Solving BPÂ’s FPSO Positioning Problem 12/21/2006 by Debra Barker
Faced with the problem of a failed GPS system on-board Schiehallion FPSO, BP recently chose the Octopus F180+ TM Precision Attitude and Positioning System. Located in the north east Atlantic Ocean, approximately 140km to the west of the Orkney Islands, UK, the vessel normally relies on conventional GPS to measure the position of the turret towards the bow. With up to 24 oil- and gas-carrying flexible risers connecting the FPSO to the sea-bed well-heads, it is imperative that the position of the turret, to which the risers are attached, is accurately known and maintained at all times. Being in a hazardous location close to volatile oil and gasses, the previous GPS system was certified and approved for such applications but being relatively old, a replacement was not available ‘off the shelf’. When this unit failed earlier this year, the Octopus F180+ was chosen as a replacement, being one of the few systems readily available that could accurately determine the position of the turret from a distance. Mounted at a remote, safe location near the bridge, some 160m back from the turret, the F180’s in-built lever-arm facility uses precision position and attitude information to calculate the position and motion at the remote position. Unlike conventional installations for hydrographic purposes, the location of this F180 unit meant that it was impossible to calibrate it by sailing in figures of eight, so a custom pre-calibrated mounting was devised. Built into a single weather-proof housing, the twin antennas and inertial sensors are co-located and calibrated prior to being installed on the vessel. This novel approach along with the F180’s precision performance enabled the whole system to be quickly bolted to an existing structure and was up and running within 15 minutes. The complete package continues to be supplied on long term rental by Ashtead Technology Rentals, Aberdeen. The Octopus F180series from CodaOctopus comprises a range of systems with enhanced performance to meet the widest range of requirements. Variants include: F180 – standard system with 20cm RTK and DGPS capability F185™ – with L1/L2 and 1cm RTK capability F190™ – with L1/L2 and integral satellite differential receiver All variants can be further enhanced to include L1/L2 on the secondary antenna for rapid heading initialisation and improved immunity to drop-out. All offer the same high performance in terms of heading and motion accuracy and can be upgraded to the next specification level. http://www.codaoctopus.com _________________________________________________________________ Advertisement: Meet Sexy Singles Today @ Lavalife - Click here http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Flavalife9%2Eninemsn%2Ecom%2Eau%2Fclickthru%2Fclickthru%2Eact%3Fid%3Dninemsn%26context%3Dan99%26locale%3Den%5FAU%26a%3D23769&_t=754951090&_r=endtext_lavalife_dec_meet&_m=EXT JALESVEVA YAYAMAHE Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/pelaut/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/pelaut/join (Yahoo! ID required) <*> To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
