Existing studies overlook the well-rock coupling process and deep wellbore heat transfer effects, making it difficult to accurately evaluate the heat extraction performance of enhanced geothermal system (EGS) in hot dry rock. To address this issue, a three-dimensional thermal flow coupling model for well-rock combination based on COMSOL was developed, and the impact of various factors on the heat extraction performance of the EGS was analyzed. The simulation results show that the heat extraction process of EGS primarily relies on heat transfer through fractures and wellbores, with heat exchange through fractures contributing 73% and that through wellbore accounting for 27%. In a single injection and production mode, the best heat extraction occurs at a 500 m spacing between wells, with an outlet temperature reaching 145.5 ℃. Increasing the injection flow rate raises the outlet temperature, but shortens the heat reservoir’s lifespan. Optimizing well layout and flow heat transfer paths reveals that the single injection and production layout has a longer lifespan and higher outlet temperature, while the single injection and four production mode achieves the highest heat extraction, 3.1 times that of the single injection and production.
ChuH Q, HuangZ, ZhangZ K, et al. Integration of carbon emission reduction policies and technologies: research progress on carbon capture, utilization and storage technologies[J]. Separation and Purification Technology, 2024, 343: 127153.
[2]
ShanD D, YanT, LiW, et al. A review of multi-field coupling simulation of wellbore and heat reservoir in enhanced geothermal system[J]. IOP Conference Series: Earth and Environmental Science, 2019, 300(2): 022076.
[3]
MaW W, YangC, AhmedS F, et al. Effects of thermophysical parameters of fracturing fluid on hot dry rock damage in hydraulic fracturing[J]. Geomechanics for Energy and the Environment, 2022, 32: 100405.
[4]
SunY X, ZhangX, LiuY S, et al. Prediction and optimization of productivity and lifespan in multi-well enhanced geothermal system[J]. Applied Thermal Engineering, 2023, 234: 121155.
[5]
WangZ W, ZhangB, ZhuX Y, et al. How does the space of production wells influence the heat extraction efficiency? Defined by a 3D modeling work in enhanced geothermal system (EGS) [J]. Frontiers in Energy Research, 2024, 12:1361290.
[6]
ChenJ L, JiangF M. Designing multi-well layout for enhanced geothermal system to better exploit hot dry rock geothermal energy[J]. Renewable Energy, 2015, 74: 37-48.
[7]
HuangW B, CaoW J, JiangF M. Heat extraction performance of EGS with heterogeneous reservoir: a numerical evaluation[J]. International Journal of Heat and Mass Transfer, 2017, 108: 645-657.
[8]
LuX, TongX L, DuX P, et al. Effect of wellbore layout and varying flow rate on fluid flow and heat transfer of deep geothermal mining system[J]. Thermal Science and Engineering Progress, 2023, 42: 101870.
[9]
YaoJ, ZhangX, SunZ X, et al. Numerical simulation of the heat extraction in 3D-EGS with thermal-hydraulic-mechanical coupling method based on discrete fractures model[J]. Geothermics, 2018, 74: 19-34.
ShanDan-dan, YanTie, LiWei, et al. Numerical simulation and analysis of thermal-hydraulic coupling in a single-fracture thermal reservoir[J]. Contemporary Chemical Industry, 2020, 49(4): 716-719, 723.
[12]
AliyuM D, ArcherR A. A thermo-hydro-mechanical model of a hot dry rock geothermal reservoir [J]. Renewable Energy, 2021, 176: 475-493.
[13]
ZhaoK, SongW J, WangX Y, et al. Study on the influence law of well location and water injection displacement on heat extraction performance of EGS[J]. Energy Science & Engineering, 2023, 11(7): 2571-2584.
[14]
ChurchillS W. Friction-factor equation spans all fluid-flow regimes [J]. Chemical Engineering, 1977, 84(24): 91-92.
[15]
KellerH H, CouchE J, BerryP M. Temperature distribution in circulating mud columns[J]. Society of Petroleum Engineers Journal, 1973, 13(1): 23-30.
[16]
JiangF M, LuoL, ChenJ L. A novel three-dimensional transient model for subsurface heat exchange in enhanced geothermal systems[J]. International Communications in Heat and Mass Transfer, 2013, 41: 57-62.
YuXiao-lei, ZhangXiao-hui, LiuZhen-wei, et al. Hot dry rocks in Liaoning Province: occurrence conditions and primary selection of target areas[J]. Geology and Resources, 2023, 32(5): 608-615.
[19]
ZengY C, SuZ, WuN Y. Numerical simulation of heat production potential from hot dry rock by water circulating through two horizontal wells at Desert Peak geothermal field [J]. Energy, 2013, 56: 92-107.
[20]
GhassemiA, TarasovsS, ChengA H D. Integral equation solution of heat extraction-induced thermal stress in enhanced geothermal reservoirs[J]. International Journal for Numerical and Analytical Methods in Geomechanics, 2005, 29(8): 829-844.