Hydraulic fracturing under high temperature and pressure conditions with micro CT applications: Geothermal energy from hot dry rocks

doi:10.1016/j.fuel.2018.05.040

CORC > 地质与地球物理研究所 > 中国科学院地质与地球物理研究所 > 中国科学院页岩气与地质工程重点实验室

	Hydraulic fracturing under high temperature and pressure conditions with micro CT applications: Geothermal energy from hot dry rocks
	Kumari, W. G. P.1; Ranjith, P. G.1; Perera, M. S. A.1,2; Li, X.3,4,5; Li, L. H.3,4,5; Chen, B. K.6; Isaka, B. L. Avanthi 1; De Silva, V. R. S.1
刊名	FUEL
	2018-10-15
卷号	230 页码:138-154
关键词	CT scanning Geothermal Granite Hydraulic fracturing Breakdown pressure High temperature Micro-scale
ISSN号	0016-2361
DOI	10.1016/j.fuel.2018.05.040
文献子类	Article
英文摘要	Hydraulic fracturing has been widely employed to enhance the permeability of tight geological formations including deep geothermal reservoirs. However, due to the complex in-situ stresses, high-temperature conditions and heterogeneity of the formations, hydraulic fracturing under deep geothermal conditions is poorly understood to date. The aim of the current study is, therefore, to investigate the effect of reservoir depth, temperature, and sample heterogeneity during hydraulic fracturing and the influences of rock micro-structure on fracture propagation. A series of hydraulic fracturing experiments was conducted on two Australian granite types under a wide range of confining pressures from 0 to 60 MPa and temperatures from room temperature to 300 degrees C simulating different geothermal environments. The corresponding micro-structural effects on the rock matrix were investigated employing high-resolution CT imaging using the IMBL facility of the Australian Synchrotron. According to the results, the breakdown pressure of reservoir rock linearly increases with reservoir depth (confining pressure). However, with increasing temperature breakdown pressure linearly decreases. This corresponds to the linear reduction of tensile strength measured by high-temperature Brazilian tensile tests. In addition, CT images showed that the injection of cold water into hot rock can result in a porous zone with porosity ranging from 2 to 3% close to the wellbore due to thermally-induced inter-and intra-crystalline cracks. In this condition, fluid leak-off is high and the measured fracture aperture of the main hydraulic fracture is relatively small. Further, fracture propagation paths and apertures are mainly controlled by the stress state and the heterogeneity of the rock matrix. It was found that fractures tend to propagate along preferential paths, mainly along grain boundaries and in large quartz and biotite minerals (grain size > 0.3 mm) and minerals with pre-existing micro-cracks.
WOS关键词	AUSTRALIAN STRATHBOGIE GRANITE ; PROPAGATION BEHAVIOR ; MECHANICAL-BEHAVIOR ; SIMULATION ; INITIATION ; SHALE ; STRESS ; DESIGN ; SYSTEM
WOS研究方向	Energy & Fuels ; Engineering
语种	英语
出版者	ELSEVIER SCI LTD
WOS记录号	WOS:000434016900017
内容类型	期刊论文
源URL	[http://ir.iggcas.ac.cn/handle/132A11/88222]
专题	地质与地球物理研究所_中国科学院页岩气与地质工程重点实验室
通讯作者	Ranjith, P. G.
作者单位	1.Monash Univ, Dept Civil Engn, Bldg 60, Melbourne, Vic 3800, Australia 2.Univ Melbourne, Dept Infrastruct Engn, Bldg 176 Engn Block D,Level 4,Room D 411, Melbourne, Vic 3010, Australia 3.Chinese Acad Sci, Inst Geol & Geophys, Key Lab Shale Gas & Geoengn, Beijing 100029, Peoples R China 4.Chinese Acad Sci, Inst Earth Sci, Beijing 100029, Peoples R China 5.Univ Chinese Acad Sci, Coll Earth Sci, Beijing 100049, Peoples R China 6.Monash Univ, Dept Mech & Aerosp Engn, Bldg 36, Melbourne, Vic 3800, Australia
推荐引用方式 GB/T 7714	Kumari, W. G. P.,Ranjith, P. G.,Perera, M. S. A.,et al. Hydraulic fracturing under high temperature and pressure conditions with micro CT applications: Geothermal energy from hot dry rocks[J]. FUEL,2018,230:138-154.
APA	Kumari, W. G. P..,Ranjith, P. G..,Perera, M. S. A..,Li, X..,Li, L. H..,...&De Silva, V. R. S..(2018).Hydraulic fracturing under high temperature and pressure conditions with micro CT applications: Geothermal energy from hot dry rocks.FUEL,230,138-154.
MLA	Kumari, W. G. P.,et al."Hydraulic fracturing under high temperature and pressure conditions with micro CT applications: Geothermal energy from hot dry rocks".FUEL 230(2018):138-154.