含水层砂岩指数在新疆新生界砂岩承压含水层单井出水量预报中的应用

Application of aquifer sandstone index in predication of water yield of single well on confined aquifer in Xinjiang

三塘湖以北地区是新疆最近探明的主要煤田之一,在煤系地层之上覆盖有水量较丰富的新生界砂岩承压含水层,是煤田开发过程中重要的供水水源之一。本文提出含水层砂岩指数的概念,以三塘湖北煤田供水水文地质详查资料为基础,建立承压含水层砂岩指数与单井出水量的关系。结果表明:承压含水层砂岩指数与单井出水量间具有极显著的线性相关关系,砂岩指数预测单井出水量的相对误差一般小于50%,平均绝对误差仅7.59m3/d,平均误差1.07%,拟合程度较高;宜井区(单井出水量>500 m3/d)相对误差一般<15%,拟合程度高。该成果对于今后宜井区承压含水层单井出水量的预测以及地下水开采井的合理布置具有重要的现实意义。

The northern area of Santanghu is one of the major coalfields which have been recently ascertained in Xinjiang. The coal-bearing stratum is covered with cenozoic sandstone confined aquifer. The cenozoic sandstone confined aquifer is one of the most important sources of water supply during coalfield development process. Based on detailed hydrogeological survey data of coalfield water supply in northern area of Santanghu,the paper propsed the concept of aquifer sandstone index( ASI) and set up the relation between ASI of confined aquifer and water yield of single well. The results show that there is a significant linear correlation between ASI of confined aquifer and water yield of single well. When using ASI to predict water yield of single well,the relative error is generally less than 50% and mean absolute error and average error is 7. 59 m3/d and 1. 07% respectively. The fitting degree is higher. The relative error is generally less than 15% in suitable well area while the water yield of single well is more than 500 m3/d with very high fitting degree. The result has important practical significance for prediction of water yield of single well of confined aquifer in suitable well area and rational arrangement of groundwater extraction well.