生产井井间距离对增强型地热系统影响分析

为揭示生产井井间距离对增强型地热系统(EGS)的影响,以中国青海共和盆地增强型地热系统为研究对象,采用数值模拟方法,建立了考虑生产井井间距离不同的三维热-固-流耦合热采模型。分析得到生产井井间距离为600 m, 700 m, 800 m, 900 m, 1000 m对EGS温度场、产出流体温度、储层寿命、总产热量、最大主应力以及最大主应变影响规律。研究结果表明,随着热开采进行,储层裂隙周围岩体温度下降,产出温度随开采年限增加而降低;从产出温度、储层寿命和总产热量三方面考虑,最优生产井井间距离为800 m;生产井井间距离对第一主应力及第一主应变影响显著,应结合实际情况选择最优生产井井间距离。

Analysis of the influence of the distance between producing Wells on the enhanced geothermal system

In order to reveal the influence of the distance between producing Wells on the enhanced geothermal system (EGS), a three-dimensional thermal-solid-fluid coupling thermal recovery model considering the different distances between producing Wells was established by numerical simulation with the enhanced geothermal system in Gonghe Basin, Qinghai Province, China as the research object.The effects of the distance between producing Wells of 600 m, 700 m, 800 m, 900 m and 1000 m on EGS temperature field, production fluid temperature, reservoir life, total heat production, maximum principal stress and maximum principal strain were analyzed.The results show that:with the development of thermal mining, the temperature of rock mass around reservoir fractures decreases, and the output temperature decreases with the increase of mining life.Considering production temperature, reservoir life and total heat production, the optimal distance between Wells is found to be 800 m.The distance of production Wells has a great influence on the first principal stress and the first principal strain, so the optimal distance of production Wells should be selected according to the actual situation.