晋城无烟煤CO_2-ECBM数值模拟研究

摘要

The gas production and CO2 injection processes of the production well and the injection well with different spacing（116,200 and 300 m）were studied using the coal reservoir simulator,SIMEDWin,developed by CSIRO Earth Science and Resources Engineering,Australia.The coal reservoir and coal property parameters used in this simulation were fully considered reflecting the in-situ coal geological conditions of the anthracite coal in Jincheng district.In addition,the hydraulic fracturing which was widely used as an enhanced methane recovery technology was also taken into consideration.The simulation results show that using CO2-ECBM technology,the gas production is improved significantly,and the recovery cycle is decreased clearly;the gas and water recovery process changing with each other,especially before the stable production stage of the production well.The cleat porosity of the coal reservoir changing dynamically under the effect of desorption of CH4,adsorption of CO2 and changing of pore pressure during the gas and water production process.In comparison,200 m well spacing is considered as the optimum well spacing with the better CH4 recovery and CO2 sequestration effects.%基于晋城无烟煤储层地质条件下的储层和煤岩参数,结合晋城无烟煤煤层气藏直井生产必须压裂增产的实际,使用澳大利亚联邦科工组织的煤层气储层数值模拟软件（SIMEDWin）模拟了不同生产井和注入井井距（116、200、300 m）条件下的煤层气增产和CO2埋存过程。研究结果表明：煤储层注CO2增产煤层甲烷效果明显;CO2-ECBM过程中煤层气生产井的气、水产量呈现联动变化;煤储层的割理孔隙度在甲烷解吸、CO2吸附、煤岩有效应力改变的综合效应下呈现增高—降低—增高—降低的变化趋势。综合考虑煤层甲烷产量和CO2的封存能力,选择200 m产注井距具有较好的注入增产效果。