3D geological modeling of mine karst geothermal reservoir and geothermal resources evaluation
ZHANG Yuan;WAN Zhijun;HU Songbo;WANG Zhuting;ZHANG Bo;ZHAO Dong
中国矿业大学 矿业工程学院中国矿业大学 煤炭精准勘探与智能开发全国重点实验室平顶山天安煤业股份有限公司 煤炭开采利用研究院平顶山天安煤业股份有限公司 十矿安徽理工大学 地球与环境学院
传统热储体积法适用于大尺度区域的地热资源量评价,用于矿井地热资源量评价时误差较大。在分析平顶山矿区“源、通、储、盖、流体”地热系统特征的基础上,建立了矿区地热成因概念模型。以平煤十矿井田为主要研究区,基于区内地热地质条件和地面、井下钻孔资料,采用地下水模型系统(Groundwater Modeling System, GMS)软件建立了研究区内地层的三维地质模型,呈现了寒武系碳酸盐岩地层及覆岩的展布情况,并对寒武系碳酸盐岩地层空间进行了数字化。提出了用于矿井地热资源评价的积分式热储体积法,采用该方法对研究区内寒武系岩溶热储静态资源量进行了估算,并评价了热储的动态资源量,得出了热储层地热资源量与地热水位标高的关系曲线。对研究区内寒武系岩溶地热水进行了水质全分析,评价了地热水的腐蚀性和结垢性。结果显示,研究区内寒武系碳酸盐岩(灰岩)层为岩溶热储层,热量主要来自寒武系朱砂洞组以深的高温岩体;地表大气降水经寒武系灰岩露头和矿区周缘深大断裂进入深部岩体,沿途被加热后储存于寒武系灰岩地层中,并持续接受深部基岩热量传输,形成水热型岩溶热储;寒武系岩溶热水静态资源量为76.8亿m3,蕴含热量1.19×1018 J;岩石中蕴含热量为3.25×1018 J;地热资源总量为4.44×1018 J;地热可采资源量为6.66×1017 J,折合标煤22.7 Mt;寒武系岩溶热水具有轻微腐蚀性,结垢性为轻微—中等,流经金属管道和容器需要做防腐和防垢处理。
The traditional geothermal reservoir volume method is suitable for the evaluation of geothermal resources in large-scale regions, but there is a significant error when it is used for the evaluation of mine geothermal resources. On the basis of analyzing the characteristics of the geothermal system of the Cambrian karst geothermal reservoir, i.e., heat sources, fluid channels, reservoirs, caprocks and the heat fluid in the Pingdingshan mining area, a conceptual model of geothermal genesis in the Pingdingshan coalfield was established. Based on the geothermal geological conditions and drilling data ground and underground in No.10 Coal Mine of Pingdingshan Tianan Coal Mining Co., LTD., a three-dimensional geological model of the strata in the study area was established using Groundwater Modeling System software. The distribution of Cambrian karst strata and its overburden strata was displayed, and the Cambrian karst strata space was gridded and digitized. The integrated geothermal reservoir volume method for evaluating geothermal resources in mines was proposed and used to estimate the static resource quantity of the Cambrian karst geothermal reservoir in the study area, and the dynamic resource quantity of the geothermal reservoir was also evaluated. The relationship curve between the geothermal reservoir resource quantity and water level elevation was obtained. A complete water quality analysis was conducted on the karst geothermal water in the study area, and the corrosiveness and scaling properties of the geothermal water were evaluated. The results show that the Cambrian carbonate strata in the study area are the karst geothermal reservoir, and the heat mainly comes from high-temperature rock mass deep in the Cambrian Zhushadong Formation; surface atmospheric precipitation enters the deep rock mass through Cambrian limestone outcrops and deep faults around the mining area, and is heated along the way and stored in Cambrian limestone, after which the water continue to receive the heat from deep bedrock and then forms a hydrothermal karst geothermal reservoir; the static hot water resource of Cambrian karst strata in the study area is 7.68 billion m3, containing heat of 1.19×1018 J; the heat contained in the rock is 3.25×1018 J, with a total geothermal resource of 4.44×1018 J; the recoverable geothermal resources are 6.66×1017 J, equivalent to 22.7 million tons of standard coal; the Cambrian karst hot water has slight corrosiveness, with a slight to moderate degree of scaling. Corrosion and scale prevention treatments are required for metal pipelines and containers of the geothermal water.
mine geothermal;karst geothermal reservoir;geological modeling;reserve evaluation;geothermal water
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会