Investigation and evaluation methods of shallow geothermal energy considering the influences of fracture water flow

Geothermal Energy

Research

Peng Pei¹  Fengqiang Deng¹  Tingting Luo¹  Yixia Chen¹  Yonglin Ren² 

[1] College of Mines, Guizhou University, North Wing Rm 426, Huaxi, 550025, Guiyang, Guizhou, China;Guizhou Lvnengxing New Energy Development Co., Ltd., 550001, Guiyang, China;

关键词: Shallow geothermal;    Fractured rock mass;    Fracture water;    Investigation and evaluation;   

DOI  :  10.1186/s40517-023-00267-1

 received in 2023-01-28, accepted in 2023-08-10,  发布年份 2023

来源: Springer

【 摘 要 】

The energy replenishment and heat convection induced by fracture water flowing through the rock mass impact the shallow geothermal energy occurrence, transfer and storage mechanisms in it. In this article, a suitability evaluation and categorization system is proposed by including judgement indexes that are more closely aligned with the actual hydrogeological conditions in fracture developed regions; an assessment approach of regional shallow geothermal energy is proposed by coupling the influences of fracture water into the calculation methods of geothermal capacity, thermal balance and heat transfer rate. Finally, by taking two typical fracture aperture distributions as examples, the impacts of fracture water on the investigation and evaluation of shallow geothermal energy are quantitatively analyzed. Although the fracture apertures only share 1.68% and 0.98% of the total length of a borehole, respectively, in the two examples, the fracture water convection contributes up to 11.01% and 6.81% of the total heat transfer rate; and the energy replenishment potential brought by the fracture water is equivalent to the total heat extraction of 262 boreholes. A single wide aperture fracture can dominate the aforementioned impacts. The research results can support more accurate evaluation and efficient recovery of shallow geothermal energy in fracture developed regions.

【 授权许可】

CC BY   
© Helmholtz Centre for Environmental Research / Helmholtz-Zentrum für Umweltforschung GmbH (UFZ), Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ, Karlsruher Institut für Technologie (KIT) 2023

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