集中式砂岩型热储地热资源开采井网优化与实践

Optimization and practice of well pattern for exploitation of geothermal resources in centralized sandstone thermal reservoir

摘要:

近年来人们对中深层砂岩型地热资源开发越来越重视，集中开采逐步成为常态。在集中式砂岩型地热井井群部署过程中，井距、井网不仅决定地热井多年后温度和水位变化，也影响着地热项目的寿命及经济性。文章以冀东曹妃甸新城2.3×10⁶ m²地热供暖项目为例，研究了集中式砂岩型地热开采井网优化。在研究区地热勘查的基础上，利用采灌试验确定地热井开采量为100 m³/h、回灌量为80 m³/h。采用数值建模优化地热采灌井井距为450 m，地热采灌井井网按交错式排状部署。采用多井先导试验验证地热井开采量、回灌量的合理性，并制定地热井采灌运维制度，实现100%自然回灌。利用井群多年采灌生产数据建模，预测热储渗流场水位与温度变化。为规模化地热资源开发提供技术支持。

Abstract:

In recent years， people have paid more and more attention to the development of medium-deep sandstone geothermal resources， and centralized exploitation has gradually become the norm. In the deployment process of centralized sandstone geothermal wells， well spacing and well pattern not only determine the temperature and water level changes of geothermal wells after many years， but also affect the life and economy of geothermal projects. This paper takes the geothermal heating project with an area of 2.3×10⁶m² in Jidong Caofeidian Newtown as an example， the optimization of centralized sandstone geothermal exploitation well pattern is studied. On the basis of geothermal exploration in the study area， the exploitation volume of geothermal wells is 100m³/h and the reinjection volume is 80m³/h. Numerical modeling is used to optimize the well spacing of geothermal production and irrigation wells to 450m， and the well pattern of geothermal production and irrigation wells is arranged in staggered rows. Multi-well pilot test is used to verify the rationality of the production and reinjection volumn of the geothermal well， and the geothermal well production and irrigation operation and maintenance system is formulated to achieve 100% natural reinjection. The water level and temperature changes for many years of the thermal reservoir seepage field are predicted by modeling the production data of the well group. It can provide technical support for large-scale geothermal resource development.