天津市东丽湖地热对井的地质与水文地球化学特征

GEOLOGICAL AND HYDROGEOCHEMICAL CHARACTERISTICS GEOTHERMAL PAIRED WELLS IN DONGLI LAKE AREA TIANJIN

SR28、SR29地热对井位于天津市东丽区,处于沧县隆起之大小东庄凸起的西缘,沧东断裂带附近,山岭子地热异常区中心。SR28、SR29地热对井采用中元古界蓟县系雾迷山组热储层作为开采和回灌目的层。根据地热水化学分析结果分析了地热水的水文地球化学特征,认为:SR28、SR29地热水属于含岩盐地层溶虑的陆相沉积水;雾迷山组碳酸盐地层为地热水的储水层,地热水来源于外源水流经上层灰岩地层的补给;SR28、SR29地热水属于未污染的天然水、微腐蚀型水,不结CaCO3垢和CaSO4.2H2O垢,有S iO2垢生成的可能。

The SR28 and SR29 geothermal paired wells are located in Dongli District of Tianjin, lying on the western fringe of big-small Dongzhuang doming in Cangxian uplift, near the Cangdong fault and at the center of the Shanlingzi geothermal anomaly area. The SR28 and SR29 geothermal paired wells use the geothermal reservoir of Wumishan Formation of Mesoproterozoic Jixian System as the target layer of exploitation and recharge. This paper analyzed the hydrogeochemieal characteristics of geothermal water according to chemical analysis, and the result shows ＂that SR28 and SR29 geothermal water belongs to continental sedimentary water formed in the strata with dissolved salt brine, that carbonate strata of Wumishan Formation constitute the storage layer of geothermal water, and that the geothermal water is likely to come from the supplement of outside sources which go through upper limestone strata. Being unpolluted and microcorrosion type water, SR28 and SR29 geothermal water does not form CaCO3 or CaSO4 · 2H2O scales, but sometimes may generate SiO2scales.