [PO.FRAC.Radial.Width](/function/po.frac.radial.width.md): Radial (Penny-shaped) fracture width at wellbore, [inches].
- [PO.FRAC.Well.Cfd](/function/po.frac.well.cfd.md): Fracture dimensionless conductivity, [dimensionless].
- [PO.FRAC.Well.SkinEq](/function/po.frac.well.skineq.md): Equivalent skin factor for vertical well with hydraulic fracture, [dimensionless].
- [PO.GL.Inj.Eff](/function/po.gl.inj.eff.md): Calculates total GLR including formation and injected gas, [scf/STB].
- [PO.GL.Inj.Grad](/function/po.gl.inj.grad.md): Calculates gas gradient in the annulus, [psi/ft].
- [PO.GL.Inj.Pd](/function/po.gl.inj.pd.md): Calculates injection gas pressure at depth, [psi].
- [PO.GL.Inj.Qgi](/function/po.gl.inj.qgi.md): Calculates required gas injection rate for target GLR, [Mscf/d].
- [PO.GL.Valve.Pdome](/function/po.gl.valve.pdome.md): Calculates dome pressure at depth from surface dome pressure, [psi].
- [PO.GL.Valve.PPE](/function/po.gl.valve.ppe.md): Calculates production pressure effect factor (PPEF), [dimensionless].
- [PO.GL.Valve.Pvc](/function/po.gl.valve.pvc.md): Calculates valve closing pressure, [psi].
- [PO.GL.Valve.Spread](/function/po.gl.valve.spread.md): Calculates valve spread (opening minus closing pressure), [psi].
- [PO.GL.Valve.ThornhillCraver](/function/po.gl.valve.thornhillcraver.md): Calculates gas throughput using Thornhill-Craver equation, [Mscf/d].
- [PO.GL.Valve.TRO](/function/po.gl.valve.tro.md): Calculates test rack opening pressure at 60°F, [psi].
- [PO.IPR.GW.D](/function/po.ipr.gw.d.md): Calculates Non-Darcy flow coefficient (D) for gas well turbulence effects, [D/mscf]. Used as input to GW.PSS.Rate.NonDarcy.
- [PO.IPR.GW.PSS.Rate](/function/po.ipr.gw.pss.rate.md): Calculates gas well flow rate for pseudosteady state condition using Darcy flow approximation, [mscf/D].
- [PO.IPR.GW.PSS.Rate.NonDarcy](/function/po.ipr.gw.pss.rate.nondarcy.md): Calculates gas well stabilized flow rate for pseudosteady state condition with Non-Darcy flow equation, [mscf/D].
- [PO.IPR.GW.PSS.Time](/function/po.ipr.gw.pss.time.md): Calculates time to reach pseudosteady state (stabilized flow boundary) in gas well, [h].
- [PO.IPR.HW.DrainArea.Ellipse](/function/po.ipr.hw.drainarea.ellipse.md): Calculates horizontal well drainage area using ellipse geometry (Joshi), [acres].
- [PO.IPR.HW.DrainArea.Rect](/function/po.ipr.hw.drainarea.rect.md): Calculates horizontal well drainage area using two half-circles at ends plus rectangle (Joshi), [acres].
- [PO.IPR.HW.PSS.PI.ByBabuOdeh](/function/po.ipr.hw.pss.pi.bybabuodeh.md): Calculates pseudosteady state productivity index for horizontal well using Babu-Odeh method for a box-shaped, anisotropic reservoir, with a well placed parallel to X(box length)-direction, [STB/(d.psi)].
- [PO.IPR.HW.PSS.PI.ByBabuOdeh.Centered](/function/po.ipr.hw.pss.pi.bybabuodeh.centered.md): Calculates pseudosteady state productivity index for horizontal well using Babu-Odeh method for a box-shaped, anisotropic reservoir, with a well centrally placed parallel to X(box length)-direction, [STB/(d.psi)].
- [PO.IPR.HW.SS.PI.ByBorisov](/function/po.ipr.hw.ss.pi.byborisov.md): Calculates steady state productivity index for horizontal well using Borisov method (isotropic reservoir), [STB/(d.psi)].
- [PO.IPR.HW.SS.PI.ByEconomides](/function/po.ipr.hw.ss.pi.byeconomides.md): Calculates steady state productivity index for horizontal well using Economides-Brand-Frick model (anisotropic reservoir, rectangular drainage), [STB/(d.psi)]. Economides et al. (1994) correlation.
- [PO.IPR.HW.SS.PI.ByEconomides.Centered](/function/po.ipr.hw.ss.pi.byeconomides.centered.md): Calculates steady state productivity index for horizontal well using Economides model for centered well (Zw = h/2), [STB/(d.psi)]. Economides et al. (1994) correlation.
- [PO.IPR.HW.SS.PI.ByGRJ](/function/po.ipr.hw.ss.pi.bygrj.md): Calculates steady state productivity index for horizontal well using Giger-Reiss-Jourdan method (anisotropic reservoir), [STB/(d.psi)].
- [PO.IPR.HW.SS.PI.ByJoshi](/function/po.ipr.hw.ss.pi.byjoshi.md): Calculates steady state productivity index for horizontal well using Joshi method (anisotropic reservoir), [STB/(d.psi)].
- [PO.IPR.HW.SS.PI.ByRenardDupuy](/function/po.ipr.hw.ss.pi.byrenarddupuy.md): Calculates steady state productivity index for horizontal well using Renard-Dupuy method (anisotropic reservoir), [STB/(d.psi)].
- [PO.IPR.Re](/function/po.ipr.re.md): Calculates effective drainage radius, [ft].
- [PO.IPR.Rwa](/function/po.ipr.rwa.md): Calculates effective wellbore radius, [ft].
- [PO.IPR.VW.Klins.d](/function/po.ipr.vw.klins.d.md): Calculates Klins-Clark pressure-dependent exponent d, [dimensionless]. Klins & Clark (1993) correlation.
- [PO.IPR.VW.PSS.AOF.ByFetkovich](/function/po.ipr.vw.pss.aof.byfetkovich.md): Calculates Fetkovich maximum flow rate (AOF) at Pwf = 0, [STB/d]. Fetkovich (1973) correlation.
- [PO.IPR.VW.PSS.PI](/function/po.ipr.vw.pss.pi.md): Calculates pseudosteady state productivity index for vertical well, [bbl/(D.psi)].
- [PO.IPR.VW.PSS.Rate](/function/po.ipr.vw.pss.rate.md): Calculates pseudosteady state production flow rate, [bbl/D].
- [PO.IPR.VW.PSS.Rate.ByFetkovich](/function/po.ipr.vw.pss.rate.byfetkovich.md): Calculates Fetkovich backpressure IPR flow rate for oil, [STB/d]. Fetkovich (1973) correlation.
- [PO.IPR.VW.PSS.Rate.ByKlins](/function/po.ipr.vw.pss.rate.byklins.md): Calculates Klins-Clark modified Vogel IPR flow rate for oil, [STB/d]. Klins & Clark (1993) correlation.
- [PO.IPR.VW.PSS.Rate.ByVogel](/function/po.ipr.vw.pss.rate.byvogel.md): Calculates Vogel inflow performance for pseudosteady state flow, [bbl/D].
- [PO.IPR.VW.PSS.Time](/function/po.ipr.vw.pss.time.md): Calculates time to reach pseudosteady state for oil well with regular-shaped drainage area, [h].
- [PO.IPR.VW.SS.PI](/function/po.ipr.vw.ss.pi.md): Calculates steady state productivity index for vertical well, [bbl/(D.psi)].
- [PO.IPR.VW.SS.Rate](/function/po.ipr.vw.ss.rate.md): Calculates steady state production flow rate, [bbl/D].
- [PO.IPR.VW.SS.Rate.ByVogel](/function/po.ipr.vw.ss.rate.byvogel.md): Calculates Vogel inflow performance for steady state flow, [bbl/D].
- [PO.IPR.VW.TF.PI](/function/po.ipr.vw.tf.pi.md): Calculates transient state productivity index for vertical well, [bbl/(D.psi)].
- [PO.IPR.VW.TF.Rate](/function/po.ipr.vw.tf.rate.md): Calculates transient-state production flow rate, [bbl/D].
- [PO.IPR.VW.TF.Rate.ByVogel](/function/po.ipr.vw.tf.rate.byvogel.md): Calculates Vogel inflow performance for transient-state flow, [bbl/D].
- [PO.Math.DataDiff](/function/po.math.datadiff.md): Calculates derivative for data samples at point t with smoothing.
- [PO.Math.Ei](/function/po.math.ei.md): Calculates the exponential integral function Ei(x).
- [PO.MBE.Aq.Fet.J](/function/po.mbe.aq.fet.j.md): Calculates aquifer productivity index for radial flow (Fetkovich), [bbl/day/psi].
- [PO.MBE.Aq.Fet.JLin](/function/po.mbe.aq.fet.jlin.md): Calculates aquifer productivity index for linear flow (Fetkovich), [bbl/day/psi].
- [PO.MBE.Aq.Fet.Pa](/function/po.mbe.aq.fet.pa.md): Calculates average aquifer pressure (Fetkovich), [psi]. pa = pi * (1 - We/Wei).
- [PO.MBE.Aq.Fet.Rate](/function/po.mbe.aq.fet.rate.md): Calculates water influx rate (Fetkovich), [bbl/day]. qw = J * (pa - pr).
- [PO.MBE.Aq.Fet.Wei](/function/po.mbe.aq.fet.wei.md): Calculates maximum encroachable water (Fetkovich), [bbl]. Wei = ct * Wi * pi.
- [PO.MBE.Aq.Fet.Wi](/function/po.mbe.aq.fet.wi.md): Calculates initial water volume in aquifer (radial), [bbl].
- [PO.MBE.Aq.Pot.Vol](/function/po.mbe.aq.pot.vol.md): Calculates aquifer pore volume for pot aquifer model, [bbl].
- [PO.MBE.Aq.Pot.We](/function/po.mbe.aq.pot.we.md): Calculates instantaneous water influx for pot aquifer, [bbl]. We = ct * Wi * deltaP.
- [PO.MBE.Aq.Sch.Rate](/function/po.mbe.aq.sch.rate.md): Calculates instantaneous water influx rate (Schilthuis), [bbl/day]. qw = C * (pi - p).
- [PO.MBE.Aq.Sch.We](/function/po.mbe.aq.sch.we.md): Calculates cumulative water influx (Schilthuis) using trapezoidal integration, [bbl]. We = C × ∫(pi − p)dt.
- [PO.MBE.Aq.VEH.reD](/function/po.mbe.aq.veh.red.md): Calculates dimensionless radius for VEH aquifer, [dimensionless]. reD = ra / rr.
- [PO.MBE.Aq.VEH.tD](/function/po.mbe.aq.veh.td.md): Calculates dimensionless time for VEH aquifer, [dimensionless]. tD = 0.00634*k*t / (phi*muw*ct*rr^2).
- [PO.MBE.Aq.VEH.U](/function/po.mbe.aq.veh.u.md): Calculates aquifer constant for VEH model, [bbl/psi]. U = 1.119 * phi * ct * h * rr^2 * (theta/360).
- [PO.MBE.Aq.VEH.WdFin](/function/po.mbe.aq.veh.wdfin.md): Calculates dimensionless influx for finite aquifer (VEH), [dimensionless].
- [PO.MBE.Aq.VEH.WdInf](/function/po.mbe.aq.veh.wdinf.md): Calculates dimensionless influx for infinite aquifer (VEH), [dimensionless]. Uses Edwardson correlation.
- [PO.MBE.Ce.Gas](/function/po.mbe.ce.gas.md): Calculates effective compressibility for gas reservoir, [1/psi].
- [PO.MBE.Ce.Geopressured](/function/po.mbe.ce.geopressured.md): Calculates effective compressibility for geopressured reservoir with gas solubility, [1/psi].
- [PO.MBE.Ce.PoreVol](/function/po.mbe.ce.porevol.md): Calculates pore volume compressibility term, [1/psi]. cpv = (cw*Swc + cf) / (1 - Swc).
- [PO.MBE.Ce.Total](/function/po.mbe.ce.total.md): Calculates total system compressibility, [1/psi]. ct = Sg*cg + Sw*cw + cf.
- [PO.MBE.Ce.UnSat.Oil](/function/po.mbe.ce.unsat.oil.md): Calculates effective compressibility for undersaturated oil reservoir, [1/psi].
- [PO.MBE.Drives.All](/function/po.mbe.drives.all.md): Calculates all drive indices. Returns [DDI, GDI, WDI, CDI, Sum]. Sum should be ~1.
- [PO.MBE.Drives.CDI](/function/po.mbe.drives.cdi.md): Calculates Compressibility Drive Index (CDI), [fraction 0-1]. CDI = N*Efw / F.
- [PO.MBE.Drives.DDI](/function/po.mbe.drives.ddi.md): Calculates Depletion Drive Index (DDI), [fraction 0-1]. DDI = N*Eo / F.
- [PO.MBE.Drives.GDI](/function/po.mbe.drives.gdi.md): Calculates Gas Cap Drive Index (GDI), [fraction 0-1]. GDI = N*m*Eg / F.
- [PO.MBE.Drives.WDI](/function/po.mbe.drives.wdi.md): Calculates Water Drive Index (WDI), [fraction 0-1]. WDI = We / F.
- [PO.MBE.Exp.Bt](/function/po.mbe.exp.bt.md): Calculates two-phase formation volume factor (Bt), [RB/STB]. Bt = Bo + (Rsi-Rs)*Bg.
- [PO.MBE.Exp.Efw](/function/po.mbe.exp.efw.md): Calculates formation/water expansion term (Efw), [RB/STB]. Accounts for rock compaction and connate water expansion.
- [PO.MBE.Exp.Eg](/function/po.mbe.exp.eg.md): Calculates gas cap expansion term (Eg) for oil reservoirs, [RB/STB]. Eg = Boi*(Bg/Bgi - 1).
- [PO.MBE.Exp.Eg.Gas](/function/po.mbe.exp.eg.gas.md): Calculates gas expansion for pure gas reservoirs, [RB/scf]. Eg = Bg - Bgi.
- [PO.MBE.Exp.Eo](/function/po.mbe.exp.eo.md): Calculates oil and dissolved gas expansion term (Eo), [RB/STB]. Eo = (Bo-Boi) + (Rsi-Rs)*Bg.
- [PO.MBE.Exp.Et](/function/po.mbe.exp.et.md): Calculates total expansion term (Et), [RB/STB]. Et = Eo + m*Eg + Efw.
- [PO.MBE.F.Gas](/function/po.mbe.f.gas.md): Calculates underground withdrawal for gas reservoir, [RB]. F = Gp*Bg + Wp*Bw.
- [PO.MBE.F.Oil](/function/po.mbe.f.oil.md): Calculates underground withdrawal for oil reservoir, [RB]. F = Np*(Bo + (Rp-Rs)*Bg) + Wp*Bw.
- [PO.MBE.Gas.ModOGIP](/function/po.mbe.gas.modogip.md): Estimates OGIP using modified p/z for geopressured reservoirs, [scf].
- [PO.MBE.Gas.ModPz](/function/po.mbe.gas.modpz.md): Calculates modified p/z for geopressured reservoirs, [psi]. Accounts for formation/water compressibility.
- [PO.MBE.Gas.OGIP](/function/po.mbe.gas.ogip.md): Estimates OGIP using standard p/z method, [scf]. Assumes volumetric depletion.
- [PO.MBE.Gas.PredGp](/function/po.mbe.gas.predgp.md): Predicts cumulative production at given reservoir pressure, [scf].
- [PO.MBE.Gas.PredP](/function/po.mbe.gas.predp.md): Predicts reservoir pressure at given cumulative production, [psi].
- [PO.MBE.Gas.Pz](/function/po.mbe.gas.pz.md): Calculates p/z ratio for gas material balance analysis, [psi].
- [PO.MBE.Gas.RF](/function/po.mbe.gas.rf.md): Calculates recovery factor for a gas reservoir, [fraction 0-1].
- [PO.MBE.Gas.URF](/function/po.mbe.gas.urf.md): Calculates ultimate recovery factor based on abandonment pressure, [fraction 0-1].
- [PO.MBE.Oil.NandM](/function/po.mbe.oil.nandm.md): Estimates N and m from F/Eo vs Eg/Eo regression. Returns [N, m].
- [PO.MBE.Oil.OOIP](/function/po.mbe.oil.ooip.md): Estimates OOIP from F vs Et (no water influx), [STB]. N = F / Et.
- [PO.MBE.Oil.OOIP.Reg](/function/po.mbe.oil.ooip.reg.md): Estimates OOIP using regression on F vs Et data, [STB]. Least-squares through origin.
- [PO.MBE.Oil.OOIP.We](/function/po.mbe.oil.ooip.we.md): Estimates OOIP with water influx, [STB]. N = (F - We) / Et.
- [PO.MBE.Oil.Residual](/function/po.mbe.oil.residual.md): Calculates normalized MBE residual for quality check, [fraction]. Should be close to 0.
- [PO.MBE.Oil.We](/function/po.mbe.oil.we.md): Infers water influx from material balance given known OOIP, [RB]. We = F - N*Et.
- [PO.PTA.FromDim.C](/function/po.pta.fromdim.c.md): Converts dimensionless storage to wellbore storage coefficient, [bbl/psi].
- [PO.PTA.FromDim.dP](/function/po.pta.fromdim.dp.md): Converts dimensionless pressure to pressure drop, [psi].
- [PO.PTA.FromDim.L](/function/po.pta.fromdim.l.md): Converts dimensionless distance to linear distance, [ft].
- [PO.PTA.FromDim.r](/function/po.pta.fromdim.r.md): Converts dimensionless radius to radial distance, [ft].
- [PO.PTA.FromDim.t](/function/po.pta.fromdim.t.md): Converts dimensionless time to elapsed time, [h].
- [PO.PTA.PD.LSS](/function/po.pta.pd.lss.md): Calculates dimensionless pressure using line source solution in infinite homogeneous reservoir, [dimensionless].
- [PO.PTA.PD.VW](/function/po.pta.pd.vw.md): Calculates dimensionless wellbore pressure drop for vertical well in infinite homogeneous reservoir, [dimensionless].
- [PO.PTA.PD.VW.LinConP](/function/po.pta.pd.vw.linconp.md): Calculates dimensionless wellbore pressure drop for vertical well in infinite homogeneous reservoir with linear constant pressure boundary, [dimensionless].
- [PO.PTA.PD.VW.LinSealF](/function/po.pta.pd.vw.linsealf.md): Calculates dimensionless wellbore pressure drop for vertical well in infinite homogeneous reservoir with linear sealing fault boundary, [dimensionless].
- [PO.PTA.PD.VW.PerpConP](/function/po.pta.pd.vw.perpconp.md): Calculates dimensionless wellbore pressure drop for vertical well in infinite homogeneous reservoir with perpendicular constant pressures boundary, [dimensionless].
- [PO.PTA.PD.VW.PerpMix](/function/po.pta.pd.vw.perpmix.md): Calculates dimensionless wellbore pressure drop for vertical well in infinite homogeneous reservoir with perpendicular mixed boundaries (boundary 1 - fault, boundary 2 - constant pressure), [dimensionless].
- [PO.PTA.PD.VW.PerpSealF](/function/po.pta.pd.vw.perpsealf.md): Calculates dimensionless wellbore pressure drop for vertical well in infinite homogeneous reservoir with perpendicular sealing faults boundary, [dimensionless].
- [PO.PTA.Pw.VW](/function/po.pta.pw.vw.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir, [psi].
- [PO.PTA.Pw.VW.LinConP](/function/po.pta.pw.vw.linconp.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with linear constant pressure boundary, [psi].
- [PO.PTA.Pw.VW.LinSealF](/function/po.pta.pw.vw.linsealf.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with linear sealing fault boundary, [psi].
- [PO.PTA.Pw.VW.PerpConP](/function/po.pta.pw.vw.perpconp.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with perpendicular constant pressures boundary, [psi].
- [PO.PTA.Pw.VW.PerpMix](/function/po.pta.pw.vw.perpmix.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with perpendicular mixed boundaries (boundary 1 - fault, boundary 2 - constant pressure), [psi].
- [PO.PTA.Pw.VW.PerpSealF](/function/po.pta.pw.vw.perpsealf.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with perpendicular sealing faults boundary, [psi].
- [PO.PTA.ToDim.CD](/function/po.pta.todim.cd.md): Converts wellbore storage coefficient to dimensionless storage, [dimensionless].
- [PO.PTA.ToDim.LD](/function/po.pta.todim.ld.md): Converts linear distance to dimensionless distance, [dimensionless].
- [PO.PTA.ToDim.PD](/function/po.pta.todim.pd.md): Converts pressure drop to dimensionless pressure, [dimensionless].
- [PO.PTA.ToDim.rD](/function/po.pta.todim.rd.md): Converts radial distance to dimensionless radius, [dimensionless].
- [PO.PTA.ToDim.tD](/function/po.pta.todim.td.md): Converts elapsed time to dimensionless time, [dimensionless].
- [PO.PVT.API.FromSGoil](/function/po.pvt.api.fromsgoil.md): Converts oil specific gravity to API gravity, [API].
- [PO.PVT.Bg.ByDefinition](/function/po.pvt.bg.bydefinition.md): Calculates gas formation volume factor, [rcf/scf].
- [PO.PVT.Bo.Sat.ByAlMarhoun](/function/po.pvt.bo.sat.byalmarhoun.md): Calculates oil formation volume factor using Al-Marhoun (1988) correlation, P <= Pb, [bbl/STB].
- [PO.PVT.Bo.Sat.ByDindorukChristman](/function/po.pvt.bo.sat.bydindorukchristman.md): Calculates oil formation volume factor using Dindoruk and Christman (2001) correlation, P <= Pb, [bbl/STB].
- [PO.PVT.Bo.Sat.ByGlaso](/function/po.pvt.bo.sat.byglaso.md): Calculates oil formation volume factor using Glaso (1980) correlation, P <= Pb, [bbl/STB].
- [PO.PVT.Bo.Sat.ByPetrosky](/function/po.pvt.bo.sat.bypetrosky.md): Calculates oil formation volume factor using Petrosky (1990) correlation, P <= Pb, [bbl/STB].
- [PO.PVT.Bo.Sat.ByStanding](/function/po.pvt.bo.sat.bystanding.md): Calculates oil formation volume factor using Standing (1947) correlation, P <= Pb, [bbl/STB].
- [PO.PVT.Bo.Sat.ByVasquezBeggs](/function/po.pvt.bo.sat.byvasquezbeggs.md): Calculates oil formation volume factor using Vasquez and Beggs (1980) correlation, P <= Pb, [bbl/STB].
- [PO.PVT.Bo.UnSat.ByDefinition](/function/po.pvt.bo.unsat.bydefinition.md): Calculates oil formation volume factor for undersaturated oil, P > Pb, [bbl/STB].
- [PO.PVT.Bw.ByMcCain](/function/po.pvt.bw.bymccain.md): Calculates water formation volume factor using McCain correlation, [bbl/STB].
- [PO.PVT.Cg.ByDefinition](/function/po.pvt.cg.bydefinition.md): Calculates gas compressibility, [1/psi].
- [PO.PVT.Co.Sat.ByVillenaLanzi](/function/po.pvt.co.sat.byvillenalanzi.md): Calculates oil compressibility using Villena-Lanzi (1985) correlation, P <= Pb, [1/psi].
- [PO.PVT.Co.UnSat.ByVasquezBeggs](/function/po.pvt.co.unsat.byvasquezbeggs.md): Calculates oil compressibility using Vasquez and Beggs (1980) correlation, P > Pb, [1/psi].
