川南—黔北地区下古生界页岩孔隙发育特征  

Pore characteristics of shale of Lower Paleozoic in southern Sichuan-northern Guizhou

作　　者：杨巍[1,2] 陈国俊[1] 胡士骏 吕成福[1] 徐勇[1,3] 杨爽[1,3] 

机构地区：[1]甘肃省油气资源研究重点实验室/中国科学院油气资源研究重点实验室,兰州730000 [2]中国石油勘探开发研究院西北分院,兰州730020 [3]中国科学院大学,北京100049

出　　处：《岩性油气藏》2015年第4期47-52,共6页Lithologic Reservoirs

基　　金：国家自然科学基金项目"鄂尔多斯盆地三叠系陆相页岩微孔隙特征与天然气赋存方式研究"(编号:41272144);中国科学院战略性先导科技专项(B类)"页岩气勘探开发基础理论与关键技术"(编号:XDB10010300);国家自然科学基金青年基金项目"四川盆地下古生界海相页岩微孔隙特征及形成机制研究"(编号:41402130)联合资助

摘　　要：采用场发射扫描电镜成像方法对川南—黔北地区下古生界筇竹寺组、五峰组—龙马溪组富有机质页岩的微观孔隙类型、孔隙大小、孔隙形态与分布特征及微裂缝发育特征进行了研究。结果表明:按形成方式的不同,可将孔隙划分为粒间孔、有机质孔、溶蚀孔和微裂缝4种主要类型;有机质孔发育广泛,对孔隙总体积贡献较大,有利于储层中吸附气的赋存;溶蚀孔零星分布,但孔径可达微米级,对孔隙总体积贡献较大;粒间孔发育相对较少,对孔隙总体积贡献相对较小;页岩中发育的微裂缝,可有效连通其他类型的孔隙,有利于页岩气的储存和渗流。对研究区样品矿物成分的分析表明,其矿物成分以石英、长石、碳酸盐矿物和黏土矿物为主,脆性矿物含量相对较高,平均体积分数为54.9%,有利于对页岩储层的压裂改造。Pore types, size, morphology, distribution and fracture feat ures by field emission scanning electron microscope imaging were studied on shale samples of the Lower Paleozoic Niutitang Formation, Wufeng Formation- Longmaxi Formation in the southern Sichuan-northem Guizhou. The results show that there are four main pore types developed in shale, including： intergranular pores, organic-matter pores, dissolved pores and microfracture. Organic- matter pores developed well in shale, which is favor of storing adsorbing-gas. Dissolved pores distributed sporadically, but the cumulative pore volume is much larger with wider pore diameters which are almost macropores and even reach to micrometer-scale. Intergranular pores developed relatively less, with little contribution to pore volume. Microfractures developed in shale can connect other types of pores, which is beneficial to shale gas store and flow. Additionally, the major components of shale are composed of quartz, feldspar, carbonate and clay minerals. The brittle minerals contentwith an average of 54.9% is conducive to the formation fracturing and exploration.

关 键 词：页岩储层 场发射扫描电镜 孔隙类型 孔隙特征 下古生界 川南—黔北地区 

分 类 号：TE122.23[石油与天然气工程—油气勘探]