过套管电阻率测井高电阻率层段不稳定性分析  

Instability Analysis of Through Casing Resistivity Logging Responses in Higher Resistance Formation

作　　者：刘福平[1,2] 陈小安 赵宝成 杨长春[2] 

机构地区：[1]北京印刷学院,北京102600 [2]中国科学院地质与地球物理研究所,北京100029 [3]中国石油长城钻探工程有限公司测井技术研究院,北京100201

出　　处：《测井技术》2013年第1期85-89,共5页Well Logging Technology

基　　金：北京市属市管高等学校人才强教计划资助项目(PHR201107145)

摘　　要：过套管电阻率测井在低电阻率层段测量结果比较稳定,重复测量结果能够稳定在一个较小的变化范围内;但在高电阻率层段重复测量结果有时变化幅度很大。根据目前所使用的2种过套管电阻率测井视电阻率计算方法,利用传输线方程计算了测量电极电势、套管漏电流随地层电阻率的变化,通过算例研究了高电阻率层段重复测量结果的不稳定性,分析了漏电流(二阶电势差)的测量误差对地层视电阻率计算造成的影响以及对高电阻率层段测量结果不稳定的影响因素。认为这主要是由电势的测量误差造成的,解决办法是提高电势测量精度,降低接触电阻对测量电势的影响。The measured result of through-casing resistivity logging is stable for the lower resistance formation, and the variational range of repeated measurements is very small. But the difference of repeated measurements is very large for the same higher resistivity formation. According to the current two apparent resistivity measurement models for the through-casing resistivity logging, the potential distribution and leaking current of casing have been computed with transmission line equation when the resistivity of formation changes. With those results we have studied the instability of the repeated measurements for higher resistivity formation, analyzed influence of the measured errors of the leaking current on the apparent resistivity meaurements, and given the instability analysis of through-casing resistivity logging results for higher resistance formation. It is believed that the instability is mainly caused by potential measurement errors. And this problem could be solved by improving measurement accuracy of electric potential in order to reduce influence of contact resistance on measured potential.

关 键 词：过套管电阻率测井 不稳定性 传输线方程 测井响应 漏电流 

分 类 号：P631.84[天文地球—地质矿产勘探]