摘要
煤层气在煤储层中的扩散是指从煤基质孔隙表面上解吸的煤层气运移到割理系统的主要过程。发生扩散的前提条件是气体浓度差的出现,衡量扩散能力大小的重要参数是扩散系数。前者为由解吸速度、解吸气量和煤层气产量、井孔压力降等因素控制的动态参数,而后者为主要受扩散物质性质、扩散介质特征、扩散系统的温度、压力和孔隙结构形态等因素影响的静态参数。煤层气在煤储层中的扩散量与煤层气浓度差和扩散系数呈正比关系。
The diffusion of coalbed methane in coal reservoirs is defined that the main process of coalbed methane desorbed from coal matrix pore surface migrated to cleat system. The premise of the diffusion is the gas concentration gradient. The important parameter of determining diffusion capability is diffusion coefficient. The former is a dynamic parameter controlled by dsorption speed,gas desorption quantity and methane output,borehole pressure drop,etc. The latter is a static parameter which is affected by diffusion matter property,diffusion medium character,the temperature,pressure,pore surface texture and shape in diffusion system,etc. The diffusion quantity of coalbed methane in coal reservoirs signifies direct ratio with methane concentration gradient and diffusion coefficient.
出处
《世界地质》
CAS
CSCD
2004年第3期266-269,共4页
World Geology
基金
国家重点基础研究发展规划973项目(2002CB211708)资助
关键词
煤层气
扩散机制
扩散系数
浓度差
压力降
coalbed methane
diffusion mechanism
diffusion coefficient
concentration gradient
pressure drop
