Key Laboratory of Deep Coal Resource Mining,Ministry of Education,China University of Mining and Technology
School ofMines,China University of Mining and Technology
Institute of Coal Mining and Utilization,Pingdingshan Tianan Coal MiningCo.,Ltd.

It is strategically significant for the mine in operation to investigate the development and utilization of geo⁃thermal water resources for realizing coal⁃thermal co⁃mining in the context of “carbon peaking and carbon neutral” in China. However,currently the coal⁃thermal co⁃mining technology is immature,and a further research is needed for thegeothermal water extraction in operating mines. Thus,this paper presented an unconventional method for the under⁃ground mining of geothermal water based on coal⁃thermal co⁃mining theory and technical framework. In the studiedmine area,the formation mechanism of thermal reserves was analyzed,the amount of geothermal water resources wasestimated by the thermal reserve volume method,and the potential of geothermal water development was evaluated.Simultaneously,the thermal reservoir temperature field and production well water temperature variation were numeri⁃cally simulated under the unconventional mining mode of geothermal water. The effects of production well⁃group pa⁃rameters on the thermal reservoir temperature field and production well water temperature were analyzed and comparedwith the conventional method of geothermal water production. Finally,the social and economic benefits generated bythe mine geothermal water mining and utilization were discussed. The results show that:① The static recoverable re⁃serves of geothermal water in the mine is 1.14×1017 J,equivalent to 3.9 Mt of standard coal. The dynamic recoverablereserves is 2.95×1016 J/ a,equivalent to 1.01 Mt/ a of standard coal.② The water temperature of the production well isinfluenced by the temperature of the recharge water,with less relation to the recharge method. Meanwhile,it is affectedby the temperature of the recharge water on the production well water temperature mainly in the late production period.③ The thermal breakthrough time of the production well⁃group is advanced and the cooling rate is increased after thethermal breakthrough point with increasing production rate. ④ Balanced production has a beneficial effect on the lifeof producing wells. ⑤ Adjusting the production strategy of the unconventional mining mode can realize the coordinatedmining of the production well⁃group and extend the life of the production well⁃group,resulting in a smaller averagecooling rate than the conventional mining mode of the production wells. ⑥ Once the mine geothermal development sys⁃tem has been completed,the heating area of 170 000 m2 in the coal mine and the bathing of all mine employees can berealized,reducing coal burning by 10 327 t and CO2 emission by 26 900 t per year,creating economic benefits of 6.938million RMB for the enterprise. Therefore,it is feasible to implement unconventional mining of underground geothermalwater for hydrothermal high⁃temperature mines. And the efficient mining of geothermal water in mines can be realizedby reasonably arranging the distribution of production well⁃group and scientifically formulating the production strategy.