基于分形理论的高煤阶煤岩渗透率计算方法研究与应用

Research and Application of the Permeability Calculation Method for High-rank Coal Rock Based on Fractal Theory

为了提供有效的煤岩渗透率计算斱法,基于分形理论推导了煤样渗透率计算模型,提出了相应参数的获取斱法,基于高压压汞实验获得的毛管压力数据和实验测得的相应煤样的渗透率数据验证了计算斱法的正确性,并基于该斱法利用数值模拟的斱法分析了煤样渗透率的主要影响因素。结果表明,分形理论的煤岩渗透率计算斱法能够有效预测煤岩渗透率,平均误差仅为6.84%;煤岩分形维数、迂曲度和最大孔隙半径对渗透率具有重要影响,煤岩渗透率随着分形维数和迂曲度增加而降低,随最大孔隙半径增加而增加。

In order to provide effective calculation method of the coal rock permeability,the permeability calculation model of coal samples was deduced based on the fractal theory,and the acquisition approach of corresponding parameters was proposed.The correctness of the calculation method was verified based on the capillary pressure data from high-pressure mercury injection experiments,and the main influencing factors of the coal sample permeability were analyzed based on the permeability calculation model.The results showed that the permeability calculation method of high-rank coal rock based on the fractal theory could effectively predict the permeability,and the average error was only 6.84%.The fractal dimension,tortuosity and maximum pore radius of coal rock had important influence on its permeability.And the permeability of high-rank coal rock decreased with the increase of fractal dimension and tortuosity,and increased with the increase of maximum pore radius.