郝志勇, 李志伟, 潘一山. 冲击倾向性煤层注水对钻进中吸钻卡钻的影响及试验[J]. 煤田地质与勘探, 2020, 48(3): 231-238. DOI: 10.3969/j.issn.1001-1986.2020.03.033
引用本文: 郝志勇, 李志伟, 潘一山. 冲击倾向性煤层注水对钻进中吸钻卡钻的影响及试验[J]. 煤田地质与勘探, 2020, 48(3): 231-238. DOI: 10.3969/j.issn.1001-1986.2020.03.033
HAO Zhiyong, LI Zhiwei, PAN Yishan. Influence of water injection in burst-prone coal seam on suction and sticking during drilling[J]. COAL GEOLOGY & EXPLORATION, 2020, 48(3): 231-238. DOI: 10.3969/j.issn.1001-1986.2020.03.033
Citation: HAO Zhiyong, LI Zhiwei, PAN Yishan. Influence of water injection in burst-prone coal seam on suction and sticking during drilling[J]. COAL GEOLOGY & EXPLORATION, 2020, 48(3): 231-238. DOI: 10.3969/j.issn.1001-1986.2020.03.033

冲击倾向性煤层注水对钻进中吸钻卡钻的影响及试验

Influence of water injection in burst-prone coal seam on suction and sticking during drilling

  • 摘要: 应用螺旋钻杆局部预测和评价冲击地压等动力灾害时易发生吸钻、卡钻等钻孔动力现象。为研究具有冲击倾向性煤层注水对吸钻、卡钻的影响规律,通过建立钻杆力学模型分析吸钻、卡钻动力现象产生机理,探明煤体应力和钻屑量是影响吸钻、卡钻发生的重要影响因素,推导了注水煤体的钻杆推力、钻杆扭矩等钻削力学参数计算公式,分析煤层注水后煤体应力重分布规律与钻屑量变化规律,并利用钻孔多参量测试系统,在井下对不同含水率煤体进行钻孔试验,从而研究钻杆推力、钻杆扭矩及钻屑量随煤体含水率的变化规律,并结合现场观测到的吸钻、卡钻动力现象,深入研究冲击倾向性煤层注水对煤体力学性质及吸钻、卡钻力学特性的影响。研究结果表明:吸钻时,钻杆推力值明显降低,卡钻时,钻杆扭矩值急剧升高;钻杆推力、钻杆扭矩均值增大幅度和钻屑量均值减小幅度随煤体含水率增大呈现先增大后减小的变化趋势;吸钻、卡钻点随煤体含水率的增大逐渐向煤壁深部转移;井下钻杆推力、钻杆扭矩及钻屑量的数据变化特征与煤体应力分布具有较好的对应关系。研究结果可为冲击地压预测和井下钻孔安全作业提供一定理论借鉴和工程指导。

     

    Abstract: When the spiral drill pipe is used to predict and evaluate the dynamic disasters such as rock burst, the drilling dynamic phenomena such as suction and sticking are easy to occur. In order to study the influence of water injection in burst-prone coal seam on suction and sticking, the mechanism of dynamic phenomenon of suction and sticking was analyzed by establishing the mechanical model of drill pipe, pointing out that the stress of coal body and the amount of drilling cuttings are the important factors that affect the occurrence of suction and sticking, deriving the calculation formula of drilling mechanical parameters such as drill pipe thrust and drill pipe torque under different water content, and clarifying the calculation formula. After the coal seam had been injected with water, the law of stress redistribution and the law of the change of the amount of cuttings in the coal body were studied. The multi parameter drilling test system was used to drill the coal body with different water content in the underground, so as to study the law of the change of the drill pipe thrust, the drill pipe torque and the amount of cuttings with the water content of the coal body. Combined with the dynamic phenomenon of suction and sticking observed in the field, the influence of water injection in burst-prone coal seam on the mechanical properties of coal body and the mechanical properties of suction and sticking was studied. The results show that: During suction, the thrust value of the drill pipe decreased obviously, and during sticking, the torque value of the drill pipe increased sharply; The increase range of drill pipe thrust, torque mean and the decrease range of drilling cuttings mean increased first and then decreased with the increase of water content in coal body; The suction and sticking points gradually transfer to the depth of coal wall with the increase of water content in coal body; The data variation characteristics of downhole drill pipe thrust, torque and drilling cuttings amount corresponded well with the stress distribution of coal body. The study can provide some theoretical and engineering guidance for the prediction of rock burst and safe drilling operation.

     

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