福建省增强地热系统CO_2封存容量的估算

ESTIMATION OF CO_2 STORAGE CAPACITY OF ENHANCED GEOTHERMAL SYSTEM IN FUJIAN PROVINCE

增强地热系统CO2是以CO2为工作介质的地热开采,既能改变能源结构,又能进行CO2地质封存减少温室气体排放,这使得增强地热系统显现出巨大的使用价值。福建省拥有丰富的地热资源,具有良好的干热岩赋存背景。在前人研究数据的基础上,获得福建省地区不同深度的可采地热田面积、干热花岗岩孔隙率和CO2溶解度值,利用体积法估算福建省3-7 km深处花岗岩的增强地热系统CO2的封存容量。结果显示,福建省3-7 km深处花岗岩CO2-EGS潜在封存总量上限为583 145.424 Mt,下限为102 050.449 Mt,上限约占全国CO2-EGS理论封存容量的7.42%,下限约占1.30%（全国CO2-EGS理论封存容量为7 862 Gt）,其中增强地热系统CO2（CO2-EGS）封存量随着深度的增加而逐渐增加,在7 km处达到最大,为场地评价和政策制定等提供参考。

Enhanced Geothermal System（ EGS） uses CO2 as medium,which not only changes energy structure,but also geologically stores CO2 to reduce green house gas emission,making EGS valuable. Fujian province possesses rich geothermal resources with excellent dry heat rocks. This paper based on Fujian＇s minable geothermal field area at difference depth,dry heat granite porosity rate and CO2 solution applies volume method to estimate the storage capacity of CO2-EGS in a depth of 3 km to 7 km,between 102 050. 449 Mt to 583 145. 424 Mt,about 1. 35% and 7. 42% in China.（ China＇s theoretical storage capacity is 7 862 Gt）. Storage capacity of CO2 rises with depth,reaching the top at the depth of 7 km. This paper provides references for field assessment and making policy.