黔西煤储层孔隙结构特征与储气性研究:以戴家田煤矿D1井为例  

Research on the Pore Structure Characteristics and Gas Storage Properties of Coal Reservoirs in Western Guizhou:A Case Study of Well D1 in Daijiatian Coal Mine

作　　者：包庆林 邓恩德 马子杰 姜秉仁 BAO Qinglin;DENG Ende;MA Zijie;JIANG Bingren(Guizhou Panjiang Coal Power Group Technology Research Institute Co.,Ltd.,Guiyang,Guizhou 550081,China;Guizhou Energy Group Corporation Limited,Guiyang,Guizhou 550081,China;Guizhou Energy Industry Research Institute Co.,Ltd.,Guiyang,Guizhou 550025,China;Guizhou Provincial CBM and Shale Gas Engineering Research Center,Guiyang,Guizhou 550016,China)

机构地区：[1]贵州盘江煤电集团技术研究院有限公司,贵州贵阳550081 [2]贵州能源集团有限公司,贵州贵阳550081 [3]贵州能源产业研究院有限公司,贵州贵阳550025 [4]贵州省煤层气页岩气工程技术研究中心,贵州贵阳550016

出　　处：《现代地质》2024年第6期1532-1544,共13页Geoscience

基　　金：贵州省科技计划项目(黔科合战略找矿[2022]ZD001);贵州省中央引导地方科技发展资金项目(黔科中引地[2021]4005);贵州省科技重大专项(黔科合重大专项字[2021]3001)。

摘　　要：煤储层的微观孔隙是烃类气体赋存的主要位置,其微观孔隙结构特征对储气能力具有重要影响。研究煤储层孔隙及储气性对煤层气开采层段选取和瓦斯治理保护层选择具有基础性意义。黔西地区煤炭及煤层气资源丰富,但尚未见对煤储层孔隙结构特征及储气性研究。基于此,本文选取黔西织纳煤田戴家田矿D1井的二叠系龙潭组煤岩样品为研究对象,综合运用场发射扫描电镜、高压压汞、低温N_(2)吸附及高温等温吸附等实验手段,对各煤层孔隙结构特征进行分析,并探讨煤储层孔隙结构特征对储气性的影响。结果表明研究区龙潭组煤储层微观孔隙类型多样,微孔、小孔、中孔和大孔均有发育,且不同煤样孔隙的种类、形态和成因类型存在差异,微孔的比表面积与CH_(4)最大吸附气量和现场解吸气量均呈现一定的正相关性,对CH_(4)吸附能力起到决定性作用。此次研究发现研究区14煤和27煤储气性较好,资源潜力较大,可考虑作为煤层气地面开采优质层段。Microscopic pores in coal reservoirs are the primary space for hydrocarbon gas occurrence,thus the structural characteristics of these pores significantly influence gas storage capacity.Understanding these pores and the gas storage properties of coal reservoirs is of great crucial for determining coalbed methane extraction intervals and gas control protection layers.The Western Guizhou region is rich in coal and coalbed methane resources,however,there is limited research on the pore structure characteristics and gas storage properties of its coal reservoirs.This paper uses coal samples from the Permian Longtan Formation,located in Well D1 of the Daijiatian Mine in the Zhina Coalfield,as a case study.The pore structure characteristics of coal reservoirs in the research area were analyzed using field emission scanning electron microscopy,high-pressure mercury method,low temperature N_(2)adsorption,and high-temperature isothermal adsorption methods.Moreover,the influence of pore structure characteristics on gas storage was discussed.The results indicate that the Longtan Formation coal reservoirs contain a diverse range of micropores,including well-developed micropores,small pores,medium pores,and large pores.The types,forms,and origins of these pores vary among different coals.The specific surface area of micropores is positively correlated with the maximum adsorption volume and on-site desorption volume of CH_(4),which plays a key role in the adsorption capacity of CH_(4).This study identified that 14 coal and 27 coal areas have strong gas storage potential and large resource potential,making them suitable as high-quality layers for surface mining of coalbed methane.

关 键 词：黔西地区 龙潭组 煤层气 孔隙结构 储气性 

分 类 号：P618.13[天文地球—矿床学] TE13[天文地球—地质学]