Quantitative Estimation on Methane Storage Capacity of Organic-Rich Shales from the Lower Silurian Longmaxi Formation in the Eastern Sichuan Basin, China

作     者：Xiaowen Guo Tao Luo Tian Dong Rui Yang Yuanjia Han Jizheng Yi Sheng He Zhiguo Shu Hanyong Bao Xiaowen Guo;Tao Luo;Tian Dong;Rui Yang;Yuanjia Han;Jizheng Yi;Sheng He;Zhiguo Shu;Hanyong Bao

作者机构：Key Laboratory of Tectonics and Petroleum ResourcesMinistry of EducationChina University of GeosciencesWuhan 430074China Jianghan Oilfield Branch CompanySINOPECWuhan 430223China 

出 版 物：《Journal of Earth Science》 (地球科学学刊（英文版）)

年 卷 期：2023年第34卷第6期

页      面：1851-1860页

核心收录：

学科分类：081803[工学-地质工程] 08[工学] 0818[工学-地质资源与地质工程] 

基　　金：funding supports from the Major Programs of National Natural Science Foundation of China(Nos.41690134 and 41690131) the National Natural Science Foundation of China(No.41872139) 

主　　题：methane shale gas Longmaxi Formation Sichuan Basin 

摘      要：The assessment of gas storage capacity is crucial to furthering shale gas exploration and development in the eastern Sichuan Basin,*** organic-rich shale samples were selected to carry out the high pressure methane sorption,low-pressure N_(2)/CO_(2) gas adsorption,and bulk and skeletal density measurements to investigate the methane storage capacity(MSC).Based on the relative content of clay,carbonates,quartz+feldspar,we grouped the 11 samples into three lithofacies:silica-rich argillaceous shale(CM-1),argillaceous/siliceous mixed shale(M-2),and clay-rich siliceous shale(S-3).The total porosity of the shale samples varies from 3.4% to 5.6%,and gas saturation ranges from 47% to 89%.The measured total gas amount ranges from 1.84 mg/g to 4.22 mg/g with the ratio of free gas to total gas amount ranging from 52.7% to 70.8%.Free gas with high content in the eastern Sichuan Basin may be the key factor controlling amount of shale gas *** TOC content critically controls the MSC of shales,because micropore,mesopore volumes and the specific surface areas associated with organic matter provide the storage sites for the free and adsorbed *** methane sorption capacities of samples from different lithofacies are also affected by clay minerals and moisture *** minerals can provide additional surface areas for methane sorption,and water can cause a 7.1%-42.8% loss of methane sorption *** total porosity,gas-bearing porosity,water saturation,free gas and adsorbed gas number of samples from different lithofacies show subtle differences if the shale samples had similar TOC *** results suggest that,in the eastern Sichuan Basin,clay-rich shale lithofacies is also prospecting targets for shale gas production.