深水中型修井系统设计与整体强度分析

Design and Overall Strength Analysis of a Deepwater Medium-Sized Workover System

中型修井系统进行修井作业能在作业类型和成本上取得平衡,是深水水下井口修井作业未来的发展趋势。基于轻型工程船舶,提出了一套针对水下井口的深水中型修井系统整体设计方案,详细介绍了底部总成、修井隔水管及提升框架等主要部件;建立了深水中型修井系统整体动力学分析模型,利用有限元方法分析了系统的强度响应。分析结果显示:深水中型修井系统可为深水修井提供流体流动通道,使得修井液、连续管等能在修井隔水管内的通道进行修井作业;随着轻型工作船舶偏移量的增大,在锥形应力短节处的等效应力和弯矩随之增大;整套修井系统的最大弯矩和最大等效应力出现在锥形应力短节的底部,后续设计应重点关注底部锥形应力短节的受力状况。研究成果可为我国深水修井装备和技术发展及其在深水油气田的安全应用提供参考。

The medium-sized workover system can achieve a balance between service type and cost in work-over operations,and is the future development trend of deepwater subsea wellhead workover operations.Based on light engineering vessels,an integrated design of deepwater medium-sized workover system for subsea wellhead was proposed.The main components such as the bottom assembly,workover riser and lift frame were introduced in de-tail,an overall dynamic analysis model for the deepwater medium-sized workover system was built,and the finite element method was used to analyze the strength response of the system.The results show that the deepwater medi-um-sized workover system can provide a fluid flow channel for deepwater workover,and allow workover fluid and coiled tubing to conduct workover operation in the channel of the workover riser.As the offset of light work vessel increases,the equivalent stress and bending moment at the tapered stress joint increases correspondingly;and the maximum bending moment and equivalent stress of the whole workover system occur at the bottom of the tapered stress joint,so the subsequent design should focus on the stress condition at the bottom of the conical stress nipple.The research findings provide reference for the development of deepwater workover equipment and technology and their safe application in deepwater oil and gas fields.