地热井井间干扰模拟研究——以重庆观音峡背斜东翼为例

Simulation of interwell interference in geothermal well——take the east wing of Guanyinxia anticline in Chongqing as an example

岩溶含水介质的地下水模拟与应用是水文地质工作中的热点与难点。基于Visual Modflow软件平台,选用重庆观音峡背斜东翼静观片区作为研究对象,利用区内3口地热井(ZK1、ZK1-1、ZK3)多次抽水试验资料,建立数值模拟模型,预测分析了不同条件下新增地热井与已有ZK1井井间干扰程度。结果表明:当新增井与ZK1井的距离和新增井开采量分别为1km和500m3/d,2km和1 000m3/d,5km和1 500,2 000,2 500m3/d时,对ZK1附近流场均无影响;当新增井与ZK1井的距离和新增井开采量分别为1km和1 000m3/d,2km和1 500m3/d,5km和3 000m3/d时,ZK1井水头分别下降19,13和8m。说明地热井井间距越小,开采量越大,对相邻井产生干扰的可能性越大,反之越小,同时说明利用Visual Modflow模型模拟地热水流场特征,预测地热井干扰程度这一方法是可行的。

Groundwater simulation and application of karst water-bearing medium are hot spots and difficulties in hydrogeological work.In this research,Jingguan area in the east wing of the Guanyinxia anticline was selected as the research object,and the multiple pumping test data of 3 geothermal wells were obtained.Based on Visual Modflow software platform,the numerical simulation model was established,and interwell interference degree of the geothermal well with the exexisting UK1 in different conditions was calculated.The results show that:when the distance between a new drill and ZK1 and its mining amount is1 km and 500 m3/d,2 km and 1 000 m3/d,5 km and 1 500 m3/d,2 000 m3/d and 2 500 m3/d,respectively,there is no effect on the flow field near the ZK1;when the distance between a new drill andZK1 and its mining amount is 1 km and 1 000 m3/d,2 km and 1 500 m3/d,5 km and 3 000 m3/d,the water head of ZK1 well decreases by 19 m,13 mand 8 mrespectively,illustrating that the smaller the spacing of geothermal wells and the larger the mining volume,the greater the probability of interference with adjacent wells.It proves feasible to simulate the characteristics of geothermal flow field using the Visual Modflow model.