首页|Coupled thermo-hydro-mechanical modelling for geothermal doublet system with 3D fractal fracture

Coupled thermo-hydro-mechanical modelling for geothermal doublet system with 3D fractal fracture

扫码查看
The existence of preferential flow paths, such as fractures and/or fault play an vital role on the thermal breakthrough of geothermal doublet system. The interaction between the preferential flow path and bedrock is often uneven and may have typical fractal characteristic. This study proposes a thermo-hydro-mechanical coupling model considering the deformation of fractal fractures. The fractal fracture is regarded as a thin elastic layer existed in the bedrock, whoes deformation depends to the bedrock and its own mechanical properties. Subsequently, the geothermal doublet system with a three-dimensional fractal fracture is modelled and the parameters affecting thermal breakthrough are investigated numerically. Research results indicate that the thin elastic layer assumption is remarkably robust for modelling fracture opening and closing under coupling conditions. Owing to complex fracture geometry, the fracture permeability evolution presents certain heterogeneity, which is related to fractal dimension, in-situ stress, and geothermal wells layout. The cool water in fracture with larger fractal dimension can interact with the bedrock more fully and further affect the thermal breakthrough. This further suggests that the site selection of geothermal wells should consider the specific geometry of preferential flow paths to avoid premature thermal breakthrough inducing low system efficiency.

3D fractal fractureThermo-hydro-mechanical couplingThin elastic layerThermal breakthrough

Liu, Jia、Xue, Yi、Zhang, Qi、Wang, Huimin、Wang, Songhe

展开 >

Xian Univ Technol, State Key Lab Ecohydraul Northwest Arid Reg, Xian 710048, Peoples R China

Beijing Res Inst Uranium Geol BRIUG, 10 Xiao Guan Dong Li,POB 9818, Beijing 100029, Peoples R China

Hohai Univ, Coll Water Conservancy & Hydropower Engn, Nanjing 210098, Peoples R China

2022

Applied thermal engineering

Applied thermal engineering

EISCI
ISSN:1359-4311
年,卷(期):2022.200
  • 33
  • 45