Microfracture characterization of shale constrained by mineralogy and bedding

doi:10.1016/j.petrol.2021.108456

	Microfracture characterization of shale constrained by mineralogy and bedding
	Chen, Junhui 1,5; Lan, Hengxing 2,5; Macciotta, Renato 2,3; Martin, C. Derek 4; Wu, Yuming 5
刊名	JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
	2021-06-01
卷号	201 页码:15
关键词	Microfracture characterization Shale gas Bedding effect Mineralogical effect Loading effect
ISSN号	0920-4105
DOI	10.1016/j.petrol.2021.108456
通讯作者	Lan, Hengxing(lanhx@igsnrr.ac.cn)
英文摘要	The characterizations of microfractures within shale, and their associations with bedding, mineralogy and loading, are important for shale gas exploration and related engineering safety. Research on this topic has been limited due to technological constraints; however, advances in scanning electron microscope (SEM) techniques allow for highly detailed observations of microfractures. In this study, Longmaxi Shale samples were obtained from the locality of Shizhu, China. The samples were cored parallel and perpendicular to the bedding, and SEM observations were performed in specimens before and after compression triaxial testing. SEM images were used for qualitative and quantitative characterization of the microfractures. These tests provided some important insights into the effects of bedding, mineralogy and loading on the characteristics of microfractures. It was observed that the size of the microfractures follows a power law distribution regardless of loading. The parameters of the power law suggest that microfractures associated with brittle minerals increase in complexity after triaxial compression testing. The characteristics of quartz and carbonates show a similar changing pattern, while clay and feldspar show the reverse due to crystal foliation. Microfracture orientations tend to be parallel to subparallel to bedding for all samples, regardless of loading and loading direction. The transition from tensile failure to shearing failure dominates the failure patterns for all minerals under external loading. The mineral's strength and crystal foliation appear to dominate the microfracture mechanisms. Microfractures through carbonates showed complex networks due to the weak grains, and those through quartz tended to develop evenly, indicating that these minerals are prone to forming fracture networks. Microfractures through clays were predominantly parallel and subparallel to the bedding, and those through feldspars showed a tendency towards foliation, indicating that stress direction has crucial effects on these minerals. These results provide microscale information on shale fracturing processes, which can benefit current efforts for hydraulic fracturing enhancement.
资助项目	National Natural Science Foundation of China[41941019] ; National Natural Science Foundation of China[4 1927806] ; National Natural Science Foundation of China[41790443] ; National Natural Science Foundation of China[42041006] ; Second Tibetan Plateau Scientific Expedition and Research (STEP) program[2019QZKK0904] ; National Key R&B Program of China[2019YFC1520601] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA19040304] ; Strategic Priority Research Program of the Chinese Academy of Sciences[XDA23090301] ; Key Research Program of Frontier Sciences of Chinese Academy of Sciences (CAS)[QYZDY-SSW-DQC019] ; 111 Center, program of the Ministry of Education of China[B18046] ; China Scholarship Council[201904910625]
WOS研究方向	Energy & Fuels ; Engineering
语种	英语
出版者	ELSEVIER
WOS记录号	WOS:000628869500049
资助机构	National Natural Science Foundation of China ; Second Tibetan Plateau Scientific Expedition and Research (STEP) program ; National Key R&B Program of China ; Strategic Priority Research Program of the Chinese Academy of Sciences ; Key Research Program of Frontier Sciences of Chinese Academy of Sciences (CAS) ; 111 Center, program of the Ministry of Education of China ; China Scholarship Council
内容类型	期刊论文
源URL	[http://ir.igsnrr.ac.cn/handle/311030/162016]
专题	中国科学院地理科学与资源研究所
通讯作者	Lan, Hengxing
作者单位	1.Minist Nat Resources, Isl Res Ctr, Pingtan 350400, Peoples R China 2.Changan Univ, Sch Geol Engn & Geomat, Xian 710054, Peoples R China 3.Univ Alberta, Fac Engn, Sch Engn Safety & Risk Management, Edmonton, AB, Canada 4.Univ Alberta, Dept Civil & Environm Engn, Edmonton, AB, Canada 5.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, State Key Lab Resource & Environm Informat Syst, Beijing 100101, Peoples R China
推荐引用方式 GB/T 7714	Chen, Junhui,Lan, Hengxing,Macciotta, Renato,et al. Microfracture characterization of shale constrained by mineralogy and bedding[J]. JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING,2021,201:15.
APA	Chen, Junhui,Lan, Hengxing,Macciotta, Renato,Martin, C. Derek,&Wu, Yuming.(2021).Microfracture characterization of shale constrained by mineralogy and bedding.JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING,201,15.
MLA	Chen, Junhui,et al."Microfracture characterization of shale constrained by mineralogy and bedding".JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING 201(2021):15.