PETROPHYSICAL_FORMULAE.pptVIP

BASIC PETROPHYSICAL FORMULAE Compiled By:- Muhammad Zahid petrophysicist786@ POROSITY Effective Porosity PHIE = PHIA * (1-Vshl) Density Porosity PHID = (RhoM - RHOB) / (RhoM - RhoF) Average Neutron Density Porosity PHIA = (PHID + PHIN) / 2 Gamma Ray Neutron Porosity Enter Values for PorMax, PorMin... PorMax = 0.35 PorMin = 0.02 Enter Values in Counts Per Second or API... CPS_PorMax = 75 CPS_PorMin = 600 B = log(PorMax/PorMin) / (CPS_PorMax - CPS_PorMin) A = PorMax / 10 ^ (B*CPS_PorMax) PHIGRN = A * 10 ^ (B * CPS) Sonic Porosity (Wyllie) PHIS = (DT - DTma) / (DTfld - DTma) Sonic Porosity (Wyllie) Enter Compaction Coefficient below, Cmp = 1.0 PHIS = (1/Cmp) * (DT - DTma) / (DTfld - DTma) Sonic Porosity (Empirical) PHIS = 0.67 * (DT - DTma) / DT Apparent Sonic Matrix DTma = ( DT - PHIA * DTfld ) / (1 - PHIA) Apparent Density Matrix RHOMa = (RHOB - PHIA * RhoF) / (1 - PHIA) Bulk Volume Water BVW = PHIA * SwA. Hydrocarbon Pore Volume HCPV = (1-SwA) * PHIA Hydrocarbon Pore Volume SoPhiH = (1-SwA) * PHIA WATER RESISTIVITY Archie Ro Ro = a * Rw / (PHIA^m) Apparent Water Resistivity Rwa = RT * PHIA^m Conductivity COND = 1000/RT Rw from Dual Water RwDW = Rw * RwBnd / (Rw * Vshl + (1-Vshl) * RwBnd) Ro from Dual Water RoDW = (1 / (PHIA^m)) * (Rw * RwBnd / (Rw * Vshl + RwBnd * (1 - Vshl))) Modified Simandoux Ro If (Vshl 1) RoMS = 1/(PHIE^m / (a* Rw*(1-Vshl)) + Vshl/Rshl) Resistivity Temp Correction T1 and T2 in F R2 = R1 * (T1 + 6.77) / (T2 + 6.77) Resistivity Temp Correction T1 and T2 in C R2 = R1 * (T1 + 21.5) / (T2 + 21.5) WATER SATURATION Archie Water Saturation SwA = sqrt( Rw / (RT * PHIA^2) ) Archie Water Saturation SwA = (a * Rw / ( RT * PHIA^m) )^(1/n) Archie Water Saturation (Humble) SwA = sqrt( .62 * Rw / (RT * PHIA ^2.15) ) Archie Water Saturation SwA = sqrt( Rw / (RT * PHID ^m) ) Archie Water Saturation SwA = sqrt(Ro / RT) Archie Water Saturation SwA = sqrt(Rw / Rwa) SwA = min( 1, max( 0, SwA ) Dual Water SwT SwE Calculate SwT Total Porosity Y = Vshl * ( RwBn