Permanent versus disconnectable FPSOs

Abstract

Floating production storage and offloading (FPSO) vessels offer a cost-effective field development solution, especially in deepwater areas lacking an adequate pipeline network. Most FPSOs are permanently moored, i.e. the complete system is designed to withstand any kind of extreme environment at the field location. FPSOs that can be quickly disconnected from their moorings and risers have also been designed and deployed. The key feature of this type of disconnectable FPSO is that it can be disconnect and so avoid dangerous environmental conditions such as icebergs, hurricanes in the Gulf of Mexico and typhoons in the South China Sea. In this paper, the concept of disconnectable FPSOs for deepwater field development is presented. Key technologies and their engineering analyses are highlighted. The merits and demerits of disconnectable vs permanent FPSOs are then evaluated. The paper concludes that both permanent and disconnectable FPSOs are versatile floating systems and their selection depends on safety, technological, cost and operational considerations.

摘 要

浮式生产储卸油系统(FPSO)是一种经济有效的浮式平台方案, 特别是在缺乏足够的输油管道系统的深海领域。 大多数FPSO 是永久系泊的, 即整个系统能够抵抗工作海域内的各种极值环境条件。 目前, 能够将FPSO与其系泊及立管系统快速解脱的装置已经设计并发展了。 可解脱式FPSO的主要特点是可解脱性, 并能避免一定的环境条件, 如冰山, 美国摩西哥湾的飓风, 中国南海的台风。 本文将针对深水海域可解脱式FPSO, 提出其主要技术和工程分析与设计思路, 评估可解脱式FPSO 与永久式FPSO的优缺点, 等等。 可见可解脱式FPSO 与永久式FPSO 都是十分有效的浮式系统, 并根据平台设计的安全性、 技术、 成本和运行要求, 来决定选择何种系泊方式。