Study on the influential factors of saturation exponent based on the equivalent rock element theory
GE Xin-min1,2, FAN Yi-ren1,2, YANG Dong-gen3, HU Hai-chuan4, DENG Shao-gui1,2
1 College of Geo-resource and Information,Chinaa University of Petroleum(East China),Qingdao,Shandong 266555,China;
2 CNPC Key Well Logging Laboratory,Chinaa University of Petroleum(East China),Qingdao,Shandong 266555,China;
3 Western New Prospect Research Center,Shengli Oilfield,Sinopec,Dongying,Shandong 257000,China;
4 Research Institute of Petroleum Exploration & Development,CNPC,Beijing 100083,China
Abstract:Rock non-Archie property is affected by pore structure,fluid distribution,rock matrix's additional conductance,wettability,critical saturation,etc.This work simulates the conductivity of porous rock using the equivalent rock element theory.We introduce a few parameters,such as pore structure efficiency,saturation factors,critical saturation and their influences on saturation exponent.The result shows that critical saturation and the first saturation factor have the largest effects on saturation exponent,secondly the second saturation factor.Pore structure efficiency has little effect on saturation exponent.Saturation exponent increases with the increase of critical saturation and the first saturation factor.But it decreases with the increase of the pore structure efficiency and the second saturation.We select core samples from G oilfield(East China) for petrophysical experiments and verification of our theory.The experiments of different permeability cores demonstrate the coefficient of saturation-resistivity index fitted by the equivalent rock element theory is between 0.93 to 0.97,higher than that by conventional Archie equations(0.76~0.84) when porosity ranges from 15.2% to 20.8%.The equivalent rock element theory depict rock non-Archie property more exactly,thus will enhance the saturation calculation precision.
葛新民, 范宜仁, 杨东根, 胡海川, 邓少贵. 基于等效岩石组分理论的饱和度指数影响因素[J]. 石油地球物理勘探, 2011, 46(3): 477-481.
GE Xin-min, FAN Yi-ren, YANG Dong-gen, HU Hai-chuan, DENG Shao-gui. Study on the influential factors of saturation exponent based on the equivalent rock element theory. OGP, 2011, 46(3): 477-481.