倾斜砂岩地层电阻率各向异性实验及校正方法  

Experiment and correction method for anisotropic resistivity in inclined sandstone formation

作　　者：唐军[1] 信毅[2] 申威 章成广[1] 许巍[1] TANG Jun;XIN Yi;SHEN Wei;ZHANG Chengguang;XU Wei(College of Geophysics and Petroleum Resources,Yangtze University,Wuhan 430100,China;PetroChina Tarim Oilfield Company,Korla 841000,China)

机构地区：[1]长江大学地球物理与石油资源学院,湖北武汉430100 [2]中国石油塔里木油田公司,新疆库尔勒841000

出　　处：《大庆石油地质与开发》2023年第1期142-149,共8页Petroleum Geology & Oilfield Development in Daqing

基　　金：中国石油天然气股份有限公司科技创新基金项目“裂缝渗透率测井计算理论模型及实验研究”(2020D-5007-0306)。

摘　　要：为提高倾斜储层流体性质评价中的岩石电阻率精度,需要明确岩石电阻率随地层各向异性、地层倾角的变化规律。在对比分析两种模拟地层倾角的实验方案基础上,开展致密砂岩样品各向异性及倾角的电阻率物理测量实验,依照“二极法”的物理测量模式,采用有限元数值模拟了地层倾角、各向异性与岩心电阻率的变化关系。结果表明:当孔隙度增大时,岩石电阻率减小;当泥质含量增大时,各向异性系数变大;当地层倾角增大时,孔隙结构系数变大,当地层倾角相同时,孔隙度越大则孔隙结构系数越大;当地层倾角大于20°时,岩石电阻率增加量大于5%,这时需要进行电阻率校正。通过建立实测电阻率与理论公式计算电阻率之间的关系,获得克服各向异性、倾角影响的电阻率校正方法。研究成果为开展不同倾角、各向异性储层的电阻率校正及饱和度多井对比分析提供了实验依据。In order to improve rock resistivity accuracy in evaluation of inclined reservoir fluid properties,it is necessary to clarify the variation law of rock resistivity with formation anisotropy and dip.On the basis of comparative analysis of 2 experimental schemes to simulate formation dip,physical resistivity measurement experiments are carried out for anisotropy and dip of tight sandstone samples.The relationship of dip and anisotropy vs.core resistivity is simulated by finite element method in“two-electrode”measuring mode.The experiment results show that rock resistivity decreases with porosity increase,and anisotropy coefficient increases with argillaceous content increase.Porosity structure coefficient increases with formation dip increase.When formation dip is constant,pore structure coefficient increases with porosity increase.When formation dip is higher than 20°,rock resistivity increment exceeds 5%,which requires resistivity correction.By establishing relationship between measured resistivity and theoretical formula calculated resistivity,a resistivity correction method for overcoming anisotropy and dip is formed.This study provides experimental basis for resistivity correction and multi-well saturation correlation analysis of reservoirs with different dips and anisotropy.

关 键 词：倾斜砂岩地层 电阻率 地层各向异性 地层倾角 校正 饱和度 

分 类 号：P631[天文地球—地质矿产勘探]