Full-scale pores and micro-fractures characterization using FE-SEM, gas adsorption, nano-CT and micro-CT: A case study of the Silurian Longmaxi Formation shale in the Fuling area, Sichuan Basin, China

被引：151

作者：

Gou, Qiyang ^{[1
]}

Xu, Shang ^{[1
]}

Hao, Fang ^{[2
]}

Yang, Feng ^{[1
]}

Zhang, Baiqiao ^{[3
]}

Shu, Zhiguo ^{[3
]}

Zhang, Aihua ^{[1
]}

Wang, Yuxuan ^{[1
]}

Lu, Yangbo ^{[1
]}

Cheng, Xuan ^{[1
]}

Qing, Jiawei ^{[1
]}

Gao, Mengtian ^{[1
]}

机构：

[1] China Univ Geosci, Key Lab Tecton & Petr Resources, Minist Educ, Lumo Rd 388, Wuhan 430074, Hubei, Peoples R China

[2] China Univ Petr, Sch Geosci, Changjiangxi Rd 66, Qingdao 266580, Shandong, Peoples R China

[3] Sinopec Jianghan Oilfield Co, Explorat & Dev Res Inst, Wuhan 430074, Hubei, Peoples R China

来源：

FUEL | 2019年 / 253卷

基金：

中国国家自然科学基金;

关键词：

Shale; Full-scale pore structure; Nano-CT; Micro-CT; Sichuan Basin; ORGANIC-MATTER; THERMAL MATURITY; SURFACE-AREA; MARINE SHALE; STORAGE; POROSITY; RESERVOIR; CAPACITY; BARNETT; SYSTEMS;

D O I：

10.1016/j.fuel.2019.04.116

中图分类号：

TE [石油、天然气工业]; TK [能源与动力工程];

学科分类号：

0807 ; 0820 ;

摘要：

Pore-fracture structure of shales is important to shale gas resource potential evaluation, exploration and development. However, investigations about the pore-fracture structure of shales were mainly focused on nano-submicron pores, while the contribution of micrometer-scaled pores and micro-fractures to pore system of shale reservoirs lack sufficient attention. Here, using a combination of field-emission scanning electronic microscopy (FE-SEM), gas adsorption (N-2 and CO2) and CT scanning (Nano-CT and Micro-CT), the Longmaxi shale cored from JYA well, in the Fuling area, was selected to comprehensively evaluate the characteristics of the pore-fracture structure at different scales. The results show that there are diverse types of pores in the organic-rich shale, mainly consisted of organic pores, inorganic pores (interP pores and intraP pores) and micro-fractures. Many pores are ink bottle-shaped characterized by narrow necks and wide bodies, while some others are slit-shaped. Pore size range from 0.305 nm to 98.5 mu m. Pores with diameter of 0.305-2 nm (micro-pores), 2-50 nm (meso-pores), 50 nm-2 mu m (macro-pores) and 2-98.5 mu m (micro-fractures) account for 33.59%, 36.28%, 14.04% and 16.09% of the total pore volume, respectively. Moreover, shale permeability and specific surface area were calculated to be 0.005 mD and 39.44 m(2)/g, respectively, based on the full-scaled pore splicing. About 92% of specific surface area is contributed by pores with diameter of 0.305-5 nm. Micro-fractures connect with each other and form net-shaped structure with great connectivity from observational results. The micro-fractures with size of 20-98.5 mu m provide the main permeability (about 90%). Micro-pores and small meso-pores in shale reservoirs provide large adsorption space for adsorbed gas, while micro-fractures enhance the seepage capability of shale gas, which are favorable for shale gas accumulation.

引用

页码：167 / 179

页数：13

共 60 条

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