致密砂岩气储层孔隙结构特征及其成因机理分析  

Pore structure characteristics and formation mechanisms analysis of tight gas sandstones

作　　者：赖锦[1] 王贵文[1,2] 孟辰卿 官斌 郑新华[5] 周磊[5] 信毅[5] 韩闯[5] 

机构地区：[1]中国石油大学(北京)地球科学学院,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]北京石油管理干部学院,北京100096 [4]陕西延长石油(集团)有限责任公司油气勘探公司,延安716000 [5]中国石油塔里木油田公司勘探开发研究院,新疆库尔勒841000

出　　处：《地球物理学进展》2015年第1期217-227,共11页Progress in Geophysics

基　　金：国家科技重大专项(2011ZX05020-008);中石油创新基金(2013D-5006-030);自然科学基金"致密砂岩储层成岩相测井识别方法研究"(41472115)联合资助

摘　　要：通过岩心观察、普通薄片、铸体薄片、荧光薄片、X衍射、物性分析、扫描电镜分析和高压压汞曲线等资料,对克深地区巴什基奇克组致密砂岩储层的岩石学特征、物性特征和微观孔隙结构特征进行了研究.结果表明储层以岩屑长石砂岩和长石岩屑砂岩为主,物性总体较差,孔隙类型多样,大小相差悬殊,孔喉组合类型以中孔微喉和小孔微喉型为主,连通性差.根据毛管压力曲线形态和参数特征分析,可将储层基质孔隙结构划分为4种类型.最后从沉积、成岩和构造三方面入手深入剖析储层孔隙结构的成因机理,认为孔隙结构受砂体原始组分和结构的先天控制,成岩过程中的压实、胶结和粘土矿物转化等将造成孔隙变小,喉道变窄,结构复杂,而溶蚀作用又可使孔隙变大,喉道变宽.侧向上构造挤压进一步减孔,而伴随构造裂缝而产生的微裂缝是改善储层物性和增强孔隙结构非均质性的另一重要因素.The lithology characteristics,reservoir property and microscopic pore structure of Bashijiqike Formation tight gas sandstone reservoirs are studied by making full use of core observation,normal thin sections,casting thin sections,fluorescent thin-section,scanning electron microscope analysis data,mercury injection test data.The results show that the sandstones are dominated by lithic arkoses and feldspathic litharenite,the reservoirs are characteristic of typical poor property,the sandstones have many kinds of pore spaces and the pore throat with various radius,the pore structure is very complicated with obvious heterogeneity and poor connectivity,the types of combination between pore and throat are mainly mesopore leptothroat and fine pore-leptothroat.The reservoir pore structure can be divided into 4 types based on the parameters obtained by the mercury injection experiment.Then the factors affecting the pore structures are studied from the aspects of sedimentation,diagenesis and tectonism,it is pointed out that the pore structures are initially controlled by sedimentary factors as composition and structure of sediments,and diagenesis as compaction,cementation and clay minerals transformation would reduce pore radius,occlude pore throats,while the dissolution of framework grains would enlarge pore radius and widen pore radius thus improving the connectivity of pores.The lateral structure compression would damage the reservoir pore structure further,however,the microfactures associated with the macroscopic fractures and faults would improve the reservoir performance,but on the other hand increase the heterogeneity of pore structure.

关 键 词：致密砂岩气 孔隙结构 压汞曲线 成因机理 巴什基奇克组 克深气田 

分 类 号：TE122[石油与天然气工程—油气勘探] P631[天文地球—地质矿产勘探]