膨胀管壁厚计算研究

CALCULATION OF WALL THICKNESS OF EXPANDABLE CASING

膨胀管技术是在井下以机械或液压的方法使管材永久变形、完成油气井建井的技术。它不仅使井身结构产生变形,还大大降低油气井建井成本。管体膨胀后的壁厚是计算抗挤强度的关键要素,根据金属材料冷变形的原理,在对管柱膨胀进行力学分析的基础上,结合金属材料冷变形的体积不变原理,应用管子膨胀时的应力—应变关系推导出膨胀管壁厚变化的计算公式,同时编制了壁厚变化的计算软件。实验数据和计算结果的对比验证了该计算公式是可靠的。

Expandable tubular technology is a process of deforming the casing metal permanently by a hydraulic or a mechanic device so as to complete the well construction. It gives rise to the great change of casing program, and largely decreases the cost of the well construction. But the key factor of calculating casing collapse strength is wall thickness of expandable casing, which is concerned by the petroleum engineers. Therefore based on the cold-deforming principle of metal, it is derived the wall thickness calculation model for expandable casings. Hence the software is compiled for wall thickness calculation. The theoretical data is coincident with the experiment data, which indicates the calculation model is reliable.