廊固凹陷JZ02井地热特征分析

Analysis of Geothermal Characteristics of JZ02 Well in Langgu Sag

廊固凹陷地热资源开发潜力巨大,对其热储层特征及成藏机制进行研究可为后续开发利用提供依据。通过对JZ02地热井热储层的地热地质条件、水化学特征、抽水回灌试验研究分析,确定了地热水的补给来源,分析了地热水的成因机制。结果表明,该地热井碳酸盐岩热储层岩溶裂隙不发育,表现为低渗透率高热导率的特征,热储层地温梯度较低,仅为1.00℃/100m。同时,大地热流值也呈现出凹陷区低值的特点,水化学类型为HCO3—Na型;太行山和燕山的大气降水经补给径流后,经大兴断裂带渗入深部地层,受到深部地热和岩石放射性生热的热量不断加热,断裂带为深部热源向上循环提供了通道,碳酸盐岩热储其上覆盖的新生界砂岩和泥岩地层形成良好的保温盖层。

The development potential of geothermal resources in Langgu Depression is enormous,and studying its thermal reservoir characteristics and reservoir formation mechanism can provide a basis for subsequent development and utilization.By studying and analyzing the geothermal geological conditions,hydrochemical characteristics,and pumping and reinjection tests of the JZ02 geothermal well thermal reservoir,the source of geothermal water supply was determined,and the genesis mechanism of geothermal water was analyzed.The results indicate that the karst fractures in the carbonate thermal reservoir of the geothermal well are not well-developed,exhibiting characteristics of low permeability and high thermal conductivity.The geothermal gradient of the thermal reservoir is relatively low,only 1.00℃/100m.At the same time,the heat flux value of the earth also shows the characteristic of low values in depressed areas,and the hydrochemical type is HCO3—Na;The atmospheric precipitation in Taihang Mountains and Yanshan Mountains,after being supplied with runoff,infiltrates deep strata through the Daxing Fault Zone and is continuously heated by deep geothermal and rock radioactive heat generation.The fault zone provides a channel for the upward circulation of deep heat sources,and carbonate thermal storage forms a good insulation cover layer for the Cenozoic sandstone and mudstone strata covering it.