面对全球气候变化和能源紧缺的巨大压力,CO_2地质利用技术成为研究的焦点。为了实现CO_2减排及资源化利用,提出了利用超临界CO_2增强卤水提取和地热能开采的CO_2地质利用集成系统的概念。通过建立CO_2注入热卤水储层的质量平衡模型,分析了不同流量的卤水生产、CO_2注入以及储层边界流对储层变化的影响,初步评估了该系统的CO_2封存量、卤水提取量以及储层流体组成变化的时间尺度。研究表明,注入CO_2提供了热卤水层的压力维持,促进卤水和地热资源的可持续开采,对于江陵凹陷研究区9*10~8 m~3的储层有效体积,注入9.95*10~6 t CO_2可提取17.12*10~6 t卤水,时间尺度超过30a。对于50~ 1 000kg/s的卤水生产速度,可以产生0.9~18.8 MW 电力。同时,该技术增加了CO_2的封存容量和效率,有利于CO_2大规模安全封存,经济和环境效益显著。
英文摘要:
Facing the great pressure under global climate change and energy shortage,CO_2 geological utilization has become the focus of research.In order to achieve CO_2 emission reduction and resource utilization, this study presents a new concept of integrated CO_2 geological utilization system that enhances brine extraction and geothermal energy production using supercritical CO_2.We establish a mass balance model of CO_2 injection into a thermal brine-filled reservoir to analyze the impact of different flows of brine production, CO_2 injection and reservoir boundary flows on changes of the reservoir,and preliminary evaluate CO_2 storage capacity,the amount of brine extraction and the time scales for reservoir fluid compositional changes within such a system.The results show that with CO_2 injection providing pressure support for thermal brine reservoir to maintain the sustainable productivity of brine and geothermal resources.For a reservoir of 9*10~8 m~3 in Jiangling Depression,an injection of 9.95 million tons of CO_2 would enable extraction of 17.12 million tons of brine,and the time scale is more than 30 years.For brine production rates of 50 to 1 000 kg/s,it could generate 0.9 to 18.8 MW of electricity.Furthermore,this technology increases CO_2 storage capacity and efficiency that is beneficial for large-scale and safe geological CO_2 storage,which can gains economic and environmental benefits.