Category
Utilities
25 functions
PO.DCA.AKB.D
Calculates instantaneous decline rate D(t) for Ansah-Knowles-Buba (2000) decline, [1/T]. Computed numerically.
PO.DCA.Arps.D
Calculates instantaneous decline rate D(t) for Arps decline, [1/T]. D(t) = Di/(1+b×Di×t). Computed numerically.
PO.DCA.Convert.AnnualToMonthly
Converts annual effective decline rate to monthly effective decline rate using compound conversion.
PO.DCA.Convert.DailyToAnnual
Converts daily effective decline rate to annual effective decline rate using compound conversion.
PO.DCA.Convert.EffectiveToNominal
Converts effective (periodic) decline rate to nominal (continuous) decline rate. Dn = -ln(1 - De).
PO.DCA.Convert.MonthlyToAnnual
Converts monthly effective decline rate to annual effective decline rate using compound conversion.
PO.DCA.Convert.NominalToEffective
Converts nominal (continuous) decline rate to effective (periodic) decline rate. De = 1 - exp(-Dn).
PO.DCA.Data.Clean
Cleans production data by interpolating over outlier points. Returns cleaned rate array with outliers replaced by interpolated values.
PO.DCA.Data.OutlierFlag
Flags outliers using rolling window Z-score analysis. Returns TRUE for data points that are outliers based on local statistics.
PO.DCA.Diag.Beta
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
Calculates the Bourdet (smoothed) derivative at point t. Used for flow regime identification and production diagnostics.
PO.DCA.Diag.bParam
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
Calculates instantaneous decline rate D(t) for Duong model, [1/T]. Computed numerically.
PO.DCA.EEDM.D
Calculates instantaneous decline rate D(t) for Extended Exponential Decline Model (EEDM), [1/T]. Computed analytically.
PO.DCA.LGM.D
Calculates instantaneous decline rate D(t) for Logistic Growth Model (LGM), [1/T]. Computed analytically.
PO.DCA.ModHyp.D
Calculates instantaneous decline rate D(t) for Modified Hyperbolic decline, [1/T]. Computed numerically.
PO.DCA.PLE.D
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.SEDM.D
Calculates instantaneous decline rate D(t) for Stretched Exponential model, [1/T]. D(t) = (n/τ)×(t/τ)^(n-1). Computed numerically.
PO.DCA.THM.D
Calculates instantaneous decline rate D(t) for Transient Hyperbolic Model, [1/T]. Computed analytically.
PO.Stats.LogSSE
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
Computes the coefficient of determination (R²) between observed and predicted sequences. R² = 1 - SSE/TSS. Returns 1.0 for perfect fit.
PO.Stats.RMSE
Computes the root mean squared error (RMSE) between observed and predicted sequences. RMSE = sqrt(SSE/n).
PO.Stats.SSE
Computes the sum of squared errors (SSE) between observed and predicted rate sequences. Returns a scalar value.
PO.Stats.WLogSSE
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
Computes the weighted SSE between observed and predicted sequences.