- [PO.PVT.Cw.Sat.ByMcCain](/function/po.pvt.cw.sat.bymccain.md): Calculates water compressibility for saturated conditions using McCain correlation, P <= Pb, [1/psi].
- [PO.PVT.Cw.UnSat.ByOsif](/function/po.pvt.cw.unsat.byosif.md): Calculates water compressibility for undersaturated conditions using Osif correlation, P >= Pb, [1/psi].
- [PO.PVT.IFT.GasOil.ByAbdulMajeed](/function/po.pvt.ift.gasoil.byabdulmajeed.md): Calculates interfacial (surface) tension for live oil using Abdul-Majeed (2000) correlation, [dynes/cm].
- [PO.PVT.IFT.GasOil.ByBakerSwerdloff](/function/po.pvt.ift.gasoil.bybakerswerdloff.md): Calculates interfacial (surface) tension for live oil using Baker and Swerdloff (1955) correlation, [dynes/cm].
- [PO.PVT.Ma.Air.Stn](/function/po.pvt.ma.air.stn.md): Molecular weight of air at standard conditions, [g/mol].
- [PO.PVT.Pb.ByAlMarhoun](/function/po.pvt.pb.byalmarhoun.md): Calculates oil bubble point pressure using Al-Marhoun (1988) correlation, [psi].
- [PO.PVT.Pb.ByDindorukChristman](/function/po.pvt.pb.bydindorukchristman.md): Calculates oil bubble point pressure using Dindoruk and Christman (2001) correlation, [psi].
- [PO.PVT.Pb.ByDoklaOsman](/function/po.pvt.pb.bydoklaosman.md): Calculates oil bubble point pressure using Dokla and Osman (1992) correlation, [psi].
- [PO.PVT.Pb.ByGlaso](/function/po.pvt.pb.byglaso.md): Calculates oil bubble point pressure using Glaso (1980) correlation, [psi].
- [PO.PVT.Pb.ByPetroskyFarshad](/function/po.pvt.pb.bypetroskyfarshad.md): Calculates oil bubble point pressure using Petrosky and Farshad (1990) correlation, [psi].
- [PO.PVT.Pb.ByStanding](/function/po.pvt.pb.bystanding.md): Calculates oil bubble point pressure using Standing (1947) correlation, [psi].
- [PO.PVT.Pb.ByVasquezBeggs](/function/po.pvt.pb.byvasquezbeggs.md): Calculates oil bubble point pressure using Vasquez and Beggs (1980) correlation, [psi].
- [PO.PVT.Ppc.ByStanding](/function/po.pvt.ppc.bystanding.md): Calculates pseudo-critical pressure of hydrocarbon gas using Standing correlation, [psi].
- [PO.PVT.Ppc.ByStanding.Sour](/function/po.pvt.ppc.bystanding.sour.md): Calculates pseudo-critical pressure of sour gas using Standing correlation with Wichert-Aziz correction, [psi].
- [PO.PVT.Ppc.BySutton](/function/po.pvt.ppc.bysutton.md): Calculates pseudo-critical pressure of hydrocarbon gas using Sutton (1985) correlation, [psi].
- [PO.PVT.Ppc.BySutton.Sour](/function/po.pvt.ppc.bysutton.sour.md): Calculates pseudo-critical pressure of sour gas using Sutton correlation with Wichert-Aziz correction, [psi].
- [PO.PVT.Rho.Gas.ByDefinition](/function/po.pvt.rho.gas.bydefinition.md): Calculates gas density, [g/cc].
- [PO.PVT.Rho.Wat.Stn](/function/po.pvt.rho.wat.stn.md): Water density at standard conditions, [lb/ft3].
- [PO.PVT.Rs.ByAlMarhoun](/function/po.pvt.rs.byalmarhoun.md): Calculates solution gas-oil ratio using Al-Marhoun (1988) correlation, P <= Pb, [scf/STB].
- [PO.PVT.Rs.ByDindorukChristman](/function/po.pvt.rs.bydindorukchristman.md): Calculates solution gas-oil ratio using Dindoruk and Christman (2001) correlation, P <= Pb, [scf/STB].
- [PO.PVT.Rs.ByGlaso](/function/po.pvt.rs.byglaso.md): Calculates solution gas-oil ratio using Glaso (1980) correlation, P <= Pb, [scf/STB].
- [PO.PVT.Rs.ByPetroskyFarshad](/function/po.pvt.rs.bypetroskyfarshad.md): Calculates solution gas-oil ratio using Petrosky and Farshad (1993) correlation, P <= Pb, [scf/STB].
- [PO.PVT.Rs.ByStanding](/function/po.pvt.rs.bystanding.md): Calculates solution gas-oil ratio using Standing correlation (1981), P <= Pb, [scf/STB].
- [PO.PVT.Rs.ByVasquezBeggs](/function/po.pvt.rs.byvasquezbeggs.md): Calculates solution gas-oil ratio using Vasquez and Beggs (1980) correlation, P <= Pb, [scf/STB].
- [PO.PVT.Rsw.ByMcCain](/function/po.pvt.rsw.bymccain.md): Calculates solution gas-water ratio for reservoir water using McCain correlation, [scf/STB].
- [PO.PVT.Rsw.Pure.ByMcCain](/function/po.pvt.rsw.pure.bymccain.md): Calculates solution gas-water ratio for pure water using McCain correlation, [scf/STB].
- [PO.PVT.Salinity.Gl.FromPct](/function/po.pvt.salinity.gl.frompct.md): Converts water salinity from percent by weight to grams NaCl per liter, [g NaCl/l].
- [PO.PVT.Salinity.Pct.FromGl](/function/po.pvt.salinity.pct.fromgl.md): Converts water salinity from grams NaCl per liter to percent by weight, [% by weight].
- [PO.PVT.SG.Gas.ByDefinition](/function/po.pvt.sg.gas.bydefinition.md): Calculates gas specific gravity from molecular weight, [dimensionless].
- [PO.PVT.SG.Oil.ByDefinition](/function/po.pvt.sg.oil.bydefinition.md): Calculates oil specific gravity from oil density, [dimensionless].
- [PO.PVT.SG.Oil.FromAPI](/function/po.pvt.sg.oil.fromapi.md): Converts API gravity to oil specific gravity, [dimensionless].
- [PO.PVT.Tpc.ByStanding](/function/po.pvt.tpc.bystanding.md): Calculates pseudo-critical temperature of hydrocarbon gas using Standing correlation, [degR].
- [PO.PVT.Tpc.ByStanding.Sour](/function/po.pvt.tpc.bystanding.sour.md): Calculates pseudo-critical temperature of sour gas using Standing correlation with Wichert-Aziz correction, [degR].
- [PO.PVT.Tpc.BySutton](/function/po.pvt.tpc.bysutton.md): Calculates pseudo-critical temperature of hydrocarbon gas using Sutton (1985) correlation, [degR].
- [PO.PVT.Tpc.BySutton.Sour](/function/po.pvt.tpc.bysutton.sour.md): Calculates pseudo-critical temperature of sour gas using Sutton correlation with Wichert-Aziz correction, [degR].
- [PO.PVT.Ug.ByLGE](/function/po.pvt.ug.bylge.md): Calculates gas viscosity using Lee, Gonzales and Eakin (1966) correlation, [cP].
- [PO.PVT.Uo.Dead.ByBeal](/function/po.pvt.uo.dead.bybeal.md): Calculates dead oil viscosity using Beal (1946) correlation. Standing's curve fit of Beal's graphical correlation. Best performer per Fotias (2022), [cP].
- [PO.PVT.Uo.Dead.ByEgbogah](/function/po.pvt.uo.dead.byegbogah.md): Calculates dead oil viscosity using Egbogah (1983) correlation, [cP].
- [PO.PVT.Uo.Dead.ByGlaso](/function/po.pvt.uo.dead.byglaso.md): Calculates dead oil viscosity using Glaso (1980) correlation. Developed for North Sea crude oils, [cP].
- [PO.PVT.Uo.Sat.ByBeggsRobinson](/function/po.pvt.uo.sat.bybeggsrobinson.md): Calculates oil viscosity with solution gas using Beggs and Robinson (1975) correlation, P <= Pb, [cP].
- [PO.PVT.Uo.Sat.ByChewConnally](/function/po.pvt.uo.sat.bychewconnally.md): Calculates oil viscosity with solution gas using Chew and Connally (1959) correlation, P <= Pb, [cP].
- [PO.PVT.Uo.UnSat.ByKouzel](/function/po.pvt.uo.unsat.bykouzel.md): Calculates oil viscosity for undersaturated conditions using Kouzel (1965) correlation, P > Pb. Exponential model with good performance across wide viscosity ranges, [cP].
- [PO.PVT.Uo.UnSat.ByVasquezBeggs](/function/po.pvt.uo.unsat.byvasquezbeggs.md): Calculates oil viscosity for undersaturated conditions using Vasquez and Beggs (1980) correlation, P > Pb, [cP].
- [PO.PVT.Uw.1Atm.ByMcCain](/function/po.pvt.uw.1atm.bymccain.md): Calculates water viscosity at atmospheric pressure and reservoir temperature using McCain correlation, [cP].
- [PO.PVT.Uw.ByMcCain](/function/po.pvt.uw.bymccain.md): Calculates water viscosity using McCain correlation, [cP].
- [PO.PVT.Z.ByBrillBeggs](/function/po.pvt.z.bybrillbeggs.md): Calculates gas compressibility factor (Z) using Brill and Beggs (1974) correlation, [dimensionless].
- [PO.PVT.Z.ByDAK](/function/po.pvt.z.bydak.md): Calculates gas compressibility factor (Z) using Dranchuk and Abou-Kassem (1975) equation of state, [dimensionless].
- [PO.RP.Load.FluidLoad](/function/po.rp.load.fluidload.md): Calculates fluid load on plunger, [lb].
- [PO.RP.Load.MPRL](/function/po.rp.load.mprl.md): Calculates Minimum Polished Rod Load using API 11L method, [lb].
- [PO.RP.Load.MPRL.Simple](/function/po.rp.load.mprl.simple.md): Calculates simplified MPRL (static, no dynamic effects), [lb].
- [PO.RP.Load.PPRL](/function/po.rp.load.pprl.md): Calculates Peak Polished Rod Load using API 11L method, [lb].
- [PO.RP.Load.PPRL.Simple](/function/po.rp.load.pprl.simple.md): Calculates simplified PPRL (static, no dynamic effects), [lb].
- [PO.RP.Load.Range](/function/po.rp.load.range.md): Calculates polished rod load range (PPRL - MPRL), [lb].
- [PO.RP.Pump.Disp.Eff](/function/po.rp.pump.disp.eff.md): Calculates effective pump displacement accounting for fillage, [bbl/d].
- [PO.RP.Pump.Displacement](/function/po.rp.pump.displacement.md): Calculates theoretical pump displacement, [bbl/d].
- [PO.RP.Pump.Displacement.FromDiameter](/function/po.rp.pump.displacement.fromdiameter.md): Calculates theoretical pump displacement from plunger diameter, [bbl/d].
- [PO.RP.Pump.Fillage](/function/po.rp.pump.fillage.md): Calculates pump fillage from actual and theoretical production, [fraction].
- [PO.RP.Pump.PIP](/function/po.rp.pump.pip.md): Calculates pump intake pressure (PIP), [psi].
- [PO.RP.Pump.Psub](/function/po.rp.pump.psub.md): Calculates submergence pressure from fluid column height, [psi].
- [PO.RP.Pump.Stroke.Eff](/function/po.rp.pump.stroke.eff.md): Calculates effective plunger stroke from surface stroke and stretch, [in].
- [PO.RP.Pump.VolEff](/function/po.rp.pump.voleff.md): Calculates volumetric efficiency of the pump system, [fraction].
- [PO.RP.Rod.Area](/function/po.rp.rod.area.md): Calculates rod cross-sectional area from diameter, [in²].
- [PO.RP.Rod.MaxStress](/function/po.rp.rod.maxstress.md): Calculates maximum rod stress from peak load, [psi].
- [PO.RP.Rod.MinStress](/function/po.rp.rod.minstress.md): Calculates minimum rod stress from minimum load, [psi].
- [PO.RP.Rod.StressRange](/function/po.rp.rod.stressrange.md): Calculates rod stress range (fatigue indicator), [psi].
- [PO.RP.Rod.Stretch.FluidLoad](/function/po.rp.rod.stretch.fluidload.md): Calculates rod stretch due to fluid load, [in].
- [PO.RP.Rod.Stretch.RodWeight](/function/po.rp.rod.stretch.rodweight.md): Calculates rod stretch due to rod weight (self-weight stretch), [in].
- [PO.RP.Rod.Stretch.Total](/function/po.rp.rod.stretch.total.md): Calculates total static rod stretch (fluid load + self-weight), [in].
- [PO.RP.Rod.Wair](/function/po.rp.rod.wair.md): Calculates rod string weight in air, [lb].
- [PO.RP.Rod.Wbuoy](/function/po.rp.rod.wbuoy.md): Calculates buoyant rod string weight (weight in fluid), [lb].
- [PO.RP.Rod.Wft](/function/po.rp.rod.wft.md): Calculates rod weight per foot for a given diameter, [lb/ft].
- [PO.RP.Torque.Adjustment](/function/po.rp.torque.adjustment.md): Calculates counterbalance adjustment needed, [lb]. Positive = add weight.
- [PO.RP.Torque.IdealCBE](/function/po.rp.torque.idealcbe.md): Calculates ideal counterbalance effect from rod weight and fluid load, [lb].
- [PO.RP.Torque.IdealCBE.Loads](/function/po.rp.torque.idealcbe.loads.md): Calculates ideal counterbalance effect from PPRL and MPRL, [lb].
- [PO.RP.Torque.Net](/function/po.rp.torque.net.md): Calculates net gearbox torque at a given crank angle, [in-lb].
- [PO.RP.Torque.Peak](/function/po.rp.torque.peak.md): Calculates estimated peak net torque (simplified), [in-lb].
- [PO.RP.Torque.PRHP](/function/po.rp.torque.prhp.md): Calculates polished rod horsepower, [HP].
- [PO.SCAL.BrooksCorey.Pc](/function/po.scal.brookscorey.pc.md): Brooks-Corey capillary pressure, [psi]. Pc = Pd × Se^(-1/λ).
- [PO.SCAL.BrooksCorey.Sw](/function/po.scal.brookscorey.sw.md): Brooks-Corey saturation from capillary pressure, [fraction]. Inverse of Pc function.
- [PO.SCAL.Cf.Lime.ByNewman](/function/po.scal.cf.lime.bynewman.md): Calculates rock pore volume compressibility in limestones using Newman correlation, [1/psi].
- [PO.SCAL.Cf.Sand.ByNewman](/function/po.scal.cf.sand.bynewman.md): Calculates rock pore volume compressibility in sandstones using Newman correlation, [1/psi].
- [PO.SCAL.Corey.Krow](/function/po.scal.corey.krow.md): Calculates Corey-type oil relative permeability, [dimensionless].
- [PO.SCAL.Corey.Krw](/function/po.scal.corey.krw.md): Calculates Corey-type water relative permeability, [dimensionless].
- [PO.SCAL.Honarpour.Carb.GasOil.Krg](/function/po.scal.honarpour.carb.gasoil.krg.md): Calculates gas relative permeability in gas-oil system using Honarpour (1982) Eq A-10 for limestone and dolomite, [dimensionless].
- [PO.SCAL.Honarpour.Carb.GasOil.Krog](/function/po.scal.honarpour.carb.gasoil.krog.md): Calculates oil relative permeability in gas-oil system using Honarpour (1982) Eq A-9 for limestone and dolomite, [dimensionless].
- [PO.SCAL.Honarpour.Carb.IW.Krow](/function/po.scal.honarpour.carb.iw.krow.md): Calculates oil relative permeability using Honarpour (1982) correlation for intermediately wet limestone and dolomite, [dimensionless].
- [PO.SCAL.Honarpour.Carb.IW.Krw](/function/po.scal.honarpour.carb.iw.krw.md): Calculates water relative permeability using Honarpour (1982) correlation for intermediately wet limestone and dolomite, [dimensionless].
- [PO.SCAL.Honarpour.Carb.WW.Krow](/function/po.scal.honarpour.carb.ww.krow.md): Calculates oil relative permeability using Honarpour (1982) correlation for water wet limestone and dolomite, [dimensionless].
- [PO.SCAL.Honarpour.Carb.WW.Krw](/function/po.scal.honarpour.carb.ww.krw.md): Calculates water relative permeability using Honarpour (1982) correlation for water wet limestone and dolomite, [dimensionless].
- [PO.SCAL.Honarpour.Sand.GasOil.Krg](/function/po.scal.honarpour.sand.gasoil.krg.md): Calculates gas relative permeability in gas-oil system using Honarpour (1982) Eq A-5 for sandstone and conglomerate, [dimensionless].
- [PO.SCAL.Honarpour.Sand.GasOil.Krog](/function/po.scal.honarpour.sand.gasoil.krog.md): Calculates oil relative permeability in gas-oil system using Honarpour (1982) Eq A-4 for sandstone and conglomerate, [dimensionless].
- [PO.SCAL.Honarpour.Sand.IW.Krow](/function/po.scal.honarpour.sand.iw.krow.md): Calculates oil relative permeability using Honarpour (1982) correlation for intermediately wet sandstone and conglomerate, [dimensionless].
- [PO.SCAL.Honarpour.Sand.IW.Krw](/function/po.scal.honarpour.sand.iw.krw.md): Calculates water relative permeability using Honarpour (1982) correlation for intermediately wet sandstone and conglomerate, [dimensionless].
- [PO.SCAL.Honarpour.Sand.WW.Krow](/function/po.scal.honarpour.sand.ww.krow.md): Calculates oil relative permeability using Honarpour (1982) correlation for water wet sandstone and conglomerate, [dimensionless].
- [PO.SCAL.Honarpour.Sand.WW.Krw](/function/po.scal.honarpour.sand.ww.krw.md): Calculates water relative permeability using Honarpour (1982) correlation for water wet sandstone and conglomerate, [dimensionless].
- [PO.SCAL.IK.Carb.GasOil.Krg](/function/po.scal.ik.carb.gasoil.krg.md): Calculates gas relative permeability in gas-oil system using Ibrahim-Koederitz correlation for carbonate, [dimensionless].
- [PO.SCAL.IK.Carb.GasOil.Krog](/function/po.scal.ik.carb.gasoil.krog.md): Calculates oil relative permeability in gas-oil system using Ibrahim-Koederitz correlation for carbonate, [dimensionless].
- [PO.SCAL.IK.Carb.IW.Krow](/function/po.scal.ik.carb.iw.krow.md): Calculates oil relative permeability using Ibrahim-Koederitz correlation for intermediate-wet carbonate, [dimensionless].
- [PO.SCAL.IK.Carb.IW.Krw](/function/po.scal.ik.carb.iw.krw.md): Calculates water relative permeability using Ibrahim-Koederitz correlation for intermediate-wet carbonate, [dimensionless].
- [PO.SCAL.IK.Carb.OW.Krow](/function/po.scal.ik.carb.ow.krow.md): Calculates oil relative permeability using Ibrahim-Koederitz correlation for oil-wet carbonate, [dimensionless].
- [PO.SCAL.IK.Carb.OW.Krw](/function/po.scal.ik.carb.ow.krw.md): Calculates water relative permeability using Ibrahim-Koederitz correlation for oil-wet carbonate, [dimensionless].
- [PO.SCAL.IK.Carb.SWW.Krow](/function/po.scal.ik.carb.sww.krow.md): Calculates oil relative permeability using Ibrahim-Koederitz correlation for strongly water-wet carbonate, [dimensionless].
- [PO.SCAL.IK.Carb.SWW.Krw](/function/po.scal.ik.carb.sww.krw.md): Calculates water relative permeability using Ibrahim-Koederitz correlation for strongly water-wet carbonate, [dimensionless].
- [PO.SCAL.IK.Carb.WW.Krow](/function/po.scal.ik.carb.ww.krow.md): Calculates oil relative permeability using Ibrahim-Koederitz correlation for water-wet carbonate, [dimensionless].
- [PO.SCAL.IK.Carb.WW.Krw](/function/po.scal.ik.carb.ww.krw.md): Calculates water relative permeability using Ibrahim-Koederitz correlation for water-wet carbonate, [dimensionless].
- [PO.SCAL.IK.GasCond.Krcg](/function/po.scal.ik.gascond.krcg.md): Calculates condensate relative permeability in gas-condensate system using Ibrahim-Koederitz correlation, [dimensionless].
- [PO.SCAL.IK.GasCond.Krg](/function/po.scal.ik.gascond.krg.md): Calculates gas relative permeability in gas-condensate system using Ibrahim-Koederitz correlation, [dimensionless].
- [PO.SCAL.IK.GasWat.Krgw](/function/po.scal.ik.gaswat.krgw.md): Calculates gas relative permeability in gas-water system using Ibrahim-Koederitz correlation, [dimensionless].
- [PO.SCAL.IK.GasWat.Krw](/function/po.scal.ik.gaswat.krw.md): Calculates water relative permeability in gas-water system using Ibrahim-Koederitz correlation, [dimensionless].
- [PO.SCAL.IK.Sand.GasOil.Krg](/function/po.scal.ik.sand.gasoil.krg.md): Calculates gas relative permeability in gas-oil system using Ibrahim-Koederitz correlation for sandstone, [dimensionless].
- [PO.SCAL.IK.Sand.GasOil.Krog](/function/po.scal.ik.sand.gasoil.krog.md): Calculates oil relative permeability in gas-oil system using Ibrahim-Koederitz correlation for sandstone, [dimensionless].
- [PO.SCAL.IK.Sand.IW.Krow](/function/po.scal.ik.sand.iw.krow.md): Calculates oil relative permeability using Ibrahim-Koederitz correlation for intermediate-wet sandstone, [dimensionless].
- [PO.SCAL.IK.Sand.IW.Krw](/function/po.scal.ik.sand.iw.krw.md): Calculates water relative permeability using Ibrahim-Koederitz correlation for intermediate-wet sandstone, [dimensionless].
- [PO.SCAL.IK.Sand.OW.Krow](/function/po.scal.ik.sand.ow.krow.md): Calculates oil relative permeability using Ibrahim-Koederitz correlation for oil-wet sandstone, [dimensionless].
- [PO.SCAL.IK.Sand.OW.Krw](/function/po.scal.ik.sand.ow.krw.md): Calculates water relative permeability using Ibrahim-Koederitz correlation for oil-wet sandstone, [dimensionless].
- [PO.SCAL.IK.Sand.SWW.Krow](/function/po.scal.ik.sand.sww.krow.md): Calculates oil relative permeability using Ibrahim-Koederitz correlation for strongly water-wet sandstone, [dimensionless].
- [PO.SCAL.IK.Sand.SWW.Krw](/function/po.scal.ik.sand.sww.krw.md): Calculates water relative permeability using Ibrahim-Koederitz correlation for strongly water-wet sandstone, [dimensionless].
- [PO.SCAL.IK.Sand.WW.Krow](/function/po.scal.ik.sand.ww.krow.md): Calculates oil relative permeability using Ibrahim-Koederitz correlation for water-wet sandstone, [dimensionless].
- [PO.SCAL.IK.Sand.WW.Krw](/function/po.scal.ik.sand.ww.krw.md): Calculates water relative permeability using Ibrahim-Koederitz correlation for water-wet sandstone, [dimensionless].
