Evolution of pore structure during diagenesis and hydrocarbon generation of marine shale: the inspiration from thermal simulation experiments

被引:0
作者
Luo W. [1 ,2 ,3 ]
Ma Z. [1 ,4 ,5 ]
Zheng L. [4 ,5 ]
Tan J. [1 ,2 ,3 ]
Wang Z. [1 ,2 ,3 ]
Ning C. [4 ,5 ]
机构
[1] School of Geosciences and Info-Physics, Central South University, Changsha, 410083, Hunan
[2] Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, Changsha, 410083, Hunan
[3] Hunan Key Laboratory of Nonferrous Resources and Geological Hazards Exploration, Changsha, 410083, Hunan
[4] Wuxi Institute of Petroleum Geology, Sinopec Petroleum Exploration and Production Research Institute, Wuxi, 214126, Jiangsu
[5] State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development, Wuxi, 214126, Jiangsu
来源
Shiyou Xuebao/Acta Petrolei Sinica | 2020年 / 41卷 / 05期
关键词
Fractal characteristics; Inhomogeneity; Marine immature shale; Nitrogen adsorption; Pore structure; Thermal simulation;
D O I
10.7623/syxb202005003
中图分类号
学科分类号
摘要
During the deposition and burial of shale, pore formation and evolution are synchronized with the diagenesis and hydrocarbon generation processes. To reveal the effect of diagenesis and hydrocarbon generation on the pore structure of shale, taking the Upper Cretaceous marine immature shale in the Western Canada Basin as the research object, this study carries out the thermal simulation experiments on the diagenesis and hydrocarbon generation of shale from immature to over-mature stages under the geological conditions, analyzes the microstructures of samples after thermal simulation using the high-resolution scanning electron microscope, and quantitatively analyzes the pore development characteristics and fractal dimensions of experimental samples using the liquid nitrogen adsorption-desorption experiment and the Frenkel-Halsey-Hill (FHH) model. The results show as follows. (1) During diagenesis and hydrocarbon generation, the pore structures of shale are complex and changeable, mainly developing mesoporous and macroporous, with the shape of wedge or parallel plate. (2) The specific surface area of pore is mainly contributed by micropores and mesopores with the diameter smaller than 15 nm in shale. (3) Organic matter abundance is not the main factor affecting the fractal characteristics of pores. There is a clear negative correlation between the fractal dimension of pore structure and the average pore size, the smaller the pore size, the poor the pore connectivity, and the more complex the pore structure. (4) The fractal characteristics of pores in different evolutionary stages are obviously different. The clay mineral transformation and mineral dissolution caused by hydrocarbon generation in the mature stage can greatly reduce the complexity of pore structure and surface, while the formation of a large number of organic matter pores in the mature stage can increase the roughness of pore surface and make shale have a high pore specific surface area. © 2020, Editorial Office of ACTA PETROLEI SINICA. All right reserved.
引用
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页码:540 / 552
页数:12
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  • [1] LOUCKS R G, REED R M, RUPPEL S C, Et al., Morphology, genesis, and distribution of nanometer-scale pores in siliceous mudstones of the Mississippian Barnett Shale, Journal of Sedimentary Research, 79, 12, pp. 848-861, (2009)
  • [2] ROSS D J K, BUSTIN R M., The importance of shale composition and pore structure upon gas storage potential of shale gas reservoirs, Marine and Petroleum Geology, 26, 6, pp. 916-927, (2009)
  • [3] TAN Jingqiang, WENIGER P, KROOSS B, Et al., Shale gas potential of the major marine shale formations in the Upper Yangtze Platform, South China, Part II: methane sorption capacity, Fuel, 129, pp. 204-218, (2014)
  • [4] CURTIS M E, SONDERGELD C H, AMBROSE R J, Et al., Microstructural investigation of gas shales in two and three dimensions using nanometer-scale resolution imaging, AAPG Bulletin, 96, 4, pp. 665-677, (2012)
  • [5] TAN Jingqiang, HU Chenger, LYU Qiao, Et al., Multi-fractal analysis for the AE energy dissipation of CO<sub>2</sub> and CO<sub>2+</sub> brine/water treated low-clay shales under uniaxial compressive tests, Fuel, 246, pp. 330-339, (2019)
  • [6] ZHANG Yan, LIU Jincheng, XU Hao, Et al., Comparison between pore structure and fractal characteristics of continental and transitional coal measures shale: a case study of Yan'an and Taiyuan formations at the northeastern margin of Ordos Basin, Acta Petrolei Sinica, 38, 9, pp. 1036-1046, (2017)
  • [7] YANG Chao, ZHANG Jinchuan, WANG Xianzeng, Et al., Nanoscale pore structure and fractal characteristics of a marine-continental transitional shale: a case study from the Lower Permian Shanxi shale in the southeastern Ordos Basin, China, Marine and Petroleum Geology, 88, pp. 54-68, (2017)
  • [8] LIANG Lixi, XIONG Jian, LIU Xiangjun, An investigation of the fractal characteristics of the Upper Ordovician Wufeng Formation shale using nitrogen adsorption analysis, Journal of Natural Gas Science and Engineering, 27, pp. 402-409, (2015)
  • [9] LI Ang, DING Wenlong, HE Jianhua, Et al., Investigation of pore structure and fractal characteristics of organic-rich shale reservoirs: a case study of Lower Cambrian Qiongzhusi Formation in Malong block of eastern Yunnan province, South China, Marine and Petroleum Geology, 70, pp. 46-57, (2016)
  • [10] MA Ming, CHEN Guojun, XU Yong, Et al., Fractal characteristics of pore structure of continental shale in the process of thermal evolution, Coal Geology & Exploration, 45, 5, pp. 41-47, (2017)