开平向斜南东翼瓦斯地质特征及控制因素分析

Analysis of Gas Geological Characteristics and Factors in Southeastern Wing of Kaiping Syncline

基于采掘生产资料、钻孔资料、实验测试数据,对开平向斜南东翼矿井瓦斯生成、赋存、涌出、异常等特征展开研究,并分别从地质构造、水文地质、煤层埋深、煤厚及顶底板特征方面分析了瓦斯赋存及异常的地质控制因素。研究表明:研究区自林西矿往吕家坨矿和钱家营矿方向瓦斯含量、瓦斯压力及绝对瓦斯涌出量均呈现逐渐增大趋势;开放性正断层发育及地下水的携带逸散导致研究区瓦斯含量整体较低;不稳定的厚煤层、良好的顶底板封盖条件及发育的小型断层是研究区瓦斯异常的主控因素,这些特征为瓦斯提供了充足的赋存空间和良好的保存条件,有利于瓦斯大量聚集形成局部高压瓦斯区,从而易受采掘扰动影响引起瓦斯异常。

Based on the data of mining production,boreholes and experiments,three mines in the southeastern wing of Kaiping syncline were selected to study generation,occurrence,emission and anomaly of gas in this paper,and the geological control factors of gas occurrence and anomaly were analyzed comprehensively from geological structure,hydrogeological conditions,the depth,thickness,roof and floor of coal seams. The results demonstrated that the gas content,gas pressure and absolute gas emission rate present a gradually increasing trend from Linxi Mine to Lyujiatuo Mine and Qianjiaying Mine,and the effect of open fault and the hydrodynamic escape lead to the relatively low content of gas in the study area. The thick coal seam with high coefficient of variation,the roof and floor with excellent sealing condition and the developed small fault are the main controlling factors of the gas anomaly in study area. All the above factors could provide adequate occurrence space and good preservation conditions for gas,which are in favor of gas enrichment in certain zone with high gas pressure in where the gas abnormal effusing can be easily triggered by mining disturbance.