- [PO.SCAL.LET.Krow](/function/po.scal.let.krow.md): Calculates LET-type oil relative permeability, [dimensionless].
- [PO.SCAL.LET.Krw](/function/po.scal.let.krw.md): Calculates LET-type water relative permeability, [dimensionless].
- [PO.SCAL.Leverett.J](/function/po.scal.leverett.j.md): Leverett J-function, [dimensionless]. J = (Pc/σcosθ) × √(k/φ).
- [PO.SCAL.Leverett.Pc](/function/po.scal.leverett.pc.md): Capillary pressure from J-function, [psi]. Pc = J × σcosθ × √(φ/k).
- [PO.SCAL.Stone.I.Krg](/function/po.scal.stone.i.krg.md): Stone I three-phase gas relative permeability, [dimensionless]. Equal to two-phase Krg.
- [PO.SCAL.Stone.I.Kro](/function/po.scal.stone.i.kro.md): Stone I three-phase oil relative permeability, [dimensionless]. Stone (1970).
- [PO.SCAL.Stone.I.Krw](/function/po.scal.stone.i.krw.md): Stone I three-phase water relative permeability, [dimensionless]. Equal to two-phase Krw.
- [PO.SCAL.Stone.II.Krg](/function/po.scal.stone.ii.krg.md): Stone II three-phase gas relative permeability, [dimensionless]. Equal to two-phase Krg.
- [PO.SCAL.Stone.II.Kro](/function/po.scal.stone.ii.kro.md): Stone II three-phase oil relative permeability, [dimensionless]. Stone (1973).
- [PO.SCAL.Stone.II.Krw](/function/po.scal.stone.ii.krw.md): Stone II three-phase water relative permeability, [dimensionless]. Equal to two-phase Krw.
- [PO.SCAL.VanGenuchten.Pc](/function/po.scal.vangenuchten.pc.md): Van Genuchten capillary pressure, [psi]. Se = [1 + (αPc)^n]^(-m).
- [PO.SCAL.VanGenuchten.Sw](/function/po.scal.vangenuchten.sw.md): Van Genuchten saturation from capillary pressure, [fraction]. Inverse of Pc function.
- [PO.SF.CH.Achong.Pwh](/function/po.sf.ch.achong.pwh.md): Wellhead pressure using Achong (1961) critical flow correlation, [psia].
- [PO.SF.CH.Achong.Rate](/function/po.sf.ch.achong.rate.md): Liquid flow rate using Achong (1961) critical flow correlation, [bbl/d]. Modified Gilbert for Lake Maracaibo conditions.
- [PO.SF.CH.Achong.Size](/function/po.sf.ch.achong.size.md): Choke diameter using Achong (1961) critical flow correlation, [inches].
- [PO.SF.CH.AshfordPierce.Pwh](/function/po.sf.ch.ashfordpierce.pwh.md): Wellhead pressure using Ashford-Pierce (1975) model, [psia]. Iterative solution for target rate.
- [PO.SF.CH.AshfordPierce.Rate](/function/po.sf.ch.ashfordpierce.rate.md): Liquid flow rate using Ashford-Pierce (1975) subcritical correction model, [bbl/d]. Extends critical flow correlations to subcritical conditions.
- [PO.SF.CH.AshfordPierce.Size](/function/po.sf.ch.ashfordpierce.size.md): Choke diameter using Ashford-Pierce (1975) model, [inches]. Iterative solution for target rate.
- [PO.SF.CH.Baxendell.Pwh](/function/po.sf.ch.baxendell.pwh.md): Wellhead pressure using Baxendell (1957) critical flow correlation, [psia].
- [PO.SF.CH.Baxendell.Rate](/function/po.sf.ch.baxendell.rate.md): Liquid flow rate using Baxendell (1957) critical flow correlation, [bbl/d]. Developed from Lake Maracaibo field data.
- [PO.SF.CH.Baxendell.Size](/function/po.sf.ch.baxendell.size.md): Choke diameter using Baxendell (1957) critical flow correlation, [inches].
- [PO.SF.CH.Gas.Pwh](/function/po.sf.ch.gas.pwh.md): Required upstream pressure for sonic gas flow, [psia].
- [PO.SF.CH.Gas.Rate](/function/po.sf.ch.gas.rate.md): Gas flow rate through choke, [Mscf/d]. Automatically determines sonic or subsonic flow regime.
- [PO.SF.CH.Gas.Rate.Sonic](/function/po.sf.ch.gas.rate.sonic.md): Gas flow rate at sonic (critical) conditions, [Mscf/d]. Rate independent of downstream pressure.
- [PO.SF.CH.Gas.Rcrit](/function/po.sf.ch.gas.rcrit.md): Critical pressure ratio for gas (Pdn/Pup at sonic conditions), [dimensionless]. Flow is sonic when actual ratio <= critical ratio.
- [PO.SF.CH.Gas.Size](/function/po.sf.ch.gas.size.md): Required choke diameter for sonic gas flow, [inches].
- [PO.SF.CH.Gilbert.Pwh](/function/po.sf.ch.gilbert.pwh.md): Wellhead pressure using Gilbert (1954) critical flow correlation, [psia]. Calculates required pressure for target rate.
- [PO.SF.CH.Gilbert.Rate](/function/po.sf.ch.gilbert.rate.md): Liquid flow rate using Gilbert (1954) critical flow correlation, [bbl/d]. Widely used for oil wells with gas.
- [PO.SF.CH.Gilbert.Size](/function/po.sf.ch.gilbert.size.md): Choke diameter using Gilbert (1954) critical flow correlation, [inches]. Calculates required choke size for target rate.
- [PO.SF.CH.Liq.dP](/function/po.sf.ch.liq.dp.md): Pressure drop across choke for liquid flow, [psi].
- [PO.SF.CH.Liq.Rate](/function/po.sf.ch.liq.rate.md): Liquid flow rate through choke, [bbl/d]. Uses Bernoulli equation for incompressible flow.
- [PO.SF.CH.Liq.Size](/function/po.sf.ch.liq.size.md): Required choke diameter for liquid flow, [inches].
- [PO.SF.CH.Pilehvari.Pwh](/function/po.sf.ch.pilehvari.pwh.md): Wellhead pressure using Pilehvari (1980) critical flow correlation, [psia].
- [PO.SF.CH.Pilehvari.Rate](/function/po.sf.ch.pilehvari.rate.md): Liquid flow rate using Pilehvari (1980) critical flow correlation, [bbl/d]. Based on U. of Tulsa experimental data.
- [PO.SF.CH.Pilehvari.Size](/function/po.sf.ch.pilehvari.size.md): Choke diameter using Pilehvari (1980) critical flow correlation, [inches].
- [PO.SF.CH.Ros.Pwh](/function/po.sf.ch.ros.pwh.md): Wellhead pressure using Ros (1960) critical flow correlation, [psia].
- [PO.SF.CH.Ros.Rate](/function/po.sf.ch.ros.rate.md): Liquid flow rate using Ros (1960) critical flow correlation, [bbl/d].
- [PO.SF.CH.Ros.Size](/function/po.sf.ch.ros.size.md): Choke diameter using Ros (1960) critical flow correlation, [inches].
- [PO.SF.CH.Sachdeva.Pwh](/function/po.sf.ch.sachdeva.pwh.md): Wellhead pressure using Sachdeva (1986) two-phase model, [psia]. Iterative solution for target rate.
- [PO.SF.CH.Sachdeva.Rate](/function/po.sf.ch.sachdeva.rate.md): Liquid flow rate using Sachdeva (1986) two-phase mechanistic model, [bbl/d]. Handles both critical and subcritical flow.
- [PO.SF.CH.Sachdeva.Size](/function/po.sf.ch.sachdeva.size.md): Choke diameter using Sachdeva (1986) two-phase model, [inches]. Iterative solution for target rate.
- [PO.SF.PL.Ff](/function/po.sf.pl.ff.md): Moody friction factor using Chen correlation
- [PO.SF.PL.Gas.PanhandleA.Pout](/function/po.sf.pl.gas.panhandlea.pout.md): Outlet pressure for gas pipeline using Panhandle A equation, [psia]
- [PO.SF.PL.Gas.PanhandleA.Rate](/function/po.sf.pl.gas.panhandlea.rate.md): Gas flow rate using Panhandle A equation for medium-pressure transmission, [Mscf/d]
- [PO.SF.PL.Gas.PanhandleB.Pout](/function/po.sf.pl.gas.panhandleb.pout.md): Outlet pressure for gas pipeline using Panhandle B equation, [psia]
- [PO.SF.PL.Gas.PanhandleB.Rate](/function/po.sf.pl.gas.panhandleb.rate.md): Gas flow rate using Panhandle B equation for high-pressure large-diameter transmission, [Mscf/d]
- [PO.SF.PL.Gas.Re](/function/po.sf.pl.gas.re.md): Reynolds number for gas pipeline flow
- [PO.SF.PL.Gas.Rho](/function/po.sf.pl.gas.rho.md): Gas density at pipeline conditions, [lb/ft3]
- [PO.SF.PL.Gas.Vel](/function/po.sf.pl.gas.vel.md): Gas velocity at pipeline conditions, [ft/s]
- [PO.SF.PL.Gas.Weymouth.Pout](/function/po.sf.pl.gas.weymouth.pout.md): Outlet pressure for gas pipeline using Weymouth equation, [psia]
- [PO.SF.PL.Gas.Weymouth.Rate](/function/po.sf.pl.gas.weymouth.rate.md): Gas flow rate using Weymouth equation for high-pressure large-diameter pipelines, [Mscf/d]
- [PO.SF.PL.Liq.dP](/function/po.sf.pl.liq.dp.md): Pressure drop for liquid pipeline using Darcy-Weisbach equation, [psi]
- [PO.SF.PL.Liq.Pin](/function/po.sf.pl.liq.pin.md): Required inlet pressure for liquid pipeline, [psia]
- [PO.SF.PL.Liq.Pout](/function/po.sf.pl.liq.pout.md): Outlet pressure for liquid pipeline, [psia]
- [PO.SF.PL.Liq.Rate](/function/po.sf.pl.liq.rate.md): Liquid flow rate for given pressure drop using Darcy-Weisbach, [bbl/d]
- [PO.SF.PL.Liq.Re](/function/po.sf.pl.liq.re.md): Reynolds number for liquid pipeline flow
- [PO.SF.PL.Liq.Vel](/function/po.sf.pl.liq.vel.md): Liquid velocity in pipeline, [ft/s]
- [PO.Spline.Cubic.Diff](/function/po.spline.cubic.diff.md): Calculates first derivative using natural cubic spline interpolation.
- [PO.Spline.Cubic.Integ](/function/po.spline.cubic.integ.md): Calculates definite integral using natural cubic spline interpolation from the start up to point t.
- [PO.Spline.Cubic.IntegT1T2](/function/po.spline.cubic.integt1t2.md): Calculates definite integral using natural cubic spline interpolation from point t1 to point t2.
- [PO.Spline.Cubic.Interp](/function/po.spline.cubic.interp.md): Calculates interpolated value using natural cubic spline interpolation.
- [PO.Spline.Cubic.Intersect](/function/po.spline.cubic.intersect.md): Calculates x value of intersection point between two cubic splines.
- [PO.Spline.Linear.Diff](/function/po.spline.linear.diff.md): Calculates first derivative using linear spline interpolation.
- [PO.Spline.Linear.Integ](/function/po.spline.linear.integ.md): Calculates definite integral using linear spline interpolation from the start up to point t.
- [PO.Spline.Linear.IntegT1T2](/function/po.spline.linear.integt1t2.md): Calculates definite integral using linear spline interpolation from point t1 to point t2.
- [PO.Spline.Linear.Interp](/function/po.spline.linear.interp.md): Calculates interpolated value using linear spline interpolation.
- [PO.Spline.Linear.Intersect](/function/po.spline.linear.intersect.md): Calculates x value of intersection point between two linear splines.
- [PO.Spline.Proximal.Interp](/function/po.spline.proximal.interp.md): Calculates interpolated value using proximal interpolation.
- [PO.Spline.Step.Interp](/function/po.spline.step.interp.md): Calculates interpolated value using step interpolation.
- [PO.Stats.LogSSE](/function/po.stats.logsse.md): Computes the sum of squared errors (SSE) in log-space between observed and predicted rate sequences. Small positive epsilon added before taking logs to avoid log(0).
- [PO.Stats.R2](/function/po.stats.r2.md): Computes the coefficient of determination (R²) between observed and predicted sequences. R² = 1 - SSE/TSS. Returns 1.0 for perfect fit.
- [PO.Stats.RMSE](/function/po.stats.rmse.md): Computes the root mean squared error (RMSE) between observed and predicted sequences. RMSE = sqrt(SSE/n).
- [PO.Stats.SSE](/function/po.stats.sse.md): Computes the sum of squared errors (SSE) between observed and predicted rate sequences. Returns a scalar value.
- [PO.Stats.WLogSSE](/function/po.stats.wlogsse.md): Computes the weighted log-space SSE between observed and predicted sequences. Small positive epsilon added before taking logs to avoid log(0).
- [PO.Stats.WSSE](/function/po.stats.wsse.md): Computes the weighted SSE between observed and predicted sequences.
- [PO.UnitConverter](/function/po.unitconverter.md): Converts value from one unit to another, [depends on units].
- [PO.VFP.Ansari.dPdL](/function/po.vfp.ansari.dpdl.md): Calculates pressure gradient using Ansari et al. (1994) mechanistic model, [psi/ft]. TUFFP industry standard for vertical upward flow.
- [PO.VFP.Ansari.Pin](/function/po.vfp.ansari.pin.md): Calculates inlet pipe pressure using Ansari et al. (1994), [psi]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.Ansari.Pout](/function/po.vfp.ansari.pout.md): Calculates outlet pipe pressure using Ansari et al. (1994), [psi]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.Aziz.dPdL](/function/po.vfp.aziz.dpdl.md): Calculates pressure gradient using Aziz et al. (1972) drift-flux model, [psi/ft]. Vertical wells, basis for mechanistic models.
- [PO.VFP.Aziz.Pin](/function/po.vfp.aziz.pin.md): Calculates inlet pipe pressure using Aziz et al. (1972), [psi]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.Aziz.Pout](/function/po.vfp.aziz.pout.md): Calculates outlet pipe pressure using Aziz et al. (1972), [psi]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.BeggsBrill.dPdL](/function/po.vfp.beggsbrill.dpdl.md): Calculates pressure gradient for multiphase pipe flow using Beggs and Brill (1973) correlation, [psi/ft]. Can be applied for any wellbore inclination and flow direction.
- [PO.VFP.BeggsBrill.Pin](/function/po.vfp.beggsbrill.pin.md): Calculates inlet pipe pressure using Beggs and Brill (1973), [psi]. For any wellbore inclination. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.BeggsBrill.Pout](/function/po.vfp.beggsbrill.pout.md): Calculates outlet pipe pressure using Beggs and Brill (1973), [psi]. For any wellbore inclination. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.DunsRos.dPdL](/function/po.vfp.dunsros.dpdl.md): Calculates pressure gradient using Duns and Ros (1963) correlation, [psi/ft]. For vertical gas wells with liquid, high GOR wells.
- [PO.VFP.DunsRos.Pin](/function/po.vfp.dunsros.pin.md): Calculates inlet pipe pressure using Duns and Ros (1963), [psi]. Vertical gas wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.DunsRos.Pout](/function/po.vfp.dunsros.pout.md): Calculates outlet pipe pressure using Duns and Ros (1963), [psi]. Vertical gas wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.Gas.Pin](/function/po.vfp.gas.pin.md): Calculates inlet pipe pressure for single phase pipe flow of gas (compressible fluid), [psi].
- [PO.VFP.Gas.Pout](/function/po.vfp.gas.pout.md): Calculates outlet pipe pressure for single phase pipe flow of gas (compressible fluid), [psi].
- [PO.VFP.Gas.Re](/function/po.vfp.gas.re.md): Calculates Reynolds number for single phase pipe flow of gas (compressible fluid), [dimensionless].
- [PO.VFP.Gray.dPdL](/function/po.vfp.gray.dpdl.md): Calculates pressure gradient for multiphase pipe flow using Gray (1974) correlation, [psi/ft]. Commonly used for gas wells that are also producing liquid.
- [PO.VFP.Gray.Pin](/function/po.vfp.gray.pin.md): Calculates inlet pipe pressure using Gray (1974), [psi]. For gas wells producing liquid. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.Gray.Pout](/function/po.vfp.gray.pout.md): Calculates outlet pipe pressure using Gray (1974), [psi]. For gas wells producing liquid. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.HagedornBrown.dPdL](/function/po.vfp.hagedornbrown.dpdl.md): Calculates pressure gradient for multiphase pipe flow using Hagedorn and Brown (1965) correlation with Griffith modification, [psi/ft]. Developed for vertical, upward flow and recommended only for near-vertical wellbores.
- [PO.VFP.HagedornBrown.Pin](/function/po.vfp.hagedornbrown.pin.md): Calculates inlet pipe pressure using Hagedorn and Brown (1965), [psi]. For vertical/near-vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.HagedornBrown.Pout](/function/po.vfp.hagedornbrown.pout.md): Calculates outlet pipe pressure using Hagedorn and Brown (1965), [psi]. For vertical/near-vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.HasanKabir.dPdL](/function/po.vfp.hasankabir.dpdl.md): Calculates pressure gradient using Hasan-Kabir (1988) mechanistic model, [psi/ft]. For deviated wells and annular geometry.
- [PO.VFP.HasanKabir.Pin](/function/po.vfp.hasankabir.pin.md): Calculates inlet pipe pressure using Hasan-Kabir (1988), [psi]. For deviated wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.HasanKabir.Pout](/function/po.vfp.hasankabir.pout.md): Calculates outlet pipe pressure using Hasan-Kabir (1988), [psi]. For deviated wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.Liq.dPfrc](/function/po.vfp.liq.dpfrc.md): Calculates frictional pressure drop from Fanning equation for single-phase flow of an incompressible, Newtonian fluid, [psi].
- [PO.VFP.Liq.dPgrv](/function/po.vfp.liq.dpgrv.md): Calculates potential energy pressure drop for single-phase flow of an incompressible, Newtonian fluid, [psi].
- [PO.VFP.Liq.Pin](/function/po.vfp.liq.pin.md): Calculates inlet pipe pressure for single phase pipe flow of incompressible, Newtonian fluid, [psi].
- [PO.VFP.Liq.Pout](/function/po.vfp.liq.pout.md): Calculates outlet pipe pressure for single phase pipe flow of incompressible, Newtonian fluid, [psi].
- [PO.VFP.Liq.Re](/function/po.vfp.liq.re.md): Calculates Reynolds number for single phase pipe flow of incompressible, Newtonian fluid, [dimensionless].
- [PO.VFP.MukherjeeBrill.dPdL](/function/po.vfp.mukherjeebrill.dpdl.md): Calculates pressure gradient using Mukherjee-Brill (1985) correlation, [psi/ft]. For inclined wells, improvement over Beggs-Brill.
- [PO.VFP.MukherjeeBrill.Pin](/function/po.vfp.mukherjeebrill.pin.md): Calculates inlet pipe pressure using Mukherjee-Brill (1985), [psi]. For inclined wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.MukherjeeBrill.Pout](/function/po.vfp.mukherjeebrill.pout.md): Calculates outlet pipe pressure using Mukherjee-Brill (1985), [psi]. For inclined wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.Orkiszewski.dPdL](/function/po.vfp.orkiszewski.dpdl.md): Calculates pressure gradient using Orkiszewski (1967) correlation, [psi/ft]. Vertical wells, widely used industry standard.
- [PO.VFP.Orkiszewski.Pin](/function/po.vfp.orkiszewski.pin.md): Calculates inlet pipe pressure using Orkiszewski (1967), [psi]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.Orkiszewski.Pout](/function/po.vfp.orkiszewski.pout.md): Calculates outlet pipe pressure using Orkiszewski (1967), [psi]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.PoettmannCarpenter.dPdL](/function/po.vfp.poettmanncarpenter.dpdl.md): Calculates pressure gradient using Poettmann-Carpenter (1952), [psi/ft]. Historical no-slip method for high-rate dispersed bubble flow.
- [PO.VFP.PoettmannCarpenter.Pin](/function/po.vfp.poettmanncarpenter.pin.md): Calculates inlet pipe pressure using Poettmann-Carpenter (1952), [psi]. No-slip method. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).
- [PO.VFP.PoettmannCarpenter.Pout](/function/po.vfp.poettmanncarpenter.pout.md): Calculates outlet pipe pressure using Poettmann-Carpenter (1952), [psi]. No-slip method. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity).

## Documentation
- [Decline Curve Analysis Overview](/doc/dca-overview.md): Comprehensive guide to decline curve models for production forecasting and reserves estimation
- [Equation of State Overview](/doc/eos-overview.md): Guide to cubic equations of state for compositional modeling, flash calculations, and phase behavior prediction
- [ESP System Design Overview](/doc/esp-overview.md): Comprehensive guide to Electric Submersible Pump system design, component selection, and calculation workflow for artificial lift optimization
- [Field Production Profiles Overview](/doc/fpp-overview.md): Guide to field-level production forecasting including buildup-plateau-decline profiles and multi-well schedule aggregation
- [Flow Assurance Overview](/doc/fa-overview.md): Comprehensive guide to flow assurance calculations including hydrate prevention, corrosion management, and erosion control for oil and gas production systems
- [Gas Lift Overview](/doc/gl-overview.md): Guide to gas lift design including continuous gas lift, valve mechanics, injection pressure, and gas lift optimization
- [Hydraulic Fracturing Overview](/doc/frac-overview.md): Comprehensive guide to hydraulic fracturing theory, fracture geometry models, leakoff, fluid efficiency, and proppant transport for well stimulation design
- [Material Balance Overview](/doc/mbe-overview.md): Guide to material balance methods for reservoir engineering including drive mechanism identification, OOIP/OGIP estimation, and aquifer modeling
- [Monte Carlo Simulation Overview](/doc/mc-overview.md): Guide to Monte Carlo methods for uncertainty quantification in petroleum engineering including probabilistic reserves, risk analysis, and sensitivity studies
- [Pipe Flow Overview](/doc/vfp-overview.md): Comprehensive guide to single-phase and multiphase pipe flow correlations for wellbore and pipeline calculations
- [Pressure Transient Analysis Overview](/doc/pta-overview.md): Comprehensive guide to well testing models and interpretation methods for reservoir characterization
- [PVT Properties Overview](/doc/pvt-overview.md): Comprehensive guide to selecting and applying PVT correlations for crude oil, gas, and water properties
- [Rod Pump Overview](/doc/rp-overview.md): Guide to sucker rod pumping system design including pump displacement, rod string analysis, polished rod loads, and counterbalance
- [SCAL Overview - Relative Permeability Correlations](/doc/scal-overview.md): Comprehensive guide to selecting and applying relative permeability correlations based on rock type, wettability, and fluid system
- [Surface Facilities Overview](/doc/sf-overview.md): Comprehensive guide to surface facility calculations including choke models for flow control and pipeline equations for fluid transport
- [System Requirements & Prerequisites](/doc/system-requirements-and-prerequisites.md): What you need to install Petroleum Office — supported Excel versions, the .NET 10 Desktop Runtime, how to check your Excel bitness, and where to download the matching runtime for 32-bit or 64-bit Excel.
