定向井中钻杆的稳定性分析

An Stability Analysis of Drill Pipe in Directional Well

分析研究钻杆在定向井中的受力及弯曲情况,建立定向井中钻杆受力弯曲的力学模型,结合工程实际,利用能量法推导出具有初弯曲钻柱稳定的临界压力计算公式,讨论初弯曲及扭矩对临界压力的影响。得出在相同条件下时,初始挠度对临界载荷的影响随着井斜角的增大而增大,扭矩对钻杆临界载荷的影响随着井斜角的增大而减小。

This paper analyzes and studies the stress and bend of drill pipe in directional well to establish the me- chanical model of drilling pipe bent by the force in directional well. Combined with engineering practice, using the energy method, it derives the computational formula of stable initial bending critical pressure of the drilling string and discusses the influence of initial bending and torque on the critical pressure. It obtains that, in the same condi- tions, the influence of initial deflection on the critical load increases with the increase of deviation angle, while the influence of torque on the critical load of drill pipe decreases with the increase of deviation angle.