豫东通许凸起回灌条件下新近系地热资源优化开采方案研究

Study on the optimal exploitation scheme of Neogene geothermal resources under the reinjection condition in Tongxu Uplift,East Henan

地热井的优化开采对地热资源的集约高效利用意义重大。本文以豫东通许凸起中部地热地质单元为研究对象,采用FEFLOW软件建立了新近系热储三维水热耦合模型,利用回灌试验成果预测了全区在“仅开采模式”、“一采二灌(采灌比38.41%)”、“一采三灌(采灌比100%)”下自2020-2030年开采年限内的地热流体压力场和温度场变化情况,并计算了新近系热储不同开采模式下可采热能。预测结果表明:回灌率100%时,研究区地热流体压力水头回升更明显,回灌引起研究区新近系热储温度下降更微弱,获得可采地热能最大为0.852×1016 J。在此基础上提出了最优化的采灌布井模式,为通许凸起深部地热资源可持续开发提供理论依据。

There is a great significance of the optimal exploitation of geothermal wells for the intensive and efficient utilization of geothermal resources.This paper takes the geothermal geological unit at the middle of Tongxu Uplift in the east of Henan Province as the research object,FEFLOW software is used to establish a three-dimensional unsteady flow heat conduction model of Neogene thermal reservoir,and the result of the reinjection test is applied to predict the change of the geothermal fluid pressure field and temperature field in the whole region from 2020 to 2030 under the conditions of"only mining mode","one well mining and two well irrigation(mining and irrigation ratio 38.41%)"and"one well mining and three well irrigation(mining and irrigation ratio 100%)".The recoverable heat energy of the Neogene thermal reservoir under different mining modes is calculated.The prediction result shows that when the reinjection rate is 100%,the pressure head of geothermal fluid in the study area rises more obviously,and the temperature of the Neogene thermal reservoir in the study area decreases more weakly due to reinjection,and the maximum recoverable geothermal energy is 0.852×1016J.On this basis,the optimal pattern of mining and irrigation well distribution is proposed,which provides a theoretical basis for the sustainable development of geothermal resources in the deep part of Tongxu Uplift.