Jeremy Beckman
Editor, Europe
North Sea Producer during outfitting at A&P Offshore.
Marginal field fervour has transformed the fortunes of North East England's offshore construction yards. A few years ago, with big-spending UK sector projects seemingly on the way out, casualties looked inevitable.
However, the pioneering efforts of Amerada Hess, ARCO and Kerr-McGee with floating production has had a knock-on effect on the yards. They invested in quayside facilities to accommodate FPSOs for topsides installation or outfitting. This in turn has had a knock-on effect on UK operators: with so many back-up services on their doorstep, they are now at liberty to fast-track developments.
So far the North East has had the field virtually to itself in Britain, with the Scottish yards only now re-aligning towards this new market. The only real British competitor is Harland & Wolff in Belfast, which can build much larger FPSO vessels. But even here there is some synergy.
For instance, another of Harland & Wolff's current offshore projects is the conversion of a double-hulled tanker into a 100,000 dwt FPSO for Amerada Hess' Durward and Dauntless fields. The vessel will be named Glas Dowr, Cornish for Bluewater which is the main contractor. This spring, Bluewater awarded the topsides process construction to Heerema Hartlepool.
Five packages are being built weighing 2,500 tonnes in total. The process plant will allow oil output of up to 60,000 b/d, with the vessel capable of storing 660,000 bbl. The completed modules will be installed on the vessel after it arrives at Swan Hunter's yard on Tyneside in October or November.
Durward/Dauntless is the first floating production construction contract for either of these yards. If first oil is achieved in early 1997, it will also represent Amerada's fastest ever standalone development: Durward was only discovered in October 1993.
Two other leading designers and procurers for FPSOs are Single Buoy Moorings and Maersk. Both are working with Amec to provide a leased vessel for Shell's Curlew development in UK block 29/7. While Maersk is supplying and converting the 100,000 dwt tanker, Amec's brief is to design, build and install the vessel's topsides, ready for first oil in October 1997. Process capacity of the vessel (to be operated by Maersk) will be around 55,000 b/d, with reserves from Curlew estimated at 70 MM bbl of oil and 180 bcf of gas.
Amec derived its experience working for Shell and SBM on the Anasuria FPSO. Here, though, it only fabricated and installed the topsides: design was handled by Stork Protech in Schiedam. Nevertheless, it was an important undertaking for Amec, as this is the largest purpose-built turret moored vessel operating on the UK shelf, with storage capacity for 850,000 bbl of oil.
Anasuria is due to start production this month on Shell's Teal, Teal South and Guillemot A Fields in central North Sea block 21/25. Combined reserves are 86 MM bbl of oil and 31 bcf of gas currently, but there are hopes of tying back future finds to the production facilities. The three fields are being produced through subsea wells connected to the FPSO through flowlines and flexible dynamic risers, with a combined production and water injection manifold stationed between Teal South and Guillemot A.
Among the topsides packages built by Amec at Tyneside, the process facilities are situated on open deck-type modules three metres above the vessel's main deck to achieve secure separation from the storage tanks. Basically this is a conventional three-stage separation train designed for maximum oil production of 60,500 b/d and 36 million cf/d of gas.
Incoming crude is stabilised, routed to the vessel reception tank for dewatering, then stored in cargo tanks before being offloaded to shuttle tankers. Associated gas is compressed in three stages, dehydrated and then exported through a gas pipeline for onward transmission into the Fulmar Gas line. Two treated seawater injection pumps with combined capacity of 85,000 b/d are used to maintain reservoir pressure.
The vessel sailed into Tyneside from the Mitsubishi shipyard in Japan this March. Amec also built the 1,500-tonne turret (its first ever): this was originally due to be built in Japan.
Quayside expansion
At SLP's Teesside complex, a new £5 million quayside development was completed recently, allowing the converted tanker for the MacCulloch Field to come in for topsides outfitting. A new 300-metre long quay was created, with the river bed alongside dredged to a depth of seven metres. Nearby, old offices formerly owned by Whessoe were refurbished to house floating production design and procurement personnel.
The new quay will also allow SLP to perform its own hull conversion/outfitting, rather than subcontract the work to one of the shipyards on the Tyne. It is designed for what seems to be the standard UK sector FPSO these days: 240 metres long, 40 metres wide and 100,000 dwt.
