煤与瓦斯突出的渗透失稳机理分析

为探索煤与瓦斯突出机理,基于流固耦合理论,对地面煤田钻井、实验室巷道增压试验及金属栅栏的抑突效应进行了分析,提出了煤与瓦斯突出属渗透性失稳的观点,其主要内容是:煤层瓦斯压力梯度是反映地应力、瓦斯压力和煤层渗透性相互影响的一种综合性指标。突出分为2个阶段:第1阶段是煤体失稳阶段,产生失稳的动力是瓦斯的渗透力;第2阶段是煤与瓦斯突出的运移阶段,其主要动力是瓦斯的膨胀压力。瓦斯的渗透力取决于瓦斯压力梯度,而瓦斯膨胀压力取决于瓦斯绝对压力。降低煤层瓦斯压力、增加巷道气压背景值及延长渗流途径是降低煤层瓦斯压力梯度的3种途径。

Analysis on Penetration Stability Lost Mechanism of Coal and Gas Outburst

In order to seek the mechanism of the coal and gas outburst,based on the fluid and solid coupling theory,an analysis was conducted on the surface coalfield drilling,the pressurized test of the gateway in lab and the outburst control effect with the metal fences.A view was provided that the coal gas outburst was the permeability stability lost.The main content of the view would be that the gas pressure gradient of the seam would be a comprehensive index to reflect the mutual influences between the ground str...