银川贺兰县地热地质条件及水化学特征研究

The geothermal geological conditions and hydrochemical characteristicsin helan county,Yinchuan

银川盆地赋有丰富的地热资源,但开发利用速度却很缓慢。本次选取地热资源开发空白区贺兰县进行研究,并成功钻凿一眼高产地热井,基于此井展开对研究区地热地质条件、热储特征以及地热水水化学特征等进行分析。结果表明:研究区地热水主要来源于大气降水,自西向东由贺兰山东麓山前断裂深循环补给地热水,邻近的银川断裂为其提供了良好的导热通道,最终赋存于新近系红柳沟组和干河沟组砂岩孔隙中,砂岩厚度大,富水性较好,上覆厚层第四系松散层作为热储保温层。地热水在吸收周围岩体的热量的同时,也在径流过程中不断地发生水-岩相互作用,溶滤围岩中的矿物成份,最终形成了水化学类型为Cl-Na型水,地热水中矿物含量丰富,具有一定的医疗价值,适用于进行温泉浴疗等产业的开发。

There are abundant geothermal resources in Yinchuan basin,but its development and utilization speed is very slow. In this paper,Helan County,a blank area of geothermal resources development,is selected for research,and a high-yield geothermal well has been successfully drilled. Based on this well,the geothermal geological conditions,geothermal reservoir characteristics and hydrochemical characteristics in the study area are analyzed. The results show that the geothermal water in the study area mainly comes from the atmospheric precipitation,which is supplied by the Helanshan piedmont fault from west to East in deep circulation. The Yinchuan fault provides a good heat conduction channel for the geothermal water.Finally,it occurs in the sandstone pores of the Neogene Hongliugou formation and Ganhegou formation. The sandstone is thick and rich in the water. The overlying thick Quaternary loose layer is used as cover. Geothermal water not only absorbs the heat of surrounding rock mass,but also constantly produces water-rock interaction in the process of runoff,dissolves and filters the mineral composition in the surrounding rock,and finally forms the hydrochemical type of Cl-Na water. The mineral content of geothermal water is high,which has certain medical value,and is suitable for the development of hot spring bath and other industries.