Next vessel in will be another topsides job. Rasmussen has ordered a spec newbuild, Tentech 700 design FPSO, currently under construction at Mitsui in Japan. In May, SLP and Granherene completed a FEED study into the topsides process equipment (they also worked together on MacCulloch). SLP now has a full EPCI contract, with fabrication of the topsides due to start in November: the vessel is scheduled to arrive at Teesside next April.
DnV will certify the FPSO to operate under Norwegian as well as British regulations: three fire walls will be incorporated for the process plant. No field contract has been announced, but Rasmussen is confident the vessel will be producing in December 1997. Presumably that means a project is within sight, as the process design has to be customised to the specific conditions of the reservoir.
Preliminary design detail includes crude oil separation; a low/high pressure gas compression system for gas lift, export, reinjection and dehydration; a produced water treatment plant; flare; distributed process control system, and water injection. Space for 15 riser tubes will be accommodated in the turret. The vessel will be able to produce 70-100,000 b/d of stabilised crude, perhaps up to 42 million cf/d of gas and up to 100,000 b/d of water for injection purposes, with oil storage capacity of 550,000 bbl.
Allseas' Solitaire undergoing conversion at Swan Hunter's Tyneside yard.
Future projects
Britain's Offshore Contractors' Association predicts seven to eight new UKCS floaters in the offing. Some would be the centrepiece of small standalone developments: others might be installed in tandem with wellhead protection platforms. Likeliest candidates are Conoco's Buckland, Texaco's Galley, Mariner and Guillemot West, Kerr-McGee's Janice and BP's Clair and Medan/Pierce fields. The latter two are currently undergoing extended well tests.
McNulty Offshore is already in the frame for one of these projects as part of an alliance with Odfjell and Aker bidding for Galley. Odfjell is under way with the FEED contract which is based around the semisub Chris Chenery, currently working in the Far East. Texaco is thought to be keen on simultaneous drilling and production from the facility, with three producer wells needed to start production just before the end of next year.
Galley was discovered in UK block 15/23 in 1974, but remained firmly in the marginal category for the next two decades. New 3D seismic was shot last year: re-evaluation may not be completed, but up to 40 MM bbl of oil could be recoverable under a first production phase yielding around 60,000 b/d. With a drilling package already onboard, and production probably piped to the Tartan or Piper platform, the level of conversion needed is unclear.
McNulty also bid the conversion of the Curlew tanker and applied for Buckland. Conoco has invited innovative proposals, but overall CAPEX must be no more than $10/bbl.
No yard in North East England has more experience with floater fit-outs than McNulty. Its record includes the AHOO1 and Uisge Gorm for Amerada Hess and the Gryphon FPSO for Kerr-McGee. According to proposals manager Doug Cambers, McNulty is better equipped than most due to its 300-metre long and nine-metre deepwater quay front on the Tyne. The company is also considering buying another yard next door: if it merged the sites to create a 560-metre long quayside, it could handle two FPSOs at once.
Last year, McNulty teamed up with Tyne Tees Dockyard in Hebburn and ship repair specialist A&P Appledore on the other side of the Tyne to bid for the Durward/Dauntless conversion. Although they didn't win, the latter two were more successful in clinching the conversion and marine outfitting of the North Sea Producer tanker for MacCulloch.
The £10 million, five-month contract was awarded to the newly launched A&P Offshore division, based in Wallsend on the site of the disused Swan Hunter Neptune shipyard. Late last year A&P acquired the site, converting it into a modern 5,000-sq metre steelwork, fabrication and marine engineering facility. This was used to build the MacCulloch vessel's module support frames and life extension brackets. The main engines and accommodation areas were also overhauled. Later, the vessel moved across the river to Hebburn for drydocking and fitting of a new stern thruster.
MacCulloch was A&P's first FPSO outfitting job, with SLP insisting on an integrated client/contractor team and a reporting system whereby each person and their work location was established within 90 minutes of a shift starting. This style is foreign to the ship repair industry, apparently, but A&P found it benefitted from the greater discipline, and eventually whittled the tracing time down to 30 minutes. The approach was necessary, as MacCulloch is an ultra-fast track development.
A new management team has invested £15 million in A&P and the Wallsend facility. Payback probably demands getting in at least two FPSO outfitting jobs per year. Like McNulty, A&P bid for both Curlew and Buckland.
Numerous oil companies have inspected the site, including Amerada Hess, BP, and Enterprise. A&P may have an edge for this type of work as it pays its workforce ship repair rates, which are not quite as high as offshore industry rates.
Copyright 1996 Offshore. All Rights Reserved.
