沁水盆地阳泉区块上古生界煤系页岩气储层特征  

Characteristics of shale gas reservoir in Upper Paleozoic coal measures in Yangquan Block,Qinshui Basin

作　　者：李阳阳 李贤庆[1,2] 张学庆 肖贤明[3] 于振锋 王保玉 LI Yangyang;LI Xianqing;ZHANG Xueqing;XIAO Xianming;YU Zhenfeng;WANG Baoyu(State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology(Beijing),Beijing 100083,China;College of Geoscience and Surveying Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Energy,China University of Geosciences(Beijing),Beijing 100083,China;Shanxi Lanyan Coalbed Methane Group Co.Ltd.,Jincheng 048006,China;Shanxi Jincheng Anthracite Coal Industry Group Co.Ltd.,Jincheng 048000,China)

机构地区：[1]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083 [2]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [3]中国地质大学(北京)能源学院,北京100083 [4]山西蓝焰煤层气集团有限责任公司,山西晋城048006 [5]山西晋城无烟煤矿业集团有限责任公司,山西晋城048000

出　　处：《煤田地质与勘探》2021年第2期142-151,共10页Coal Geology & Exploration

基　　金：国家自然科学基金项目(U1810201);国家科技重大专项课题(2016ZX05007-003);中央高校基本科研业务费专项资金项目(2020YJSMT02)。

摘　　要：页岩储层特征是进行页岩气储集能力评价的基础内容。为探究高演化阶段煤系页岩气储层性质和优选有利储层,运用岩石热解、X射线衍射、扫描电子显微镜、高压压汞、低温N_(2)和CO_(2)气体吸附多种实验方法,对沁水盆地阳泉区块上古生界煤系页岩岩心样品进行储层特征研究。结果表明:沁水盆地阳泉区块上古生界煤系页岩,有机碳含量较高(TOC平均为4.9%),处于过成熟阶段(Rran平均为2.32%),黏土矿物质量分数较高(平均为50.0%),具有低孔低渗的特征(孔隙率平均为6.61%,渗透率平均为0.0063×10^(–3)μm^(2)),孔隙类型以粒间孔、粒内孔和微裂缝为主,微米–纳米级孔隙为页岩气的赋存提供了储集空间;孔隙总孔容为0.0255~0.0517 mL/g,平均0.0389 mL/g,总比表面积为12.64~40.98 m^(2)/g,平均28.43 m^(2)/g,微孔(<2 nm)、介孔(2~50 nm)的孔容与比表面积呈良好的正相关性,宏孔(>50 nm)孔容与比表面积则相关性不明显,表明微孔和介孔是阳泉区块煤系页岩气储集的主要载体。总体来说,阳泉区块上古生界煤系页岩具有较好的页岩气储集性能,但页岩储层可压裂性较差,影响页岩气的开发。Shale reservoir characteristics are the basic content of shale gas storage capacity evaluation.In order to explore the properties of high-evolved coal-measures shale gas reservoirs and optimize favorable reservoirs,various experimental methods of rock pyrolysis,X-ray diffraction,scanning electron microscopy,high-pressure mercury intrusion,low-temperature N_(2)and CO_(2)gas adsorption were applied to the Qinshui Basin.Reservoir characteristics were studied with core samples of coal-measure shale core from the Upper Paleozoic in Yangquan Block.The results show that the Upper Paleozoic coal-measures shale in Yangquan Block of the Qinshui Basin has a high content of organic carbon(average TOC is 4.9%),is in an over-mature stage(average Rran is 2.32%),and has a high content of clay minerals(average is 50.0%),with the characteristics of low porosity and low permeability(average porosity of 6.61%,average permeability of 0.0063×10^(–3)μm^(2)).The pore types are mainly intergranular pores,intragranular pores and microcracks,and micro-nano-scale pores provide the storage space for the occurrence of shale gas;the total pore volume of pores is 0.0255-0.0517 mL/g,the average is 0.0389 mL/g,the total specific surface area is 12.64-40.98 m^(2)/g,the average is 28.43 m^(2)/g,the pore volume of the micropores(<2 nm),and the mesopores(2-50 nm)has a good positive correlation with the specific surface area,while the pore volume of macropores(>50 nm)has no obvious correlation with the specific surface area,indicating that the micropores and the mesopores are Yangquan blocks.The main carrier of coal-measure shale gas accumulation.In general,the Upper Paleozoic coal-measure shale in the Yangquan Block has good shale gas storage performance,but the shale reservoir has poor fracturing properties,which will affect the development of shale gas.

关 键 词：页岩气储层 煤系页岩 储集物性 孔隙结构 阳泉区块 沁水盆地 

分 类 号：P618.13[天文地球—矿床学] TD712[天文地球—地质学]