双向应力椭圆方程在连续油管作业中的应用

连续油管作为简单、快捷的不压井修井设备，越来越受到油气田的重视。由于连续油气管在起下过程中将受到拉伸力、压缩力、内外流体压力及其它井下各种复杂力的作用，以及与钻具、常规油管相比的轻、柔特性，所以连续油管的性能和质量对连续油管作业成功与否十分重要。为避免连续油管发生屈服形变，影响作业的安全和质量，充分认识连续油管受力形变具有重要的意义。文中引入双向应力椭圆方程来指导连续油管的强度计算。

Application of Bidirectional Stress Elliptical Equation in Coiled Tu bing Operation

Coiled Tubing( CT) is getting more and more attentions as a simple and quick snubbing unit in oil/gas fields. There are tensile force, compressive force, external or internal hydraulic pressure and other force acting on CT as the string is being either run into the hole or being pulled out of the hole. And CT has characteri- stics of light and soft compared with drilling tools and regular tubings. Thus, the property and quality of CT is very important for CT operating. In order to avoid yield failure and ensure safety and quality of CT operating, force strength of CT is considered. And the strength of CT is calculated by bidirectional stress elliptical equation.