过套管电阻率测井方法研究

The Research of Through-Casing Resistivity Logging Method

赵俊峰^{1 ,2} ,李俊舫²

Zhao Junfeng, Li Junfang

1. 石油大学,北京,2.中原石油勘探局钻井三公司

University of Petroleum, Beijing 102249 , P. R. China

过套管电阻率测井( TCRL) 是电法测井的一个新领域。根据Kaufman A 提出的传输线方程,导出了优化的地层视电导率公式;相对于地层,钢套管的电阻率很低,也就是说,钢套管相对于地层是短路的,由趋肤效应可以确定TCRL 的工作频率;在详细分析了水泥环、套管对测量结果的影响的基础上,提出了消除这些影响的一些方法,从而使过套管电阻率测井方法更趋完善。

Through-Casing Resistivity Logging ( TCRL ) is a new field in the electric logging. According to the transmission line equation which was put forward by Kaufman , we deduced the optimum formula of apparent conductivity of formation :σf = K SΔU/ U ; The resistivity of steel casing is much lower than that of formation ,that is to say ,the casing is a short circult to formation. We can decide the working frequency of TCRL according to the skin-depth phenomenon ; Having analysed the influence of casing and cement on measurement in detail , we put forward some methods to eliminate the influence. Our study made the TCRL method perfect .