下保护层开采卸压瓦斯分布预测及抽采技术

Prediction of Pressure Relief Gas Distribution and Extraction Technology for Lower Protective Seam Mining

为了保证被保护层瓦斯的消突和治理工作,掌握保护层开采的卸压效果和预测卸压瓦斯的主要分布区域,运用UDEC离散元模拟得到了下保护层开采后被保护层的卸压效果、瓦斯运移规律及分布情况,并根据模拟结果相应地提出了留巷钻孔法抽采卸压瓦斯,实现了无煤柱开采,消除了被保护层应力集中区煤与瓦斯突出危险威胁。经现场实测抽采后3号煤层瓦斯压力降低了1.36 MPa,瓦斯含量降低了9.51 MPa,抽采效果良好。

In order to ensure the gas outburst elimination and the gas control management of the protected seam, the effect of thepressure-relief in protecting coal seams is grasped, main regional distribution of pressure-relief gas is predicted; we got the effectof pressure relief, gas migration and distribution law of protected layer after the protection layer mining by using UDEC numericalsimulation software of discrete elements; pressure relief gas is extracted by the method of drilling along gob-side entry retaining onthe basis of the simulation results to achieve no pillar mining and eliminate the danger of coal and gas outburst in the stress con-centration area of outburst coal seam. The test results show that gas pressure was reduced by 1.36 MPa, gas content reduced by9.51 MPa and good extraction results are obtained.