关于高温高压地热井水温及水量降低的试验研究

Experimental Study on the Reduction of Water Temperature and Volume in High Temperature and High Pressure Geothermal Wells

地热井进入生产阶段后,井内高温流体与外界通道会逐步打开,经过高压清水洗井、自流涌水洗井和振荡抽水洗井3种方法,致使含水层压力释放,水温、水量逐渐降低。本文通过试验研究了甘肃张掖已投入生产的高温高压地热井使用情况,自流水量由287.41 m^(3)/h减少到150 m^(3)/h,水温由76℃降低至73℃。经过通井出砂、抽拉洗井、高压喷射洗井,井口自流水温、水量并没有增加。通过采用填砾滤水管和回灌开采方式可有效延长地热井的使用年限,实现地热开发的可持续性。

When the geothermal well enters the production stage,the channel between the high-temperature fluid in the well and the outside world will be gradually opened,the pressure of the aquifer will be released,the water temperature and volume will be gradually reduced through three methods of well flushing with high-pressure clean water,self-gushing water and oscillating pumping.In this paper,the application of high temperature and high pressure geothermal wells that have been put into production in Zhangye,Gansu Province,is studied by experiments.The artesian water volume reduces from 287.41 m^(3)/h to 150 m^(3)/h,and the water temperature decreases from 76℃to 73℃.There is no increase in the artesian water temperature and volume at wellhead after sand production through well,pumping and cleaning,as well as high pressure jet cleaning.The service life of geothermal wells can be effectively extended by using gravel filled filter pipes and reinjection mining to realize the sustainability of geothermal development.