开采状态下河北平原孔隙热储地热水资源的构成——以辛集集中开采区为例

地热水属于承压水,其储存量包括容积储存量和弹性储存量两部分,当水位处于含水层顶板以上时,已开采出的地热水只能是弹性储存量。在河北平原区进行区域地热资源评价时,地热水可开采量按照开采系数法、解析法等不同方法计算,与弹性储存量存在巨大差距。为研究地热水开采资源的构成并更加准确评价集中开采区地热水的可开采量,采用地下水均衡法对辛集集中开采区地热水开采资源量进行了计算,结果显示: 侧向补给量为126×10⁴ m³,占开采资源量的60.9%; 越流补给量为19.7×10⁴ m³,占开采资源量的9.55%; 弹性释水量为33.1×10⁴ m³,占开采资源量的16.1%; 弱透水层压密释水量为27.4×10⁴ m³,占开采资源量的13.3%。研究结果说明,集中开采区地热水的开采资源量不仅仅来自于热储层的弹性释水量,还包括侧向补给量、越流补给量和弱透水层的压密释水量。研究成果对于科学合理地开发地热资源、更好地遏制和缓解地热水开采引发的地质环境问题具有一定意义。

Composition of geothermal water in porous geothermal reservoir under exploitation in Hebei Plain: A case study in Xinji area

Geothermal water belongs to confined water, and its storage capacity includes volume storage capacity and elastic storage capacity. When the water level is above the aquifer roof, the exploited geothermal water can only be elastic storage capacity. The recoverable amount of geothermal water was calculated by mining coefficient method and analytical method in the evaluation of regional geothermal resources in Hebei Plain, which has a huge difference with elastic storage amount. In order to study the composition of geothermal water exploitation resources and evaluate more accurately the exploitable quantity of geothermal water in the concentrated exploitation area, the author of this paper has adopted the groundwater balance method to calculate the exploitation quantity of geothermal water in Xinji concentrated exploitation area. The results show that lateral recharge is 126×10⁴ m³, accounting for 60.9% of the exploitation resources; the overflow recharge is 19.7×10⁴ m³,accounting for 9.55% of the exploitation resources; the elastic water release is 33.1×10⁴ m³,accounting for 16.1% of the exploitation resources, and the impermeable water release is 27.4×10⁴ m³, accounting for 13.3% of the exploitation resources. The exploitation resources of geothermal water in the concentrated mining area not only come from the elastic water release of thermal reservoir, but also include lateral recharge, overflow recharge and compaction water release. These results are of great significance to the scientific and reasonable development of geothermal resources, and to better control and alleviation of the geological environment problems caused by geothermal water exploitation.