Qualification of a DP-Based FPSO Offloading Vessel

Abstract As the oil and gas industry moves into deeper and deeper waters, the need foran efficient system to offload crude oil from FPSOs to tankers is steadilyincreasing. Furthermore, oil transportation and trading has becoming moreinternational, where oil companies tend to seek solutions that allow forconventional oil tankers to offload directly from FPSOs and transport the crudeoil directly to the market. Traditionally, offloading of crude oil from FPSOs to the tankers is carried outeither in tandem configuration or via a remote Single Point Mooring (SPM) buoysolution. Tandem operations are normally carried out by use of specially builtDynamically Positioned (DP) tankers or with conventional tankers along with theuse of several tugs in order to keep the tanker at a safe distance from theFPSO. The new DP based offloading vessel is designed to dock onto and keep anyof the existing 2000 conventional tankers, from Aframax to VLCC size, safe onposition during the typical 24 hours of offloading operations. First applications of new innovative technologies are often perceived asinvolving potentially increased risks, with possible significant adverseconsequences and high levels of uncertainties. Hence, the development anddeployment of an innovative technology is often hindered by the view of suchrisks and uncertainties. This paper is prepared and presented by Remora and it addresses the steps andresults of a 10-year development and qualification process for new DP basedFPSO offloading vessel particularly suited for the new deepwater fields in WestAfrica, Brazil, GOM, etc. The paper explains the methodology applied for the qualification and describesthe entire qualification process. It outlines the main challenges anduncertainties identified during the process and the mitigations implemented anddescribe the results obtained. As part of the qualification process for the DPbased offloading vessel, extensive Sea Trial's with simulator validations andfollowing real life operations have been executed off of the west coast ofNorway throughout Q1 and Q2 2011.