Abstract: It is very important for the designs of well casing strings, especially for those of deep wells and super deep wells to analyze the load bearing capacity of tubes inside slips. There are many different model to deal with this problem including that of API. However, those models didn't consider the local bending stresses at tube walls due to the actions of slips to tubes. That means their analysis are applied only to the calculations of plastic load bearing capacity of tubes inside of slip. Based on shell theory, this paper presents a new model about the elastic load bearing capacity of tubes inside of slips and the calculated results shows that it is consistent with those of FEM and experiments.

Key words: slips, tube, shell theory, load bearing capacity

摘要： 分析卡瓦内悬挂管柱的承载能力,对油井特别是深井和超深井的套管柱设计十分重要.以往国内外对此的研究以API为代表,由于模型上的局限,分析中未考虑管柱表面由于卡瓦夹持产生的局部弯曲应力,分析的结果适用于管柱塑性承载能力的计算,而我国油井套管柱的设计实际上是按弹性设计的,因此以往的大部分套管柱设计均存在安全系数过小的问题.针对这一问题分析了以往这些研究中存在的不足,以弹性力学中薄壳理论为基础,根据卡瓦内管柱的变形形态,提出了一种较合理的可计算卡瓦内悬挂管柱弹性承载能力的解析方法,计算结果与有限元数值计算结果和试验实测结果符合良好.

关键词: 卡瓦, 套管柱, 薄壳理论, 承载强度