雄安新区高阳地热田东北部深部古潜山聚热机制

Heat accumulation mechanism of deep ancient buried hill in the northeast of Gaoyang geothermal field,Xiong'an New Area

为查明雄安新区深部碳酸盐岩热储的赋存特征与聚热机制,中国地质调查局近两年组织实施的雄安新区地热清洁能源调查评价工作,综合地温场背景、深部地质结构、凹凸相间构造格局、深浅断裂系统控热导热、地球物理场特征、区域水动力场、水化学场与温度场的多场耦合指示等综合探测手段,分析总结了高阳地热田东北部深部古潜山地热资源的最新勘查成果,阐述了雄安新区深部高温古潜山热田的聚热机制:①受太平洋板块向西俯冲影响,华北克拉通东部破坏明显,岩石圈、地壳厚度大嵋减薄,有利于幔源热向浅部的传导;②区域马西断层等深大走滑断裂切穿了岩石圈,有利于深部的幔源热物质和深部岩浆上侵入地壳;③热流由低热导率的凹陷区向高热导率的凸起区聚集,地下水沿断裂的深循环对流加热,区域岩溶地下水的汇流区等也有一定的聚热效应。在雄安新区深部碳酸盐岩热储聚热机制理论指导下,在高阳地热田东北部古潜山布设施工了两眼高温、高产地热井,井口水温分别达到109.2℃,123.4℃,揭示验证了雄安新区深部存在地热开发的第二空间——蓟县系碳酸盐岩热储,深部碳酸盐岩地热水温度高、流量大、开发潜力巨大。研究成果对雄安新区乃至华北盆地高温、高产地热井位的布设与深部碳酸盐岩热储开发利用的科学部署具有很好的示范与指导意义。

There are two high-temperature and high-yield geothermal wells,located in the deep ancient buried hill northeast of the Gaoyang geothermal field at the Xiong'an New Area,are constructed by China Geological Survey during the past two years.The successful implementation of the two deep wells reveal that there is a second space for geothermal development in deep Xiong'an New Area.The deep carbonate rock has a high thermal storage temperature,large flow rate,and huge development potential.On the basis of previous studies,this article fully summarizes the latest survey results of geothermal resources in deep buried hills in the northeast of Gaoyang Geothermal Field and these comprehensive analysis show that the heat accumulation mechanism of the study area are as follows:①Affected by the westward subduction of the Pacific Plate,the eastern North China Craton is significantly damaged,and the thickness of the lithosphere and crust has been greatly reduced,which is conducive to conduct the mantle-derived heat to the shallow depth;②The regional Marcy fault and other deep strike-slip faults cut through the lithosphere,which contributed to the deep mantle-derived thermal material and deep magma intruding into the crust;③The heat flow is gathered from the low thermal conductivity depression to the high thermal conductivity.Besides,groundwater is heated by deep cycle and convection along the fault,and the confluence area of regional karst groundwater also has a certain heat accumulation effect.Because of the combined effect of various favorable factors,a high-temperature and high-productivity carbonate type reservoir is formed in the northeast of the Gaoyang geothermal field.