Numerical simulation analysis of E-Ex mode of the wide-field electromagnetic method for identifying deep, low-resistance thin layers
Liu Guang-Di, Tian Hong-Jun*
1. School of Biological and Environmental Engineering, Jingdezhen University, Jingdezhen 333400, Jiangxi Province, China.
2. School of Geosciences and Info-physics, Central South University, Changsha 410083, China.
Abstract Shale gas reservoirs have large burial depths, thin thickness, and low resistance, which lead to problems with weak surface observation, abnormal information, and multiple inversion solutions. The traditional electromagnetic method cannot effectively identify information from deep, low-resistance thin layers in terms of detection depth and accuracy. Wide fi eld electromagnetic method (WFEM) with large depth and high precision has become the main method for deep earth exploration. This method has been widely used in the exploration of deep oil and gas energy, as well as mineral resources. However, an in-depth analysis of the various factors that affect the deep detection ability of WFEM is lacking. Therefore, the analysis of system parameters has significant theoretical importance and practical value for studying the effectiveness of WFEM in deep-layer identification. In this study, a multilayer geoelectric model is established in this study using the measured well data. The influence characteristics of different observation system parameters on the resolution of specific deep-seated targets under the WFEM_E-Ex mode are analyzed in detail through forward modeling and inversion. Results show that the resolution ability of WFEM for deep, low-resistance thin layers is affected by factors such as transceiver distance, target layer thickness, and resistivity difference between the target body and the surrounding rock, but the influence range differs. This study analyzes the influence characteristics of various system parameters. It provides targeted work scheme design and feasibility analysis for deep shale gas exploration. It also off ers an important theoretical basis for optimizing construction schemes and improving the recognition ability of WFEM for deep, low-resistance targets.
Fund: This work was supported by the Jingdezhen Science and Technology Plan Project (No. 20234SF005) and the Jingdezhen University Science and Technology Project (No. 2023xjkt-02).
About author: Guangdi Liu, Ph.D., a lecturer and engineer, obtained his Bachelor's degree in Exploration Technology and Engineering and Master' sdegree in Geologica l Engineering from China University of Geosciences (Beijing) in June 2009 and June 2012, respectively; He obtained his doctor's degree in Geological Resources and Geological Engineering from Central South University in December 2022. He is mainly engaged in research on the theoretical methods and technological applications of geophysical exploration in the fi elds of resources and environment. E-mail: liugd@jdzu.edu.cn
Cite this article:
. Numerical simulation analysis of E-Ex mode of the wide-field electromagnetic method for identifying deep, low-resistance thin layers[J]. APPLIED GEOPHYSICS, 2025, 22(4): 1125-1140.
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2025, Vol. 22 
