PHREEQC模拟宝坻区地表水回灌雾迷山组地热井探析

天津市蕴藏着丰富的中低温地热资源,但是近年来地热集中开采区内热储压力持续下降,为了提高地热资源的可持续利用强度,对地热回灌方法的研究势在必行.本文从水文地球化学角度入手,分析了不同比例地表水与地热流体混合后流体主要离子组分的变化情况及结垢性,并以潮白河河水回灌宝坻区雾迷山组地热井(BD-02井)为例,采用PHREEQC软件对混合作用进行了不同比例模拟,结果显示混合比例达到1:1时,主要离子组分含量稳定,未对原地热流体水质造成影响.河水与地热流体混合时,碳酸盐矿物、含铁矿物、温石棉和滑石的饱和指数呈现降低趋势,不会出现结垢的现象,回灌能长期稳定进行.

Analysis on PHREEQC Simulating Surface Water Reinjection of Jxw Geothermal Wells in Baodi District,Tianjin

Tianjin contains abundant low-temperature geothermal resources, but geothermal exploitation thermal storage pressure declined continually in recent years. It is imperative to exploring new reinjection methods for im-proving the sustainable utilization of geothermal resources. From the point of the hydrological geochemical as-pects, this paper analyzed the main iron composition changes and trend of scaling after surface water and geother-mal fluid mixing with different proportions. It used the example that Chaobai River reinjects Jxw geothermal well in Baodi District (BD-02 well), and used PHREEQC software to simulate the mixing action of different ion pro-portions. The results show that the main ion concentration is stable and had no effect on the water quality of the original geothermal fluid when the mixture ratio reached 1:1. When the water was mixed with geothermal fluids, carbonate minerals, iron bearing minerals, and the saturation index of asbestos and talc showed a decreasing trend, and there will not be a phenomenon of scaling. Reinjection can be stable for a long time.