电阻率和极化率测深法的正演修正法反演  

The forward modified inversion of resistivity and induced-polarization sounding

作　　者：苏朱刘[1] 胡文宝[1] 严良俊[1] 

机构地区：[1]中国石油天然气集团公司物探重点实验室江汉石油学院重点研究室,湖北荆州434023

出　　处：《石油物探》2005年第2期194-198,共5页Geophysical Prospecting For Petroleum

基　　金：科学技术部国际科技合作重点项目(2002DF000022)资助。

摘　　要：提出了电阻率和极化率测深法。该方法采用同一野外装置(直流电测深)同时进行直流效应和激发极化效 应观测,测深点沿一条测线呈密集分布。对单一测深点的观测结果进行一维层状介质反演,得到地下电性介质 层界面的深度、每层的电阻率和极化率参数。一维反演采用正演修正法,即通过比较电阻率转换函数的实测值 和一维正演计算的理论(拟合)值,依次修正每一个电性层的电阻率、极化率和厚度。该方法将地下介质划分成 与积分变量点数一样多的介质层,在纵向上能最大限度地反映观测资料分辨介质层的能力。在电法固有的等值 性范围内,正演修正法能恢复各电性层的电阻率、极化率和厚度。模型试验表明,正演修正方法是一种稳定收敛 和实用的方法。For resistivity and induced-polarization sounding method, DC sounding response would observe simultaneous with induced-polarization response use of the same field layout. Stations distribute along surveying line with dense array format. The resistivity, polarizability and thickness for each conducting layer of underground 1-D layered medium can be calculated by using forward modified method. Through comparison of real resistivity transfer function with theoretic resistivity transfer function by 1-D forward computation, the method modified in turn the resistivity, polarizability and the thickness for each conducting layer. Because the method can divide underground medium into as many conducting layer as points of integral variable, it can vertically reflect the resolution of conducting layer in maximum which can reflect in surveying data. In a range of intrinsic e quivalence of Resistivity and Induced-Polarization Sounding Method,forward modified method can correctly restore resistivity, polarizability and thickness of each conducting layer. The model test showed that forward modified method is more accurate, stably convergent and practical method.

关 键 词：电阻率 极化率 测深法 正法反演 直流电测深 介质层 极化效应 介质反演 观测结果 一维反演 正演计算 转换函数 积分变量 地下介质 观测资料 模型试验 修正方法 修正法 电性 实测值 等值性 厚度 电法 

分 类 号：P631.322[天文地球—地质矿产勘探] O437[天文地球—地质学]