冀中馆陶组砂岩热储开发采灌试验研究

Experimental study on thermal reservoir balanced pumping and recharging in Guantao Formation sandstone in Jizhong

砂岩孔隙热储100%回灌难度大,亦为世界性难题。冀中某地上第三系馆陶组砂岩热储出水量大,水温高。为实现经济可持续开发,确定热储层水力连通性、单井采灌速度、井网井距、回扬及回灌制度等地热开发参数,设计了4口井的单井抽水试验及89d的大型井组间采灌试验。试验结果为进一步的开发方案运行提供了方法及数据支撑,对同类型热储开发借鉴意义大。经计算研究区馆陶组热储层渗透系数为0.33~0.5m/d,导水系数为19.95~40.30m^(2)/d,贮水系数为(7.41~9.85)×10^(-5);根据抽水试验水位降深关系确定地下水力连通性最好的方向为东北至西南;单井采灌速度建议控制在50~60m^(3)/h;热储层在1800m左右存在高渗层,热水井距布设至少应在400m以上;回扬制度推荐选择大排量+中排量+小排量,回灌制度推荐选择小排量+中排量+大排量。

Recharging into sandstone pore thermal reservoir after pumping groundwater is difficult worldwide.The thermal storage capacity of sandstone of Guantao Formation of Neogene in Jizhong is large with high temperature.In order to keep economic sustainable development,the relevant parameters including the hydraulic connectivity of the thermal reservoir,the pumping and recharging rate of single well,well pattern and well spacing,pumping and recharging model are determined through a large scale experiment with 4 nos.single well pumping tests and 89 days pumping and recharging tests.The test results provide methods and data information for further development,and are significant for the similar thermal storage works.The permeability coefficient of Guantao Formation thermal reservoir is 0.33~0.5 m/d,the hydraulic conductivity coefficient is 19.95~40.3 m^(2)/d,and the elastic water release coefficient is(7.41~9.85)×10^(-5);the pumping and injection speed of a single well is suggested to be controlled at 50~60 m^(3)/h;there is a high permeability layer around 1800 m,and the spacing of hot water well should be at least 400 m.The recommended selection of periodical backwashing system is large,medium,small backwashing;and the recommended selection of recharging system is small,medium,large discharging.