煤样渗透率对有效应力敏感性实验分析

Coefficient of sensitiveness between permeability and effective pressure of coal samples

研究煤样渗透率对有效应力的敏感性。实验结果表明,在低有效应力水平下,煤样渗透率随着有效应力的增加而迅速减小,其变化规律符合负指数函数关系。由于煤层渗透率的影响因素比较复杂,定义了煤样渗透率对有效应力的敏感性系数,从而将影响因素进行归一化处理。根据渗透实验结果,拟合得到敏感系数与有效应力之间的幂函数关系,该敏感系数反映出煤样渗透率随有效应力的变化趋势。最后推导出基于敏感系数的煤样渗透率与有效应力的函数关系式。

A study of the coefficient of sensitiveness between permeability and effective pressure of coal samples is conducted based on experimentation and analysis. Test results indicate that the permeability of coal samples drops rapidly as the effective pressure increases under a low effective pressure level. The variation relationship between them can be described by an exponential equation. The coupling mechanism of seepage in coal beds has not been completely made clear so far, and the coupling factors affecting the permeability of coal samples are too complex to describe. The coefficient of sensitiveness between the permeability of coal samples and effective pressure is defined accordingly so as to normalize these factors. It is shown that the variation relationship between the coefficient and the effective pressure can be described by a power function. Such a coefficient can evaluate well the changing trend of the permeability of coal samples related to the effective pressure. The between deduced based on the coefficient of sensitiveness.