Progress and application of key technologies for CO2 enhancing coalbed methane
ZHANG Shouren,SANG Shuxun,WU Jian,ZHOU Xiaozhi,ZHANG Bing,YANG Ruizhao, GUO Jianchun,LIU Xudong,ZHANG Weiqi,LI Yong
中联煤层气有限责任公司中国矿业大学 资源与地球科学学院中国矿业大学(北京) 地球科学与测绘工程学院西南石油大学 油气藏地质及开发工程国家重点实验室
CO2驱煤层气(CO2-ECBM)工业化应用是促进煤炭清洁高效利用、加快国家天然气发展、实现“碳达峰”和“碳中和”目标的重要途径。立足CO2注入、运移、封存和产出的全过程控制和监测技术需求,结合理论和现场工程实践,提出地质适配性的CO2-ECBM技术体系。研究成果表明,构建“分子-微纳米-岩心-近工程-工程”衔接的CO2,CH4和H2O多尺度赋存和流动实(试)验体系是揭示CO2-ECBM机理与技术应用的前提。实施CO2-ECBM需综合考虑CO2可注入性、CH4可增产性和CO2可封存性,结合高精度三维地质和数值模型优选有利井区。CH4增产效果受CO2注入方式、注入压力、注入速度和井底流压等多因素协同影响,为实现长期增产和有效封存双重目标,提出了包含“阶梯式增注提压、限压注入驱替、气驱水产能抑制、采气井增产、间歇式排采、采气井井场复垦”6阶段的CO2注-采技术体系。为监测CO2运移和封存效果,形成了涵盖“注入-驱替-封存”全过程的“空-天-地-井”立体监测网络,可通过地表微形变与环境变化遥感监测、近地表被动地震裂缝层析成像、动态多向多分量VSP监测技术和深井实时温压监测装置有效跟踪CO2运移路径。依托上述技术在沁水盆地柿庄TS-634井区实现CO2注入2 001.04 t,并有效监测了CO2运移方向和增产效果。结论认为,上述技术可服务于CO2-ECBM,进一步推动CO2-ECBM工业化进程,需从政策制定、市场机制和需求驱动等多方面综合优化,以期为我国能源结构调整和“双碳”战略实现提供技术支撑。
The industrial application of CO2 enhancing coalbed methane ( CO2 - ECBM ) is an important way promote the clean and efficient utilization of coal,accelerate the development of natural gas,and achieve the goals of “carbon peaking” and “carbon neutrality”. In view of the current lack of monitoring and control technology for the whole process of CO2 injection,migration,storage and production,this paper systematically carried out key technology exploration,and formed CO2 -ECBM technology system suitable for well groups with geological adaptability.The results show that the construction of a multi⁃scale experimental system for the occurrence and flow of CO2,CH4 and H2O in “ molecular,micro⁃nano,core,near⁃engineering,and engineering” scales is the basis to reveal the CO2 -ECBM mecha⁃ nism and its technical application. To promote CO2 -ECBM,it is necessary to comprehensively consider CO2 inject⁃ ability,CH4 stimulation and CO2 sequestration,and combine high⁃precision 3D geological and numerical models to se⁃ lect favorable well areas. The effect of CH4 stimulation is affected by CO2 injection mode,injection pressure,injection speed and bottom⁃hole flow pressure. A 6⁃stage technology sequence including“stepped injection and pressure boos⁃ ting,pressure⁃limiting injection displacement,gas flooding water productivity suppression,gas production well stimula⁃ tion,intermittent drainage,and gas production well site reclamation” is promoted. To monitor CO2 transport and stor⁃ age,a three⁃dimensional monitoring network covering CO2“injection⁃displacement⁃storage” based on “underground⁃ well⁃surface” technical system is built,which can monitor CO2 migration path by remote sensing monitoring of sur⁃ face micro⁃deformation and environmental changes, near⁃surface passive seismic fracture tomography, dynamic multi⁃directional and multi⁃component VSP monitoring technology,and deep well real⁃time temperature and pres⁃ sure monitoring devices. Based on the above technology, CO2 injection was realized in the TS - 634 well area of Shizhuang in Qinshui Basin by 2 001.04 t,and the CO2 migration direction and production enhancement effect were ef⁃ fectively monitored. It is concluded that the above technologies can serve CO2 -ECBM,and promoting the industrializa⁃ tion process of CO2 -ECBM needs to comprehensively optimization in terms of policy formulation,market mechanism and demand⁃driven. Thus,the technology can serve energy structure transition and “dual carbon” strategy realization.
coalbed methane production;CO2 fracturing;CO2 migration;CO2 storage;recovery;Qinshui Basin
主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会