超深水钻井隔水管设计影响因素

Influential factors for the design of ultra-deepwater drilling risers

超深水钻井隔水管设计的影响因素主要为环境因素与作业因素,前者主要包括水深、波浪、海流,后者主要包括钻井液密度、脱离后隔水管系统悬挂模式、浮力块分布、涡激抑制设备等。系统总结了超深水钻井隔水管设计影响因素,研究了各因素影响隔水管设计的机理,定性或定量分析了各因素对隔水管设计的影响。研究表明,水深和海流是隔水管设计最显著的影响因素,水深增加导致隔水管材料、结构、配置产生重大变化,海流导致隔水管产生涡激疲劳,并增加隔水管下放与收回的难度。悬挂模式影响隔水管系统的浮力系数和浮力块分布,涡激抑制设备造成隔水管作业困难,钻井液密度影响隔水管的有效张力和底部球铰转角进而影响隔水管系统的稳定性。相关结论可为超深水钻井隔水管设计、配置、作业、管理提供参考。

Environmental and operational factors are the main factors affecting the design of ultra-deepwater drilling risers. The former includes water depth, wave, current, and the latter includes drilling fluid density, hang-off mode after disconnection, buoyancy modules distribution, and vortex-induced vibration （VIV） suppression devices. This paper described the factors affecting the design of the ultra-deepwater drilling risers, identified the influential mechanism of these factors, and analyzed the influences qualitatively or quantitatively. Water depth and current are the most significant influencing factors. The material, structure and configuration of the drilling riser change with the increase of water depth. Current can cause vortex-induced fatigue in the riser, and cause difficulty in drilling riser installation and retrieval. Hangoff mode affects the buoyancy factor and the distribution of buoyancy modules. VIV suppression device causes difficulty in riser operation, and the density of drilling mud affects the flex joint angle and effective tension, and thus affecting the stability of the drilling riser system.