川东南龙马溪组页岩孔隙分形特征  

Fractal characteristics of shale pores of Longmaxi Formation in southeast Sichuan Basin

作　　者：徐勇[1,2] 吕成福[1] 陈国俊[1] 仲佳爱[1,2] 杨巍[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,兰州730000 [2]中国科学院大学,北京100049

出　　处：《岩性油气藏》2015年第4期32-39,共8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)联合资助

摘　　要：基于低温氮气吸附分形几何学研究方法,对川东南龙马溪组页岩储层进行了孔隙分形特征研究,并运用分形FHH模型计算了孔隙分形维数,讨论了分形维数与孔隙结构、有机碳含量、页岩矿物成分之间的关系。研究表明：川东南龙马溪组页岩以中孔为主,孔隙内部特征以墨水瓶状孔和狭缝状孔为主;页岩样品分形维数为2.629 2~2.898 0,反映了页岩孔隙结构复杂和非均质性强的特征;页岩平均孔径越小、微小孔隙越多,孔隙结构越复杂,孔表面越不规则,比表面积和分形维数则越大;有机碳含量和微孔发育程度对分形维数影响较大。通过分形维数可定量描述孔隙结构的复杂程度和不均一性,为研究页岩孔隙结构的分布特征提供了思路。Based on fractal theory and methods and the nitrogen adsorption results of shale samples from the Lower Silurian Longmaxi Formation in southeast Sichuan Basin, the fractal characteristics of pores were studied, the fractal dimension was calculated by using the fractal Frenkel-Halsey-Hill （FHH） model, and the relations of fraetal dimension with pore structure, organic carbon content and shale composition were discussed. The results show that mesopores are the main pores in shale, and mainly consist of ink-bottle-like and slit-shaped pore. The fractal dimension of shale samples is between 2.629 2 and 2.898 0, which reflects the complexity and heterogeneity of the shale porosity. The smaller the average pore diameter is, the more the micropores are, the more complex the pore structure is, the more irregular the specific shale face is, the larger the specific surface face is, and the higher the fractaJ dimension is. Organic carbon content and the degree of micropore development impact a lot on the fractal dimension.

关 键 词：页岩储层 低温氮气吸附 分形特征 龙马溪组 川东南地区 

分 类 号：TE121.2[石油与天然气工程—油气勘探]