摘要
“双碳”目标的实现与煤层气大规模商业化开发迫切需要新技术。在对煤层气开发与CCUS技术系统分析的基础上,以煤层气生物工程为依托,探讨和展望了地面煤层气开发、煤矿瓦斯抽采以及采空区煤层气开发过程中的低负碳减排关键技术。地面煤层气开发阶段,将煤层气开发转化为煤系气开发、将常规水力压裂转化为大规模缝网改造是实现煤层气商业化开发的有效途径;将液相CO_(2)和微生物发酵液作为储层改造的工作液,在实现煤系三气储层一体化缝网改造的同时又实现了微生物与CO_(2)联作下的增气增压、储层改性、CO_(2)驱替甲烷等多重增产效应,为煤层气增产提供了一条新途径,达到低碳减排目的;此外,通过CO_(2)的生物甲烷化和同步地质封存实现了负碳减排。可见,对于煤层气开发而言,CO_(2)可以促使其增产;对于CO_(2)封存而言,煤储层是其最佳归宿。由此,地面煤层气开发实现了“一低两负”的碳减排。在井下瓦斯抽采阶段,根据硬煤的造缝增透增产、软煤的增容增透增产机制以及相关理论,提出了第1代水力强化技术——水力压裂和第2代水力强化技术——钻冲压一体化增透增产技术、三堵两注固液两相封孔技术、老孔修复增透和下向孔智能排水排粉气驱增产技术。这一技术体系实现了瓦斯由“抽得出”向“抽得快、抽得省、抽得净、抽得纯”转变,大幅提升瓦斯抽采的质和量,获取低碳能源,达到减少甲烷排空与碳减排的目的。同时,研发了能够准确测定瓦斯含量的钻取一体化密闭取心装置,建立了基于低速非线性渗流的煤层渗透性评价技术。在采空区煤层气开发阶段,粉煤灰将成为强化煤层生物气产出、充填采空区减沉和实现CO_(2)矿化封存的首选材料。在具备圈闭条件的采空区首先注入菌液、少量粉煤灰和CO_(2)实现煤和CO_(2)的微生物甲烷化,以此获取低碳能源;抽采结束后进一步注入CO_(2)和粉煤灰,粉煤灰和采空区积水中的钙镁等离子与溶解的CO_(2)结合生成碳酸盐对粉煤灰胶结,实现了CO_(2)矿化封存和采空区固化减沉,具有显著的低负碳减排和生态环境治理意义。煤层气井地联合抽采全过程低负碳减排技术体系始终立足煤层气这一低碳能源的增产和CCUS,为我国碳中和目标的实现提供新的发展思路。
The realization of the“dual carbon”goal and the large-scale commercial development of coalbed methane urgently require some new technologies.Coalbed methane development with carbon dioxide capture utilization and storage(CCUS)technology is systematically analyzed.Based on coalbed gas bioengineering,some key technologies for low-negative carbon emission reduction in the process of CBM development,coal mine gasextraction,and goaf CBM development are discussed and prospected.In the stage of CBM development,converting coalbed methane development into coal measure methane development and converting conventional hydraulic fracturing into large-scale fracture network reconstruction are effective ways to realize the commercial development of coalbed methane.Liquid-phase CO_(2)and microbial culture solutionare used as working fluids for reservoir modification,the integrated fracture network reconstruction of coal-measure gas reservoirs and the multiple stimulation effects of CBM based on CO_(2)are realized,including the reservoir modification under the combined action of microorganisms and CO_(2),carbon dioxide to displace methane.This provides a new way for CBM production enhancement and low carbon emission reduction.Meanwhile,the CO_(2)biomethanation and geological storage achieve a negative carbon emission reduction.Therefore,for the development of coalbed methane,CO_(2)can increase its production.For the storage of CO_(2),the coal reservoir is the best destination.In the underground gas extraction stage in coal mines,according to the mechanism of permeability improvement from the fracture generation of hard coal,and the capacity and permeability enhancement of soft coal through unloading coal and pressure relief,and related theories,the first-generation technology of hydraulic strengthening,i.e.,hydraulic fracture,and the second-generation technologies of hydraulic strengthening including the technology to increase permeability and yield of integrated drilling and stamping,the solid-liquid two-phase hole sealing technology for three blocks and two injections,the increase production technology of old hole repair and increase permeability,and the technology of downhole automatic drainage,slag discharge and gas flooding are proposed.This technological system can realize the transformation of gas extraction from"regular extraction to the quick,economical,pure and clean extraction".The quality and quantity of gas extraction have been improved greatly,achieving to access low-carbon energy,and to reduce methane emissions.In addition,the closed coring device for integrated drilling and sampling is developed,which can accurately determine the gas content.Coal seam permeability evaluation technology based on low-speed nonlinear seepage is established.In the development stage of CBM in goaf,fly ash is considered to be the material of choice for enhancing coalbed biogas production,filling gobs for subsidence reduction and realizing CO_(2)mineralization and storage.In the goaf with gas trap conditions,microbial culture solution,fly ash and CO_(2)are injected into the goaf to achieve microbial methanation of coal and CO_(2),so as to obtain low-carbon energy.After the gas drainage is completed,a large amount of CO_(2)and fly ash are injected into the goaf.The calcium and magnesium plasmas in fly ash and goaf water combine with dissolved CO_(2)to form carbonate cementation from fly ash,realizing CO_(2)mineralization and sequestration and goaf solidification and sedimentation reduction.This is of great significance in terms of low carbon and negative carbon emission reduction and ecological environment.The low-negative carbon emission reduction technology system for the whole process of coalbed methane combined well-ground extraction is based on coalbed methane production stimulation and the CCUS and provides some new development ideas for the realization of carbon neutrality goals.
作者
苏现波
赵伟仲
王乾
于世耀
汪露飞
宋金星
王小明
夏大平
伏海蛟
郭红玉
孙长彦
郭红光
鲍园
何环
黄津
SU Xianbo;ZHAO Weizhong;WANG Qian;YU Shiyao;WANG Lufei;SONG Jinxing;WANG Xiaoming;XIA Daping;FU Haijiao;GUO Hongyu;SUN Changyan;GUO Hongguang;BAO Yuan;HE Huan;HUANG Jin(School of Resources and Environment,Henan Polytechnic University,Jiaozuo 454000,China;Unconventional Gas research Institute,Henan Polytechnic University,Jiaozuo 454000,China;School of Energy Resources,China University of Geosciences,Wuhan 430074,China;Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region,Jiaozuo 454000,China;School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo 454000,China;College of Safety and Emergency Management and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;College of Geology and Environment,Xi’an University of Science and Technology,Xi'an 710054,China;School of Chemical Engineering and Technology,China University of Mining and Technology,Xuzhou 221116,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2023年第1期335-356,共22页
Journal of China Coal Society
基金
国家自然科学基金重点资助项目(42230804)
国家自然科学基金面上资助项目(42072193)。
关键词
煤层气生物工程
地面煤层气开发
煤矿瓦斯抽采
采空区煤层气开发
低负碳减排
CCUS
coalbed gas bioengineering
coalbed methane development
coal mine gas extraction
coalbed methane development in goaf
low-negative carbon emission reduction
carbon dioxide capture utilization and storage
