酸压、生产一体化油管柱的力学分析

The Mechanic Analysis of Integrated Tubing String for Acid Fracturing and Production

摘要: 一体化油管柱一次下井后完成酸压、生产等多种井下作业，节省了多次更换管柱的作业成本，且有效提高了作业效率。基于三维弯曲井眼中管柱的几何描述，建立考虑井身结构、管柱几何、物理特性和作业参数的管柱力学模型，分析一体化管柱在下入、酸压、生产等过程的力学特点，提出计算封隔器作用力的方法，确定了各过程中管柱的载荷、应力分布以及轴向变形，结合典型井参数得出酸压为管柱的最恶劣工况，井口处是管柱的最危险位置，最小安全系数1.75能满足强度要求。另外，各工况下管柱无正弦和螺旋变形发生，可判定管柱满足稳定性要求。通过该研究，建立了一体化油管柱的力学分析方法，给出封隔器作用力的计算步骤，从管柱的强度和稳定性两方面评价了管柱的安全性能，有利于保障一体化管柱的安全服役。

Abstract: The integrated tubing string saved the operation cost of replacing the pipe string and increased the operation efficiency as it could complete plenty of down hole operations such as acid fracturing and production. Based on the geometrical description of the pipe string in the 3D curved borehole, a mechanical model of pipe string considering wellbore structure, string geometry, physical characteristics and operation parameters was established, and the calculate method for the packer force was presented by analyzing the mechanical characteristics of the integrated pipe string in the process of its running down, acid fracturing and production. The load, stress distribution and axial deformation of the tubing string were determined in each process. The result shows that the fracturing is the worst working condition to the tubing string and the wellhead is the most dangerous position, and the intensity requirements can be met with the minimum safety coefficient of 1.75. Furthermore, the tubing string is stable as sinusoidal or spiral deformation is not appeared in all working conditions. Through the research, the mechanical analysis method of the integrated tubing string and the calculation steps of packer force are given, and the safety performance of the tubing string is evaluated with its strength and stability. The results of the study are beneficial for the security service of the integrated tubing string.