煤层钻孔失稳机理研究进展

高瓦斯松软煤层、软硬复合煤层和突出煤层深孔钻进是公认的世界性难题,已成为制约部分高瓦斯和突出矿井瓦斯治理效果的瓶颈。尽管众多研究者在钻孔施工装备及工艺的改进方面开展了大量卓有成效的工作,但因煤层钻孔失稳机理尚未完全揭示,钻孔成孔工艺缺乏理论支撑,上述难题至今仍未破解。从煤体结构判识及分类、含流体煤力学特性、失稳机理三方面入手,系统介绍了煤层钻孔失稳机理的研究进展,探讨了该领域亟待解决的问题;最后指出,含流体煤卸载过程中,煤层钻孔在流-固-应力耦合作用下的失稳破坏机制研究,是破解煤层深孔钻进难题的重点方向之一。

Progress in research on instability mechanism of coalbed borehole

It is well known that the deep hole drilling in high gas soft coal seam , hard and soft compound coal seam and outburst coal seam is a worldwide problem , which has become the bottleneck restricts gas control effect of some high gas and outburst coal mines .For a long time , numerous fruitful studies about drilling construction equipment and process have been carried out at home and abroad , but the instability mechanism of coalbed borehole is not revealed completely , the hole-making technology in coal seam lacks theory support , therefore above difficult problems have not been solved yet .The progress in research on instability mechanism of coalbed borehole were systematically introduced , mainly including recognition and classification of coal structure , mechanical properties of coal containing fluid and instability mechanism .Then the problems needed to be solved urgently in this field were discussed . Finally, it was pointed out that the instability mechanism of coalbed borehole under fluid-solid-stress coupling effect during the unloading course of coal containing fluid is one of the key research directions to solve the difficult problem of deep hole drilling .