松软煤层瓦斯抽采钻孔易失稳、密封难的问题直接影响着松软煤层瓦斯高效抽采，在松软煤层施工钻孔成孔退钻后孔内塌孔导致无法及时密封，除此之外孔口煤体破碎区也形成大量漏气通道致使密封失效，由此对矿井生产带来安全隐患且造成了时间和经济上的浪费。从理论分析钻孔密封段受力情况入手，在利用黏弹性力学模型求解孔口破碎区煤体受力的基础上，结合影响松软煤层孔口塌孔外界条件理论研究松软煤层钻孔孔口易塌孔原因并提出合理解决办法，据此提出“同心环”加固密封技术，并从物理模型、技术原理与流程等方面进行详细阐述，最后在山西某矿区N2106松软煤层工作面开展现场应用试验。结果表明：松软煤层孔口破碎区在时间效应下易进入快速变形阶段，由于其吸附性强、易膨胀性等特点加之打钻偏移后钻杆对孔口的剧烈扰动，最终致使孔口退钻后易变形坍塌；采用“同心环”加固密封的试验钻孔均未出现退钻后塌孔的问题，瓦斯浓度在前30天均保持在30%以上，抽采第30天时钻孔最大瓦斯纯流量达到0.053 m3/min，与传统密封钻孔比较后发现“同心环”加固密封钻孔密封技术密封效果优于传统密封技术。

The problems of easy-to-stability and difficult sealing of gas drainage boreholes in soft coal seams directly affect the efficient extraction of gas in soft coal seams. After the holes are drilled and retreated in the construction of soft coal seams, the holes in the holes fail to be sealed in time. In addition, a large number of gas leakage channels are formed in the coal crushing area at the orifice, resulting in seal failure, which brings hidden dangers to mine production and a waste of time and economy. This paper starts with the theoretical analysis of the stress on the sealing section of the drill hole, and on the basis of solving the stress on the coal body in the hole breaking area by using the viscoelastic mechanical model, combined with the theory of the external conditions affecting the hole collapse of the hole opening in the soft coal seam, studies the causes of the hole collapse of the hole opening in the soft coal seam and puts forward reasonable solutions. Based on this, the “concentric ring”reinforcement sealing technology is proposed, and it is described in detail from the aspects of the physical model, technical principle and process, Finally, the field application test was carried out in the N2106 soft coal seam working face of a mining area in Shanxi. The results show that under the time effect, the broken area of the hole opening in the soft coal seam is easy to enter the stage of rapid deformation, and its strong adsorption line, easy expansion and other characteristics, coupled with the severe disturbance of the drill pipe to the hole opening after drilling offset, eventually lead to the deformation and collapse of the hole opening after drilling withdrawal; The test boreholes reinforced and sealed with “concentricring” did not collapse after withdrawal. The gas concentration remained above 30% in the first 30 days. The maximum pure gas flow of the boreholes reached 0.053 m3/min on the 30th day of extraction. Compared with the traditional sealed boreholes, it was found that the sealing effect of “concentric ring” reinforced and sealed boreholes was better than the traditional sealing technology.