沁水盆地南部煤储层显微裂隙发育的影响因素  

Study on the influencing factors of the microfracture development in coal reservoir in southern Qinshui basin

作　　者：胡咤咤 黄文辉[1] 刘素平 张谦[1] 许启鲁 冯小龙[1] HU Zhazha HUANG Wenhui LIU Suping ZHANG Qian XU Qilu FENG Xiaolong(School of Energy Resources, China University of Geosciences （Beijing）, Key Laboratory of Marine ReservoirEvolution and Hydrocarbon Enrichment Mechanism of Ministry of Education, Key Laboratory of UnconventionalNatural Gas Geology Evaluation and Development Engineering, Beijing 100083, China Oil and gas resourcesexploration team, Bureau of Coal Geology of Hunan Province, Changsha 410014, China)

机构地区：[1]中国地质大学(北京)能源学院海相储层演化与油气富集机理教育部重点实验室非常规天然气地质评价及开发工程北京市重点实验室,北京100083 [2]湖南省煤田地质局油气资源勘探队,湖南长沙410014

出　　处：《煤田地质与勘探》2016年第5期63-70,共8页Coal Geology & Exploration

基　　金：国家重点基础研究发展计划(973计划)课题(2014CB238901);国家科技重大专项课题(2011ZX05042-001);中央高校基本科研业务费专项资金(2652011266)~~

摘　　要：为研究沁水盆地南部3号和15号煤储层显微裂隙的发育情况,借助扫描电镜显微裂隙分析、荧光显微镜显微裂隙统计、X射线衍射分析等手段,总结了地应力、煤岩显微组分、煤变质程度、煤中矿物质与显微裂隙发育的关系,探讨了影响煤储层显微裂隙发育主要因素。结果表明,该区煤储层显微裂隙较为发育,显微裂隙密度一般为7~59条/9 cm^2,以C型和D型裂隙为主,扫描电镜下常见张性裂隙、剪性裂隙,对煤储层渗透性贡献较大,内生裂隙较少见。显微裂隙通常发育于镜质组中,裂隙密度随变质程度的升高表现出降低的趋势,煤中矿物的充填作用对于显微裂隙的发育影响较大,对煤样渗透性造成了直接破坏作用,地应力场的方向和大小控制着外生显微裂隙的开合程度,进而对煤储层的渗透性产生影响。因此认为,地应力和煤中矿物是影响该区煤储层显微裂隙发育的主要因素。The developmental characteristics of microfractures in No.3 and No.15 coal seams in southern Qinshuibasin were studied by means of scanning electron microscope, fluorescence microscope, X ray diffraction and so on.The relationship between microfracture and influencing factors including crustal stress, micropetrological unit,metamorphic grade and mineral were summarized. The main factors affecting the development of microfractures incoal reservoir were discussed. The results show that the microfractures in coal reservoir of this area are relativelydeveloped and the density is generally 7~59 strips per 9 cm2. Microfractures of type D and type C dominate. Tensilefractures and shear fractures that make relatively larger contribution to the permeability are common in scanningelectron microscope, whereas endogenetic fractures are rare. Microfractures are generally developed invitrinite component. Microfracture density decreases with the increase of metamorphic grade. The mineral fillingeffect in coal has great influence on the development of microfracture and destroys the permeability of coal directly.The magnitude and direction of crustal stress field control the opening degree of exogenous microfracture and thenaffect coal permeability. Therefore, crustal stress and mineral in coal are the main factors that influence the developmentof microfractures in coal reservoir of this area.

关 键 词：沁水盆地南部 煤储层 显微裂隙 影响因素 

分 类 号：P618.11[天文地球—矿床学]