Stress sensitivity of coal reservoir and its impact on coalbed methane production in the southern Qinshui Basin, north China

作     者：Huimin JIA Yidong CAI Qiujia HU Cong ZHANG Feng QIU Bin FAN Chonghao MAO Huimin JIA;Yidong CAI;Qiujia HU;Cong ZHANG;Feng QIU;Bin FAN;Chonghao MAO

作者机构：CBM Exploration and Development BranchPetroChina Huabei Oilfeld CompanyChangzhi 046000China School of Energy ResourcesChina University of GeosciencesBeijing 100083China 

出 版 物：《Frontiers of Earth Science》 (地球科学前沿（英文版）)

年 卷 期：2023年第17卷第1期

页      面：4-17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：This research was supported by National Science and Technology Major Project(No.2017ZX05064) the National Natural Science Foundation of China(Grant Nos.42130806,41830427,and 41922016) 

主　　题：coalbed methane stress sensitivity curvature stages division drainage 

摘      要：Stress sensitivity has significant negative effects on the permeability and production of coalbed methane(CBM)*** effectively minimize these negative effects,the degree of stress sensitivity during the CBM production process should be carefully *** this work,the curvature of the stress-sensitivity curve was adopted to explore the degree of stress sensitivity,dividing the stress-sensitivity curve and the drainage process into five stress stages:sharp decrease,rapid decrease,low-speed decrease,slower decrease and harmless with four critical stress points—transition,sensitivity,relief and *** actual stages were determined by the initial permeability,stress-sensitivity coefficient and difference between the reservoir pressure and desorption *** four critical stress points did not completely exist in the stress-sensitivity *** an increase in the initial permeability of coal,the number of existing critical stresses increases,leading to different gas-water drainage strategies for CBM *** reservoirs with a certain stress-sensitivity coefficient,the permeability at the sensitive stress point was successively greater than that at the transition,relief and the harmless *** the stress-sensitivity coefficient is different,the stage is different at the beginning of drainage,and with an increase in the stress-sensitivity coefficient,the decrease rate of the permeability ***,the stress-sensitivity coefficient determines the ability to maintain stable CBM *** well-fractured CBM reservoirs,with a high stress-sensitivity coefficient,permeability damage mainly occurs when the reservoir pressure is less than the relief stress;therefore,the depressurization rate should be *** CBM reservoirs with fewer natural fractures,the reverse applies,and the depressurization rate can be much *** higher the difference between the reservoir and desorption pressures,the higher the effective stress and perme