- [Utilities Overview](/doc/utilities-overview.md): Guide to utility functions including unit conversion, interpolation methods, and mathematical tools for petroleum engineering calculations
- [Well Flow Overview](/doc/ipr-overview.md): Comprehensive guide to well inflow performance, productivity index calculations, and flow rate estimation for oil and gas wells
- [Getting Started with Petroleum Office](/doc/getting-started-with-petroleum-office.md): Step-by-step guide to installing Petroleum Office, exploring the ribbon, and using your first Excel function for petroleum engineering calculations.
- [Connect to the Petroleum Office MCP Server](/doc/po-mcp-connect.md): Setup instructions for connecting AI assistants (Claude for Excel, Claude.ai, Grok) to the Petroleum Office MCP server.
- [Function Naming Conventions in Petroleum Office](/doc/function-naming-conventions-in-petroleum-office.md): Guide to understanding the dot-separated naming convention used by Petroleum Office Excel functions, including categories, properties, qualifiers, and author names.
- [Using Array Functions in Petroleum Office](/doc/using-array-functions-in-petroleum-office.md): Tutorial on using Petroleum Office functions that return multiple values using Excel's dynamic array (spill range) feature.
- [Using Blueprints in Petroleum Office](/doc/using-blueprints-in-petroleum-office.md): Guide to browsing, inserting, and using blueprints — reusable Excel worksheet templates with pre-built petroleum engineering calculations.
- [Unit Conversion in Petroleum Office](/doc/unit-conversion-in-petroleum-office.md): Complete guide to using Petroleum Office unit converter for converting between 1500+ petroleum engineering units including pressure, temperature, volume, and flow rates.
- [Import Eclipse Result Files In Excel](/doc/import-eclipse-result-files-in-excel.md): Tutorial on importing Eclipse reservoir simulator output files into Excel using Petroleum Office toolbox for analysis and visualization.
- [How To Use Case Generation](/doc/how-to-use-case-generation.md): Step-by-step guide to using the Petroleum Office Case Generator tool to batch-create simulation input files from Excel templates with token replacement.
- [How To Use Petroleum Office Addin Functions From VBA](/doc/how-to-use-petroleum-office-addin-functions-from-vba.md): Learn how to call Petroleum Office functions from VBA macros in Excel with code examples and best practices for automation.
- [Import LAS Files In Excel](/doc/import-las-files-in-excel.md): Tutorial on importing LAS well log files (v2.0 and v3.0) into Excel using Petroleum Office for petrophysical analysis and visualization.
- [Troubleshooting Common Errors in Petroleum Office](/doc/troubleshooting-common-errors-in-petroleum-office.md): Solutions for common Excel errors when using Petroleum Office functions, including #NAME?, #VALUE!, #NUM!, #N/A, and #SPILL! errors.
- [Choke Models for Multiphase, Gas, and Liquid Flow](/doc/sf-choke-models.md): Theory and equations for critical and subcritical choke flow including Gilbert-type correlations, Sachdeva, Ashford-Pierce, and single-phase choke models
- [Drilling Schedule and Multi-Well Forecasting](/doc/fpp-drilling-schedule.md): Multi-well production aggregation methods, drilling schedule impact on field profiles, and schedule-based cumulative production forecasting
- [ESP Pump Performance - Head, Staging, Efficiency, and Horsepower](/doc/esp-pump-performance.md): Theory and equations for ESP pump performance including head-capacity curves, total dynamic head, staging calculations, brake horsepower, and best efficiency point analysis
- [Fracture Geometry Models - PKN, KGD, and Radial](/doc/frac-geometry-models.md): Complete theory and equations for classical 2D hydraulic fracture geometry models including PKN, KGD, and Radial (penny-shaped) with Carter leakoff and fluid efficiency
- [Gas Lift Valve Mechanics](/doc/gl-valve-mechanics.md): Theory and calculations for gas lift valve operation including dome pressure, opening and closing pressures, spread, and gas throughput
- [Gas Reservoir Material Balance](/doc/mbe-gas-reservoirs.md): p/z method for volumetric gas reservoirs, modified p/z for geopressured reservoirs, and OGIP estimation techniques
- [Hydrate Prevention](/doc/fa-hydrate-prevention.md): Gas hydrate formation conditions, Hammerschmidt equation for temperature depression, and thermodynamic inhibitor calculations for methanol and MEG
- [Migrating Functions from v1.8 to v2.0](/doc/migrating-functions-from-v1-8-to-v2-0.md): Reference for upgrading Excel workbooks from Petroleum Office v1.8 to v2.0. Maps all 213 old UDFs to their new dotted-namespace equivalents and flags parameter reorders and unit changes that silently affect results.
- [Peng-Robinson Equation of State](/doc/eos-peng-robinson.md): Theory and equations for the Peng-Robinson cubic equation of state including mixing rules, alpha functions, and volume translation
- [Probability Distributions for Monte Carlo](/doc/mc-distributions.md): Common probability distributions used in petroleum engineering Monte Carlo simulation including normal, lognormal, triangular, uniform, PERT, and truncated distributions
- [Rod Pump Displacement and Efficiency](/doc/rp-pump-displacement.md): Pump displacement calculation, fillage analysis, volumetric efficiency, effective stroke length, and pump intake pressure for sucker rod pumping
- [Corrosion and Erosion](/doc/fa-corrosion-erosion.md): CO2 corrosion prediction using the de Waard-Milliams model, NACE severity classification, and erosional velocity calculations per API RP 14E
- [ESP Gas Handling - Free Gas, Void Fraction, and Gas Separation](/doc/esp-gas-handling.md): Theory and equations for gas interference in ESP systems including free gas volume at pump intake, void fraction calculations, gas separator efficiency, and Turpin-Dunbar correction factors
- [Flash Calculations](/doc/eos-flash-calculations.md): Theory and methods for PT flash calculations, Rachford-Rice equation, stability analysis, and K-value estimation
- [Oil Reservoir Material Balance](/doc/mbe-oil-reservoirs.md): Havlena-Odeh straight-line method for oil reservoir analysis, OOIP estimation, gas cap ratio determination, and Campbell plot interpretation
- [Pipeline Flow Equations for Gas, Liquid, and Two-Phase Systems](/doc/sf-pipeline-flow.md): Theory and equations for pipeline pressure drop and flow capacity including Weymouth, Panhandle A/B, Darcy-Weisbach, and two-phase correlations
- [Proppant Transport in Hydraulic Fractures](/doc/frac-proppant.md): Theory and equations for proppant settling velocity, wall effects, hindered settling, power-law fluid corrections, and transport ratio calculations in hydraulic fractures
- [Rod String Analysis](/doc/rp-rod-string.md): Sucker rod string design including rod weight, stretch calculations, polished rod loads, stress analysis, and API 11L dynamic factors
- [Aquifer Models](/doc/mbe-aquifer-models.md): Theory and application of aquifer models for water influx calculation: Pot, Schilthuis steady-state, Fetkovich pseudo-steady-state, and Van Everdingen-Hurst unsteady-state
- [ESP Viscosity Corrections - Turpin and Stepanoff Methods](/doc/esp-viscosity-corrections.md): Theory and equations for correcting ESP pump performance curves for viscous fluid effects, including Turpin and Stepanoff correction factor methods for head, efficiency, and flow rate derating
- [Phase Envelope](/doc/eos-phase-envelope.md): Theory and construction of phase envelopes showing bubble point and dew point curves, cricondentherm, and cricondenbar
- [C7+ Characterization](/doc/eos-characterization.md): Methods for estimating critical properties, splitting heavy fractions, and lumping components for equation of state modeling
- [ESP Motor and Cable Sizing - Horsepower, Amperage, and Voltage Drop](/doc/esp-motor-cable-sizing.md): Theory and equations for ESP motor horsepower selection, amperage calculations, load factor analysis, cable voltage drop, cable size selection, and power loss estimation
- [Underground Withdrawal and Expansion Terms](/doc/mbe-underground-withdrawal.md): Calculation of underground withdrawal F, expansion terms Eo, Eg, Efw, effective compressibility, and two-phase formation volume factor Bt
- [Compositional Viscosity Models](/doc/eos-viscosity.md): Viscosity prediction methods for compositional EoS modeling including Lee-Gonzalez-Eakin, Lorentz-Bray-Clark, and Pedersen models
- [Ansah-Knowles-Buba (AKB) Decline Model](/doc/dca-ansah-knowles-buba.md): Semi-analytical decline model for gas wells under boundary-dominated flow, derived from material balance principles
- [Arps Decline Curve Analysis - Exponential, Hyperbolic, and Harmonic Models](/doc/dca-arps.md): Complete theory and equations for classical Arps decline curves including exponential, hyperbolic, and harmonic models for production forecasting and EUR estimation.
- [Beggs and Brill Multiphase Flow Correlation](/doc/vfp-beggs-brill.md): Comprehensive correlation for predicting pressure drop and liquid holdup in multiphase flow through pipes at any inclination angle
- [Bounded Reservoir Solutions for Pressure Transient Analysis](/doc/pta-bounded-reservoir.md): Method of images for modeling boundary effects including sealing faults, constant pressure boundaries, and combinations in well test analysis.
- [Bubble Point Pressure Correlations](/doc/pvt-bubble-point-pressure-correlations.md): Empirical correlations for predicting the saturation pressure of crude oil from surface-measured fluid properties
- [Corey and LET Relative Permeability Models](/doc/scal-corey-let.md): Analytical relative permeability models using power-law (Corey) and three-parameter (LET) formulations
- [Decline Curve Statistics](/doc/dca-statistics.md): Objective functions for evaluating decline curve model fit quality including SSE, log-space SSE, and weighted variants
- [Dimensionless Variables for Pressure Transient Analysis](/doc/pta-dimensionless-variables.md): Definitions and equations for dimensionless pressure, time, radius, distance, and wellbore storage used in well test analysis and type curve matching.
- [Duong Decline Model for Unconventional Wells](/doc/dca-duong.md): Theory and equations for the Duong decline model designed for multi-fractured horizontal wells in shale and tight reservoirs with extended linear flow.
- [Field Production Profiles](/doc/dca-field-profiles.md): Aggregate production modeling for multi-well field development using parametric and discrete convolution approaches
- [Formation Water PVT Properties](/doc/pvt-water-properties.md): McCain correlations for formation water density, formation volume factor, compressibility, viscosity, and solution gas-water ratio
- [Gas PVT Properties](/doc/pvt-gas-properties.md): Comprehensive correlations for natural gas compressibility factor, viscosity, density, formation volume factor, and pseudo-critical properties
- [Gas Well Deliverability](/doc/ipr-gas-wells.md): Darcy and non-Darcy gas flow equations for vertical gas well performance and deliverability testing
- [Honarpour Relative Permeability Correlations](/doc/scal-honarpour.md): Empirical relative permeability equations for consolidated rocks based on regression analysis of laboratory data
- [Horizontal Well Productivity](/doc/ipr-horizontal-wells.md): Productivity index and drainage area correlations for horizontal and deviated wells
- [Ibrahim-Koederitz Relative Permeability Correlations](/doc/scal-ibrahim-koederitz.md): Comprehensive linear regression relative permeability equations for all rock types, wettability states, and fluid systems
- [Infinite Acting Reservoir Solutions for Pressure Transient Analysis](/doc/pta-infinite-reservoir.md): Line source solution, Ei function, Stehfest numerical inversion, and wellbore storage/skin effects for infinite homogeneous reservoir well testing.
- [Interfacial Tension Correlations](/doc/pvt-interfacial-tension.md): Gas-oil interfacial tension correlations for wellbore hydraulics calculations
- [Interpolation and Integration Functions](/doc/utilities-interpolation.md): Numerical methods for interpolating, differentiating, and integrating tabular data using spline techniques
- [Modified Hyperbolic Decline Model](/doc/dca-modified-hyperbolic.md): Hybrid decline model combining hyperbolic and exponential decline with a terminal decline rate for realistic long-term production forecasting.
- [Oil Compressibility Correlations](/doc/pvt-oil-compressibility.md): Empirical correlations for predicting isothermal compressibility of crude oil at saturated and undersaturated conditions
- [Oil Formation Volume Factor (Bo) Correlations](/doc/pvt-oil-formation-volume-factor.md): PVT correlations for oil formation volume factor including Standing, Vazquez-Beggs, Glasø, Al-Marhoun, Petrosky-Farshad, and Dindoruk-Christman methods.
- [Oil Viscosity Correlations](/doc/pvt-oil-viscosity.md): Empirical correlations for predicting crude oil viscosity at dead, saturated, and undersaturated conditions
- [Power Law Exponential (PLE) Decline Model](/doc/dca-power-law-exponential.md): Theory and equations for the Ilk et al. Power Law Exponential decline model for tight gas and unconventional reservoirs, capturing transient-to-BDF transition.
- [Rock Compressibility Correlations](/doc/scal-rock-compressibility.md): Pore volume compressibility correlations for sandstone and limestone reservoirs
- [Single-Phase Pipe Flow](/doc/vfp-single-phase.md): Reynolds number, friction factor, and pressure drop calculations for single-phase liquid and gas flow in pipes
- [Solution Gas-Oil Ratio (Rs) Correlations](/doc/pvt-solution-gas-oil-ratio.md): PVT correlations for solution gas-oil ratio including Standing, Vazquez-Beggs, Glasø, Al-Marhoun, Petrosky-Farshad, and Dindoruk-Christman methods.
- [Stretched Exponential Production Decline (SEPD) Model](/doc/dca-stretched-exponential.md): Theory and equations for the Valkó-Lee Stretched Exponential decline model based on statistical physics, ideal for shale and unconventional reservoir analysis.
- [Unit Conversions and Special Functions](/doc/utilities-conversions.md): Utility functions for unit conversions, gravity transforms, and mathematical special functions used in petroleum engineering
- [Vertical Multiphase Flow Correlations](/doc/vfp-vertical-correlations.md): Hagedorn-Brown and Gray correlations for predicting pressure gradients in vertical and near-vertical wells
- [Vogel Inflow Performance Relationship](/doc/ipr-vogel.md): Dimensionless IPR curve for solution-gas drive wells producing below bubble point pressure
- [Well Productivity Index](/doc/ipr-productivity-index.md): Productivity index calculations for vertical and horizontal wells under steady-state, pseudosteady-state, and transient flow conditions

## Blueprints
- [Arps Decline Forecast](/blueprint/po.dca.arps.forecast.md): Decline curve analysis using the Arps hyperbolic decline equation. Calculates rate and cumulative production over time for production forecasting.
- [DCA Auto-Fit Model Comparison](/blueprint/po.dca.autofit.compare.md): Auto-fit Arps hyperbolic and Duong decline models to the same production data, then compare R² and EUR to select the best model. Arps works well for conventional reservoirs; Duong is better for unconventional (tight/shale) with linear flow.
- [Decline Rate Conversions](/blueprint/po.dca.conversions.rates.md): Convert between different decline rate representations. Understanding the difference between nominal and effective decline rates, and between different time bases, is essential for consistent decline analysis.
- [Production Data QC](/blueprint/po.dca.data.cleaning.md): Clean production data before decline curve analysis by detecting and removing outliers using a rolling-window Z-score method. Compare raw vs cleaned data and show the impact on Arps curve fitting — noisy data produces unreliable decline parameters.
- [Decline Diagnostics Analysis](/blueprint/po.dca.diagnostics.analysis.md): Diagnostic analysis for decline curve interpretation using derivative-based methods. These tools help identify flow regimes and validate decline model selection.
- [Duong Decline Forecast](/blueprint/po.dca.duong.forecast.md): Decline curve forecast using the Duong model, specifically designed for unconventional reservoirs exhibiting transient linear flow. The Duong model captures the power-law behavior common in tight oil and shale gas wells.
- [EUR Calculator](/blueprint/po.dca.eur.calculator.md): Calculate Estimated Ultimate Recovery (EUR) for different economic limits and decline parameters. Essential for reserves estimation and economic analysis.
- [EUR Sensitivity Analysis](/blueprint/po.dca.eur.sensitivity.md): Sensitivity analysis of Estimated Ultimate Recovery (EUR) to Arps decline parameters. Understanding parameter uncertainty impact on EUR is critical for reserves estimation and economic analysis.
- [Decline Model Comparison](/blueprint/po.dca.models.compare.md): Compare multiple decline curve models for the same well. Different models may be more appropriate depending on reservoir type and flow regime. Arps is standard for conventional, Duong for unconventional transient, and PLE for tight/shale.
- [Modified Hyperbolic Decline](/blueprint/po.dca.modhyp.forecast.md): Modified Hyperbolic decline model that transitions from hyperbolic to exponential decline at a specified terminal decline rate. This addresses the unrealistic EUR predictions from pure hyperbolic decline with high b-factors.
- [Bubble & Dew Point](/blueprint/po.eos.bubble.dew.point.md): Calculates bubble point and dew point (pressure and temperature) for a ternary hydrocarbon mixture using Peng-Robinson EoS.
- [Component Database](/blueprint/po.eos.component.database.md): Browse all available components and their thermodynamic properties.
- [PT Flash Calculation](/blueprint/po.eos.flash.calculation.md): Performs rigorous PT flash calculation for a ternary mixture (ethane, propane, n-pentane) using the property-array workflow:
- [Fluid Model Setup](/blueprint/po.eos.fluid.model.setup.md): Build a fluid property table combining database components, SCN (Single Carbon Number) pseudo-components, and mixture molecular weight. This is the foundational step for all EoS calculations.
- [Binary Interaction Parameters](/blueprint/po.eos.kij.estimation.md): Estimates binary interaction parameters using available correlations:
- [Phase Envelope](/blueprint/po.eos.phase.envelope.md): Generates a phase envelope (P-T diagram boundaries) for a natural gas mixture using Peng-Robinson EoS. Returns:
- [Separator Test](/blueprint/po.eos.separator.test.md): Demonstrates array composability by chaining Flash calculations in a two-stage separator:
- [EoS Tuning Setup](/blueprint/po.eos.tuning.setup.md): Framework for EoS tuning by comparing calculated vs. observed bubble point pressures. The property table uses editable cells for Tc, Pc, omega, and Mw, enabling manual adjustment or Solver-based regression.
- [ESP Cable Voltage Drop Analysis](/blueprint/po.esp.cable.analysis.md): Analyze ESP cable voltage drop, power loss, and sizing requirements. Critical for ensuring adequate voltage at the downhole motor.
- [ESP Gas Handling Analysis](/blueprint/po.esp.gas.handling.md): Analyze gas handling requirements for ESP systems. Calculate void fraction and evaluate need for gas separators.
- [ESP Motor Selection and Sizing](/blueprint/po.esp.motor.selection.md): Select and size ESP motors based on pump requirements. Includes load factor analysis and temperature rise calculations.
- [ESP Operating Point Analysis](/blueprint/po.esp.operating.point.md): Determine the ESP operating point by intersecting the pump performance curve (head vs rate) with the system curve (TDH vs rate). Size the pump (number of stages), check BEP proximity, and calculate motor requirements. The operating point must fall within the pump's recommended range for reliable operation.
- [ESP Pump Sizing and Selection](/blueprint/po.esp.pump.sizing.md): Calculate ESP pump sizing requirements including hydraulic horsepower, brake horsepower, number of stages, and discharge pressure.
- [ESP System Design - TDH Calculation](/blueprint/po.esp.system.design.md): Complete ESP system design calculating Total Dynamic Head (TDH) and all head components.
- [CO2 Corrosion Analysis](/blueprint/po.fa.corrosion.analysis.md): CO2 corrosion analysis using the de Waard-Milliams correlation. Calculates corrosion rate, severity classification, inhibited rate, and required corrosion allowance for carbon steel pipelines.
- [Erosion Velocity Analysis](/blueprint/po.fa.erosion.analysis.md): Erosion velocity analysis using API RP 14E methodology. Calculates erosional velocity limit, actual mixture velocity, erosion ratio, and risk classification for multiphase pipelines.
- [Hydrate Inhibitor Dosing](/blueprint/po.fa.hydrate.inhibitor.md): Hydrate inhibitor dosing calculations using the Hammerschmidt equation. Compares methanol and MEG for temperature depression and calculates required injection rates.
- [Integrated Flow Assurance Assessment](/blueprint/po.fa.integrated.assessment.md): Integrated flow assurance assessment combining hydrate, corrosion, and erosion risk evaluation. Provides a comprehensive view of flow assurance challenges for production systems.
- [Field Production Profile](/blueprint/po.fpp.field.profile.md): Field-level production forecasting using buildup-plateau-decline model. Models the complete production lifecycle: ramp-up to plateau, sustained plateau production, and Arps decline phase.
- [Multi-Well Schedule Aggregation](/blueprint/po.fpp.sched.aggregation.md): Aggregated field production from a multi-well drilling schedule. Uses convolution of a typical well decline profile with a well drilling schedule to forecast total field production over time.
- [Fracture Design Screening](/blueprint/po.frac.design.screening.md): Screen a hydraulic fracture design using PKN geometry to predict fracture dimensions, then evaluate production improvement via equivalent skin and dimensionless conductivity (CfD). Answers the question: "Is this well a good fracture candidate, and what production uplift can I expect?"
- [PKN Fracture Geometry Analysis](/blueprint/po.frac.pkn.geometry.md): Calculate PKN (Perkins-Kern-Nordgren) fracture geometry for vertically confined fractures.
- [Proppant Settling Analysis](/blueprint/po.frac.proppant.settling.md): Analyze proppant settling behavior for hydraulic fracturing treatment design.
- [Gas Lift Injection Design](/blueprint/po.gl.injection.design.md): Gas lift injection design calculations. Determines required gas injection rate to achieve target GLR and calculates total GLR from formation and injected gas contributions.
- [Injection Pressure Profile](/blueprint/po.gl.injection.pressure.md): Injection gas pressure profile calculations. Determines gas gradient in the annulus and calculates injection pressure at various depths for gas lift system design.
- [Gas Lift Valve Setting](/blueprint/po.gl.valve.setting.md): Gas lift valve setting calculations. Determines dome pressure at depth, test rack opening pressure (Ptro), closing pressure, and valve spread for IPO (injection pressure operated) valves.
- [Valve Throughput Analysis](/blueprint/po.gl.valve.throughput.md): Gas lift valve throughput calculations using the Thornhill-Craver equation. Determines gas flow rate through an orifice valve based on port size and pressure differential.
- [Composite IPR Curve (Darcy + Vogel)](/blueprint/po.ipr.composite.curve.md): Build a composite IPR curve that uses linear Darcy flow above the bubble point and Vogel's correlation below it. Most real wells produce through the bubble point, making neither pure Darcy nor pure Vogel correct alone. The composite curve captures both single-phase and two-phase flow regimes.
- [Fetkovich IPR Curve](/blueprint/po.ipr.fetkovich.curve.md): Construct an IPR curve using the Fetkovich backpressure equation. This empirical method works for both single-phase and two-phase flow by fitting well test data to Qo = C(Pr² - Pwf²)ⁿ.
- [Flow Regime Comparison](/blueprint/po.ipr.flowregime.compare.md): Compare well productivity under different flow regimes: pseudosteady state (bounded reservoir), steady state (constant pressure boundary), and transient (infinite-acting). Understanding flow regime impacts is essential for accurate production forecasting.
- [Gas Well Deliverability](/blueprint/po.ipr.gas.deliverability.md): Gas well deliverability analysis comparing Darcy flow (low rate) with non-Darcy flow that includes turbulence effects at high rates. The non-Darcy coefficient D accounts for inertial resistance near the wellbore.
- [Horizontal Well PI Comparison](/blueprint/po.ipr.horizontal.compare.md): Compare horizontal well productivity index calculations using different correlations. Useful for understanding the sensitivity of PI estimates to the chosen method.
