深水水下井口完井作业窗口分析

摘要

完井作业窗口是进行完井作业的各种极限环境条件，对于指导深水海底井口完井作业具有重要意义，根据完井作业模式可分为下钻刮管窗口、完井管串下放窗口和极限连接窗口等。完井作业时，隔水管强度、井口与导管强度、井口倾斜角度、完井工具的通过性以及挠性接头的转角等都是限制完井作业的重要因素。通过建立张紧器–隔水管柱–井口及导管和土壤的耦合模型，研究并量化影响深水海底井口完井作业最重要的限制条件隔水管上、下挠性接头转角，并结合其他限制条件形成海底井口完井作业的作业窗口确定方法。对南海某探井进行了实例计算，明确了该井完井作业各种模式所允许的极限环境条件，为深水油气田开发的完井作业提供参考。%The completion operation window, namely various extreme environmental conditions for implementation of completion operation, is of great signiifcance for guiding the completion operation at deepwater subsea wellhead, and falls into running and scraping pipe window, production string running window and extreme connection window on the basis of completion operation modes. In the course of completion operation, the strength of riser, the strength of wellhead and conductor, the inclination angle of wellhead, accessibility of completion tool and the angle of lfexible joint are the important factors which restrict the completion operation. By means of creating the coupling model of tensioner-waterproof string-wellhead and conductor and soil, the rotational angle of lfexible joint at top and bottom of waterproof pipe which, as the most important limiting condition, affects the completion operation of deepwater subsea wellhead is researched and quantitated, and is used to form the determination method of operation window during the completion operation of subsea wellhead combining with other limiting conditions. Through the practical calculation for a prospecting well in the South Sea, this method deifnite the extreme environment conditions allowed for all modes of completion operation, which maybe the reference for the completion operation in the development of deepwater oil and gas ifeld.