Seepage characteristics of thermally and chemically treated Mesozoic granite from geothermal region of Liaodong Peninsula

doi:10.1007/s12665-021-09838-6

	Seepage characteristics of thermally and chemically treated Mesozoic granite from geothermal region of Liaodong Peninsula
	Liu, Hejuan 1,2; Shi, Yingkun 3; Fang, Zhiming 1,2; Liu, JianFeng 4,5; Zhang, Liwei 1,2; Tong, Rongchen 1,2
刊名	ENVIRONMENTAL EARTH SCIENCES
	2021-09-01
卷号	80 期号:17 页码:23
关键词	Thermal treatment Chemical solution Granite Permeability Microstructure
ISSN号	1866-6280
DOI	10.1007/s12665-021-09838-6
英文摘要	The seepage characteristics of granite are complicated due to flow exchange between fractures and micropores, which are strongly heterogeneous and anisotropic. The potential geothermal reservoirs of hot dry rocks are often related to granite. The key to geothermal production from hot dry rocks is to generate an efficient fracture network through enhanced geothermal system (EGS) technologies. Although hydraulic fracturing technology is applied in most EGS projects worldwide, it has been indicated that thermal and chemical stimulation methods are also efficient. In this paper, different thermal and chemical treatments are applied to Mesozoic granite samples obtained from geothermal region of Liaodong Peninsula in northeastern China, and their impacts on the seepage characteristics of the granite are carefully analyzed. The thermal and chemical damage mechanisms of granite, in terms of the mineral components, microstructures and physical properties, are also studied. The results show that cooling in cold water results in a much larger permeability increase than that achieved with cooling in air after the granite is heated to a specific temperature. Thermal treatments cause mechanical damage (e.g., compressive strength, elastic modulus, etc.) of granite. However, the differences between the damage factors of various granite samples are large, which are highly dependent on the original mineral composition and microstructures. Thermal cracking induced by either thermal fatigue or thermal shock causes changes in the porosity and permeability of granite. The permeability of the granite changes substantially, i.e., 3-4 orders of magnitude, after soaking in mud acid solutions, while it changes by less than 1 order of magnitude after soaking in alkaline solutions. The dissolution ability of the mud acid solution with the highest concentration (12% HCl + 3% HF) is the strongest among the three types of mud acid solutions tested (S1, S2 and S3). But it mainly acts on improving the proportion of small pores with the size of 0.01-10 mu m. It has the least impact on the generation of large pores (10-50 mu m), which may be caused by the heterogeneity of mineralogy among different granite samples. Different chemical solutions infiltrate the interior of the granite through various micropores and fissures, enhancing the chemical interaction through the dissolution and precipitation of minerals, the porosity, and the permeability, destroying not only the grains and minerals but also the microstructures of the granite.
资助项目	CAS Pioneer Hundred Talents Program ; National Natural Science Foundation of China[51809259] ; National Natural Science Foundation of China[51774056] ; State Key Laboratory of Hydraulics and Mountain River Engineering affiliated to Sichuan University[SKHL1917] ; Key Laboratory of Deep Earth Science and Engineering (Sichuan University), Ministry of Education[DESE202002]
WOS研究方向	Environmental Sciences & Ecology ; Geology ; Water Resources
语种	英语
出版者	SPRINGER
WOS记录号	WOS:000687680000010
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/27847]
专题	中科院武汉岩土力学所
通讯作者	Liu, JianFeng
作者单位	1.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Peoples R China 2.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 3.Shenyang Univ Technol, Shenyang 110870, Peoples R China 4.Sichuan Univ, Minist Educ, Key Lab Deep Earth Sci & Engn, Chengdu 610065, Peoples R China 5.Sichuan Univ, State Key Lab Hydraul & Mt River Engn, Chengdu 610065, Peoples R China
推荐引用方式 GB/T 7714	Liu, Hejuan,Shi, Yingkun,Fang, Zhiming,et al. Seepage characteristics of thermally and chemically treated Mesozoic granite from geothermal region of Liaodong Peninsula[J]. ENVIRONMENTAL EARTH SCIENCES,2021,80(17):23.
APA	Liu, Hejuan,Shi, Yingkun,Fang, Zhiming,Liu, JianFeng,Zhang, Liwei,&Tong, Rongchen.(2021).Seepage characteristics of thermally and chemically treated Mesozoic granite from geothermal region of Liaodong Peninsula.ENVIRONMENTAL EARTH SCIENCES,80(17),23.
MLA	Liu, Hejuan,et al."Seepage characteristics of thermally and chemically treated Mesozoic granite from geothermal region of Liaodong Peninsula".ENVIRONMENTAL EARTH SCIENCES 80.17(2021):23.