二氧化碳地质封存及提高油气和地热采收率技术进展与展望

Progress and Prospects of CO_(2)Storage and Enhanced Oil,Gas and Geothermal Recovery

国内外碳捕集、利用与封存(CCUS)技术已取得初步进展.通过系统调研及研究实践,总结了二氧化碳地质封存及提高油气和地热采收率的技术进展,并对下一阶段的研究趋势进行了展望.研究表明:二氧化碳提高油气采收率是目前CCUS的主流应用方向,并且CCUS项目主要应用于常规油气藏,每注入1 t二氧化碳可采出原油0.1~0.6 t.如何应对二氧化碳气窜是二氧化碳提高油气采收率面临的关键问题.下一阶段的研究主要围绕二氧化碳提高非常规油气藏的采收率,如何使注入的二氧化碳能够有效地进入页岩或煤层基质仍是该类油气藏提高采收率的研发重点方向.除了二氧化碳提高油气采收率之外,二氧化碳还可用于提高地热采收率,目前的研究主要围绕二氧化碳与水作为工质开发地热的效果对比,温度场、应力场、渗流场、化学场的耦合作用对二氧化碳开发地热过程的影响仍有待进一步的研究.在同一个油气藏中利用二氧化碳作为工作流体先后开展提高油气采收率、提高地热采收率和二氧化碳地质封存一体化可能成为CCUS的发展趋势.该研究对加速CCUS部署以及油气和地热的协同开发及实施双碳战略有重要意义.

Carbon capture,utilization and storage(CCUS)technology has achieved preliminary progress worldwide.This paper summarizes the progress in CO_(2)geological storage with enhanced oil recovery and enhanced geothermal recovery by literature review and our previous research,the future trend of the CO_(2)geological storage with enhanced oil recovery and enhanced geothermal recovery is presented.Results show that most CCUS deployment focuses on the CO_(2)enhanced oil recovery,especially in the conventional oil and gas fields.0.1-0.6 ton of oil can be produced by each ton of CO_(2)injection.The way to handle CO_(2)breakthrough in the producer is the main challenge in the CO_(2)enhanced oil recovery process.The research on the CO_(2)enhanced oil recovery will move to the unconventional reservoirs,the future research should focus on increasing amount of CO_(2)migration into the matrix of the unconventional reservoirs including shale oil and gas reservoirs,and coalbed methane reservoir.In addition,CO_(2)can be used to enhance geothermal recovery.The research on CO_(2)enhanced geothermal recovery mainly focuses on the comparisons of water and CO_(2)as the working fluid.However,the further research on Thermal(T)-Hydro(H)-Mechanical(M)-Chemical(C)coupling with CO_(2)enhance geothermal recovery is required.The CO_(2)geological storage with CO_(2)enhanced oil recovery,enhanced geothermal recovery in the same oil or gas reservoir may become popular in the future CCUS deployment.This paper helps to accelerate the CCUS deployment,to develop the oil and gas fields and heat mining in the same reservoir,and helps to reach the goal of carbon peak and carbon neutrality.