棱状钻杆应用于松软突出煤层钻进强度匹配研究

为解决棱状钻具的强度匹配问题，应用实体设计和数值分析软件，建立不同结构棱状钻具力学分析模型，对其进行强度分析，优化棱状钻具结构。分析结果表明，常规棱状类钻具整体强度匹配不合理，丝扣位置存在受力薄弱点，安全系数较低且整体分布不均衡。可采取加大接头直径、优化接头及棱边结构、应用摩擦焊接工艺等技术手段提高棱状钻具整体强度；改进后的棱状钻杆，整体安全系数分布均衡、波动小，钻杆整体力学性能得到了有效的提高。通过工程应用，解决了煤矿复杂条件煤层钻孔施工丢钻、断钻频繁的被动局面，平均深度超过了设计深度，钻进效率提高20

Study on strength matching of prismatic drilling rod when drilling soft and outburst coal seam

To solve the problem in strength matching of prismatic drilling rod, the mechanical analysis model of different prismatic drilling rods were established by the physical design and numerical analysis software, and its strength and edges structure were analyzed. The results showed that the strength matching of conventional prismatic drilling rod is unreasonable. The thread of drilling rod exists the problems of vulnerabilities, lower safety factor and unbalance distribution. The technical means, such as increasing the diameter of the joint, optimizing joint and edge structure, and applying friction welding technology etc., were adopted to improve the overall strength of the prismatic drilling rod. The overall safety factor of improved prismatic drilling rod had more balanced distribution and less undulation, and the overall mechanical properties of the drilling rod were effectively improved. By engineering application, the problems of drilling rod dropping and breaking frequently when drilling in complex conditions coal seam were solved. The average depth of borehole exceeded the design depth, and the drilling efficiency improved by 20%, without the accidents of drilling rod dropping and breaking during the test.