- [Klins-Clark Modified Vogel IPR](/blueprint/po.ipr.klins.curve.md): Construct an IPR curve using the Klins-Clark (1993) modified Vogel equation. This correlation improves on the original Vogel method by introducing a pressure-dependent exponent d that accounts for the ratio of reservoir pressure to bubble point pressure.
- [Productivity Index Calculation](/blueprint/po.ipr.pi.calculation.md): Calculate well productivity index (PI) and understand the impact of skin damage. Also shows drainage radius and effective wellbore radius calculations.
- [Skin Damage Impact on Productivity](/blueprint/po.ipr.skin.sensitivity.md): Quantify how skin factor affects well productivity by computing PI and IPR curves at five skin values: stimulated (S=-2), ideal (S=0), mild damage (S=5), moderate (S=10), and severe (S=20). Shows the production rate gain from stimulation or the cost of leaving damage untreated.
- [Vogel IPR Curve](/blueprint/po.ipr.vogel.curve.md): Construct an IPR curve using the Vogel correlation for solution-gas-drive reservoirs producing below bubble point. Shows the characteristic concave-downward shape of two-phase flow.
- [Fetkovich Aquifer Model](/blueprint/po.mbe.aquifer.fetkovich.md): Calculate water influx using the Fetkovich pseudo-steady state aquifer model. This simplified approach treats the aquifer as a tank with a productivity index.
- [Aquifer Model Matching](/blueprint/po.mbe.aquifer.matching.md): Estimate cumulative water influx using the Fetkovich aquifer model and match aquifer parameters (permeability, outer radius) to observed pressure-production data. The Fetkovich model uses a productivity index (J) and maximum encroachable water (Wei) to compute stepwise water influx.
- [Van Everdingen-Hurst Aquifer Model](/blueprint/po.mbe.aquifer.veh.md): Calculate water influx using the Van Everdingen-Hurst (VEH) transient aquifer model. This rigorous method handles both infinite and finite aquifers with time-dependent pressure response.
- [Effective Compressibility Calculations](/blueprint/po.mbe.compressibility.effective.md): Calculate effective compressibility for different reservoir types. Effective compressibility is critical for material balance and pressure buildup analysis.
- [Reservoir Drive Mechanism Indices](/blueprint/po.mbe.drives.indices.md): Calculate drive mechanism indices to identify the dominant energy source driving oil production. Drive indices sum to 1.0 and indicate relative contribution of each mechanism.
- [Material Balance Expansion Terms](/blueprint/po.mbe.expansion.terms.md): Calculate material balance expansion terms for oil reservoir analysis. These terms quantify fluid and rock expansion as pressure drops during production.
- [Gas Reservoir Production Forecast](/blueprint/po.mbe.gas.forecast.md): Forecast gas reservoir pressure and production using material balance equations. Given OGIP, predict pressure at future production levels or vice versa.
- [Geopressured Gas p/z Analysis](/blueprint/po.mbe.gas.geopressured.md): Compare standard vs modified p/z analysis for geopressured (abnormally pressured) gas reservoirs. Standard p/z overestimates OGIP because it ignores formation and water compressibility. The modified p/z method corrects for this, producing a straight line even for geopressured reservoirs.
- [Gas Reservoir p/z Analysis](/blueprint/po.mbe.gas.pzanalysis.md): Perform p/z analysis for gas reservoirs to estimate OGIP (Original Gas in Place). The p/z vs Gp plot is linear for volumetric depletion, with x-intercept = OGIP.
- [Havlena-Odeh Oil MBE Analysis](/blueprint/po.mbe.oil.havlena.odeh.md): Estimate OOIP and gas cap ratio for a saturated oil reservoir using the Havlena-Odeh straight-line method. Production history with PVT data at each pressure step are used to compute underground withdrawals (F) and expansion terms (Eo, Eg). Plotting F/Eo vs Eg/Eo yields a straight line whose intercept is N (OOIP) and slope is N·m.
- [Underground Withdrawal Calculation](/blueprint/po.mbe.withdrawal.calculation.md): Calculate underground withdrawal (F term) for material balance analysis. F represents total reservoir voidage from oil, gas, and water production.
- [Boundary Effects Analysis](/blueprint/po.pta.boundary.effects.md): Analysis of boundary effects on wellbore pressure. Compares infinite acting reservoir with single linear fault and perpendicular sealing faults.
- [Buildup Near Sealing Fault — Boundary Detection](/blueprint/po.pta.buildup.boundary.md): Pressure buildup interpretation near a linear sealing fault. Demonstrates the classic derivative doubling signature: early IARF yields the correct permeability, then the Bourdet derivative doubles as the pressure signal reaches the fault and reflects back. Compares fault model against infinite reservoir to highlight the boundary effect.
- [Constant Pressure Boundary](/blueprint/po.pta.constant.pressure.md): Analysis of constant pressure boundary effects. Compares sealing boundaries with constant pressure boundaries (aquifer support).
- [Dimensionless Variables Conversion](/blueprint/po.pta.dimensionless.variables.md): Conversion between real and dimensionless variables for pressure transient analysis. Essential for type curve matching and analytical solutions.
- [Constant-Rate Drawdown Analysis](/blueprint/po.pta.drawdown.analysis.md): Constant-rate drawdown test interpretation using MDH (Miller-Dyes-Hutchinson) semilog analysis with Bourdet derivative for IARF identification. The most fundamental well test — a single rate from initial conditions. Includes forward model for synthetic data generation and round-trip validation.
- [DST Sequence Analysis — Horner Interpretation](/blueprint/po.pta.dst.sequence.md): Standard four-period drill stem test analysis: Initial Flow (IF) → Initial Shut-In (ISI) → Final Flow (FF) → Final Shut-In (FSI). Forward model generates synthetic gauge data using PO.PTA.Pw.VW with built-in superposition across all rate changes. Horner analysis of the FSI buildup extracts permeability, skin, and extrapolated pressure P*. Cross-checks ISIP against Horner P* as an independent reservoir pressure estimate.
- [Horner Plot Analysis — P* Calculation](/blueprint/po.pta.horner.pstar.md): Pressure buildup interpretation using Horner semilog analysis with Bourdet derivative for IARF identification. Includes forward model for synthetic data generation and round-trip validation.
- [Multi-Rate Drawdown — Step-Rate Test](/blueprint/po.pta.multirate.test.md): Step-rate drawdown test with three rate periods. Demonstrates PO's built-in superposition via the `prod_data` array parameter — a single PO.PTA.Pw.VW call handles the full rate history. Uses rate-normalized pressure ΔP/q for interpretation, which removes rate dependence and allows permeability and skin extraction from any single rate period.
- [Radial Flow Analysis](/blueprint/po.pta.radial.flow.md): Infinite acting radial flow analysis using line source solution and vertical well models. Calculates dimensionless pressure for pressure transient interpretation.
- [Skin Factor Effect](/blueprint/po.pta.skin.factor.md): Demonstrates the effect of skin factor on wellbore pressure. Positive skin indicates damage, negative skin indicates stimulation.
- [Wellbore Storage & Skin — Type Curve Diagnostic](/blueprint/po.pta.wellbore.storage.md): Dimensionless type curve display for wellbore storage and skin effects. Compares three WBS/skin scenarios showing how the CDe²ˢ grouping controls the transition from unit-slope storage to radial flow. Includes end-of-WBS time estimation and the 1.5 log-cycle rule for IARF onset.
- [Bubble Point Estimation](/blueprint/po.pvt.bubblepoint.compare.md): Estimate bubble point pressure using different correlations. Compare Standing and Vasquez-Beggs methods side by side.
- [Bubble Point Correlation Comparison](/blueprint/po.pvt.bubblepoint.regional.md): Compare bubble point pressure correlations from different sources and regions. Each correlation was developed for specific oil types and geographic regions, showing significant variation in predictions.
- [PVT Fluid Properties Report](/blueprint/po.pvt.fluid.report.md): Generate a complete PVT fluid property report below the bubble point using Standing (Rs, Bo, Pb) and Beggs-Robinson (viscosity) correlations. The pressure sweep table shows how solution GOR, oil FVF, and oil viscosity change during reservoir depletion.
- [Gas PVT Properties](/blueprint/po.pvt.gas.properties.md): Complete gas PVT property table including Z-factor, gas formation volume factor (Bg), gas compressibility (Cg), gas viscosity, and gas density across pressure range.
- [Complete Oil PVT Table](/blueprint/po.pvt.oil.fullpvt.md): Complete oil PVT property table from undersaturated through saturated conditions. Includes bubble point, solution GOR, oil FVF, oil compressibility, and oil viscosity across the full pressure range.
- [PVT Sensitivity to Oil Gravity](/blueprint/po.pvt.sensitivity.api.md): Compare PVT fluid properties across three oil gravities (25, 35, 45 °API) to quantify how API uncertainty affects bubble point, solution GOR, FVF, and viscosity. Heavy oils (low API) have lower Pb, less dissolved gas, and higher viscosity — light oils are the opposite.
- [Sour Gas PVT Properties](/blueprint/po.pvt.sour.gas.md): Calculate gas PVT properties for sour gas (containing H2S and CO2) using Wichert-Aziz pseudo-critical corrections. Compare sweet vs sour pseudo-critical properties and show how acid gas content affects Z-factor, Bg, density, and viscosity across a pressure range.
- [Oil PVT Table - Standing](/blueprint/po.pvt.standing.oil.md): Complete PVT properties table using the Standing correlation. Calculates oil formation volume factor (Bo) and solution gas-oil ratio (Rs) for a range of pressures. **Usage:** Insert at desired location, modify input values in the Inputs section.
- [Oil Viscosity Correlation Comparison](/blueprint/po.pvt.viscosity.compare.md): Compare oil viscosity calculations showing the progression from dead oil through saturated conditions. Dead oil viscosity depends only on temperature and API gravity, while saturated oil viscosity also depends on solution GOR.
- [Oil Viscosity Table](/blueprint/po.pvt.viscosity.oil.md): Calculate oil viscosity using Egbogah (dead oil) and Beggs-Robinson (saturated) correlations.
- [Water/Brine PVT Properties](/blueprint/po.pvt.water.properties.md): Water/brine PVT property table using McCain correlations. Includes water FVF, gas solubility in water, water compressibility, and water viscosity.
- [Gas Z-Factor Comparison](/blueprint/po.pvt.zfactor.compare.md): Compare gas compressibility factor (Z) calculations using different correlations. Shows DAK (Dranchuk-Abou-Kassem) and Brill-Beggs methods side by side.
- [Polished Rod Load Analysis](/blueprint/po.rp.load.analysis.md): Polished rod load analysis using simplified static method. Calculates fluid load, peak and minimum polished rod loads for rod pump design.
- [Rod Pump Sizing](/blueprint/po.rp.pump.sizing.md): Rod pump sizing calculations. Determines theoretical and effective pump displacement, fillage, and volumetric efficiency for sucker rod pump systems.
- [Rod String Stress Analysis](/blueprint/po.rp.rod.stress.md): Rod string stress analysis for sucker rod pumping systems. Calculates rod weight, stretch, and stress levels for fatigue assessment.
- [Rod Pump System Design](/blueprint/po.rp.system.design.md): Integrated rod pump system design. Combines pump sizing, rod string analysis, load calculations, and power requirements for complete system evaluation.
- [Pumping Unit Torque Analysis](/blueprint/po.rp.torque.analysis.md): Pumping unit torque analysis. Calculates counterbalance requirements, peak torque, and polished rod horsepower for rod pump systems.
- [Capillary Pressure Models Comparison](/blueprint/po.scal.capillary.pressure.md): Compare capillary pressure curves using Brooks-Corey and Van Genuchten models. Includes Leverett J-function for scaling between different rock types.
- [Rock Compressibility Estimation](/blueprint/po.scal.cf.compressibility.md): Estimate rock (formation) compressibility using Newman's correlations. Rock compressibility is critical for material balance calculations and pressure transient analysis.
- [Corey Relative Permeability Curves](/blueprint/po.scal.corey.relperm.md): Generate oil-water relative permeability curves using the Corey power-law model. This simple model requires only endpoint values and exponents, making it ideal for screening studies.
- [SCAL Endpoint Analysis](/blueprint/po.scal.endpoint.analysis.md): Tabulate SCAL endpoint data from multiple core plugs (Swi, Sorw, Krow@Swi, Krw@Sorw), apply user-defined Corey exponents, and generate model relative permeability curves. This is the "lab data to simulation input" workflow — taking raw core measurements and producing smooth kr curves for reservoir simulation.
- [Waterflood Fractional Flow Analysis](/blueprint/po.scal.fractional.flow.md): Buckley-Leverett fractional flow analysis for waterflood performance prediction. Computes water fractional flow curve from Corey relative permeability and fluid viscosities, applies the Welge tangent construction to determine breakthrough saturation and oil recovery factor.
- [Honarpour Gas-Oil Relative Permeability](/blueprint/po.scal.honarpour.gasoil.md): Generate gas-oil relative permeability curves using Honarpour et al. (1982) empirical correlations. Separate equations for sandstone (Eq A-4, A-5) and carbonate (Eq A-9, A-10) rock types.
- [J-Function Capillary Pressure Scaling](/blueprint/po.scal.jfunction.scaling.md): Scale capillary pressure from a reference core plug to a different rock type using the Leverett J-function. Essential for transferring SCAL data between reservoir facies with different porosity and permeability.
- [LET Relative Permeability Curves](/blueprint/po.scal.let.relperm.md): Generate oil-water relative permeability curves using the LET (Lomeland-Ebeltoft-Thomas) correlation. This model offers more flexibility than Corey for matching laboratory data.
- [Relative Permeability Model Comparison](/blueprint/po.scal.models.compare.md): Compare relative permeability predictions from Corey, LET, and Honarpour correlations. Model selection affects waterflood performance predictions.
- [Stone Three-Phase Relative Permeability](/blueprint/po.scal.stone.threephase.md): Calculate three-phase oil relative permeability using Stone I and Stone II models. These models combine two-phase water-oil and gas-oil data to predict oil mobility when all three phases are present.
- [Capillary Transition Zone Profile](/blueprint/po.scal.transition.zone.md): Compute water saturation as a function of height above the free water level using Brooks-Corey capillary pressure. Essential for initializing reservoir simulation models and estimating OOIP in the transition zone.
- [Wettability Effect on Relative Permeability](/blueprint/po.scal.wettability.compare.md): Compare relative permeability curves for different wettability conditions using Ibrahim-Koederitz correlations. Wettability significantly impacts waterflood efficiency.
- [Choke Sizing Comparison](/blueprint/po.sf.choke.sizing.md): Compare choke diameter sizing using different critical flow correlations (Gilbert, Ros, Baxendell, Achong, Pilehvari).
- [Gas Pipeline Sizing](/blueprint/po.sf.gas.pipeline.sizing.md): Size a gas pipeline by comparing three diameters across three correlations (Weymouth, Panhandle A, Panhandle B) to find the smallest pipe that delivers the target flow rate with acceptable outlet pressure. Also evaluates how pipeline length affects capacity for the selected diameter.
- [Gas Pipeline Flow Analysis](/blueprint/po.sf.pipeline.gas.md): Calculate gas pipeline flow rates and outlet pressures using Weymouth, Panhandle A, and Panhandle B equations.
- [Liquid Pipeline Sizing](/blueprint/po.sf.pipeline.liquid.md): Design a liquid pipeline using Darcy-Weisbach pressure drop calculations. Determine required pressures, flow capacity, and verify velocity limits.
- [Exponential Integral Functions](/blueprint/po.utilities.math.functions.md): Demonstrate the exponential integral (Ei) function used in pressure transient analysis and well test interpretation.
- [SI Unit Conversion Reference (62 Pairs)](/blueprint/po.utilities.si.unit.conversion.md): Comprehensive reference of all 62 unit conversion pairs used by the SI lambda wrappers. Each row converts a value of 1 to show the conversion factor between SI/metric and field/imperial units.
- [Spline Interpolation and Analysis](/blueprint/po.utilities.spline.interpolation.md): Demonstrate spline interpolation functions for data analysis. Compare cubic and linear spline methods for interpolation, differentiation, and integration.
- [Unit Conversion Examples](/blueprint/po.utilities.unit.conversion.md): Demonstrate unit conversion for common petroleum engineering quantities. Includes pressure, temperature, volume, and flow rate conversions.
- [Vertical Lift Performance - Beggs & Brill](/blueprint/po.vfp.beggsbrill.verticallift.md): Calculate vertical lift performance (VLP) for a producing oil well using the Beggs & Brill (1973) correlation. This correlation handles multiphase (gas-liquid) flow and is applicable for any wellbore inclination.
- [Multiphase Correlation Comparison](/blueprint/po.vfp.correlations.compare.md): Compare pressure drop predictions from all ten industry-standard multiphase flow correlations. Understanding correlation differences helps engineers select the most appropriate method for specific well conditions.
- [Deviated Well VLP Analysis](/blueprint/po.vfp.deviated.well.md): Analyze vertical lift performance in deviated and inclined wells using correlations that properly account for inclination angle. Four correlations support non-vertical wells:
- [Single-Phase Gas Well Pressure](/blueprint/po.vfp.gas.singlephase.md): Calculate pressure drop in single-phase gas wells using the compressible flow equations. Suitable for dry gas wells with no liquid loading.
- [Gas Well Tubing Performance](/blueprint/po.vfp.gas.well.md): Calculate tubing performance for a gas well using single-phase gas flow correlation. Compare bottomhole pressures at different gas rates and tubing sizes to identify the optimal tubing diameter. Smaller tubing increases friction but maintains velocity above liquid loading threshold.
- [Single-Phase Liquid Pipe Flow](/blueprint/po.vfp.liquid.singlephase.md): Calculate pressure drop for single-phase liquid flow in pipes using the Fanning equation. Applicable to water injection, water disposal, and single-phase oil lines.
- [Nodal Analysis (IPR + VLP)](/blueprint/po.vfp.nodal.analysis.md): Determine well operating point by intersecting the IPR curve (Vogel) with the VLP curve (Beggs-Brill multiphase tubing correlation). The node is at bottomhole — sweep flowing pressure to compute IPR rates and corresponding VLP bottomhole pressures. The operating point occurs where IPR Pwf equals VLP Pwf at the same rate.
- [Tubing Size Selection Analysis](/blueprint/po.vfp.tubing.sizing.md): Compare pressure drops across different tubing sizes to optimize well production. Smaller tubing increases friction but maintains velocity for liquid lift; larger tubing reduces friction but may cause liquid loading in gas wells.

## Lambdas
- [ESP BrakeHP.FromRate (SI)](/lambda/po.lm.esp.brakehp.fromrate.si.md): Calculates brake horsepower directly from rate and head, [kW] (SI units).
- [ESP BrakeHP (SI)](/lambda/po.lm.esp.brakehp.si.md): Calculates brake horsepower accounting for pump efficiency, [kW] (SI units).
- [ESP Cable.MinSize (SI)](/lambda/po.lm.esp.cable.minsize.si.md): Determines minimum cable size for voltage drop limit, [AWG] (SI units).
- [ESP Cable.PowerLoss.Pct (SI)](/lambda/po.lm.esp.cable.powerloss.pct.si.md): Calculates power loss as percentage of motor power, [%] (SI units).
- [ESP Cable.PowerLoss (SI)](/lambda/po.lm.esp.cable.powerloss.si.md): Calculates power loss in cable, [kW] (SI units).
- [ESP Cable.Resistance (SI)](/lambda/po.lm.esp.cable.resistance.si.md): Returns cable resistance at temperature, [ohm/km] (SI units).
- [ESP Cable.Temperature (SI)](/lambda/po.lm.esp.cable.temperature.si.md): Estimates cable temperature with current, [degC] (SI units).
- [ESP Cable.Vdrop.Full (SI)](/lambda/po.lm.esp.cable.vdrop.full.si.md): Complete voltage drop calculation, [V] (SI units).
- [ESP Cable.Vdrop (SI)](/lambda/po.lm.esp.cable.vdrop.si.md): Calculates voltage drop in ESP cable (3-phase), [V] (SI units).
- [ESP Curve.BEP.Eff (SI)](/lambda/po.lm.esp.curve.bep.eff.si.md): Returns maximum efficiency value from pump curve, [fraction] (SI units).
- [ESP Curve.BEP (SI)](/lambda/po.lm.esp.curve.bep.si.md): Returns Best Efficiency Point flow rate from pump curve, [m3/d] (SI units).
- [ESP Curve.Efficiency (SI)](/lambda/po.lm.esp.curve.efficiency.si.md): Interpolates efficiency from pump performance curve, [fraction] (SI units).
- [ESP Curve.Head (SI)](/lambda/po.lm.esp.curve.head.si.md): Interpolates head from pump performance curve, [m/stage] (SI units).
- [ESP Curve.Power (SI)](/lambda/po.lm.esp.curve.power.si.md): Interpolates power per stage from pump curve, [kW] (SI units).
- [ESP Gas.Qg.Free (SI)](/lambda/po.lm.esp.gas.qg.free.si.md): Calculates free gas rate at pump intake conditions, [m3/d] (SI units).
- [ESP Gas.Ql.Total (SI)](/lambda/po.lm.esp.gas.ql.total.si.md): Calculates total liquid rate at pump intake, [m3/d] (SI units).
- [ESP Gas.RhoMix (SI)](/lambda/po.lm.esp.gas.rhomix.si.md): Calculates gas-liquid mixture density, [kg/m3] (SI units).
- [ESP Gas.Sep.Eff (SI)](/lambda/po.lm.esp.gas.sep.eff.si.md): Estimates rotary gas separator efficiency, [fraction] (SI units).
- [ESP Gas.Turpin.Factor (SI)](/lambda/po.lm.esp.gas.turpin.factor.si.md): Calculates Turpin gas handling factor, [dimensionless] (SI units).
- [ESP Gas.Void.Full (SI)](/lambda/po.lm.esp.gas.void.full.si.md): Complete gas void fraction calculation from field data, [fraction] (SI units).
- [ESP Gas.Void (SI)](/lambda/po.lm.esp.gas.void.si.md): Calculates gas void fraction at pump intake, [fraction] (SI units).
- [ESP Head.FromPressure (SI)](/lambda/po.lm.esp.head.frompressure.si.md): Converts pressure to head using fluid specific gravity, [m] (SI units).
- [ESP Head.PressureAtDepth (SI)](/lambda/po.lm.esp.head.pressureatdepth.si.md): Calculates pressure at depth given surface pressure, [kPa] (SI units).
- [ESP Head.Static (SI)](/lambda/po.lm.esp.head.static.si.md): Calculates static head from vertical depth, [m] (SI units).
- [ESP Head.ToPressure (SI)](/lambda/po.lm.esp.head.topressure.si.md): Converts head to pressure using fluid specific gravity, [kPa] (SI units).
- [ESP HydraulicHP.GPM (SI)](/lambda/po.lm.esp.hydraulichp.gpm.si.md): Calculates theoretical hydraulic horsepower (gpm basis), [kW] (SI units).
- [ESP HydraulicHP (SI)](/lambda/po.lm.esp.hydraulichp.si.md): Calculates theoretical hydraulic horsepower (bbl/d basis), [kW] (SI units).
- [ESP Motor.Amps.FromNameplate (SI)](/lambda/po.lm.esp.motor.amps.fromnameplate.si.md): Calculates current from motor nameplate data, [A] (SI units).
- [ESP Motor.Amps (SI)](/lambda/po.lm.esp.motor.amps.si.md): Calculates motor current draw (3-phase), [A] (SI units).
- [ESP Motor.LoadFactor (SI)](/lambda/po.lm.esp.motor.loadfactor.si.md): Calculates motor load as fraction of rating, [fraction] (SI units).
