张力腿平台丛式立管钻完井作业窗口分析方法

Analysis method for drilling and completion windows of TLP cluster-risers

针对张力腿平台(TLP)钻完井过程中丛式立管的作业安全问题,基于HUSE尾流模型和切片分析理论,考虑丛式立管之间的干涉作用,建立了TLP丛式立管系统力学分析模型,确定了TLP丛式立管钻完井作业准则,并提出了TLP丛式立管钻完井作业窗口分析方法及流程。以我国南海某深水油井为例,开展了TLP丛式立管钻完井作业窗口及其影响因素分析,结果表明:TLP丛式立管钻完井作业窗口总体上呈倒锥形,在低流速区域受立管最大弯曲角度限制,在高流速区域受立管最大等效应力限制;钻井液密度对立管钻完井作业窗口的影响较小,顶张力和立管间距对TLP丛式立管系统的钻完井作业窗口具有显著影响,顶张力不足会导致TLP丛式立管在高流速区域无法作业,立管间距设计较小会引起立管碰撞进而导致TLP钻完井作业失败。本文研究成果可为我国南海TLP丛式立管钻完井作业安全管理提供参考。

Aiming at the operational safety problem of TLP cluster - risers during drilling and completion, the mechani-cal analysis model of TLP cluster - risers was established considering the interference between cluster - risers based on the HUSE empirical wake model and microtome section theory. The drilling and completion criteria, with TLP cluster- risers were determined,and analysis method and procedure for drilling and completion windows with TLP cluster-ris -ers were proposed. Taking a deep water oil well in the South China Sea as an example, the windows for drilling and completion with TLP cluster - risers and the relevant influencing factors were analyzed. The results show that the win -dow has an inverted cone shape, and is limited by the maximum angle of the riser when the current speed is low , and limited by the maximum equivalent stress in the riser when the current speed is high . The mud density has minor in -fluence on the operation window , while the top tension and the riser spacing have significant influence. Insufficient top tension will result in the TLP cluster- risers incapable to work when the current speed is high ; the risers would collide each other if there is narrow spacing between risers, which may lead to the failure of drilling and completion. This paper can provide a reference for the safety management of drilling and completion with TLP cluster- risers in the South China Sea.