深水钻井隔水管避台撤离动力与长度优化

钻井平台作业过程中遭遇强台风时,可能由于种种原因导致隔水管未被完全回收,平台只能下挂隔水管实施撤离。撤离过程中隔水管受到强烈的海流载荷作用,使平台的撤离航向与航速受到严重限制。提出隔水管避台撤离分析方法,建立软硬两种悬挂模式下撤离隔水管有限元模型,进行不同航向与航速下的隔水管悬挂撤离分析,研究隔水管悬挂撤离作业窗口,并对隔水管悬挂长度进行优化。分析表明,隔水管软悬挂撤离作业窗口较大,推荐平台采用软悬挂模式进行撤离,如不具备软悬挂实施条件,提前回收部分隔水管并将其余部分硬悬挂在平台上进行撤离也是一种可行的方案。

Dynamic and length optimization of typhoon-avoidance evacuation for deepwater drilling risers

When encountering severe typhoon in the operation process,drilling platform must evacuate with the hang off riser which may not be completely retrieved due to various reasons.In the evacuation process,the hang off riser suffers strong current load and the speed and heading of platform is seriously restricted.The analysis method of riser typhoon-avoidance is proposed.The finite element model of the hang off riser evacuation analysis is established to research the evacuation envelopes and optimize the length of hang off riser.Analysis indicates that soft hang off mode extends the evacuation envelopes of hang off riser and it should be selected in the evacuation.When the soft hang off can not be carried out,partly retrieving the riser and hanging the rest in hard configuration is also a feasible plan.