摘要
为全面表征致密油储层的微观孔隙结构,对松辽盆地下白垩统青山口组致密砂岩储集层样品进行微米、亚微米尺度CT三维成像研究.在微米尺度下,样品1的孔喉结构表现一定的非均质性;样品2的孔吼结构整体均质性较强.在亚微米尺度下,样品1的孔喉直径主要为2.0-3.9μm,其中存在一些较小的短管状、孤立球状微米级孔隙;样品2的孔喉直径主要为2.2-4.2μm,颗粒周围存在一些具有一定连通性的短管状微孔,兼具喉道与孔隙的双重功能.利用格子Boltzmann方法进行单相微观渗流模拟分析,在0.7μm分辨率下,样品1、2的提取孔隙度分别为6.25%、9.3%,模拟渗透率分别为0.042、0.13 mD;在1.46μm分辨率下,样品2的提取孔隙度为9.14%,模拟渗透率为0.071 mD.两块样品的渗透率都具有一定的各向异性.基于上述结果,总结出该地区超低渗的五个决定性因素.
In order to characterize the micro pore structure of the tight oil reservoir comprehensively ,multi-scale （submicron-to-micro）three-dimensional CT imaging was used to study the tight sandstone reservoir sample which was taken from Lower cretaceous Qingshankou formation of Songliao basin. On a micrometer scale ,the pore throat structure of sample 1 is heterogeneous,and that of sample 2 has strong heterogeneity. On a submicron scale,the diameter of sample 1 pore throat ranges from 2.0 to 3.9μm,and there are some small tube-shaped and ball-shaped micropores in microscale. The diameter of sample 2 pore throat ranges from 2.2 to 4.2μm,and there are some tube-shaped micropores around the particles showing certain connectivity. Therefore,these tube-shaped micropores serve as throats and pores. Then the Lattice Boltzmann method was used to do the single-phase microscopic flowing simulation and analysis. Under 0.7μm resolution,the extraction porosity of sample 1 and sample 2 are 6.25%and 9.3%,and the stimulated permeability are 0.042 mD and 0.13 mD. Under 1.46μm resolution,the extraction porosity of sample 2 is 9.14%and the stimulated permeability is 0.071 mD. The permeability of two samples have a certain anisotropy. Based on the above results,five crucial factors which cause the low permeability of this area have been concluded.
作者
沈珊
卢双舫
唐明明
梁宏儒
燕贲惠
Shen Shan Lu Shuangfang Tang Mingming Liang Hongru Yan Bihui(Institute of Unconventional Hydrocarbon and New Energy Sources,China University of Petroleum,Qingdao 266580,Shandong China School of Geoscience,China University of Petroleum,Qingdao 266580,Shandong China)
出处
《河南科学》
2016年第10期1699-1705,共7页
Henan Science
基金
国家自然科学基金(41172134
41402108)
国家科技重大专项(2011ZX05004-001)
关键词
X射线CT三维成像
致密砂岩
微观孔喉结构
微观渗流模拟
3D X-ray CT
tight sandstone reservoirs
micro pore throat structure
micro seepage stimulation
