摘要
气体钻井中常出现断钻铤事故。文章通过对钻柱受力和钻柱本身性能的分析,得到气体钻井断钻铤的原因。在钻柱受力分析方面,从钻柱动力学出发对钻柱反转、钻柱扭转振动和钻柱横向振动等进行了分析,认为钻柱的这些运动是产生钻柱交变弯曲应力并集中,造成钻柱疲劳破坏;在钻柱本身性能的分析上,弯曲强度比不是造成钻铤内螺纹断裂的原因,利用Morrow应变周期方程结合有限元分析方法,得出高的平均应力和应变幅度是造成钻铤内螺纹断裂的主要因素。预防气体钻井断钻具应从降低钻铤内螺纹根部应力集中和改善钻柱的受力状况着手,在降低钻铤内螺纹根部应力集中上采用应力减轻槽,高扭矩接头和高摩擦螺纹油;在改善钻柱的受力状况上推广使用气体螺杆,试验抗涡动的PDC钻头,钻柱中加装纵向减振器的同时,要保证钻铤接头的偏心度小。
The drill collar breaking accidents appear in gas drilling frequently.Through analyzing the drill stem stress and its performance,the reasons of drill collar failure in gas drilling is gotten.The paper analyzed the drill string reversion,drill string torsional vibration and drill string lateral vibration,and the!analysis results showed that these vibration made the string alternating bending and the string stress concentrated,which result in the string endurance failure.By analyzing string performance,bending intensity ratio isn't the main reason of the string female screw failure.Using Morrow strain period equation and finite element analysis method,we know that the high average stress and high strain amplitude are the main reason of string female screw failure.To prevent the string breaking accident,the stress concentration of the female screw root should be decreased by using stress lightening channel,high torque joint,and high friction thread compound,and the drill stem stress should be improved by using air screw,anti-swirling PDC bit,equiping the longitudinal shock reducer in the string to ensure low eccentricity of the drill collar joint.
出处
《钻采工艺》
CAS
北大核心
2007年第6期6-8,共3页
Drilling & Production Technology
基金
中国石化科技部"川西特殊复杂地层气体钻井技术应用研究"项目
关键词
气体钻井
断钻铤
原因分析
预防
gas drilling,drill collar breaking,reason analysis,protection
