RIASSUNTO
Abstract
The risk of an export buoy's loading hose being pierced by the spear of abillfish such as marlin is very real. Such incidents are proving especiallyfrequent on FPSOs offshore Angola, where several cases are recorded everyyear.
The consequences can be critical, to the extent of halting production ifstorage capacity aboard is insufficient to cover the time it takes to replacethe damaged item. This is precisely what happened on Girassol in January 2010,resulting in shortfalls in the region of 790,000 barrels.
The Angolan deep offshore, where most of the country's FPSOs are concentrated,is conducive to the development of marlin as the waters bordering on thecontinental plateau stay warm and clear for the greater part of the year. Infact, petroleum activities themselves tend to draw marlin by attracting thespecies they feed on to the locations.
The attacks on flexibles are not deliberate, but the collateral damage, as itwere, of the creatures' hunting excursions. As there is no known deterrent,episodic recurrences are to be expected.
The best way of coping with these incidents is to be prepared for them bykeeping spare hoses on site and having the appropriate vessels, procedures andpersonnel ready to quickly replace the damaged item. The development oftemporary repair kits should also improve the response.
Introduction
Actors in the oil industry are used to having to accommodate the surprisesdealt out by Mother Nature.
But it is hard to admit, in the face of enormous damage, that it was not one ofthe carefully anticipated disaster scenarios that got the better of us but amere harmless animal. Who would boast of losing hundreds of thousands ofbarrels and dollars because of a single fish? And yet this happens, regularly,especially in the Gulf of Guinea and still more frequently offshoreAngola.
Once in a while, the floating export hose of an FPSO is found to have beenpunctured by a billfish. Usually, the bill breaks off the creature's head andremains stuck in the hose. The floating line is then no longer tight and mustbe repaired. When stocks on board are high, production may need to be cut backor even stopped, with all the consequences that entails, if the damaged hosesection cannot be replaced before the next offload.
Production of the Girassol field on Block 17 (Angola), for example, had to beslowed and finally stopped in January 2010 to proceed with just such a repair,resulting in a production shortfall of three quarters of a million barrels. Yetthis was not the first time a marlin bill had pierced one of the ""doublecarcass"" flexible hose segments of the FPSO Girassol's floating exportline.
Information on such incidents is - understandably - not easy to come by, butdiscreet probing has turned up evidence of similar events happening all overthe world every year.
The first query is: why do marlin attack the floating hoses? And the second, ofcourse: how can we stop them? This article will try to provide an answer bypresenting the view of the Total group.