Oil Material Balance Functions
Havlena-Odeh straight lines, expansion terms, underground withdrawal, drive indices and effective compressibility.
24 functions
PO.MBE.Oil.OOIP(F, Et)
Estimates OOIP from F vs Et (no water influx), [STB]. N = F / Et.
PO.MBE.Oil.OOIP.Reg(F, Et)
Estimates OOIP using regression on F vs Et data, [STB]. Least-squares through origin.
PO.MBE.Oil.OOIP.We(F, Et, We)
Estimates OOIP with water influx, [STB]. N = (F - We) / Et.
PO.MBE.Oil.NandM(F, Eo, Eg)
Estimates N and m from F/Eo vs Eg/Eo regression. Returns [N, m].
PO.MBE.Oil.We(F, N, Et)
Infers water influx from material balance given known OOIP, [RB]. We = F - N*Et.
PO.MBE.Oil.Residual(F, N, Et, We)
Calculates normalized MBE residual for quality check, [fraction]. Should be close to 0.
PO.MBE.Exp.Eo(Bo, Boi, Rs, Rsi, Bg)
Calculates oil and dissolved gas expansion term (Eo), [RB/STB]. Eo = (Bo-Boi) + (Rsi-Rs)*Bg.
PO.MBE.Exp.Eg(Boi, Bg, Bgi)
Calculates gas cap expansion term (Eg) for oil reservoirs, [RB/STB]. Eg = Boi*(Bg/Bgi - 1).
PO.MBE.Exp.Eg.Gas(Bg, Bgi)
Calculates gas expansion for pure gas reservoirs, [RB/scf]. Eg = Bg - Bgi.
PO.MBE.Exp.Efw(Boi, cw, cf, Swc, m, deltaP)
Calculates formation/water expansion term (Efw), [RB/STB]. Accounts for rock compaction and connate water expansion.
PO.MBE.Exp.Et(Eo, Eg, Efw, m)
Calculates total expansion term (Et), [RB/STB]. Et = Eo + m*Eg + Efw.
PO.MBE.Exp.Bt(Bo, Rs, Rsi, Bg)
Calculates two-phase formation volume factor (Bt), [RB/STB]. Bt = Bo + (Rsi-Rs)*Bg.
PO.MBE.F.Oil(Np, Bo, Rp, Rs, Bg, Wp, Bw)
Calculates underground withdrawal for oil reservoir, [RB]. F = Np*(Bo + (Rp-Rs)*Bg) + Wp*Bw.
PO.MBE.F.Gas(Gp, Bg, Wp, Bw)
Calculates underground withdrawal for gas reservoir, [RB]. F = Gp*Bg + Wp*Bw.
PO.MBE.Drives.DDI(N, Eo, F)
Calculates Depletion Drive Index (DDI), [fraction 0-1]. DDI = N*Eo / F.
PO.MBE.Drives.GDI(N, m, Eg, F)
Calculates Gas Cap Drive Index (GDI), [fraction 0-1]. GDI = N*m*Eg / F.
PO.MBE.Drives.WDI(We, F)
Calculates Water Drive Index (WDI), [fraction 0-1]. WDI = We / F.
PO.MBE.Drives.CDI(N, Efw, F)
Calculates Compressibility Drive Index (CDI), [fraction 0-1]. CDI = N*Efw / F.
PO.MBE.Drives.All(N, Eo, m, Eg, Efw, We, F)
Calculates all drive indices. Returns [DDI, GDI, WDI, CDI, Sum]. Sum should be ~1.
PO.MBE.Ce.UnSat.Oil(co, cw, cf, Swc)
Calculates effective compressibility for undersaturated oil reservoir, [1/psi].
PO.MBE.Ce.Gas(cw, cf, Sw)
Calculates effective compressibility for gas reservoir, [1/psi].
PO.MBE.Ce.Geopressured(cw, cf, Sw, Rsw, Bg)
Calculates effective compressibility for geopressured reservoir with gas solubility, [1/psi].
PO.MBE.Ce.PoreVol(cw, cf, Swc)
Calculates pore volume compressibility term, [1/psi]. cpv = (cw*Swc + cf) / (1 - Swc).
PO.MBE.Ce.Total(cg, cw, cf, Sg, Sw)
Calculates total system compressibility, [1/psi]. ct = Sg*cg + Sw*cw + cf.