煤矿井下碎软煤层瓦斯抽采钻孔钻进工艺

Drilling technology for soft broken coal seam underground gas extraction in coalmines

摘要:

碎软煤层在我国煤矿区分布广泛，具有瓦斯含量高、压力大、渗透率低等特征，在碎软煤层中钻进存在喷孔、塌孔、排渣不畅等问题，导致碎软煤层钻进困难、孔内事故频发，进而影响成孔深度和成孔率，造成瓦斯治理盲区；尤其是随着我国煤矿开采深度的增加，碎软煤层瓦斯抽采孔工作量和成孔难度不断增大。针对碎软煤层瓦斯抽采对钻孔施工需求，研究开发了高转速螺旋钻进工艺、中风压空气钻进工艺、气体定向钻进工艺等实用、经济的碎软煤层高效钻进技术，破解了碎软煤层钻孔排渣护孔、轨迹控制和高效成孔等方面难题，实现了碎软煤层钻孔在服役周期内的长效利用，相关技术在安徽、贵州、山西等地区成功推广应用，达到高效、精准抽采的目的，为矿井安全生产提供了技术保障。

Abstract:

Soft broken coal seams are widely distributed in coalmines in China， with the characteristics of high gas content， high pressure， and low permeability. because of the problems such as blowout， hole collapse， difficulty in removal of cuttings， it is difficult to drill in soft broken coal seams and hole accidents happen frequently， with the drilling depth and hole completion rate compromised， leading to blind gas treatment areas. Especially with the increase of coal mining depth， the workload and drilling difficulty in soft broken coal seam continue to increase. In response to the construction requirements for gas extraction drilling in soft brokencoal seams， practical and economical high-speed technologies have been developed， such as high-speed auger drilling technology， medium-pressure air drilling technology， air directional drilling technology， which has solved the problems about removal of cuttings and hole protection， trajectory control and efficient drilling， achieving the long-term utilization of the soft broken coal seam boreholes in the service life. The technology has been successfully promoted and applied in Anhui， Guizhou， Shanxi and other regions， achieved the purpose of high-efficiency and precise extraction， which provides technical guarantee for safe production in mines.