鲁西北平原砂岩热储地热地质特征及成因模式

Geothermal geological characteristics and genetic modelof sandstone thermal reservoirs in northwestern plain of Shandong

为了分析鲁西北平原砂岩热储地热地质特征及成因模式,笔者采用资料收集和实验测试相结合的方法对热储层、地温场、水化学和水位动态变化特征进行研究。结果表明,鲁西北平原砂岩热储类型为新近纪馆陶组和古近纪东营组热储,热储层顶板埋深及地层厚度最大值区域均位于聊城临邑县。热储地温梯度普遍低于3.4℃/100 m,但平原县凸起区地温梯度大于4.0℃/100 m。地热水化学类型以Cl-Na型为主,表现出Na+、K+及Cl-富集的特点。地热水温度为54.4~85.9℃,聊城市临清地区热储温度较高。砂岩热储地热水与深层地下水之间水力联系较小,地热水位变化主要受人工采灌的影响。

To analyze the geothermal geological characteristics and formation model of the sandstone geothermal reservoirs in the northwestern plain of Shandong,the authors used a combination of data collection and experimental testing methods to study the characteristics of geothermal reservoirs,geothermal gradient,hydrochemistry,and dynamic changes in water levels.The results show that the sandstone geothermal reservoirs in the northwestern plain of Shandong are mainly of the Neogene Guantao Formation and Paleogene Dongying Formation,with the deepest burial depth of the reservoir top and maximum formation thickness located in Linyi County,Liaocheng.The geothermal gradient is generally below 3.4℃/100 m,except in the uplifted area of Pingyuan County,where the gradient exceeds 4.0℃/100 m.The geothermal water is primarily of the Cl-Na type,characterized by an enrichment of Na+,K+,and Cl-ions.The geothermal water temperature ranges from 54.4 to 85.9℃,with the highest reservoir temperatures observed in Linqing,Liaocheng.There is minimal hydraulic connectivity between the geothermal water in the sandstone reservoir and deep groundwater,and changes in geothermal water levels are mainly influenced by artificial extraction and recharge activities.