四川盆地东南部龙马溪组页岩微—纳米孔隙结构特征及控制因素

发布时间：2018-01-11 17:42

本文关键词：四川盆地东南部龙马溪组页岩微—纳米孔隙结构特征及控制因素　出处：《石油学报》2016年02期 　论文类型：期刊论文

【摘要】：以四川盆地东南部重庆地区下志留统龙马溪组页岩为研究对象,通过场发射扫描电镜、CO2及N2低温低压吸附实验,探讨海相页岩储层微—纳米孔孔隙结构特征及其控制因素。结果表明:龙马溪组页岩发育有机孔、粒间孔、粒内孔、晶间孔、溶蚀孔和微裂缝6种孔隙类型,其中有机孔、黏土矿物层间粒内孔最为发育,由于热演化程度高也发育大量的溶蚀孔隙;龙马溪组页岩BET比表面积介于3.5~18.1 m2/g,BJH总孔容介于0.002 34~0.013 38cm3/g,DA微孔比表面积介于1.3~7.3 m2/g,DA微孔孔容介于0.000 52~0.002 73cm3/g。页岩微孔比表面积占总比表面积的23.1%~80.2%,平均占比50.3%,微孔孔容占总孔容的12.1%~48.5%,平均占比32.3%,微孔提供比表面积的能力远大于中孔和宏孔,是页岩储层中甲烷吸附的主要场所;泥页岩孔径分布复杂,孔径分布曲线存在多个不同的峰值,在0~100nm范围内主要呈现双峰或三峰特征,偶见四峰特征;有机碳含量与泥页岩微孔、中孔+宏孔及总孔的孔隙结构参数均呈现非常好的线性关系,表明TOC是泥页岩中微—纳米孔隙结构最重要的控制因素,将孔隙结构参数对TOC进行归一化处理后,总孔和中孔+宏孔孔隙结构参数与黏土矿物含量呈正线性关系,与脆性矿物含量呈负线性关系,表明黏土矿物和脆性矿物主要控制页岩的中孔和宏孔的发育。
[Abstract]:The low temperature and low pressure adsorption experiments of CO _ 2 and N _ 2 in the Lower Silurian Longmaxi formation shale in the southeast of Sichuan Basin were carried out by means of field emission scanning electron microscope (SEM). The pore structure characteristics and controlling factors of micropore and nano-pore in marine shale reservoir are discussed. The results show that organic pore, intergranular pore, intragranular pore, intergranular pore, solution pore and microfracture are developed in the shale of Longmaxi formation. Among them, organic pore, clay mineral interlayer intergranular pore is the most developed, because of the high degree of thermal evolution, a large number of dissolution pores are also developed. The specific surface area of shale BET in Longmaxi formation is between 3.5N ~ 18.1 m ~ (-2) m ~ (-2) 路g ~ (-1) and 0.013 ~ (38) cm ~ (-3) 路g ~ (-1) 路g ~ (-1). The specific surface area of DA micropore is between 1.3 and 7.3 m2 / g. DA micropore volume is between 0.000 52n 0.002 73 cm 3 / g. Shale micropore specific surface area accounts for 23.1g / 80.2% of the total specific surface area, with an average ratio of 50.3%. The micropore volume accounts for 12.1% of the total pore volume, with an average of 32.3%. The ability of micropore to provide specific surface area is much larger than that of mesopore and macropore, which is the main site for methane adsorption in shale reservoir. The pore size distribution of shale is complex, and there are many different peaks in pore size distribution curve. In the range of 0 ~ 100 nm, there are mainly two or three peaks and occasionally four peaks. The organic carbon content has a very good linear relationship with the pore structure parameters of shale micropore, mesoporous macro pore and total pore, indicating that TOC is the most important controlling factor of micro-nano pore structure in shale. After normalizing the pore structure parameters to TOC, the pore structure parameters of total and mesoporous macropores have a positive linear relationship with clay mineral content, and a negative linear relationship with brittle mineral content. The results show that clay minerals and brittle minerals mainly control the development of mesopore and macropore in shale.
【作者单位】：中国石油大学油气资源与探测国家重点实验室;中国石油大学非常规天然气研究院;中国石油勘探开发研究院;
【基金】：国家重大科技专项(2011ZX05018-002) 国家自然科学基金项目(No.41472112)资助
【分类号】：P618.13
【正文快照】： (1.State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing102249,China;2.Unconventional Natural Gas Institute,China University of Petroleum,Beijing102249,China;3.PetroChinaResearch Institute of Petroleum Explorat

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