基于Klinkenberg效应的水力冲孔有效半径数值解算方法

Numerical Solution of Effective Radius of Hydraulic Punching Based on Klinkenberg Effect

根据瓦斯渗流场、地应力场与煤体变形场之间的耦合关系,建立了考虑Klinkenberg效应的瓦斯运移气固耦合模型。进行了不同出煤量条件下水力冲孔耦合模型的数值模拟研究,结果表明:水力冲孔有效半径随抽采时间与出煤量的增加而增加;Klinkenberg效应对低透气性煤层中瓦斯的运移起促进作用,随着抽采时间的增加其促进作用愈加显著;煤层瓦斯压力的降低促使煤体骨架受到的有效应力增加,煤体内孔隙被压缩,导致孔隙率与渗透率的降低。

Based on the coupling relationship among gas seepage field, stress field and coal deformation field, a gas transport gassolid coupling model is established under considering the Klinkenberg effect and the numerical simulation of hydraulic punching coupling model under different coal output conditions is carried out. The results show that the effective radius of hydraulic punching increases with the increase of extraction time and coal output. The Klinkenberg effect promotes the transport of gas in low permeability coal seam, and in the same time, the effect increases with the increasing of extraction time. The decrease of gas pressure in coal seam increases the effective stress of coal skeleton, and the pores in the coal are compressed, which results in a decrease in porosity and permeability.