Three-dimensional forward modeling and inversion of borehole-to-surface electrical imaging with different power sources  

不同激励源井地电位成像技术三维正反演方法研究（英文）

作　　者：Bai Ze Tan Mao-Jin Zhang Fu-Lai 白泽;谭茂金;张福莱(中国地质大学地球物理与信息技术学院,北京100083;地下信息探测技术与仪器教育部重点试验室(中国地质大学(北京)),北京100083;东方华隆(北京)石油技术有限公司,北京100049)

机构地区：[1]School of Geophysics and Information Technology of China University of Geosciences, Beijing 100083, China [2]Key laboratory of Geo-detection （China University of Geosciences）, Ministry of Education, Beijing 100083, China [3]Beijing Horizontal Hualong Technology Ltd., Beijing 100049, China.

出　　处：《Applied Geophysics》2016年第3期437-448,578,共13页应用地球物理（英文版）

基　　金：sponsored by the National Major Project(No.2016ZX05014-001);the National Natural Science Foundation of China(No.41172130 and U1403191);the Fundamental Research Funds for the Central Universities(No.2-9-2015-209)

摘　　要：Borehole-to-surface electrical imaging （BSEI） uses a line source and a point source to generate a stable electric field in the ground. In order to study the surface potential of anomalies, three-dimensional forward modeling of point and line sources was conducted by using the finite-difference method and the incomplete Cholesky conjugate gradient （ICCG） method. Then, the damping least square method was used in the 3D inversion of the formation resistivity data. Several geological models were considered in the forward modeling and inversion. The forward modeling results suggest that the potentials generated by the two sources have different surface signatures. The inversion data suggest that the low- resistivity anomaly is outlined better than the high-resistivity anomaly. Moreover, when the point source is under the anomaly, the resistivity anomaly boundaries are better outlined than when using a line source.井地电位成像是通过套管向井中供电或将电源放在井中,在地表观测电位异常的一项技术,其供电源有线源和点源两种类型。为了研究这两种电源对地下异常体产生的电位异常特征,本文针对不同激励源,采用有限差分方法进行数值模拟研究,在线性方程组求解电位时引入不完全Cholesky共轭梯度(ICCG)迭代方法,分别实现了点源和线源井地电位成像技术的三维正演。最后,基于阻尼最小二乘法实现了井地电位成像技术的电阻率三维反演。设计不同地电模型分别进行正演和反演试算,正演结果表明,供电电源的类型不同,异常体在地表的电位异常特征也不同;反演结果表明,低阻体的反演结果要好于高阻体,点源置于异常体下方时反演的电阻率对异常体边界的识别比线源更加准确。

关 键 词：Borehole-to-surface electrical imaging different types of exciting sources potential characteristic forward modeling resistivity inversion 

分 类 号：P631.811[天文地球—地质矿产勘探]