Comparisons of fracturing mechanism of tight sandstone using liquid CO2 and water

doi:10.1016/j.jngse.2021.104108

	Comparisons of fracturing mechanism of tight sandstone using liquid CO2 and water
	Ma, Dongdong 1,2; Cheng, Changkun 3; Ding, Changdong 1,2; Song, Jinliang 1,2; Hu, Dawei 1,2; Zhou, Hui 1,2
刊名	JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
	2021-10-01
卷号	94 期号:-页码:11
关键词	Tight sandstone CT scanning NMR Multi-scale investigation Liquid CO(2 )fracturing
ISSN号	1875-5100
DOI	10.1016/j.jngse.2021.104108
英文摘要	CO2 is recently applied as fracturing liquid in exploitation of tight oil and gas resources and could significantly increase the oil and gas production. However, the changes in micro-scale pore and crack and in macro-crack due to liquid CO2 fracturing are still not completely understood and need multi-scale investigation. In this study, liquid CO2 and water fracturing tests were performed on tight sandstone under different confining pressure to analyze their different fracturing mechanism. Three methods (CT scanning, 3-D fracture morphology scanning and NMR measurement) were applied to identify pore and crack characteristics of fractured samples from microto macro-scale. Comparing with water fracturing, liquid CO2 fracturing can significantly reduce the breakdown pressure under the same confining pressure. The breakdown pressures using both water fracturing and liquid CO2 fracturing increase with increasing confining pressure, while the increasing ratio of the latter one is larger. For liquid CO2 fracturing, CT scanning results show that fractures tend to deflect and produce secondary branched cracks in the direction of propagation, and fracture tortuosity is greater than that of water fracturing. Moreover, NMR results show water fracturing mainly produces large-scale macro-cracks, whereas both large-scale macrocracks and micro-scale cracks could be observed for liquid CO2 fracturing. The main reason is that the liquid CO2 permeation generates more the micro-scale cracks, and induces irreversible crack initiation and preferred propagation, resulting in more tortuous fracture plane and lower breakdown pressure. The test results could improve our knowledge of CO2 fracturing in unconventional oil/gas exploitation.
资助项目	National Key R&D Program of China[2018YFC0809600] ; National Key R&D Program of China[2018YFC0809601] ; Hubei Province Natural Science Foundation innovation group[2018CFA013] ; National Natural Science Foundation of China[51779252]
WOS研究方向	Energy & Fuels ; Engineering
语种	英语
出版者	ELSEVIER SCI LTD
WOS记录号	WOS:000679396400001
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/27590]
专题	中科院武汉岩土力学所
作者单位	1.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Hubei, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Qinghai Oilfield Co, Well Drilling & Oil Prod Tech Res Inst, Petr 736202, Peoples R China
推荐引用方式 GB/T 7714	Ma, Dongdong,Cheng, Changkun,Ding, Changdong,et al. Comparisons of fracturing mechanism of tight sandstone using liquid CO2 and water[J]. JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING,2021,94(-):11.
APA	Ma, Dongdong,Cheng, Changkun,Ding, Changdong,Song, Jinliang,Hu, Dawei,&Zhou, Hui.(2021).Comparisons of fracturing mechanism of tight sandstone using liquid CO2 and water.JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING,94(-),11.
MLA	Ma, Dongdong,et al."Comparisons of fracturing mechanism of tight sandstone using liquid CO2 and water".JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING 94.-(2021):11.