鄂尔多斯盆地东南部延长组长7段富有机质页岩孔隙特征  

Micropore Characteristics of the Organic-rich Shale in the 7^(th) Member of the Yanchang Formation in the Southeast of Ordos Basin

作　　者：杨巍[1,2] 陈国俊[1] 吕成福[1] 仲佳爱[1,2] 徐勇[1,2] 杨爽[1,2] 薛莲花[1] 

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,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《天然气地球科学》2015年第3期418-426,591,共10页Natural Gas Geoscience

基　　金：国家自然科学基金"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2012年"西部之光"项目"甘肃陇东地区三叠系湖相页岩气的赋存条件研究";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);甘肃省科技计划(编号:1309RTSA041)联合资助

摘　　要：为研究鄂尔多斯盆地长7段陆相富有机质页岩孔隙发育特征,采用覆压孔隙度测量、脉冲衰减渗透率测量、低温氮气吸附实验等结合氩离子抛光—扫描电镜成像分析,对页岩孔隙发育特征进行深入研究。结果表明,页岩储层孔隙主要为纳米量级,少量黏土矿物粒间孔可达微米级别;孔隙类型主要有粒间孔、黄铁矿微球粒晶间孔、粒内孔、有机孔及少量微裂缝,其中黏土矿物粒间孔最发育,有机孔相对较少;页岩孔径分布复杂,含有大量的中孔(2~50nm)、大孔(>50nm)及少量的微孔(0~2nm),中孔和大孔是孔隙体积的主要贡献者,微孔和细中孔(2~10nm)是比表面积的主要贡献者;样品渗透率变化幅度大,与页岩中裂缝的发育程度及孔隙结构有关。Micro-porosity structure and morphology of organic-rich shale in the 7^th Member of the Yanchang Formation in Ordos Basin was investigated using low pressure N2 adsorption analysis,field emission scanning electron microscope observations, and combined with effective porosity and Pulse-Decay permeability. The results show that the pores in the black shale are generally in nano-scale except some interparticle pores in micrometer-scale developed between clay minerals. Pores can be classified into interparticle pores, intergranular pores in pyrite framboids, dissolved intragranular pores, organic pores, and micro-fractures. The interparticle pores in clay minerals are the best in pores,and the organic pores are relative less. The pore size are complex with abundant mesopores （2-50nm）,macropores （〉50nm） and a small number of rnicropores （0-2nm）. Samples with the highest pore volumes contain a plenty of mecropores and macropores,and samples with the highest special surface area have high quality micropores and finer mecropores （2-10nm）. The permeability in samples has no relative with other parameter for it is related to the degree of fracture development, pore structure, etc.

关 键 词：页岩 孔隙特征 低温氮气吸附 扫描电镜 鄂尔多斯盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]