地质科学2024，Vol.59Issue(6)：1662-1674,13.DOI:10.12017/dzkx.2024.114
深层煤层气储层现今地应力测井计算方法:以大宁—吉县地区本溪组煤层为例
Present‑day in‑situ stress calculation by conventional logs of deep coalbed methane reservoirs:A case study in the deep coal reservoir of the Benxi Formation in Daning‑Jixian area,Ordos Basin
摘要
Abstract
The Daning⁃Jixian(Daji)area is one of the hot areas of coalbed methane exploration and development in China.The distribution of the present⁃day in⁃situ stress affects the permeability and fracturing of coal seams,thus affecting the production effect of coalbed methane.This work takes the No.8 coal seam of the Benxi Formation in the proven area of Daji coalbed methane field as the research object.Based on the analysis and test data of dipole acoustic logs,hydraulic fracturing,conventional logs,high temperature and high pressure triaxial rock mechanics experiment,combined with the modified Newberry model,the direction and magnitude of the present⁃day in⁃situ stress of single wells are studied.The results show that the maximum horizontal principal stress direction of the Benxi Formation No.8 coal seam in Daning⁃Jixian area is from NE⁃SWW to nearly EW.The maximum and minimum horizontal principal stresses of the No.8 coal seam calculated by conventional logs vary from 41.2 MPa to 55.8 MPa,with an average of 51.2 MPa,and 32.0 MPa to 42.6 MPa,with an average of 38.3 MPa,respectively.Compare to the maximum and minimum horizontal principal stresses of the No.8 coal seam measured by hydraulic fracturing data,the relative errors of those calculated by conventional logs are within 10％,which shows that the calculated results by conventional logs are reliable.The factors,affecting the calculation accuracy of the present⁃day in⁃situ stress obtained by conventional logs,mainly include the selection of appropriate formation model,the accuracy of P⁃wave and S⁃wave time difference acquisition,the determination of rock mechanics parameters,the calculation of pore pressure,and the determination of effective stress coefficient.This paper explores a suitable method for the present⁃day in⁃situ stress evaluation by conventional logs for the deep coal reservoirs in relatively flat areas,thus providing a reference for the study of present⁃day in⁃situ stress in deep coal reservoirs.关键词
常规测井/现今地应力/煤储层/深部/大宁—吉县地区Key words
Conventional logs/Present⁃day in⁃situ stress/Coal reservoir/Deep/Daning⁃Jixian area分类
天文与地球科学引用本文复制引用
皇甫展鸿,吕文雅,唐英航,曾联波,邓泽,吴雨蕙..深层煤层气储层现今地应力测井计算方法:以大宁—吉县地区本溪组煤层为例[J].地质科学,2024,59(6):1662-1674,13.基金项目
中石油战略合作科技专项(编号:ZLZX2020⁃02)和辽宁省矿产资源绿色开发重点实验室开放重点基金项目(编号:LNTU/GDMR⁃2303)资助 （编号:ZLZX2020⁃02）
