川藏铁路沿线地热资源形成机理与开发潜力  

Formation Mechanism and Development Potential of Geothermal Resources along the Sichuan-Tibet Railway

作　　者：汪新伟[1] 王婷灏 高楠安 刘慧盈 毛翔[1] 罗璐 吴陈冰洁 崔梓贤 Wang Xinwei;Wang Tinghao;Gao Nan'an;Liu Huiying;Mao Xiang;Luo Lu;Wu Chenbingjie;Cui Zixian(SINOPEC Star Petroleum Corporation Limited,Beijing 100083,China)

机构地区：[1]中国石化集团新星石油有限责任公司,北京100083

出　　处：《地球科学》2022年第3期995-1011,共17页Earth Science

基　　金：中国石油化工集团有限公司重点科技项目(Nos.JP21007,JKL21005)。

摘　　要：川藏铁路从西至东依次穿越了拉萨-喜马拉雅活动带、昌都-川西造山带与四川盆地3个大地构造单元,其沿线地热资源成因机制的研究对于陆-陆碰撞型地热域不同类型地热田展布规律的认识及其开发利用有着重要的理论与现实意义.本文在系统总结前人成果的基础上,根据区域构造演化、构造变形对地热田成因要素的影响,对比了川藏铁路沿线地热田在热源、热储构造与水运移模式方面的差异性.川藏铁路沿线的地热域依照变形强度分别以怒江断裂带、龙门山断裂带为界,从西至东划分为板缘碰撞造山型、板内逆冲推覆型、盆内稳定坳陷型3个地热带,分别发育高温岩浆岩型、中-低温断裂深循环型、低温坳陷盆地型3类地热田,其大地热流值从西至东逐步减少(即从138.2 mW/m^(2)→71 mW/m^(2)→51 mW/m^(2));热储的构造模型可归纳为伸展地堑型、冲起构造型、花状构造型与隐伏背斜型,热储的层位亦逐渐变老、埋藏变深(即从Q+J-T_(3)→T_(2-3)→T_(1-2)).尽管各类地热田有着相同的水源(主要来自大气降水),基本相似的水化学类型(以Cl-Na型、HCO_(3)-Na型为主)与矿化度(2500~3500 mg/L),但有着完全不同的地热水运移模式,尤其在水循环深度、壳源流体的贡献、垂向/水平径流路径等方面.依据不同类型地热田资源禀赋的差异,分别建议川藏铁路沿线地热开发的主要方式为:林芝-拉萨段的高温发电、供暖与制冷;雅安-林芝段的中低温发电、供暖与制冷;以及成都-雅安段的低温供暖、温泉洗浴等.The Sichuan-Tibet Railway from west to east passes through three geotectonic units including the Lhasa-Himalayan activity zone,Qamdo-Sanjiang orogeny and Sichuan basin.The study of the genetic mechanism of geothermal resources along the Sichuan-Tibet Railway is of great theoretical and practical significance for the understanding of its distribution and the development of geothermal fields among the land-land collision geothermal domain.On the basis of previous results,the differences between the heat source,reservoir structure and water transport mode of the geothermal fields along the Sichuan-Tibet Railway are discussed considering of the influence of regional structural evolution and structural deformation on the causes of them.According to the extrusion deformation strength,the geothermal domain along the Sichuan-Tibet Railway is divided into three geothermal belts by the Nujiang fault and the Longmenshan fault from west to east.The three geothermal belts are the collision-orogeny type of plate edge,the thrust type of interpolate and the stable depression type of inter basin,and develop 3 types of geothermal fields respectively,namely,the magma-rock type of high temperature,the fracture deep-cycle type of medium-low temperature,and the depression-basin type of low temperature.The terrestrial heat flow values of the three geothermal belts is gradually reduced from west to east(i.e.from 138.2 mW/m^(2) to 71 mW/m^(2),then to 51 mW/m^(2));their structural models of reservoir are respectively the extended grabens,the pup-up structures,the flower structures and the hidden anticlines,and the layer of thermal reservoir is gradually older and deeper(i.e.from Q+J-T_(3) toT_(2-3) then to T_(1-2)).Although all kinds of geothermal fields have the same source of water(mainly from atmospheric precipitation),basically similar hydrochemical types(mainly Cl-Na type,HCO_(3)-Na type)and mineralization degree(2500-3500 mg/L),they have completely different geothermal water transport modes,especially in water circulation depth,cont

关 键 词：地热资源类型 热储构造 成因机制 开发潜力 川藏铁路沿线 地热能 

分 类 号：P314[天文地球—固体地球物理学]