双碳目标下煤层发育区CO_(2)地质封存研究与评价

Carbon dioxide geological storage system in coal seam development area under the premise of double carbon target

煤炭等传统资源碳减排对实现“碳中和”目标具有决定性作用。在“双碳”和“煤炭去产能”政策背景下,研究煤层发育区CO_(2)地质封存体系具有鲜明的时代背景和实践基础。本文聚焦于煤层发育区CO_(2)地质封存体系,将煤层发育区详细划分为煤矿已采区、煤层未采区两区域进行单独阐述,从CO_(2)相态转化、CO_(2)储存能力、地质封盖条件等方面分析了采空区、煤层、咸水层3种储存空间地质封存原理和研究现状。充分借鉴煤和煤层气地质学理论,探讨了储层改造技术在CO_(2)强化封存领域的适用性,并厘定了不同封存模式亟需关注方向。在此基础上,重点阐述了CO_(2)强化封存的概念,探讨了煤层已采区和未采区CO_(2)逐级联合地质封存模式的应用前景。在单一封存和逐级联合封存2种思路下,初步提出煤层发育区CO_(2)地质封存适用性评价方法。

Carbon emission reduction of traditional resources such as coal plays a decisive role in achieving the goal of“carbon neutralization”.Under the policy background of“double carbon”and“coal de productivity”,CO_(2) geological storage system study in coal seam development area has a distinct era background and practical basis.Taking the CO_(2) geological storage system in the coal seam development area as the research object,development area can be divided into two areas,including mined area and untapped area.The geological storage principle and research status of three storage spaces of goaf,coal seam and salt water layer are clarified from the aspects of CO_(2) phase state transformation,CO_(2) storage capacity and geological capping conditions.Based on the theories of material mechanics,coalbed methane geology,the applicability of low-temperature freezing and thawing,acoustic(microwave)antireflection,hydraulic fracturing and other technologies in the field of CO_(2) enhanced storage are discussed,and the urgent attention direction of different storage modes is clarified.On this basis,the application prospect of CO_(2) step-by-step combined geological storage model in mined and untapped areas are studied.The applicability evaluation method of CO_(2) geological storage in coal seam development area is put forward under the consideration of single storage and step-by-step joint storage.