Characteristics and controlling factors of shale gas reservoir in the Fuling area,Sichuan Basin  

作　　者：Xiaoming Zhang Wanzhong Shi Gangyi Zhai Qinghai Xu Ren Wang Zhuang Xu Jian Wang Chao Wang Qi Yuan 

机构地区：[1]Faculty of Earth Resources,China University of Geosciences,Hubei 430074,China [2]Key Laboratory of Tectonics and Petroleum Resources of the Ministry of Education,Hubei 430074,China [3]Oil and Gas Survey Center,China Geological Survey,Beijing 100029,China

出　　处：《Petroleum Research》2017年第1期25-40,共16页石油研究（英文）

基　　金：This studywas jointly supported by the National Natural Science Foundation of China(No.41672134);the Programme of Introducing Talents of Scientific Disciplines to Universities(No.B14031);the 13th“Five-Year”Plan of the Ministry of Science and Technology of China(No.2016ZX05034002-003);the Shale Gas Survey of National Geological Survey(No.12120114055801).

摘　　要：Statistical analysis of massive laboratory analytical data shows that for intervals in the Upper Ordovician Wufeng Formation and the Lower Silurian Longmaxi Formation in the Fuling area,Sichuan Basin,the total organic carbon content is 0.55%-5.89%with an average of 2.54%,presenting a gradual increase trend from top to bottom.Based on whole-rock X-ray diffraction data,the content of clay minerals of the shale is 16.6%-62.8%with an average of 40.9%,gradually decreasing from top to bottom.The content of brittle minerals gradually increases from top to bottom,ranging from 37.2%to 83.4%with an average of 59.1%.Porosity is 1.17%-7.98%with an average of 4.61%through the helium injection method.The horizontal permeability is 0.002-335.209 mD with an average of 23.785 mD by the steady-state method.Massive analytical data from the high-pressure mercury injection method show the micropores are well developed in the shale,and mainly provide the primary specific surface area of pores,while the micropores,transitional pores and mesopores primarily contribute to permeability.The pore types were observed using SEM in combination with argon ion polishing technology.From top to bottom of the shale interval,the organic pores increase and the inorganic pores decrease.Gas desorption data show that the total gas content is 0.44-5.19 m^(3)/t with an average of 1.97 m^(3)/t,and gradually increase from top to bottom of the shale interval.The development of marine shale gas reservoir in Well A is controlled by mineral compositions,the development characteristics of organic matter.TOC is not only a major intrinsic factor controlling the lower reservoir interval,but also an important material to provide the reservoir space for the shale gas.In the late diagenetic stage,the clay mineral assemblages changed from montmorillonite to illite,forming new micropores and leading to an increase of the porosity and great influences on the upper reservoir interval.The content of brittle minerals is more than 50%,facilitating formation of fractures,and

关 键 词：Shale gas reservoir Controlling factor Upper Ordovician Lower Silurian Fuling area 

分 类 号：P61[天文地球—矿床学]