Numerical modelling of the cooling effect in geothermal reservoirs induced by injection of CO2 and cooled geothermal water

doi:10.2516/ogst/2020005

	Numerical modelling of the cooling effect in geothermal reservoirs induced by injection of CO2 and cooled geothermal water
	Liu, Hejuan 5,6; Li, Qi 5,6; Gou, Yang 4; Zhang, Liwei 5,6; Feng, Wentao 4; Liao, Jianxing 4; Zhu, Zhengwen 3; Wang, Hongwei 2; Zhou, Lei 1
刊名	OIL & GAS SCIENCE AND TECHNOLOGY-REVUE D IFP ENERGIES NOUVELLES
	2020-03-20
卷号	75 页码:21
ISSN号	1294-4475
DOI	10.2516/ogst/2020005
英文摘要	The utilization of geothermal energy can reduce CO2 emissions into the atmosphere. The reinjection of cooled return water from a geothermal field by a closed loop system is an important strategy for maintaining the reservoir pressure and prolonging the depletion of the geothermal reservoir by avoiding problems, e.g., water level drawdown, ground subsidence, and thermal pollution. However, the drawdown of water injectivity affected by physical and chemical clogging may occur in sandstone aquifers, and the reservoir temperature may be strongly affected by the reinjection of large amounts of cooled geothermal water, thus resulting in early thermal breakthrough at production wells and a decrease in production efficiency. In addition to the injection of cooled geothermal water, the injection of CO2 can be used to maintain the reservoir pressure and increase the injectivity of the reservoir by enhancing water-rock interactions. However, the thermal breakthrough and cooling effect of the geothermal reservoir may become complex when both CO2 and cooled geothermal water are injected into aquifers. In this paper, a simplified small-scale multilayered geological model is established based on a low-medium geothermal reservoir in Binhai district, Tianjin. The ECO2N module of the TOUGH2MP simulator is used to numerically simulate temperature and pressure responses in the geothermal reservoir while considering different treatment strategies (e.g., injection rates, temperatures, well locations, etc.). The simulation results show that a high injection pressure of CO2 greatly shortens the CO2 and thermal breakthrough at the production well. A much lower CO2 injection pressure is helpful for prolonging hot water production by maintaining the reservoir pressure and eliminating the cooling effect surrounding the production wells. Both pilot-scale and commercial-scale cooled water reinjection rates are considered. When the water production rate is low (2 kg/s), the temperature decrease at the production well is negligible at a distance of 500 m between two wells. However, when both the production and reinjection rates of cooled return water are increased to 100 m(3)/h, the temperature decrease in the production well exceeds 10 degrees C after 50 years of operation.
资助项目	CAS Pioneer Hundred Talents Program ; National Natural Science Foundation of China[51809259] ; National Natural Science Foundation of China[51774056]
WOS研究方向	Energy & Fuels ; Engineering
语种	英语
出版者	EDP SCIENCES S A
WOS记录号	WOS:000522105800002
内容类型	期刊论文
源URL	[http://119.78.100.198/handle/2S6PX9GI/23767]
专题	中科院武汉岩土力学所
通讯作者	Liu, Hejuan
作者单位	1.Chongqing Univ, State Key Lab Coal Mine Disaster Dynam & Control, Chongqing 400030, Peoples R China 2.Chengdu Univ Technol, Coll Energy, Chengdu 610059, Peoples R China 3.Southwest Petr Univ, Sch Geosci & Technol, Chengdu 610500, Peoples R China 4.TUC, Energie Forschungszentrum Niedersachsen, Stollen 19A, D-38640 Goslar, Germany 5.Univ Chinese Acad Sci, Beijing 100049, Peoples R China 6.Chinese Acad Sci, Inst Rock & Soil Mech, State Key Lab Geomech & Geotech Engn, Wuhan 430071, Peoples R China
推荐引用方式 GB/T 7714	Liu, Hejuan,Li, Qi,Gou, Yang,et al. Numerical modelling of the cooling effect in geothermal reservoirs induced by injection of CO2 and cooled geothermal water[J]. OIL & GAS SCIENCE AND TECHNOLOGY-REVUE D IFP ENERGIES NOUVELLES,2020,75:21.
APA	Liu, Hejuan.,Li, Qi.,Gou, Yang.,Zhang, Liwei.,Feng, Wentao.,...&Zhou, Lei.(2020).Numerical modelling of the cooling effect in geothermal reservoirs induced by injection of CO2 and cooled geothermal water.OIL & GAS SCIENCE AND TECHNOLOGY-REVUE D IFP ENERGIES NOUVELLES,75,21.
MLA	Liu, Hejuan,et al."Numerical modelling of the cooling effect in geothermal reservoirs induced by injection of CO2 and cooled geothermal water".OIL & GAS SCIENCE AND TECHNOLOGY-REVUE D IFP ENERGIES NOUVELLES 75(2020):21.