废弃矿井遗留煤层气资源次生富集成藏研究现状及展望  

Research status and prospects of secondary enrichment and accumulation of residual coalbed methane resources in abandoned mines

作　　者：王家琛[1] 杨兆彪[1] 秦勇[1] 杨彦群[2] 董志勇 孟祥昊 WANG Jiachen;YANG Zhaobiao;QIN Yong;YANG Yanqun;DONG Zhiyong;MENG Xianghao(Key Laboratory of Coalbed Methane Resources&Reservoir Formation Process,Ministry of Education,China University of Mining and Technology,Xuzhou 221008,China;Technical Center,Shanxi Coking Coal Group Co.,Ltd.,Taiyuan 030024,China)

机构地区：[1]中国矿业大学煤层气资源与成藏过程教育部重点实验室,江苏徐州221008 [2]山西焦煤集团公司技术中心,山西太原030024

出　　处：《煤田地质与勘探》2022年第4期35-44,共10页Coal Geology & Exploration

基　　金：国家自然科学基金项目(42130802);山西省科技重大专项揭榜项目(20191101016);山西省科技重大专项项目(20201102001)。

摘　　要：在当前国家大力推进“双碳目标”落实阶段,废弃矿井遗留煤层气资源开发具有重要的现实意义。然而,废弃矿井遗留煤层气资源开发具有其独特性,源于其在原始地质条件下扰动后的二次动态成藏。通过综述近些年国内外研究成果得出:(1)煤层开采覆岩及底板扰动区可以依次分为导气裂隙带、卸压带及不易解吸带,长臂法开采煤层覆岩采动影响范围可达到100 m左右,底板采动影响范围可达到50 m左右。(2)遗留煤层气资源主要以游离态、吸附态及溶解态赋存于开采扰动区内,与原位储层相比游离气占比增大。依据开采扰动应力场–裂隙场–渗流场分布规律,可将遗留煤层气赋存空间分为:三维卸压带、一维卸压带、原始位区,覆岩三维卸压带顶部为潜在煤层气富集区。(3)废弃矿井煤层气资源量评估方法主要有月下降曲线法、分源叠加法及间接扣减法,后2种方法在国内有较高的适用性。最后指出准确圈定遗留煤层气富集空间及其采动裂隙场,揭示遗留煤层气的赋存特征及其动态运聚过程,建立遗留煤层气资源量的动态评价模型是废弃矿井遗留煤层气资源成功开发的地质理论基础,也是今后的重点研究方向。In promoting the achievement of the carbon peak and carbon neutrality goals in China,the development of residual coalbed methane resources in abandoned mines is of important practical significance.However,the development of the residual coalbed methane is characterized by its secondary dynamic reservoir formation after disturbed under original geological conditions.Therefore,the related literature at home and abroad in recent years is summarized as follows.(1)The disturbed area of the overburden and floor in coal seam mining can be divided into the gas conduction fracture zone,pressure relief zone and non-desorption zone.The influence range of coal seam overburden mining by the long arm method can reach about 100 m,and the influence range of floor mining can reach about 50 m.(2)The residual coalbed methane resources in the mining disturbed area are mainly in the free state,adsorbed state and dissolved state,and the proportion of free gas increases compared with the in-situ reservoir.According to the distribution law of the mining disturbed stress field,fracture field,seepage field,the storage space of residual coalbed methane can be divided into the three-dimensional pressure relief zone,one-dimensional pressure relief zone and original location area.The top of the three-dimensional pressure relief zone of the overburden is the potential coalbed methane enrichment area.(3)The evaluation methods of residual coalbed methane resources in abandoned mines mainly include the monthly decline curve method,source superposition method and indirect deduction method.The latter two methods have high applicability in China.Finally,it is pointed out that accurately delineating the enrichment space and mining fracture field of residual coalbed methane,revealing its occurrence characteristics and dynamic migration and accumulation process,and establishing its dynamic evaluation model are the geological theoretical basis for the successful development of residual coalbed methane resources in abandoned mines.

关 键 词：遗留煤层气 废弃矿井 扰动区 运移富集 资源量评价 

分 类 号：TD984[矿业工程—选矿]