石油学报 ›› 1991, Vol. 12 ›› Issue (1): 129-138.DOI: 10.7623/syxb199101015

• 石油工程 • 上一篇    

非线性有限元混合法分析油井封隔器胶筒

范家齐, 曲宪刚, 杨晓翔   

  1. 大庆石油学院
  • 收稿日期:1988-12-26 出版日期:1991-01-25 发布日期:2013-07-08

NON-LINEAR MIXED FINITE ELEMENT METHOD FOR THE ANALYSIS OF ELASTOMERIC SEALED ELEMENT IN OIL WELL PACKER

Fan Jiaqi, Qu Xiangang, Yang Xiaoxiang   

  1. Daqing Petroleum Institute
  • Received:1988-12-26 Online:1991-01-25 Published:2013-07-08

摘要: 油井封隔器胶筒是由橡胶类材料制成的。橡胶类材料构件的几何形态和材料性能都是非线性的,材料的非线性关系一般用三个变形张量不变量表述。本文基于势能驻值原理,采用整体Lagrange法,建立适用于橡胶类材料的大位移和大应变的增量形式的非线性有限元混合法的计算列式。用四结点四边形等参数环元,对受均匀内压无限大厚壁圆筒进行计算,其结果与精确解符合很好,表明这种方法是有效和可靠的。油井封隔器胶筒的位移、应力和接触压力的计算结果表明:(1)胶筒外壁的上角部位有被挤上翘的趋势,(2)胶筒内的应力基本上是受压的,(3)胶筒的内外壁都有一定的接触压力,计算方法为合理设计封隔器胶筒提供了理论基础。

关键词: 封隔器胶筒, 有限元混合法, 非线性, 橡胶类材料, 接触压力, 油井, 精确解, 厚壁圆筒, 势能驻值原理, 大位移

Abstract: The sealing elements in an oil well packer are made of elastomeric materials with non-linear geometry and material behavior.The non-linear relation of the materials is generally expressed in terms of a deformation tensor with three invariants of in this paper, on the basis of the principle of stationary potential energy and total Lagrange formalation, an incremental non-linear mixed finite element formulations of large displacement and large strain have been developed for elastomeric materials.Four-node quadrilateral isopa rametric ring elements are used to analyze an infinitely long thick-walled cylinder subjected to internal pressure. The computed results agree very closely with the exact solution, and the procedure is effective and reliable. The computations of the displacements, stresses and contact pressures are given which shows that: (1) the sealed tube is compressed on the external wall in the upper corner to turn upwards gradually; (2) the stresses in the sealed tube are basically compressible; (3) there are certain contact pressures on the internal wall and external wall of the sealing elements.The findings are useful for the rational design of the elastomeric sealing elements.