CO_(2)基增强型地热系统中流体-花岗岩相互作用研究进展及展望  

Research progress of fluid-granite interaction in CO_(2) based enhanced geothermal system

作　　者：薛卉 舒彪[1] 陈科平[1] 路伟 张森 胡永鹏 Xue Hui;Shu Biao;Chen Keping;Lu Wei;Zhang Sen;Hu Yongpeng(School of Geosciences and Info-physics,Central South University,Changsha 410012,China)

机构地区：[1]中南大学地球科学与信息物理学院,长沙410012

出　　处：《地质科技通报》2021年第3期45-53,共9页Bulletin of Geological Science and Technology

基　　金：国家自然科学基金面上项目(42072304);国家自然科学基金青年基金项目(41702387)。

摘　　要：CO_(2)与水相比,膨胀性大、黏度低、与岩石反应程度低,并且在作为增强型地热系统(EGS)渗流传热流体时,比水具有更高的换热效率。对CO_(2)-EGS生产过程中储层岩石物性变化的研究具有重要意义,从理论研究、实验研究、数值模拟3个方面,对CO_(2)基增强型地热系统CO_(2)-EGS中流体-岩石相互作用的研究现状进行了总结,并且从矿物成分、微观孔结构和力学性质3个方面对储层岩石性质的变化进行了评价。结果表明,CO_(2)-水-岩石相互作用参与反应的矿物主要为石英、长石类;而沉淀的矿物为蒙脱石、伊利石及方解石等。CO_(2)-水-岩石相互作用会导致储层岩石的力学性质下降,孔隙结构特征改变。最后,讨论了CO_(2)作为EGS渗流传热流体仍需攻克的难点问题,包括:CO_(2)的热动力学特征、换热效率,CO_(2)-水-岩石的相互作用及其对储层性质的改变,影响CO_(2)-EGS经济性的因素,以及CO_(2)-EGS数值模型的研究等。针对这些方面的研究可为今后CO_(2)-EGS的开发奠定基础。Compared with water,CO_(2) has larger expansibility,lower viscosity and lower reaction degree with rock.As an enhanced geothermal system(EGS)seepage heat transfer fluid,CO_(2) has higher heat transfer efficiency than water.This paper summarizes the research status of fluid/rock interaction in CO_(2)-EGS from three aspects:theoretical research,experimental research and numerical simulation.The changes of reservoir rock properties are evaluated from mineral composition,micro pore structure and mechanical properties.The results show that the main reaction minerals of CO_(2)-water-rock interaction are quartz and feldspar,and the precipitation minerals are montmorillonite,illite and calcite.The interaction of CO_(2)-waterrock will lead to the decline of mechanical properties of reservoir rocks and the change of pore structure characteristics.Finally,the existing problems and development trend of CO_(2)-water-rock interaction in CO_(2)-EGS are discussed,which provides a reference for the development and research of CO_(2)-EGS in the future.

关 键 词：CO_(2)基增强型地热系统(CO_(2)-EGS) 花岗岩 化学作用 实验研究 数值模拟 

分 类 号：P588.121[天文地球—岩石学] P641.3[天文地球—地质学]