煤矿安全2025，Vol.56Issue(8)：1-13,13.DOI:10.13347/j.cnki.mkaq.20241605
基于不同储层参数及注入时机的CO2强化煤层气抽采效果研究
Research on CO2-enhanced coalbed methane extraction effect based on different reservoir parameters and injection timing
摘要
Abstract
The CO2 injection enhanced coalbed methane extraction technology(CO2-ECBM)can not only significantly improve the efficiency of coalbed methane extraction,but also reduce greenhouse gas emissions,which is crucial for alleviating the global en-ergy crisis and the greenhouse effect.To realistically restore the CH4 recovery situation in coal seams,a thermal-hydro-mechanical coupling model was constructed,considering coal deformation,gas-water transport,and thermal expansion.Utilizing numerical sim-ulation,the coalbed methane production performance of conventional extraction and CO2-enhanced extraction was compared and studied.The impacts of injection temperature,injection pressure,and initial water saturation on CO2-ECBM engineering were analy-zed,and the optimal starting time for CO2 injection was determined.The results show that the enhancement factor of 3#coal seam in Qinshui Basin is 1.37 after 4000 days of extraction,which indicates the feasibility of CO2-enhanced coalbed methane recovery;due to the competitive effects of pore pressure,gas adsorption/desorption and thermoelastic expansion strain,the permeability shows a decreasing-increasing-decreasing trend;increasing the injection temperature and pressure will raise the temperature of the coal rese-rvoir,promote the production of CH4 and the storage of CO2,and increase the decline in permeability;the greater the initial water sat-uration,the less favorable it is for gas production and storage,and the smaller the decline in permeability;Delaying the injection time helps to increase the recovery rate of CH4 and the well closure threshold,but it will have a negative impact on the average produc-tion rate of CH4;when the start time of CO2 injection was 2 500 days,the average output rate was 1 142.10 m3/d,and the economic benefits of this demonstration project reached the optimum.The research results have enriched the stimulation mechanism of CO2-ECBM under different reservoir parameters and provided a new theoretical perspective for the optimization of its injection timing.关键词
注CO2强化煤层气抽采/气-水运移/储层参数/最佳注入时机/数值模拟Key words
CO2-enhanced coalbed methane extraction/gas-water transport/reservoir parameters/optimal injection timing/numer-ical simulation分类
矿业与冶金引用本文复制引用
李傲,师铁连,苏传云,何学明,毕思存,林治忠,宋留妮,郭晓阳..基于不同储层参数及注入时机的CO2强化煤层气抽采效果研究[J].煤矿安全,2025,56(8):1-13,13.基金项目
国家自然科学基金青年科学基金资助项目(52204231) （52204231）
