【摘要】 地热系统属于地质系统的一种,是指一个动态的,由相互联系的若干地热构成要素所组成的集合,这些要素包括热源、通道、水源、储盖层等,动态过程则主要包含热的传导与地下水循环。含油气盆地因其特有的形成演化过程而形成的构造、沉积以及水动力条件,使其具有形成大中型地热田的良好基础。本研究以南襄盆地为例,在区域地质研究的基础上,综合地震、测井、地化分析以及地温资料,分析了典型沉积盆地型地热系统的构成。结果表明:南襄盆地地热田热源以幔源热及壳源热为主,而区内可作为热源的喜山期岩浆岩不发育,规模小,热量多散失,不能作为本研究区主要热源;通道为边界深大断裂以及沉积盆地骨架砂体;热水来源为大气降水,其中盆地北面伏牛山山区、盆地南面桐柏山山区为大气降水汇集的重要场所;储盖层为中新生代沉积的古近纪、新近纪地层。综合这些要素与动态过程,本次研究揭示了典型的沉积盆地型地热田的地热系统构成方式以及聚热规律,在地热系统研究的基础上,并利用"体积法"计算了泌阳、南阳凹陷的地热资源量。更多还原

【Abstract】 The geothermal system,a type of geological system,is defined as a dynamic assembly of certain correlative geological elements primarily consisting of the heat source,passage,water source,reservoir and seal,and two processes of heat transmission and underground water circulation.The condition of tectonics,sedimentary environment and hydraulics resulted from the peculiar evolution process of petroliferous basins provides strong basis for the large and medium geothermal field.Using well logging,seismic and geochemistry data,this paper illustrates the compositional characteristics of a typical sedimentary-basin geothermal system from a case study of the Nanxiang Basin.The results demonstrate that(1)the heat source of the Nanxiang geothermal field is dominated by crust and mantle heat sources,where small size magmatic rocks cannot provide sufficient heat;(2)the passage is composed of boundary fractures and depositional sand bodies;and(3)the depositional strata of the Paleogene and Neogene are the main reservoirs.Through a comprehensive analysis,this research investigates the composition and heat trapping rules of a sedimentary-basin geothermal system;the extent of geothermal resources is also calculated by the volumetric method.更多还原