沁水盆地柿庄南区块煤层气藏自改造动态分析

Coal gas reservoirs self-transformation dynamic analysis in Shizhuang south block of Qinshui basin

不同于常规气藏,煤层气藏开采过程中存在自改造效应,即随着地层压力的降低,储层渗透率会发生复杂变化。大量研究表明:有效应力、煤基质收缩、Klinkenberg效应是自改造效应的三大控制因素,改进的SD模型更能准确描述欠饱和煤层气藏渗透率动态变化规律,结合实际数据,计算分析表明,杨氏模量对自改造效应影响最大,泊松比对自改造效应影响最小。

Unlike conventional gas reservoirs, coalbed methane reservoirs have the effect of self-transform, namely with decreasing reservoir pressure, reservoir permeability complexchanges occur. Numerous studies show that, effective stress and coal matrix shrinkage, Klinkenberg effect is self-transformation effect of the three controlling factors, improved SDmodel more accurately describes undersaturated coalbed methane reservoir permeability dynamic variation, combined with the actual data, calculation and analysis show that Young＇smodulus of the greatest impact on self-transformation effect, Poisson＇s ratio of self-transformation effect with minimal impact.