四川盆地煤层气勘探开发现状与前景  

Current situation and prospects of coalbed methane exploration and development in Sichuan Basin

作　　者：朱苏阳[1,2] 刘伟 王运峰[3] 贾春生 陈朝刚 彭小龙 ZHU Suyang;LIU Wei;WANG Yunfeng;JIA Chunsheng;CHEN Chaogang;PENG Xiaolong(State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China;Tianfu New Energy Institute,Chengdu,Sichuan 610041,China;Sichuan Energy Investment Group Co.,LTD.,Chengdu,Sichuan 610041,China;Sichuan Energy Investment Oil and Gas Exploration and Development Co.,LTD.,Chengdu,Sichuan 610000,China)

机构地区：[1]西南石油大学油气藏地质及开发工程全国重点实验室,四川成都610500 [2]天府新能源研究院,四川成都610041 [3]四川省能源投资集团有限责任公司,四川成都610041 [4]四川省能投油气勘探开发有限公司,四川成都610000

出　　处：《油气藏评价与开发》2025年第2期185-193,204,共10页Petroleum Reservoir Evaluation and Development

基　　金：国家自然科学基金青年基金项目“基于煤粉群运移动力学特征的煤层气-水-固耦合传质机理研究”(52104036);四川省自然科学基金青年基金项目“考虑纳米尺度效应与微纳跨尺度流动的煤层气临界解吸机制研究”(2023NSFSC0932)。

摘　　要：四川盆地煤炭资源丰富,近年来也取得了部分煤层气探井的突破。为了探讨四川盆地建成煤层气生产基地的可行性,研究综述了四川盆地内煤层气藏的层位发育情况,以及川东南和川南地区煤层气开发区块的地质和动态特征。四川盆地内第一个煤层气生产基地筠连沐爱矿区地面抽排井已达450余口,连续5 a年产气量超过1.00×10^(8)m^(3);蜀南矿区内生产井数328口,年产气量达0.79×10^(8)m^(3)。然而,盆地内以煤层作为目标层位的煤层气井日均产量不到700 m^(3),但对煤层及附近砂岩层段进行笼统压裂改造的先导探产井却能达到5000~8000 m^(3)/d的规模,这说明四川盆地煤层气生产动态与国内其他煤层气生产基地差异较大,这是源于盆地内多发育薄层以及与致密砂岩互层的构造煤,因此,不能沿用沁水、鄂尔多斯等典型厚煤层的“甜点”评价和开发方式,亟须改变以“煤层”作为煤层气井唯一目标层位的开发思路。实践表明:四川盆地煤层多发育于海陆过渡相地层,虽然煤层自身横向发育并不稳定,但是稳定发育了“煤层+砂岩+泥岩”3种岩性的组合,特殊的岩性组合可以形成“煤—砂—煤”烃源封存箱体,对四川盆地薄互层煤层气的开发和产能建设具有重要意义。另外,四川盆地近年来关停大量煤矿,废弃煤矿中富集的煤层气亟须结合地面钻井开发手段进行二次开发。综上所述,根据四川盆地的地质资源量和现有开采技术,为建设继沁水盆地和鄂尔多斯盆地东缘之后的第三个煤层气产业基地提供了可能。The Sichuan Basin is abundant in coal resources and has achieved breakthroughs in coalbed methane exploration wells in recent years.To explore the feasibility of establishing a coalbed methane production base in the Sichuan Basin,this study reviews the stratigraphic development of coalbed methane reservoirs in the Sichuan Basin,as well as the geological and dynamic characteristics of coalbed methane development blocks in the southeastern and southern regions of Sichuan.The first coalbed methane production base in the Sichuan Basin,the Junlian-Mu’ai mining area,has more than 450 surface extraction wells,with an annual gas production of over 1.00×10^(8)m^(3)for five consecutive years.In the Shunan mining area,there are 328 production wells,with an annual gas production of 0.79×10^(8)m^(3).However,in the basin,the average daily production of coalbed methane wells targeting coal seams is less than 700 m^(3),while pilot exploration wells that apply general fracturing to coal seams and adjacent sandstone layers can achieve production rates of 5000 to 8000 m^(3)/day.This indicates that the production dynamics of coalbed methane in the Sichuan Basin differ significantly from those in other domestic coalbed methane production bases.This difference is attributed to the widespread development of thin coal seams and the structural coal layers interbedded with tight sandstone.Consequently,it is not appropriate to apply the“sweet spot”evaluation and development methods used for typical thick coal seams in basins such as the Qinshui Basin and Ordos Basin.There is an urgent need to shift away from the approach of considering only coal seams as the sole target layer for coalbed methane wells.Practice shows that coal seams in the Sichuan Basin are primarily developed in transitional marine-continental strata.Although the lateral development of coal seams is not stable,a stable combination of“coal,sandstone,and mudstone”has formed.This special lithologic combination can create“coal-sand-coal”hydrocarbon source stora

关 键 词：四川盆地 煤层气 煤系气 薄互层 烃源封存箱体 

分 类 号：TE37[石油与天然气工程—油气田开发工程]