- [ESP Motor.Qcool (SI)](/lambda/po.lm.esp.motor.qcool.si.md): Calculates minimum flow rate for motor cooling, [m3/d] (SI units).
- [ESP Motor.RequiredHP (SI)](/lambda/po.lm.esp.motor.requiredhp.si.md): Calculates minimum motor horsepower with safety factor, [kW] (SI units).
- [ESP Motor.Temp.Rise (SI)](/lambda/po.lm.esp.motor.temp.rise.si.md): Estimates motor temperature at operating conditions, [degC] (SI units).
- [ESP Nodal.AOF (SI)](/lambda/po.lm.esp.nodal.aof.si.md): Calculates Absolute Open Flow potential, [m3/d] (SI units).
- [ESP Nodal.Drawdown (SI)](/lambda/po.lm.esp.nodal.drawdown.si.md): Calculates drawdown at given production rate, [kPa] (SI units).
- [ESP Nodal.Submergence (SI)](/lambda/po.lm.esp.nodal.submergence.si.md): Calculates submergence above pump intake, [m] (SI units).
- [ESP Pump.Efficiency (SI)](/lambda/po.lm.esp.pump.efficiency.si.md): Calculates pump efficiency from hydraulic and brake HP, [fraction] (SI units).
- [ESP Pump.Pdis (SI)](/lambda/po.lm.esp.pump.pdis.si.md): Calculates pump discharge pressure, [kPa] (SI units).
- [ESP Pump.TotalHead (SI)](/lambda/po.lm.esp.pump.totalhead.si.md): Calculates total head from number of stages, [m] (SI units).
- [ESP Pump.TotalPower (SI)](/lambda/po.lm.esp.pump.totalpower.si.md): Calculates total power from number of stages, [kW] (SI units).
- [ESP Stages.Actual (SI)](/lambda/po.lm.esp.stages.actual.si.md): Returns exact (non-rounded) stage count for sensitivity analysis, [stages] (SI units).
- [ESP Stages (SI)](/lambda/po.lm.esp.stages.si.md): Calculates required number of pump stages (rounded up), [stages] (SI units).
- [ESP System.Hfric (SI)](/lambda/po.lm.esp.system.hfric.si.md): Simplified friction head calculation, [m] (SI units).
- [ESP TDH.Full (SI)](/lambda/po.lm.esp.tdh.full.si.md): Extended TDH calculation with IPR-based PIP, [m] (SI units).
- [ESP TDH.NetLift (SI)](/lambda/po.lm.esp.tdh.netlift.si.md): Calculates net vertical lift (pump depth minus fluid level), [m] (SI units).
- [ESP TDH (SI)](/lambda/po.lm.esp.tdh.si.md): Calculates Total Dynamic Head for ESP sizing, [m] (SI units).
- [ESP Viscosity.Head.Corr (SI)](/lambda/po.lm.esp.viscosity.head.corr.si.md): Applies viscosity correction to head, [m] (SI units).
- [ESP Viscosity.Rate.Corr (SI)](/lambda/po.lm.esp.viscosity.rate.corr.si.md): Applies viscosity correction to flow rate, [m3/h] (SI units).
- [FA Corrosion.CR.CO2 (SI)](/lambda/po.lm.fa.corrosion.cr.co2.si.md): Calculates CO2 corrosion rate using de Waard-Milliams correlation, [mm/yr] (SI units).
- [FA Corrosion.Fug.CO2 (SI)](/lambda/po.lm.fa.corrosion.fug.co2.si.md): Calculates CO2 fugacity for accurate corrosion predictions, [kPa] (SI units).
- [FA Corrosion.Pp.CO2 (SI)](/lambda/po.lm.fa.corrosion.pp.co2.si.md): Calculates CO2 partial pressure from total pressure and mole fraction, [kPa] (SI units).
- [FA Erosion.Dmin (SI)](/lambda/po.lm.fa.erosion.dmin.si.md): Calculates minimum pipe diameter to avoid erosion, [cm] (SI units).
- [FA Erosion.Ratio (SI)](/lambda/po.lm.fa.erosion.ratio.si.md): Calculates erosion ratio (V/Ve). Values >1.0 indicate erosion risk, [dimensionless] (SI units).
- [FA Erosion.RhoMix (SI)](/lambda/po.lm.fa.erosion.rhomix.si.md): Calculates gas-liquid mixture density, [kg/m3] (SI units).
- [FA Erosion.Ve (SI)](/lambda/po.lm.fa.erosion.ve.si.md): Calculates erosional velocity limit using API RP 14E, [m/s] (SI units).
- [FA Erosion.Vmix (SI)](/lambda/po.lm.fa.erosion.vmix.si.md): Calculates mixture velocity in pipe, [m/s] (SI units).
- [FA Hydrate.dT.MEG (SI)](/lambda/po.lm.fa.hydrate.dt.meg.si.md): Calculates temperature depression from MEG using Hammerschmidt equation, [degK] (SI units).
- [FA Hydrate.dT.MeOH (SI)](/lambda/po.lm.fa.hydrate.dt.meoh.si.md): Calculates temperature depression from methanol using Hammerschmidt equation, [degK] (SI units).
- [FA Hydrate.dT (SI)](/lambda/po.lm.fa.hydrate.dt.si.md): Calculates temperature depression from inhibitor using Hammerschmidt equation, [degK] (SI units).
- [FA Hydrate.dTsub (SI)](/lambda/po.lm.fa.hydrate.dtsub.si.md): Calculates subcooling (hydrate formation temp minus operating temp), [degK] (SI units).
- [FA Hydrate.Qinj.MEG (SI)](/lambda/po.lm.fa.hydrate.qinj.meg.si.md): Calculates MEG injection rate required, [L/d] (SI units).
- [FA Hydrate.Qinj.MeOH (SI)](/lambda/po.lm.fa.hydrate.qinj.meoh.si.md): Calculates methanol injection rate required, [L/d] (SI units).
- [FRAC KGD.Length.Leakoff (SI)](/lambda/po.lm.frac.kgd.length.leakoff.si.md): Khristianovic-Geertsma-de Klerk (KGD) fracture half-length with Carter leakoff, [m] (SI units).
- [FRAC KGD.Length.NoLoss (SI)](/lambda/po.lm.frac.kgd.length.noloss.si.md): Khristianovic-Geertsma-de Klerk (KGD) fracture half-length without fluid loss, [m] (SI units).
- [FRAC KGD.Pnet (SI)](/lambda/po.lm.frac.kgd.pnet.si.md): Khristianovic-Geertsma-de Klerk (KGD) net fracturing pressure, [kPa] (SI units).
- [FRAC KGD.Volume (SI)](/lambda/po.lm.frac.kgd.volume.si.md): Khristianovic-Geertsma-de Klerk (KGD) fracture volume (both wings), [m3] (SI units).
- [FRAC KGD.Wavg (SI)](/lambda/po.lm.frac.kgd.wavg.si.md): Khristianovic-Geertsma-de Klerk (KGD) average fracture width, [cm] (SI units).
- [FRAC KGD.Width.General (SI)](/lambda/po.lm.frac.kgd.width.general.si.md): Khristianovic-Geertsma-de Klerk (KGD) fracture width (generalized with Poisson's ratio), [cm] (SI units).
- [FRAC KGD.Width (SI)](/lambda/po.lm.frac.kgd.width.si.md): Khristianovic-Geertsma-de Klerk (KGD) fracture width at wellbore, [cm] (SI units).
- [FRAC Leakoff.Cc (SI)](/lambda/po.lm.frac.leakoff.cc.si.md): Compressibility-controlled leakoff coefficient (Cc), [m/sqrt(min)] (SI units).
- [FRAC Leakoff.Cumulative (SI)](/lambda/po.lm.frac.leakoff.cumulative.si.md): Cumulative fluid volume lost per unit area, [m] (SI units).
- [FRAC Leakoff.Cv (SI)](/lambda/po.lm.frac.leakoff.cv.si.md): Viscosity-controlled leakoff coefficient (Cv), [m/sqrt(min)] (SI units).
- [FRAC Leakoff.Eff (SI)](/lambda/po.lm.frac.leakoff.eff.si.md): Fracturing fluid efficiency, [fraction] (SI units).
- [FRAC Leakoff.Velocity (SI)](/lambda/po.lm.frac.leakoff.velocity.si.md): Carter leakoff velocity at given time, [m/min] (SI units).
- [FRAC Leakoff.Vol (SI)](/lambda/po.lm.frac.leakoff.vol.si.md): Total leakoff volume from fracture, [m3] (SI units).
- [FRAC PKN.Length.Leakoff (SI)](/lambda/po.lm.frac.pkn.length.leakoff.si.md): Perkins-Kern-Nordgren (PKN) fracture half-length with Carter leakoff, [m] (SI units).
- [FRAC PKN.Length.NoLoss (SI)](/lambda/po.lm.frac.pkn.length.noloss.si.md): Perkins-Kern-Nordgren (PKN) fracture half-length without fluid loss, [m] (SI units).
- [FRAC PKN.Pnet (SI)](/lambda/po.lm.frac.pkn.pnet.si.md): Perkins-Kern-Nordgren (PKN) net fracturing pressure, [kPa] (SI units).
- [FRAC PKN.Volume (SI)](/lambda/po.lm.frac.pkn.volume.si.md): Perkins-Kern-Nordgren (PKN) fracture volume (one wing), [m3] (SI units).
- [FRAC PKN.Wavg (SI)](/lambda/po.lm.frac.pkn.wavg.si.md): Perkins-Kern-Nordgren (PKN) average fracture width, [cm] (SI units).
- [FRAC PKN.Width.Leakoff (SI)](/lambda/po.lm.frac.pkn.width.leakoff.si.md): Perkins-Kern-Nordgren (PKN) fracture width with Carter leakoff (large time), [cm] (SI units).
- [FRAC PKN.Width.NoLoss (SI)](/lambda/po.lm.frac.pkn.width.noloss.si.md): Perkins-Kern-Nordgren (PKN) fracture width without fluid loss, [cm] (SI units).
- [FRAC PKN.Width (SI)](/lambda/po.lm.frac.pkn.width.si.md): Perkins-Kern-Nordgren (PKN) fracture width at wellbore, [cm] (SI units).
- [FRAC Proppant.Ds (SI)](/lambda/po.lm.frac.proppant.ds.si.md): Proppant settling distance during transport, [m] (SI units).
- [FRAC Proppant.Re (SI)](/lambda/po.lm.frac.proppant.re.si.md): Particle Reynolds number for settling, [dimensionless] (SI units).
- [FRAC Proppant.TR (SI)](/lambda/po.lm.frac.proppant.tr.si.md): Proppant transport ratio (horizontal/settling velocity), [dimensionless] (SI units).
- [FRAC Proppant.Vs.Hindered (SI)](/lambda/po.lm.frac.proppant.vs.hindered.si.md): Hindered settling velocity (Richardson-Zaki), [m/min] (SI units).
- [FRAC Proppant.Vs.Stokes (SI)](/lambda/po.lm.frac.proppant.vs.stokes.si.md): Stokes settling velocity (infinite dilution), [m/min] (SI units).
- [FRAC Proppant.Vs.StokesField (SI)](/lambda/po.lm.frac.proppant.vs.stokesfield.si.md): Stokes settling velocity using specific gravity (field units), [m/min] (SI units).
- [FRAC Proppant.WallFactor (SI)](/lambda/po.lm.frac.proppant.wallfactor.si.md): Wall correction factor for settling in narrow fracture (Faxen), [dimensionless] (SI units).
- [FRAC Radial.Pnet (SI)](/lambda/po.lm.frac.radial.pnet.si.md): Radial (Penny-shaped) fracture net pressure, [kPa] (SI units).
- [FRAC Radial.Radius.Leakoff (SI)](/lambda/po.lm.frac.radial.radius.leakoff.si.md): Radial (Penny-shaped) fracture radius with Carter leakoff, [m] (SI units).
- [FRAC Radial.Radius.NoLoss (SI)](/lambda/po.lm.frac.radial.radius.noloss.si.md): Radial (Penny-shaped) fracture radius without fluid loss, [m] (SI units).
- [FRAC Radial.Volume (SI)](/lambda/po.lm.frac.radial.volume.si.md): Radial (Penny-shaped) fracture volume, [m3] (SI units).
- [FRAC Radial.Wavg (SI)](/lambda/po.lm.frac.radial.wavg.si.md): Radial (Penny-shaped) fracture average width, [cm] (SI units).
- [FRAC Radial.Width (SI)](/lambda/po.lm.frac.radial.width.si.md): Radial (Penny-shaped) fracture width at wellbore, [cm] (SI units).
- [FRAC Well.Cfd (SI)](/lambda/po.lm.frac.well.cfd.si.md): Fracture dimensionless conductivity, [dimensionless] (SI units).
- [FRAC Well.SkinEq (SI)](/lambda/po.lm.frac.well.skineq.si.md): Equivalent skin factor for vertical well with hydraulic fracture, [dimensionless] (SI units).
- [GL Inj.Eff (SI)](/lambda/po.lm.gl.inj.eff.si.md): Calculates total GLR including formation and injected gas, [sm3/sm3] (SI units).
- [GL Inj.Grad (SI)](/lambda/po.lm.gl.inj.grad.si.md): Calculates gas gradient in the annulus, [kPa/m] (SI units).
- [GL Inj.Pd (SI)](/lambda/po.lm.gl.inj.pd.si.md): Calculates injection gas pressure at depth, [kPa] (SI units).
- [GL Inj.Qgi (SI)](/lambda/po.lm.gl.inj.qgi.si.md): Calculates required gas injection rate for target GLR, [sm3/d] (SI units).
- [GL Valve.Pdome (SI)](/lambda/po.lm.gl.valve.pdome.si.md): Calculates dome pressure at depth from surface dome pressure, [kPa] (SI units).
- [GL Valve.Pvc (SI)](/lambda/po.lm.gl.valve.pvc.si.md): Calculates valve closing pressure, [kPa] (SI units).
- [GL Valve.Spread (SI)](/lambda/po.lm.gl.valve.spread.si.md): Calculates valve spread (opening minus closing pressure), [kPa] (SI units).
- [GL Valve.ThornhillCraver (SI)](/lambda/po.lm.gl.valve.thornhillcraver.si.md): Calculates gas throughput using Thornhill-Craver equation, [sm3/d] (SI units).
- [GL Valve.TRO (SI)](/lambda/po.lm.gl.valve.tro.si.md): Calculates test rack opening pressure at 60°F, [kPa] (SI units).
- [IPR GW.D (SI)](/lambda/po.lm.ipr.gw.d.si.md): Calculates Non-Darcy flow coefficient (D) for gas well turbulence effects, [1/(sm3/d)]. Used as input to GW.PSS.Rate.NonDarcy (SI units).
- [IPR GW.PSS.Rate.NonDarcy (SI)](/lambda/po.lm.ipr.gw.pss.rate.nondarcy.si.md): Calculates gas well stabilized flow rate for pseudosteady state condition with Non-Darcy flow equation, [sm3/d] (SI units).
- [IPR GW.PSS.Rate (SI)](/lambda/po.lm.ipr.gw.pss.rate.si.md): Calculates gas well flow rate for pseudosteady state condition using Darcy flow approximation, [sm3/d] (SI units).
- [IPR GW.PSS.Time (SI)](/lambda/po.lm.ipr.gw.pss.time.si.md): Calculates time to reach pseudosteady state (stabilized flow boundary) in gas well, [h] (SI units).
- [IPR HW.DrainArea.Ellipse (SI)](/lambda/po.lm.ipr.hw.drainarea.ellipse.si.md): Calculates horizontal well drainage area using ellipse geometry (Joshi), [m2] (SI units).
- [IPR HW.DrainArea.Rect (SI)](/lambda/po.lm.ipr.hw.drainarea.rect.si.md): Calculates horizontal well drainage area using two half-circles at ends plus rectangle (Joshi), [m2] (SI units).
- [IPR HW.PSS.PI.ByBabuOdeh.Centered (SI)](/lambda/po.lm.ipr.hw.pss.pi.bybabuodeh.centered.si.md): Calculates pseudosteady state productivity index for horizontal well using Babu-Odeh method for a box-shaped, anisotropic reservoir, with a well centrally placed parallel to X(box length)-direction, [m3/(d.kPa)] (SI units).
- [IPR HW.PSS.PI.ByBabuOdeh (SI)](/lambda/po.lm.ipr.hw.pss.pi.bybabuodeh.si.md): Calculates pseudosteady state productivity index for horizontal well using Babu-Odeh method for a box-shaped, anisotropic reservoir, with a well placed parallel to X(box length)-direction, [m3/(d.kPa)] (SI units).
- [IPR HW.SS.PI.ByBorisov (SI)](/lambda/po.lm.ipr.hw.ss.pi.byborisov.si.md): Calculates steady state productivity index for horizontal well using Borisov method (isotropic reservoir), [m3/(d.kPa)] (SI units).
- [IPR HW.SS.PI.ByEconomides.Centered (SI)](/lambda/po.lm.ipr.hw.ss.pi.byeconomides.centered.si.md): Calculates steady state productivity index for horizontal well using Economides model for centered well (Zw = h/2), [m3/(d.kPa)]. Economides et al. (1994) correlation (SI units).
- [IPR HW.SS.PI.ByEconomides (SI)](/lambda/po.lm.ipr.hw.ss.pi.byeconomides.si.md): Calculates steady state productivity index for horizontal well using Economides-Brand-Frick model (anisotropic reservoir, rectangular drainage), [m3/(d.kPa)]. Economides et al. (1994) correlation (SI units).
- [IPR HW.SS.PI.ByGRJ (SI)](/lambda/po.lm.ipr.hw.ss.pi.bygrj.si.md): Calculates steady state productivity index for horizontal well using Giger-Reiss-Jourdan method (anisotropic reservoir), [m3/(d.kPa)] (SI units).
- [IPR HW.SS.PI.ByJoshi (SI)](/lambda/po.lm.ipr.hw.ss.pi.byjoshi.si.md): Calculates steady state productivity index for horizontal well using Joshi method (anisotropic reservoir), [m3/(d.kPa)] (SI units).
- [IPR HW.SS.PI.ByRenardDupuy (SI)](/lambda/po.lm.ipr.hw.ss.pi.byrenarddupuy.si.md): Calculates steady state productivity index for horizontal well using Renard-Dupuy method (anisotropic reservoir), [m3/(d.kPa)] (SI units).
- [IPR Re (SI)](/lambda/po.lm.ipr.re.si.md): Calculates effective drainage radius, [m] (SI units).
- [IPR Rwa (SI)](/lambda/po.lm.ipr.rwa.si.md): Calculates effective wellbore radius, [m] (SI units).
- [IPR VW.Klins.d (SI)](/lambda/po.lm.ipr.vw.klins.d.si.md): Calculates Klins-Clark pressure-dependent exponent d, [dimensionless]. Klins & Clark (1993) correlation (SI units).
- [IPR VW.PSS.AOF.ByFetkovich (SI)](/lambda/po.lm.ipr.vw.pss.aof.byfetkovich.si.md): Calculates Fetkovich maximum flow rate (AOF) at Pwf = 0, [m3/d]. Fetkovich (1973) correlation (SI units).
- [IPR VW.PSS.PI (SI)](/lambda/po.lm.ipr.vw.pss.pi.si.md): Calculates pseudosteady state productivity index for vertical well, [m3/(d.kPa)] (SI units).
- [IPR VW.PSS.Rate.ByFetkovich (SI)](/lambda/po.lm.ipr.vw.pss.rate.byfetkovich.si.md): Calculates Fetkovich backpressure IPR flow rate for oil, [m3/d]. Fetkovich (1973) correlation (SI units).
- [IPR VW.PSS.Rate.ByKlins (SI)](/lambda/po.lm.ipr.vw.pss.rate.byklins.si.md): Calculates Klins-Clark modified Vogel IPR flow rate for oil, [m3/d]. Klins & Clark (1993) correlation (SI units).
- [IPR VW.PSS.Rate.ByVogel (SI)](/lambda/po.lm.ipr.vw.pss.rate.byvogel.si.md): Calculates Vogel inflow performance for pseudosteady state flow, [m3/d] (SI units).
- [IPR VW.PSS.Rate (SI)](/lambda/po.lm.ipr.vw.pss.rate.si.md): Calculates pseudosteady state production flow rate, [m3/d] (SI units).
- [IPR VW.PSS.Time (SI)](/lambda/po.lm.ipr.vw.pss.time.si.md): Calculates time to reach pseudosteady state for oil well with regular-shaped drainage area, [h] (SI units).
- [IPR VW.SS.PI (SI)](/lambda/po.lm.ipr.vw.ss.pi.si.md): Calculates steady state productivity index for vertical well, [m3/(d.kPa)] (SI units).
- [IPR VW.SS.Rate.ByVogel (SI)](/lambda/po.lm.ipr.vw.ss.rate.byvogel.si.md): Calculates Vogel inflow performance for steady state flow, [m3/d] (SI units).
- [IPR VW.SS.Rate (SI)](/lambda/po.lm.ipr.vw.ss.rate.si.md): Calculates steady state production flow rate, [m3/d] (SI units).
- [IPR VW.TF.PI (SI)](/lambda/po.lm.ipr.vw.tf.pi.si.md): Calculates transient state productivity index for vertical well, [m3/(d.kPa)] (SI units).
- [IPR VW.TF.Rate.ByVogel (SI)](/lambda/po.lm.ipr.vw.tf.rate.byvogel.si.md): Calculates Vogel inflow performance for transient-state flow, [m3/d] (SI units).
- [IPR VW.TF.Rate (SI)](/lambda/po.lm.ipr.vw.tf.rate.si.md): Calculates transient-state production flow rate, [m3/d] (SI units).
- [MBE Aq.Fet.J (SI)](/lambda/po.lm.mbe.aq.fet.j.si.md): Calculates aquifer productivity index for radial flow (Fetkovich), [m3/d/kPa] (SI units).
- [MBE Aq.Fet.JLin (SI)](/lambda/po.lm.mbe.aq.fet.jlin.si.md): Calculates aquifer productivity index for linear flow (Fetkovich), [m3/d/kPa] (SI units).
- [MBE Aq.Fet.Pa (SI)](/lambda/po.lm.mbe.aq.fet.pa.si.md): Calculates average aquifer pressure (Fetkovich), [kPa]. pa = pi * (1 - We/Wei) (SI units).
- [MBE Aq.Fet.Rate (SI)](/lambda/po.lm.mbe.aq.fet.rate.si.md): Calculates water influx rate (Fetkovich), [m3/d]. qw = J * (pa - pr) (SI units).
- [MBE Aq.Fet.Wei (SI)](/lambda/po.lm.mbe.aq.fet.wei.si.md): Calculates maximum encroachable water (Fetkovich), [m3]. Wei = ct * Wi * pi (SI units).
- [MBE Aq.Fet.Wi (SI)](/lambda/po.lm.mbe.aq.fet.wi.si.md): Calculates initial water volume in aquifer (radial), [m3] (SI units).
- [MBE Aq.Pot.Vol (SI)](/lambda/po.lm.mbe.aq.pot.vol.si.md): Calculates aquifer pore volume for pot aquifer model, [m3] (SI units).
- [MBE Aq.Pot.We (SI)](/lambda/po.lm.mbe.aq.pot.we.si.md): Calculates instantaneous water influx for pot aquifer, [m3]. We = ct * Wi * deltaP (SI units).
- [MBE Aq.Sch.Rate (SI)](/lambda/po.lm.mbe.aq.sch.rate.si.md): Calculates instantaneous water influx rate (Schilthuis), [m3/d]. qw = C * (pi - p) (SI units).
