井简内杆管柱双层接触有限元分析及应用

THE ANALYSIS AND APPLICATION OF DOUBLE LAYER CONTACT FINITE ELEMENT ABOUT ROD AND TUBING STRING IN WELL BORE

构造双层多向接触间隙元描述细长油管柱与内外杆管柱的随机接触摩擦问题,与空间梁单元相结合,采用变刚度与等刚度交替方式求解,得出抽油杆柱与油管柱以及油管柱与套管柱的接触状态、接触位置、摩阻力大小以及抽油杆柱与油管柱在任意井深处的广义内力、应力和变形.三口井算例表明,抽油杆柱与油管柱的井口悬重误差低于10%,能够为抽油杆和油管柱设计和失效分析提供可靠的计算方法和理论依据.

Constructing the double layer multi-directional contact gap element to describe the random contact problem about slim tubing string with inside and outside string, combining with dimensional beam element and adopting variable and equivalent stiffness to solve equations, the contact condition, the contact position, the size of friction and the generalized inner force, stress and deformation in arbitrary well depth of the rod and tubing string were obtained. The arithmetic example about three wells demonstrated that the corrigendum of hang weight in well head was low by 10 percent. Therefor, it supplied reliable computational methods and theoretical references for designing and failure analysis of the rod and tubing string.