深水钻井动力定位平台应急解脱范围分析

摘要

Dynamically positioned platforms for deep water drilling will be out of control and drift in the cases of electricity outage or adverse natural conditions exceeding the DP (dynamic position) capacity,which will cause serious impact on the normal drilling operations.Based on the flexible joint angle,slip joint stroke,riser connector disconnection angle,EDS (emergency disconnection system) procedure,and operation experiences,the systematic procedures for calculating the allowable drift-off range of dynamically positioned platforms were established.The analysis model of LMRP and the lower BOP stack for the drilling platform in question (1 500 m rated DP3) were established with ABAQUS software.The results of dynamic analysis under different conditions shows that LMRP can be disconnected at 6 degrees under overload of 711 kN.With increasing Beaufort scale level or decreasing water depth,drift-off limited time for drilling platforms decreases.Current velocity has similar but lower influence than Beaufort scale level.%深水钻井动力定位平台在推进器由于失电或自然环境恶劣且超过其能力的情况下,会失去对位置的控制而产生漂移,对正常钻井作业产生重大的影响.基于深水钻井平台隔水管系统挠性接头和伸缩节冲程、隔水管连接器解锁角度、平台应急解脱程序和作业经验,建立了深水钻井动力定位平台应急解脱允许漂移范围的系统计算流程,针对目标平台(1 500 m作业水深的DP3钻井平台)使用ABAQUS软件对LMRP及下BOP组进行建模,并进行了不同工况下的动态分析,结果表明:目标平台在过提711 kN情况下LMRP倾斜6°可完成解锁;在应急解脱前,可用的解脱时间随着蒲福氏等级的增大与水深的减小而降低,海流流速与蒲福等级对平台漂移产生的影响规律相似,海流流速对平台漂移产生的影响较小.