- [MBE Aq.Sch.We (SI)](/lambda/po.lm.mbe.aq.sch.we.si.md): Calculates cumulative water influx (Schilthuis) using trapezoidal integration, [m3]. We = C x integral(pi - p)dt (SI units).
- [MBE Aq.VEH.reD (SI)](/lambda/po.lm.mbe.aq.veh.red.si.md): Calculates dimensionless radius for VEH aquifer, [dimensionless]. reD = ra / rr (SI units).
- [MBE Aq.VEH.tD (SI)](/lambda/po.lm.mbe.aq.veh.td.si.md): Calculates dimensionless time for VEH aquifer, [dimensionless]. tD = 0.00634*k*t / (phi*muw*ct*rr^2) (SI units).
- [MBE Aq.VEH.U (SI)](/lambda/po.lm.mbe.aq.veh.u.si.md): Calculates aquifer constant for VEH model, [m3/kPa]. U = 1.119 * phi * ct * h * rr^2 * (theta/360) (SI units).
- [MBE Ce.Gas (SI)](/lambda/po.lm.mbe.ce.gas.si.md): Calculates effective compressibility for gas reservoir, [1/kPa] (SI units).
- [MBE Ce.Geopressured (SI)](/lambda/po.lm.mbe.ce.geopressured.si.md): Calculates effective compressibility for geopressured reservoir with gas solubility, [1/kPa] (SI units).
- [MBE Ce.PoreVol (SI)](/lambda/po.lm.mbe.ce.porevol.si.md): Calculates pore volume compressibility term, [1/kPa]. cpv = (cw*Swc + cf) / (1 - Swc) (SI units).
- [MBE Ce.Total (SI)](/lambda/po.lm.mbe.ce.total.si.md): Calculates total system compressibility, [1/kPa]. ct = Sg*cg + Sw*cw + cf (SI units).
- [MBE Ce.UnSat.Oil (SI)](/lambda/po.lm.mbe.ce.unsat.oil.si.md): Calculates effective compressibility for undersaturated oil reservoir, [1/kPa] (SI units).
- [MBE Exp.Bt (SI)](/lambda/po.lm.mbe.exp.bt.si.md): Calculates two-phase formation volume factor (Bt), [rm3/sm3]. Bt = Bo + (Rsi-Rs)*Bg (SI units).
- [MBE Exp.Efw (SI)](/lambda/po.lm.mbe.exp.efw.si.md): Calculates formation/water expansion term (Efw), [rm3/sm3]. Accounts for rock compaction and connate water expansion (SI units).
- [MBE Exp.Eo (SI)](/lambda/po.lm.mbe.exp.eo.si.md): Calculates oil and dissolved gas expansion term (Eo), [rm3/sm3]. Eo = (Bo-Boi) + (Rsi-Rs)*Bg (SI units).
- [MBE F.Oil (SI)](/lambda/po.lm.mbe.f.oil.si.md): Calculates underground withdrawal for oil reservoir, [m3]. F = Np*(Bo + (Rp-Rs)*Bg) + Wp*Bw (SI units).
- [MBE Gas.ModOGIP (SI)](/lambda/po.lm.mbe.gas.modogip.si.md): Estimates OGIP using modified p/z for geopressured reservoirs, [sm3] (SI units).
- [MBE Gas.ModPz (SI)](/lambda/po.lm.mbe.gas.modpz.si.md): Calculates modified p/z for geopressured reservoirs, [kPa]. Accounts for formation/water compressibility (SI units).
- [MBE Gas.OGIP (SI)](/lambda/po.lm.mbe.gas.ogip.si.md): Estimates OGIP using standard p/z method, [sm3]. Assumes volumetric depletion (SI units).
- [MBE Gas.PredGp (SI)](/lambda/po.lm.mbe.gas.predgp.si.md): Predicts cumulative production at given reservoir pressure, [sm3] (SI units).
- [MBE Gas.PredP (SI)](/lambda/po.lm.mbe.gas.predp.si.md): Predicts reservoir pressure at given cumulative production, [kPa] (SI units).
- [MBE Gas.Pz (SI)](/lambda/po.lm.mbe.gas.pz.si.md): Calculates p/z ratio for gas material balance analysis, [kPa] (SI units).
- [MBE Gas.URF (SI)](/lambda/po.lm.mbe.gas.urf.si.md): Calculates ultimate recovery factor based on abandonment pressure, [fraction 0-1] (SI units).
- [PTA FromDim.C (SI)](/lambda/po.lm.pta.fromdim.c.si.md): Converts dimensionless storage to wellbore storage coefficient, [m3/kPa] (SI units).
- [PTA FromDim.dP (SI)](/lambda/po.lm.pta.fromdim.dp.si.md): Converts dimensionless pressure to pressure drop, [kPa] (SI units).
- [PTA FromDim.L (SI)](/lambda/po.lm.pta.fromdim.l.si.md): Converts dimensionless distance to linear distance, [m] (SI units).
- [PTA FromDim.r (SI)](/lambda/po.lm.pta.fromdim.r.si.md): Converts dimensionless radius to radial distance, [m] (SI units).
- [PTA FromDim.t (SI)](/lambda/po.lm.pta.fromdim.t.si.md): Converts dimensionless time to elapsed time, [h] (SI units).
- [PTA Pw.VW.LinConP (SI)](/lambda/po.lm.pta.pw.vw.linconp.si.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with linear constant pressure boundary, [kPa] (SI units).
- [PTA Pw.VW.LinSealF (SI)](/lambda/po.lm.pta.pw.vw.linsealf.si.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with linear sealing fault boundary, [kPa] (SI units).
- [PTA Pw.VW.PerpConP (SI)](/lambda/po.lm.pta.pw.vw.perpconp.si.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with perpendicular constant pressures boundary, [kPa] (SI units).
- [PTA Pw.VW.PerpMix (SI)](/lambda/po.lm.pta.pw.vw.perpmix.si.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with perpendicular mixed boundaries (boundary 1 - fault, boundary 2 - constant pressure), [kPa] (SI units).
- [PTA Pw.VW.PerpSealF (SI)](/lambda/po.lm.pta.pw.vw.perpsealf.si.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir with perpendicular sealing faults boundary, [kPa] (SI units).
- [PTA Pw.VW (SI)](/lambda/po.lm.pta.pw.vw.si.md): Calculates wellbore pressure drop for vertical well in infinite homogeneous reservoir, [kPa] (SI units).
- [PTA ToDim.CD (SI)](/lambda/po.lm.pta.todim.cd.si.md): Converts wellbore storage coefficient to dimensionless storage, [dimensionless] (SI units).
- [PTA ToDim.LD (SI)](/lambda/po.lm.pta.todim.ld.si.md): Converts linear distance to dimensionless distance, [dimensionless] (SI units).
- [PTA ToDim.PD (SI)](/lambda/po.lm.pta.todim.pd.si.md): Converts pressure drop to dimensionless pressure, [dimensionless] (SI units).
- [PTA ToDim.rD (SI)](/lambda/po.lm.pta.todim.rd.si.md): Converts radial distance to dimensionless radius, [dimensionless] (SI units).
- [PTA ToDim.tD (SI)](/lambda/po.lm.pta.todim.td.si.md): Converts elapsed time to dimensionless time, [dimensionless] (SI units).
- [PVT Bg ByDefinition (SI)](/lambda/po.lm.pvt.bg.bydefinition.si.md): Calculates gas formation volume factor by definition in SI units.
- [PVT Bo Sat ByAlMarhoun (SI)](/lambda/po.lm.pvt.bo.sat.byalmarhoun.si.md): Calculates saturated oil formation volume factor using Al-Marhoun (1988) correlation in SI units.
- [PVT Bo Sat ByDindorukChristman (SI)](/lambda/po.lm.pvt.bo.sat.bydindorukchristman.si.md): Calculates saturated oil formation volume factor using Dindoruk and Christman (2001) correlation in SI units.
- [PVT Bo Sat ByGlaso (SI)](/lambda/po.lm.pvt.bo.sat.byglaso.si.md): Calculates saturated oil formation volume factor using Glaso (1980) correlation in SI units.
- [PVT Bo Sat ByPetrosky (SI)](/lambda/po.lm.pvt.bo.sat.bypetrosky.si.md): Calculates saturated oil formation volume factor using Petrosky (1990) correlation in SI units.
- [PVT Bo Sat ByStanding (SI)](/lambda/po.lm.pvt.bo.sat.bystanding.si.md): Calculates saturated oil formation volume factor using Standing (1947) correlation in SI units.
- [PVT Bo Sat ByVasquezBeggs (SI)](/lambda/po.lm.pvt.bo.sat.byvasquezbeggs.si.md): Calculates saturated oil formation volume factor using Vasquez and Beggs (1980) correlation in SI units.
- [PVT Bo UnSat ByDefinition (SI)](/lambda/po.lm.pvt.bo.unsat.bydefinition.si.md): Calculates undersaturated oil formation volume factor by definition in SI units.
- [PVT Bw ByMcCain (SI)](/lambda/po.lm.pvt.bw.bymccain.si.md): Calculates water formation volume factor using McCain (1990) correlation in SI units.
- [PVT Cg ByDefinition (SI)](/lambda/po.lm.pvt.cg.bydefinition.si.md): Calculates isothermal gas compressibility by definition, [1/kPa] (SI units).
- [PVT Co Sat ByVillenaLanzi (SI)](/lambda/po.lm.pvt.co.sat.byvillenalanzi.si.md): Calculates saturated oil compressibility using Villena-Lanzi (1985) correlation, [1/kPa] (SI units).
- [PVT Co UnSat ByVasquezBeggs (SI)](/lambda/po.lm.pvt.co.unsat.byvasquezbeggs.si.md): Calculates undersaturated oil compressibility using Vasquez and Beggs (1980) correlation, [1/kPa] (SI units).
- [PVT Cw Sat ByMcCain (SI)](/lambda/po.lm.pvt.cw.sat.bymccain.si.md): Calculates saturated water compressibility using McCain (1990) correlation, [1/kPa] (SI units).
- [PVT Cw UnSat ByOsif (SI)](/lambda/po.lm.pvt.cw.unsat.byosif.si.md): Calculates undersaturated water compressibility using Osif (1988) correlation, [1/kPa] (SI units).
- [PVT IFT GasOil ByAbdulMajeed (SI)](/lambda/po.lm.pvt.ift.gasoil.byabdulmajeed.si.md): Calculates gas-oil interfacial tension using Abdul-Majeed (2000) correlation, [mN/m] (SI units).
- [PVT IFT GasOil ByBakerSwerdloff (SI)](/lambda/po.lm.pvt.ift.gasoil.bybakerswerdloff.si.md): Calculates gas-oil interfacial tension using Baker and Swerdloff (1955) correlation, [mN/m] (SI units).
- [PVT Pb ByAlMarhoun (SI)](/lambda/po.lm.pvt.pb.byalmarhoun.si.md): Calculates oil bubble point pressure using Al-Marhoun (1988) correlation, [kPa] (SI units).
- [PVT Pb ByDindorukChristman (SI)](/lambda/po.lm.pvt.pb.bydindorukchristman.si.md): Calculates oil bubble point pressure using Dindoruk and Christman (2001) correlation, [kPa] (SI units).
- [PVT Pb ByDoklaOsman (SI)](/lambda/po.lm.pvt.pb.bydoklaosman.si.md): Calculates oil bubble point pressure using Dokla and Osman (1992) correlation, [kPa] (SI units).
- [PVT Pb ByGlaso (SI)](/lambda/po.lm.pvt.pb.byglaso.si.md): Calculates oil bubble point pressure using Glaso (1980) correlation, [kPa] (SI units).
- [PVT Pb ByPetroskyFarshad (SI)](/lambda/po.lm.pvt.pb.bypetroskyfarshad.si.md): Calculates oil bubble point pressure using Petrosky and Farshad (1990) correlation, [kPa] (SI units).
- [PVT Pb ByStanding (SI)](/lambda/po.lm.pvt.pb.bystanding.si.md): Calculates oil bubble point pressure using Standing (1947) correlation, [kPa] (SI units).
- [PVT Pb ByVasquezBeggs (SI)](/lambda/po.lm.pvt.pb.byvasquezbeggs.si.md): Calculates oil bubble point pressure using Vasquez and Beggs (1980) correlation, [kPa] (SI units).
- [PVT Ppc ByStanding (SI)](/lambda/po.lm.pvt.ppc.bystanding.si.md): Calculates pseudocritical pressure using Standing (1977) correlation, [kPa] (SI units).
- [PVT Ppc ByStanding Sour (SI)](/lambda/po.lm.pvt.ppc.bystanding.sour.si.md): Calculates pseudocritical pressure for sour gas using Standing (1977) with Wichert-Aziz correction, [kPa] (SI units).
- [PVT Ppc BySutton (SI)](/lambda/po.lm.pvt.ppc.bysutton.si.md): Calculates pseudocritical pressure using Sutton (1985) correlation, [kPa] (SI units).
- [PVT Ppc BySutton Sour (SI)](/lambda/po.lm.pvt.ppc.bysutton.sour.si.md): Calculates pseudocritical pressure for sour gas using Sutton (1985) with Wichert-Aziz correction, [kPa] (SI units).
- [PVT Rho Gas ByDefinition (SI)](/lambda/po.lm.pvt.rho.gas.bydefinition.si.md): Calculates gas density by definition, [kg/m3] (SI units).
- [PVT Rho Wat Stn (SI)](/lambda/po.lm.pvt.rho.wat.stn.si.md): Returns water density at standard conditions, [kg/m3] (SI units).
- [PVT Rs ByAlMarhoun (SI)](/lambda/po.lm.pvt.rs.byalmarhoun.si.md): Calculates solution gas-oil ratio using Al-Marhoun (1988) correlation, [sm3/sm3] (SI units).
- [PVT Rs ByDindorukChristman (SI)](/lambda/po.lm.pvt.rs.bydindorukchristman.si.md): Calculates solution gas-oil ratio using Dindoruk and Christman (2001) correlation, [sm3/sm3] (SI units).
- [PVT Rs ByGlaso (SI)](/lambda/po.lm.pvt.rs.byglaso.si.md): Calculates solution gas-oil ratio using Glaso (1980) correlation, [sm3/sm3] (SI units).
- [PVT Rs ByPetroskyFarshad (SI)](/lambda/po.lm.pvt.rs.bypetroskyfarshad.si.md): Calculates solution gas-oil ratio using Petrosky and Farshad (1993) correlation, [sm3/sm3] (SI units).
- [PVT Rs ByStanding (SI)](/lambda/po.lm.pvt.rs.bystanding.si.md): Calculates solution gas-oil ratio using Standing correlation (1981), [sm3/sm3] (SI units).
- [PVT Rs ByVasquezBeggs (SI)](/lambda/po.lm.pvt.rs.byvasquezbeggs.si.md): Calculates solution gas-oil ratio using Vasquez and Beggs (1980) correlation, [sm3/sm3] (SI units).
- [PVT Rsw ByMcCain (SI)](/lambda/po.lm.pvt.rsw.bymccain.si.md): Calculates solution gas-water ratio using McCain (1990) correlation, [sm3/sm3] (SI units).
- [PVT Rsw Pure ByMcCain (SI)](/lambda/po.lm.pvt.rsw.pure.bymccain.si.md): Calculates pure water solution gas-water ratio using McCain (1990) correlation, [sm3/sm3] (SI units).
- [PVT SG Oil ByDefinition (SI)](/lambda/po.lm.pvt.sg.oil.bydefinition.si.md): Calculates oil specific gravity from density in SI units.
- [PVT Tpc ByStanding (SI)](/lambda/po.lm.pvt.tpc.bystanding.si.md): Calculates pseudocritical temperature using Standing (1977) correlation, [degK] (SI units).
- [PVT Tpc ByStanding Sour (SI)](/lambda/po.lm.pvt.tpc.bystanding.sour.si.md): Calculates pseudocritical temperature for sour gas using Standing (1977) with Wichert-Aziz correction, [degK] (SI units).
- [PVT Tpc BySutton (SI)](/lambda/po.lm.pvt.tpc.bysutton.si.md): Calculates pseudocritical temperature using Sutton (1985) correlation, [degK] (SI units).
- [PVT Tpc BySutton Sour (SI)](/lambda/po.lm.pvt.tpc.bysutton.sour.si.md): Calculates pseudocritical temperature for sour gas using Sutton (1985) with Wichert-Aziz correction, [degK] (SI units).
- [PVT Ug ByLGE (SI)](/lambda/po.lm.pvt.ug.bylge.si.md): Calculates gas viscosity using Lee, Gonzalez and Eakin (1966) correlation, [mPa*s] (SI units).
- [PVT Uo Dead ByBeal (SI)](/lambda/po.lm.pvt.uo.dead.bybeal.si.md): Calculates dead oil viscosity using Beal (1946) correlation, [mPa*s] (SI units).
- [PVT Uo Dead ByEgbogah (SI)](/lambda/po.lm.pvt.uo.dead.byegbogah.si.md): Calculates dead oil viscosity using Egbogah (1983) correlation, [mPa*s] (SI units).
- [PVT Uo Dead ByGlaso (SI)](/lambda/po.lm.pvt.uo.dead.byglaso.si.md): Calculates dead oil viscosity using Glaso (1980) correlation, [mPa*s] (SI units).
- [PVT Uo Sat ByBeggsRobinson (SI)](/lambda/po.lm.pvt.uo.sat.bybeggsrobinson.si.md): Calculates saturated oil viscosity using Beggs and Robinson (1975) correlation, [mPa*s] (SI units).
- [PVT Uo Sat ByChewConnally (SI)](/lambda/po.lm.pvt.uo.sat.bychewconnally.si.md): Calculates saturated oil viscosity using Chew and Connally (1959) correlation, [mPa*s] (SI units).
- [PVT Uo UnSat ByKouzel (SI)](/lambda/po.lm.pvt.uo.unsat.bykouzel.si.md): Calculates undersaturated oil viscosity using Kouzel (1965) correlation, [mPa*s] (SI units).
- [PVT Uo UnSat ByVasquezBeggs (SI)](/lambda/po.lm.pvt.uo.unsat.byvasquezbeggs.si.md): Calculates undersaturated oil viscosity using Vasquez and Beggs (1980) correlation, [mPa*s] (SI units).
- [PVT Uw 1Atm ByMcCain (SI)](/lambda/po.lm.pvt.uw.1atm.bymccain.si.md): Calculates water viscosity at 1 atm using McCain (1990) correlation, [mPa*s] (SI units).
- [PVT Uw ByMcCain (SI)](/lambda/po.lm.pvt.uw.bymccain.si.md): Calculates water viscosity at pressure using McCain (1990) correlation, [mPa*s] (SI units).
- [RP Load.FluidLoad (SI)](/lambda/po.lm.rp.load.fluidload.si.md): Calculates fluid load on plunger, [N] (SI units).
- [RP Load.MPRL (SI)](/lambda/po.lm.rp.load.mprl.si.md): Calculates Minimum Polished Rod Load using API 11L method, [N] (SI units).
- [RP Load.MPRL.Simple (SI)](/lambda/po.lm.rp.load.mprl.simple.si.md): Calculates simplified MPRL (static, no dynamic effects), [N] (SI units).
- [RP Load.PPRL (SI)](/lambda/po.lm.rp.load.pprl.si.md): Calculates Peak Polished Rod Load using API 11L method, [N] (SI units).
- [RP Load.PPRL.Simple (SI)](/lambda/po.lm.rp.load.pprl.simple.si.md): Calculates simplified PPRL (static, no dynamic effects), [N] (SI units).
- [RP Load.Range (SI)](/lambda/po.lm.rp.load.range.si.md): Calculates polished rod load range (PPRL - MPRL), [N] (SI units).
- [RP Pump.Disp.Eff (SI)](/lambda/po.lm.rp.pump.disp.eff.si.md): Calculates effective pump displacement accounting for fillage, [m3/d] (SI units).
- [RP Pump.Displacement.FromDiameter (SI)](/lambda/po.lm.rp.pump.displacement.fromdiameter.si.md): Calculates theoretical pump displacement from plunger diameter, [m3/d] (SI units).
- [RP Pump.Displacement (SI)](/lambda/po.lm.rp.pump.displacement.si.md): Calculates theoretical pump displacement, [m3/d] (SI units).
- [RP Pump.Fillage (SI)](/lambda/po.lm.rp.pump.fillage.si.md): Calculates pump fillage from actual and theoretical production, [fraction] (SI units).
- [RP Pump.PIP (SI)](/lambda/po.lm.rp.pump.pip.si.md): Calculates pump intake pressure (PIP), [kPa] (SI units).
- [RP Pump.Psub (SI)](/lambda/po.lm.rp.pump.psub.si.md): Calculates submergence pressure from fluid column height, [kPa] (SI units).
- [RP Pump.Stroke.Eff (SI)](/lambda/po.lm.rp.pump.stroke.eff.si.md): Calculates effective plunger stroke from surface stroke and stretch, [cm] (SI units).
- [RP Pump.VolEff (SI)](/lambda/po.lm.rp.pump.voleff.si.md): Calculates volumetric efficiency of the pump system, [fraction] (SI units).
- [RP Rod.Area (SI)](/lambda/po.lm.rp.rod.area.si.md): Calculates rod cross-sectional area from diameter, [cm2] (SI units).
- [RP Rod.MaxStress (SI)](/lambda/po.lm.rp.rod.maxstress.si.md): Calculates maximum rod stress from peak load, [kPa] (SI units).
- [RP Rod.MinStress (SI)](/lambda/po.lm.rp.rod.minstress.si.md): Calculates minimum rod stress from minimum load, [kPa] (SI units).
- [RP Rod.StressRange (SI)](/lambda/po.lm.rp.rod.stressrange.si.md): Calculates rod stress range (fatigue indicator), [kPa] (SI units).
- [RP Rod.Stretch.FluidLoad (SI)](/lambda/po.lm.rp.rod.stretch.fluidload.si.md): Calculates rod stretch due to fluid load, [cm] (SI units).
- [RP Rod.Stretch.RodWeight (SI)](/lambda/po.lm.rp.rod.stretch.rodweight.si.md): Calculates rod stretch due to rod weight (self-weight stretch), [cm] (SI units).
- [RP Rod.Stretch.Total (SI)](/lambda/po.lm.rp.rod.stretch.total.si.md): Calculates total static rod stretch (fluid load + self-weight), [cm] (SI units).
- [RP Rod.Wair (SI)](/lambda/po.lm.rp.rod.wair.si.md): Calculates rod string weight in air, [N] (SI units).
- [RP Rod.Wbuoy (SI)](/lambda/po.lm.rp.rod.wbuoy.si.md): Calculates buoyant rod string weight (weight in fluid), [N] (SI units).
- [RP Rod.Wft (SI)](/lambda/po.lm.rp.rod.wft.si.md): Calculates rod weight per foot for a given diameter, [kg/m] (SI units).
- [RP Torque.Adjustment (SI)](/lambda/po.lm.rp.torque.adjustment.si.md): Calculates counterbalance adjustment needed, [N]. Positive = add weight (SI units).
- [RP Torque.IdealCBE.Loads (SI)](/lambda/po.lm.rp.torque.idealcbe.loads.si.md): Calculates ideal counterbalance effect from PPRL and MPRL, [N] (SI units).
- [RP Torque.IdealCBE (SI)](/lambda/po.lm.rp.torque.idealcbe.si.md): Calculates ideal counterbalance effect from rod weight and fluid load, [N] (SI units).
