冀中坳陷岩溶热储地下水对流活动的聚热效应  

Heat accumulation effect of groundwater convective activity in karst geothermal reservoir in Jizhong Depression,Bohai Bay Basin

作　　者：饶松 罗洋[3] 黄顺德 张英 王社教[6] 王一波 胡圣标 RAO Song;LUO Yang;HUANG ShunDe;ZHANG Ying;WANG SheJiao;WANG YiBo;HU ShengBiao(State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development,Beijing 100083,China;SINOPEC Key Laboratory of Geology and Resources in Deep Stratum,Beijing 100083,China;School of Earth Sciences,Yangtze University,Wuhan 430100,China;No.1 Mud Logging Company,BHDC,CNPC,Tianjin 300280,China;Petroleum Exploration and Production Research Institute of SINOPEC,Beijing 102206,China;PetroChina Shenzhen New Energy Research Institute Co.,Ltd.,Shenzhen Guangdong 518052,China;Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]页岩油气富集机理与有效开发国家重点实验室,北京100083 [2]中国石化深部地质与资源重点实验室,北京100083 [3]长江大学地球科学学院,武汉430100 [4]中国石油渤海钻探第一录井公司,天津300280 [5]中国石化石油勘探开发研究院,北京102206 [6]中石油深圳新能源研究院有限公司,广东深圳518052 [7]中国科学院地质与地球物理研究所,北京100029

出　　处：《地球物理学报》2024年第8期3075-3088,共14页Chinese Journal of Geophysics

基　　金：国家自由科学基金(42372350,41877210);中国石化深部地质与资源重点实验室开放基金课题(22-ZC0613-0241)资助。

摘　　要：地形起伏及浮力均可以驱动地下水流,在此过程中通过对流方式快速传递热量,进而改变温度分布模式,造成局部显著热异常,对岩溶储层地热资源聚敛有着重要意义.冀中坳陷岩溶热储发育,岩溶缝洞系统为地下水提供了良好的垂向和水平径流条件,形成了独特的对流-传导复合型地热系统.通过温度场、水动力场耦合数值模拟,本文聚焦冀中坳陷岩溶热储强迫对流和自由对流联合作用模式及其聚热效应.二维有限元数值模拟结果表明,在自由对流模型的基础上,地形驱动的强迫对流叠加作用使岩溶层内地下水流速显著增加.地形驱动流体可以推动自由对流单元向坡下滚动,强化了地下水对流的聚热效应.高阳凸起和献县凸起显著的热异常主要归因于岩溶储层和断裂带内地下水自由对流的传热效应,基底起伏造成的热流折射聚热效应是次要的.此外,地形驱动下,自由对流单元向流域下游方向推进可能是献县凸起较高阳凸起热异常更为显著的重要原因.Groundwater flow can be driven by both topographic fluctuation and buoyancy.In this process,heat is transferred rapidly by convection,and then the temperature distribution pattern is changed,resulting in obvious local thermal anomalies.It is of great significance for the heat accumulation of geothermal resources in karst reservoir.Karst geothermal reservoir was well developed in Jizhong Depression,in which karst fracture-cavity system provided good vertical and horizontal conditions for groundwater convection,and formed a unique convection-conduction geothermal system.Through numerical simulation of coupled temperature and hydrodynamic fields,this paper focuses on the model of combined forced convection and free convection,and its heat accumulation effect in Jizhong Depression.The results of 2D finite element numerical simulation show that the superimposed effect of topography-driven forced convection on the base of the free convection model increases the groundwater flow rate within the karst reservoir significantly.The topography-driven fluid can push free convection units to roll downslope,which reinforces the heat accumulation effect of groundwater convection.The significant thermal anomalies in Gaoyang Uplift and Xian County Uplift were mainly attributed to the geothermal transfer effect of free convection in the karst reservoir and the fault zones,which meant the heat refraction accumulation effect caused by basement fluctuation was secondary.In addition,driven by topography,the advance of free convection units to the downstream of the basin may be an important reason for the more significant thermal anomaly of Xian County Uplift than that of Gaoyang Uplift.

关 键 词：聚热效应 地下水对流 自由对流 强迫对流 岩溶热储 冀中坳陷 

分 类 号：P314[天文地球—固体地球物理学]