The prediction of shale gas favorable area based on wide area electromagnetic method: A case study of Wushan area in northeast Chongqing
Fan-Yang MENG1(), Shu-Jing BAO1, Ke CHEN1, Peng WANG1, Liu-De LI2
1. Oil and Gas Survey, China Geological Survey, Beijing 100029, China 2. Institute of Zhuangsheng Mining, Central South University, Changsha 410083, China
Wushan area in northeastern Chongqing is an important prospective area for shale gas exploration; nevertheless, the exploration degree of this area is low. In this study, based on rock physics and well logging data, the authors used the wide area electromagnetic method to evaluate the favorable area of shale gas in this area. Through the analysis of the surface sample and borehole resistivity logging data, the authors detected that the resistivity of the target layer with rich organic shale in the study area exhibits obvious characteristics of low resistivity, and the features of overlying and underlying layers are significantly different, suggesting that the upper Ordovician Wufeng-Lower Silurian Longmaxi Formation with rich organic matter shale has the physical conditions for electrical prospecting. Based on processing and interpretation of electromagnetic data, the authors found out the structural pattern of "uplift and depression" in Wushan area of Chongqing. The main fault is reverse fault. Ordovician Wufeng-Lower Silurian Longmaxi organic rich shale exhibits characteristics of continuously stable distribution and low resistance, with the depth in the range of 800~4800 m. Considering the resistivity, polarizability and burial depth of the target layer, the authors predicted three favorable areas of shale gas. The organic shale is well developed in this area, and the prospect of shale gas exploration is good.
孟凡洋, 包书景, 陈科, 王鹏, 李柳德. 基于广域电磁法的页岩气有利区预测——以渝东北巫山地区为例[J]. 物探与化探, 2018, 42(1): 68-74.
Fan-Yang MENG, Shu-Jing BAO, Ke CHEN, Peng WANG, Liu-De LI. The prediction of shale gas favorable area based on wide area electromagnetic method: A case study of Wushan area in northeast Chongqing. Geophysical and Geochemical Exploration, 2018, 42(1): 68-74.