Abstract:Using the magnetotelluric sounding method, we explore the 3D seismic deep structural characteristics in Shanxi reservoir area for the first time and obtain the 3D electrical structure of 70 km2. Then we establish the 3D geological structure model in this area and discuss the deep structural environment of reservoir-induced earthquakes. The results show: 1) In Shanxi reservoir area, there is a triangular fault block trending to south-west which is mainly composed of three faults, the Shuangxi-Jiaoxiyang faults is the principal of the three faults, and almost all earthquakes with magnitude greater than 2.5 basically occurred in this special structure area. 2) There are three main low-resistance channels in the deep part. Seismic activity is concentrated along the middle f11-3 low-resistance channel. With groundwater permeating from southeast to northwest along the f11-3 fluid channel, seismic activity also migrates periodically along this direction. 3) Wenzhou-Taishun fault and granite in the east block the eastward development of Shuangxi-Jiaoxiyang fault, resulting in the inability of in-situ stress to propagate eastward, which may be the main reason for the absence of earthquakes to the east of the fault.
YANG Fuping,ZHAO Lifang,YU Gangqun et al. Research on the Three-Dimensional Structural Characteristics and Deep Reservoir-Induced Seismic Environment in Shanxi Reservoir Area[J]. jgg, 2021, 41(12): 1264-1270.