The enhanced geothermal system (EGS) is an engineering technique that has been created to extract economical amounts of heat from geothermal resources of low permeability and porosity. After the heat-exchange fluid is injected into the deep geothermal reservoir, there will be a water-rock interaction in the fracture channel, causing the dissolution and precipitation of reservoir minerals and changing the physical properties of the fracture channel, influencing long-time running of EGS significantly. This paper concerns a typical granite in Soultz as a geothermal reservoir and builds up a one-dimensional MINC model. Then CO2 and water with identical temperatures and pressures are injected to contrast the effects of injected fluid water/CO2-rock interactions on the fractures in EGS. Results show that the effect of water-rock interaction of CO2-EGS on fracture channel properties is less obvious than that of H2OEGS on the same operation mode.
BAO Xinhua
,
WU Yongdong
,
WEI Mingcong
,
JIN Xianpeng
,
WANG Shuyuan
. Impact of Water/CO2-Rock Interactions on Formation Physical Properties in EGS[J]. Science & Technology Review, 2014
, 32(14)
: 42
-47
.
DOI: 10.3981/j.issn.1000-7857.2014.14.006
[1] 康玲, 王时龙, 李川. 增强地热系统EGS 的人工热储技术[J]. 机械设 计与制造, 2008(9): 141-143. Kang Ling, Wang Shilong, Li Chuan. Reservoir technology in enhanced geothermal systems[J]. Machinery Design & Manufacture, 2008(9): 141-143.
[2] 张建英. 增强型地热系统(EGS) 资源开发利用研究[J]. 中国能源, 2011, 33(1): 29-32. Zhang Jianying. Study on exploitation and utilization in an enhanced geothermal system (EGS)[J]. Energy of China, 2011, 33(1): 29-32.
[3] Durst A C, Lee P A. Microwave conductivity due to scattering from extended linear defects in d-wave superconductors[J]. Physical Review B, 2002, 65(9): 094501.
[4] Rabemanana V, Violette S, De Marsily G, et al. Origin of the high variability of water mineral content in the bedrock aquifers of Southern Madagascar[J]. Journal of Hydrology, 2005, 310(1): 143-156.
[5] 王洋, 张可霓. 增强型地热系统(EGS) 的裂隙模拟方法[J]. 上海国土 资源, 2011, 32(3): 77-80. Wang Yang, Zhang Keni. Modeling approaches for fractures in an enhanced geothermal system (EGS)[J]. Shanghai Land and Resources, 2011, 32(3): 77-80.
[6] Xu T, Sonnenthal E, Spycher N, et al. TOUGHREACT: A simulation program for non-isothermal multiphase reactive geochemical transport in variably saturated geologic media: applications to geothermal injectivity and CO2 geological sequestration[J]. Computers & Geosciences, 2006, 32(2): 145-165.
[7] Vinsome P K W, Westerveld J. A simple method for predicting cap and base rock heat losses in thermal reservoir simulators[J]. Journal of Canadian Petroleum Technology, 1980, 19(3): 87-90.
[8] Pruess K. Enhanced geothermal systems (EGS) using CO2 as working fluid: A novel approach for generating renewable energy with simultaneous sequestration of carbon[J]. Geothermics, 2006, 35(4): 351-367.
[9] Pruess K. On production behavior of enhanced geothermal systems with CO2 as working fluid[J]. Energy Conversion and Management, 2008, 49 (6): 1446-1454.
[10] Xu T, Rose P, Fayer S, et al. On modeling of chemical stimulation of an enhanced geothermal system using a high pH solution with chelating agent[J]. Geofluids, 2009, 9(2): 167-177.
[11] Xu T, Pruess K, Apps J. Numerical studies of fluid-rock interactions in enhanced geothermal systems (EGS) with CO2 as working fluid[R]. Berkeley: Lawrence Berkeley National Laboratory, 2008.