- [RP Torque.Net (SI)](/lambda/po.lm.rp.torque.net.si.md): Calculates net gearbox torque at a given crank angle, [N.m] (SI units).
- [RP Torque.Peak (SI)](/lambda/po.lm.rp.torque.peak.si.md): Calculates estimated peak net torque (simplified), [N.m] (SI units).
- [RP Torque.PRHP (SI)](/lambda/po.lm.rp.torque.prhp.si.md): Calculates polished rod horsepower, [kW] (SI units).
- [SCAL BrooksCorey.Pc (SI)](/lambda/po.lm.scal.brookscorey.pc.si.md): Brooks-Corey capillary pressure, [kPa]. Pc = Pd × Se^(-1/λ) (SI units).
- [SCAL BrooksCorey.Sw (SI)](/lambda/po.lm.scal.brookscorey.sw.si.md): Brooks-Corey saturation from capillary pressure, [fraction]. Inverse of Pc function (SI units).
- [SCAL Cf.Lime.ByNewman (SI)](/lambda/po.lm.scal.cf.lime.bynewman.si.md): Calculates rock pore volume compressibility in limestones using Newman correlation, [1/kPa] (SI units).
- [SCAL Cf.Sand.ByNewman (SI)](/lambda/po.lm.scal.cf.sand.bynewman.si.md): Calculates rock pore volume compressibility in sandstones using Newman correlation, [1/kPa] (SI units).
- [SCAL Leverett.J (SI)](/lambda/po.lm.scal.leverett.j.si.md): Leverett J-function, [dimensionless]. J = (Pc/σcosθ) × √(k/φ) (SI units).
- [SCAL Leverett.Pc (SI)](/lambda/po.lm.scal.leverett.pc.si.md): Capillary pressure from J-function, [kPa]. Pc = J × σcosθ × √(φ/k) (SI units).
- [SCAL VanGenuchten.Pc (SI)](/lambda/po.lm.scal.vangenuchten.pc.si.md): Van Genuchten capillary pressure, [kPa]. Se = [1 + (αPc)^n]^(-m) (SI units).
- [SCAL VanGenuchten.Sw (SI)](/lambda/po.lm.scal.vangenuchten.sw.si.md): Van Genuchten saturation from capillary pressure, [fraction]. Inverse of Pc function (SI units).
- [SF CH.Achong.Pwh (SI)](/lambda/po.lm.sf.ch.achong.pwh.si.md): Wellhead pressure using Achong (1961) critical flow correlation, [kPa] (SI units).
- [SF CH.Achong.Rate (SI)](/lambda/po.lm.sf.ch.achong.rate.si.md): Liquid flow rate using Achong (1961) critical flow correlation, [m3/d]. Modified Gilbert for Lake Maracaibo conditions (SI units).
- [SF CH.Achong.Size (SI)](/lambda/po.lm.sf.ch.achong.size.si.md): Choke diameter using Achong (1961) critical flow correlation, [cm] (SI units).
- [SF CH.AshfordPierce.Pwh (SI)](/lambda/po.lm.sf.ch.ashfordpierce.pwh.si.md): Wellhead pressure using Ashford-Pierce (1975) model, [kPa]. Iterative solution for target rate (SI units).
- [SF CH.AshfordPierce.Rate (SI)](/lambda/po.lm.sf.ch.ashfordpierce.rate.si.md): Liquid flow rate using Ashford-Pierce (1975) subcritical correction model, [m3/d]. Extends critical flow correlations to subcritical conditions (SI units).
- [SF CH.AshfordPierce.Size (SI)](/lambda/po.lm.sf.ch.ashfordpierce.size.si.md): Choke diameter using Ashford-Pierce (1975) model, [cm]. Iterative solution for target rate (SI units).
- [SF CH.Baxendell.Pwh (SI)](/lambda/po.lm.sf.ch.baxendell.pwh.si.md): Wellhead pressure using Baxendell (1957) critical flow correlation, [kPa] (SI units).
- [SF CH.Baxendell.Rate (SI)](/lambda/po.lm.sf.ch.baxendell.rate.si.md): Liquid flow rate using Baxendell (1957) critical flow correlation, [m3/d]. Developed from Lake Maracaibo field data (SI units).
- [SF CH.Baxendell.Size (SI)](/lambda/po.lm.sf.ch.baxendell.size.si.md): Choke diameter using Baxendell (1957) critical flow correlation, [cm] (SI units).
- [SF CH.Gas.Pwh (SI)](/lambda/po.lm.sf.ch.gas.pwh.si.md): Required upstream pressure for sonic gas flow, [kPa] (SI units).
- [SF CH.Gas.Rate (SI)](/lambda/po.lm.sf.ch.gas.rate.si.md): Gas flow rate through choke, [sm3/d]. Automatically determines sonic or subsonic flow regime (SI units).
- [SF CH.Gas.Rate.Sonic (SI)](/lambda/po.lm.sf.ch.gas.rate.sonic.si.md): Gas flow rate at sonic (critical) conditions, [sm3/d]. Rate independent of downstream pressure (SI units).
- [SF CH.Gas.Size (SI)](/lambda/po.lm.sf.ch.gas.size.si.md): Required choke diameter for sonic gas flow, [cm] (SI units).
- [SF CH.Gilbert.Pwh (SI)](/lambda/po.lm.sf.ch.gilbert.pwh.si.md): Wellhead pressure using Gilbert (1954) critical flow correlation, [kPa]. Calculates required pressure for target rate (SI units).
- [SF CH.Gilbert.Rate (SI)](/lambda/po.lm.sf.ch.gilbert.rate.si.md): Liquid flow rate using Gilbert (1954) critical flow correlation, [m3/d]. Widely used for oil wells with gas (SI units).
- [SF CH.Gilbert.Size (SI)](/lambda/po.lm.sf.ch.gilbert.size.si.md): Choke diameter using Gilbert (1954) critical flow correlation, [cm]. Calculates required choke size for target rate (SI units).
- [SF CH.Liq.dP (SI)](/lambda/po.lm.sf.ch.liq.dp.si.md): Pressure drop across choke for liquid flow, [kPa] (SI units).
- [SF CH.Liq.Rate (SI)](/lambda/po.lm.sf.ch.liq.rate.si.md): Liquid flow rate through choke, [m3/d]. Uses Bernoulli equation for incompressible flow (SI units).
- [SF CH.Liq.Size (SI)](/lambda/po.lm.sf.ch.liq.size.si.md): Required choke diameter for liquid flow, [cm] (SI units).
- [SF CH.Pilehvari.Pwh (SI)](/lambda/po.lm.sf.ch.pilehvari.pwh.si.md): Wellhead pressure using Pilehvari (1980) critical flow correlation, [kPa] (SI units).
- [SF CH.Pilehvari.Rate (SI)](/lambda/po.lm.sf.ch.pilehvari.rate.si.md): Liquid flow rate using Pilehvari (1980) critical flow correlation, [m3/d]. Based on U. of Tulsa experimental data (SI units).
- [SF CH.Pilehvari.Size (SI)](/lambda/po.lm.sf.ch.pilehvari.size.si.md): Choke diameter using Pilehvari (1980) critical flow correlation, [cm] (SI units).
- [SF CH.Ros.Pwh (SI)](/lambda/po.lm.sf.ch.ros.pwh.si.md): Wellhead pressure using Ros (1960) critical flow correlation, [kPa] (SI units).
- [SF CH.Ros.Rate (SI)](/lambda/po.lm.sf.ch.ros.rate.si.md): Liquid flow rate using Ros (1960) critical flow correlation, [m3/d] (SI units).
- [SF CH.Ros.Size (SI)](/lambda/po.lm.sf.ch.ros.size.si.md): Choke diameter using Ros (1960) critical flow correlation, [cm] (SI units).
- [SF CH.Sachdeva.Pwh (SI)](/lambda/po.lm.sf.ch.sachdeva.pwh.si.md): Wellhead pressure using Sachdeva (1986) two-phase model, [kPa]. Iterative solution for target rate (SI units).
- [SF CH.Sachdeva.Rate (SI)](/lambda/po.lm.sf.ch.sachdeva.rate.si.md): Liquid flow rate using Sachdeva (1986) two-phase mechanistic model, [m3/d]. Handles both critical and subcritical flow (SI units).
- [SF CH.Sachdeva.Size (SI)](/lambda/po.lm.sf.ch.sachdeva.size.si.md): Choke diameter using Sachdeva (1986) two-phase model, [cm]. Iterative solution for target rate (SI units).
- [SF PL.Gas.PanhandleA.Pout (SI)](/lambda/po.lm.sf.pl.gas.panhandlea.pout.si.md): Outlet pressure for gas pipeline using Panhandle A equation, [kPa] (SI units).
- [SF PL.Gas.PanhandleA.Rate (SI)](/lambda/po.lm.sf.pl.gas.panhandlea.rate.si.md): Gas flow rate using Panhandle A equation for medium-pressure transmission, [sm3/d] (SI units).
- [SF PL.Gas.PanhandleB.Pout (SI)](/lambda/po.lm.sf.pl.gas.panhandleb.pout.si.md): Outlet pressure for gas pipeline using Panhandle B equation, [kPa] (SI units).
- [SF PL.Gas.PanhandleB.Rate (SI)](/lambda/po.lm.sf.pl.gas.panhandleb.rate.si.md): Gas flow rate using Panhandle B equation for high-pressure large-diameter transmission, [sm3/d] (SI units).
- [SF PL.Gas.Re (SI)](/lambda/po.lm.sf.pl.gas.re.si.md): Reynolds number for gas pipeline flow (SI units).
- [SF PL.Gas.Rho (SI)](/lambda/po.lm.sf.pl.gas.rho.si.md): Gas density at pipeline conditions, [kg/m3] (SI units).
- [SF PL.Gas.Vel (SI)](/lambda/po.lm.sf.pl.gas.vel.si.md): Gas velocity at pipeline conditions, [m/s] (SI units).
- [SF PL.Gas.Weymouth.Pout (SI)](/lambda/po.lm.sf.pl.gas.weymouth.pout.si.md): Outlet pressure for gas pipeline using Weymouth equation, [kPa] (SI units).
- [SF PL.Gas.Weymouth.Rate (SI)](/lambda/po.lm.sf.pl.gas.weymouth.rate.si.md): Gas flow rate using Weymouth equation for high-pressure large-diameter pipelines, [sm3/d] (SI units).
- [SF PL.Liq.dP (SI)](/lambda/po.lm.sf.pl.liq.dp.si.md): Pressure drop for liquid pipeline using Darcy-Weisbach equation, [kPa] (SI units).
- [SF PL.Liq.Pin (SI)](/lambda/po.lm.sf.pl.liq.pin.si.md): Required inlet pressure for liquid pipeline, [kPa] (SI units).
- [SF PL.Liq.Pout (SI)](/lambda/po.lm.sf.pl.liq.pout.si.md): Outlet pressure for liquid pipeline, [kPa] (SI units).
- [SF PL.Liq.Rate (SI)](/lambda/po.lm.sf.pl.liq.rate.si.md): Liquid flow rate for given pressure drop using Darcy-Weisbach, [m3/d] (SI units).
- [SF PL.Liq.Re (SI)](/lambda/po.lm.sf.pl.liq.re.si.md): Reynolds number for liquid pipeline flow (SI units).
- [SF PL.Liq.Vel (SI)](/lambda/po.lm.sf.pl.liq.vel.si.md): Liquid velocity in pipeline, [m/s] (SI units).
- [VFP Ansari.dPdL (SI)](/lambda/po.lm.vfp.ansari.dpdl.si.md): Calculates pressure gradient using Ansari et al. (1994) mechanistic model, [kPa/m]. TUFFP industry standard for vertical upward flow (SI units).
- [VFP Ansari.Pin (SI)](/lambda/po.lm.vfp.ansari.pin.si.md): Calculates inlet pipe pressure using Ansari et al. (1994) mechanistic model, [kPa]. TUFFP industry standard for vertical upward flow (SI units).
- [VFP Ansari.Pout (SI)](/lambda/po.lm.vfp.ansari.pout.si.md): Calculates outlet pipe pressure using Ansari et al. (1994), [kPa]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP Aziz.dPdL (SI)](/lambda/po.lm.vfp.aziz.dpdl.si.md): Calculates pressure gradient using Aziz et al. (1972) drift-flux model, [kPa/m]. Vertical wells, basis for mechanistic models (SI units).
- [VFP Aziz.Pin (SI)](/lambda/po.lm.vfp.aziz.pin.si.md): Calculates inlet pipe pressure using Aziz et al. (1972), [kPa]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP Aziz.Pout (SI)](/lambda/po.lm.vfp.aziz.pout.si.md): Calculates outlet pipe pressure using Aziz et al. (1972), [kPa]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP BeggsBrill.dPdL (SI)](/lambda/po.lm.vfp.beggsbrill.dpdl.si.md): Calculates pressure gradient for multiphase pipe flow using Beggs and Brill (1973) correlation, [kPa/m]. Can be applied for any wellbore inclination and flow direction (SI units).
- [VFP BeggsBrill.Pin (SI)](/lambda/po.lm.vfp.beggsbrill.pin.si.md): Calculates inlet pipe pressure using Beggs and Brill (1973), [kPa]. For any wellbore inclination. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP BeggsBrill.Pout (SI)](/lambda/po.lm.vfp.beggsbrill.pout.si.md): Calculates outlet pipe pressure using Beggs and Brill (1973), [kPa]. For any wellbore inclination. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP DunsRos.dPdL (SI)](/lambda/po.lm.vfp.dunsros.dpdl.si.md): Calculates pressure gradient using Duns and Ros (1963) correlation, [kPa/m]. For vertical gas wells with liquid, high GOR wells (SI units).
- [VFP DunsRos.Pin (SI)](/lambda/po.lm.vfp.dunsros.pin.si.md): Calculates inlet pipe pressure using Duns and Ros (1963), [kPa]. Vertical gas wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP DunsRos.Pout (SI)](/lambda/po.lm.vfp.dunsros.pout.si.md): Calculates outlet pipe pressure using Duns and Ros (1963), [kPa]. Vertical gas wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP Gas.Pin (SI)](/lambda/po.lm.vfp.gas.pin.si.md): Calculates inlet pipe pressure for single phase pipe flow of gas (compressible fluid), [kPa] (SI units).
- [VFP Gas.Pout (SI)](/lambda/po.lm.vfp.gas.pout.si.md): Calculates outlet pipe pressure for single phase pipe flow of gas (compressible fluid), [kPa] (SI units).
- [VFP Gas.Re (SI)](/lambda/po.lm.vfp.gas.re.si.md): Calculates Reynolds number for single phase pipe flow of gas (compressible fluid), [dimensionless] (SI units).
- [VFP Gray.dPdL (SI)](/lambda/po.lm.vfp.gray.dpdl.si.md): Calculates pressure gradient for multiphase pipe flow using Gray (1974) correlation, [kPa/m]. Commonly used for gas wells that are also producing liquid (SI units).
- [VFP Gray.Pin (SI)](/lambda/po.lm.vfp.gray.pin.si.md): Calculates inlet pipe pressure using Gray (1974), [kPa]. For gas wells producing liquid. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP Gray.Pout (SI)](/lambda/po.lm.vfp.gray.pout.si.md): Calculates outlet pipe pressure using Gray (1974), [kPa]. For gas wells producing liquid. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP HagedornBrown.dPdL (SI)](/lambda/po.lm.vfp.hagedornbrown.dpdl.si.md): Calculates pressure gradient for multiphase pipe flow using Hagedorn and Brown (1965) correlation with Griffith modification, [kPa/m]. Developed for vertical, upward flow and recommended only for near-vertical wellbores (SI units).
- [VFP HagedornBrown.Pin (SI)](/lambda/po.lm.vfp.hagedornbrown.pin.si.md): Calculates inlet pipe pressure using Hagedorn and Brown (1965), [kPa]. For vertical/near-vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP HagedornBrown.Pout (SI)](/lambda/po.lm.vfp.hagedornbrown.pout.si.md): Calculates outlet pipe pressure using Hagedorn and Brown (1965), [kPa]. For vertical/near-vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP HasanKabir.dPdL (SI)](/lambda/po.lm.vfp.hasankabir.dpdl.si.md): Calculates pressure gradient using Hasan-Kabir (1988) mechanistic model, [kPa/m]. For deviated wells and annular geometry (SI units).
- [VFP HasanKabir.Pin (SI)](/lambda/po.lm.vfp.hasankabir.pin.si.md): Calculates inlet pipe pressure using Hasan-Kabir (1988), [kPa]. For deviated wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP HasanKabir.Pout (SI)](/lambda/po.lm.vfp.hasankabir.pout.si.md): Calculates outlet pipe pressure using Hasan-Kabir (1988), [kPa]. For deviated wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP Liq.dPfrc (SI)](/lambda/po.lm.vfp.liq.dpfrc.si.md): Calculates frictional pressure drop from Fanning equation for single-phase flow of an incompressible, Newtonian fluid, [kPa] (SI units).
- [VFP Liq.dPgrv (SI)](/lambda/po.lm.vfp.liq.dpgrv.si.md): Calculates potential energy pressure drop for single-phase flow of an incompressible, Newtonian fluid, [kPa] (SI units).
- [VFP Liq.Pin (SI)](/lambda/po.lm.vfp.liq.pin.si.md): Calculates inlet pipe pressure for single phase pipe flow of incompressible, Newtonian fluid, [kPa] (SI units).
- [VFP Liq.Pout (SI)](/lambda/po.lm.vfp.liq.pout.si.md): Calculates outlet pipe pressure for single phase pipe flow of incompressible, Newtonian fluid, [kPa] (SI units).
- [VFP Liq.Re (SI)](/lambda/po.lm.vfp.liq.re.si.md): Calculates Reynolds number for single phase pipe flow of incompressible, Newtonian fluid, [dimensionless] (SI units).
- [VFP MukherjeeBrill.dPdL (SI)](/lambda/po.lm.vfp.mukherjeebrill.dpdl.si.md): Calculates pressure gradient using Mukherjee-Brill (1985) correlation, [kPa/m]. For inclined wells, improvement over Beggs-Brill (SI units).
- [VFP MukherjeeBrill.Pin (SI)](/lambda/po.lm.vfp.mukherjeebrill.pin.si.md): Calculates inlet pipe pressure using Mukherjee-Brill (1985), [kPa]. For inclined wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP MukherjeeBrill.Pout (SI)](/lambda/po.lm.vfp.mukherjeebrill.pout.si.md): Calculates outlet pipe pressure using Mukherjee-Brill (1985), [kPa]. For inclined wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP Orkiszewski.dPdL (SI)](/lambda/po.lm.vfp.orkiszewski.dpdl.si.md): Calculates pressure gradient using Orkiszewski (1967) correlation, [kPa/m]. Vertical wells, widely used industry standard (SI units).
- [VFP Orkiszewski.Pin (SI)](/lambda/po.lm.vfp.orkiszewski.pin.si.md): Calculates inlet pipe pressure using Orkiszewski (1967), [kPa]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP Orkiszewski.Pout (SI)](/lambda/po.lm.vfp.orkiszewski.pout.si.md): Calculates outlet pipe pressure using Orkiszewski (1967), [kPa]. Vertical wells. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP PoettmannCarpenter.dPdL (SI)](/lambda/po.lm.vfp.poettmanncarpenter.dpdl.si.md): Calculates pressure gradient using Poettmann-Carpenter (1952), [kPa/m]. Historical no-slip method for high-rate dispersed bubble flow (SI units).
- [VFP PoettmannCarpenter.Pin (SI)](/lambda/po.lm.vfp.poettmanncarpenter.pin.si.md): Calculates inlet pipe pressure using Poettmann-Carpenter (1952), [kPa]. No-slip method. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).
- [VFP PoettmannCarpenter.Pout (SI)](/lambda/po.lm.vfp.poettmanncarpenter.pout.si.md): Calculates outlet pipe pressure using Poettmann-Carpenter (1952), [kPa]. No-slip method. Gas properties (ρg, μg, Bg) use DAK (Z-factor) and LGE (viscosity) (SI units).

## Workbooks
- [Decline Curve Analysis — Arps with EUR](/workbook/po.wb.dca.decline-functions.md): Complete Arps decline analysis: forecast rate and cumulative production over 20 years,
calculate EUR at economic limit, and compare b-exponent sensitivity (b=0, 0.5, 1.0).
Named input cells for qi, Di, b, and economic limit rate.
- [Decline Model Comparison — Arps, Duong, PLE](/workbook/po.wb.dca.decline-model-fitters.md): Side-by-side comparison of three decline models with EUR analysis. Named inputs for all
model parameters. 21 time steps out to 360 months with model spread analysis.
- [Inflow Performance & Nodal Analysis](/workbook/po.wb.ipr.inflow-performance.md): Demonstrates IPR curves using Fetkovich and Vogel models, then overlays a single-phase
VFP (tubing performance) curve to find the well operating point. The intersection of IPR
and VFP is the most fundamental production engineering calculation.
- [Material Balance — Expansion Terms](/workbook/po.wb.mbe.black-oil-model.md): MBE expansion terms (Eo, Eg, Efw) for a black oil reservoir with gas cap. Named input cells
for initial conditions. 9 pressure steps with PVT data and computed expansions.
- [Spline Interpolation — PVT Table Application](/workbook/po.wb.numerics.spline-interpolation.md): Demonstrates cubic and linear spline interpolation on a real petroleum engineering problem:
interpolating Bo (oil formation volume factor) between lab measurement pressures. Shows where
cubic interpolation matters most — at high-curvature regions of the PVT curve.
- [Field Production Profile — Buildup-Plateau-Decline](/workbook/po.wb.profiles.field-production-profile.md): Three-phase field production profile with formula-derived phase transitions. Named input
cells for buildup time, plateau duration, plateau rate, and decline parameters. 25 time
steps out to 120 months.
- [Pressure Transient Analysis — Boundary Effects](/workbook/po.wb.pta.boundary-effects.md): Demonstrates pressure transient analysis with three boundary models: infinite reservoir,
single sealing fault, and perpendicular faults (channel). Shows PD vs tD on a table with
log-log diagnostic chart showing characteristic boundary signatures.
- [Complete PVT Properties — Oil, Gas & Water](/workbook/po.wb.pvt.complete-pvt.md): Multi-sheet PVT workbook demonstrating all major fluid property correlations
across oil, gas, and water phases. Uses named input cells so engineers can
quickly adapt to their reservoir conditions.
- [Capillary Pressure Models — Brooks-Corey, Van Genuchten, Leverett J](/workbook/po.wb.scal.capillary-pressure.md): Compare three capillary pressure models with named inputs: Brooks-Corey, Van Genuchten,
and Leverett J-function. 20 saturation points with J-function scaling chart.
- [Relative Permeability — Corey vs LET](/workbook/po.wb.scal.corey-relative-permeability.md): Side-by-side comparison of Corey and LET relative permeability models. Named input cells
for endpoints and model parameters. 23 saturation points from Swi to 1-Sorw.
- [Petroleum Engineering Unit Conversions](/workbook/po.wb.utilities.unit-converter.md): Comprehensive unit conversion reference for petroleum engineers. Live input cells
in each category update all conversions automatically. Covers pressure, temperature,
volume, rate, GOR, density, viscosity, compressibility, length, area, and permeability.
- [Single-Phase Liquid Pipe Flow](/workbook/po.wb.vfp.pipe-flow-functions.md): Single-phase liquid flow in vertical tubing with named inputs and rate sensitivity analysis.
Shows friction loss, gravity head, Reynolds number, and required BHP at 14 rate points.