Draugen beneath the waves

person Kristin Øye Gjerde, Norwegian Petroleum Museum
The seabed installations on Draugen were developed by the subsea department of Kongsberg Våpenfabrikk (KV, later Kongsberg Offshore (KOS) and FMC), aided by an R&D collaboration with Shell. This cooperation was successful for both sides. Shell saved money through intelligent solutions, while Kongsberg’s subsea team was able to demonstrate its capability to an international company. Amplified by Shell’s big network of contacts, that proved a springboard into becoming a substantial exporter of subsea technology.
— Development plan for the Drugen field. Illustration: A/S Norske Shell
© Norsk Oljemuseum

Goodwill agreements

Norway’s Ministry of Petroleum and Energy took several initiatives towards the offshore sector in 1979-80 aimed at strengthening Norwegian industry. This also benefitted operations at Kongsberg west of Oslo.

First, the government took steps with the fourth licensing round in 1979. Aimed primarily at regional development, these required the oil companies to describe how they could establish activities outside the Stavanger area – which was suffering growth pressures.

This acquired even greater significance after the Storting (parliament) opened the Norwegian continental shelf (NCS) above the 62nd parallel to oil operations in 1980.

Next, foreign oil companies seeking new licence interests on the NCS were required to establish technology joint ventures with Norwegian industry, public bodies and research institutions.

Such goodwill agreements (GWAs), also known as supply and industrial collaboration agreements, would be taken into account when assessing licence applications from foreign companies.

Those willing to invest in research and development (R&D) partnerships would thereby come first in the queue for the award of blocks on the NCS.

The government’s aim was to get the foreign companies to conduct R&D in Norway – and thereby use Norwegian suppliers of such services – rather than in their homelands.

GWAs have subsequently been characterised as highly successful. The R&D collaboration they sparked created a golden age for Norwegian scientific institutions and companies.

International firms devoted more than NOK 10 billion to research, product development and expertise enhancement in Norway between 1979 and 1994.

A survey showed that suppliers were more satisfied with the scheme than the oil companies, which regarded it as an imposition on their operations.

It also ceased when the European Economic Area (EEA) agreement with the EU came into force in 1994 and made such special demands on foreign companies illegal.[REMOVE]Fotnote: Wiig, Heidi (1993): Olje mot forskning: en oppgave om goodwillavtalen i norsk forskningspolitikk og teknologioverføring i FoU-samarbeidene, University of Oslo.

Subsea projects

These official stipulations were a crucial reason why Shell entered into a long-term agreement on R&D collaboration with KV’s oil department as early as 1979.

Signed by Roar Rose, research head at Shell’s Norwegian arm, this deal was the first of its kind to be established by a foreign oil company.

It clearly wanted to demonstrate that the signals from the government were being taken seriously, and to ensure a place at the head of the queue for licence awards.

Shell was the oil company with the greatest knowledge about and longest experience of subsea technology in the world, having worked in this field since the 1960s.

The goal now was to develop, build, test and qualify equipment for use under water, particularly with an eye to bringing Troll on stream.

Discovered in 1979, this North Sea field contained huge quantities of gas and was being operated by Shell in the development phase.[REMOVE]Fotnote: Aftenposten, 5 January 1984, “Elf og KV med teknologiavtale”.

Its agreement with KV and the resources this made available meant that the manufacturing and technical personnel in Kongsberg could learn subsea production from the bottom up.[REMOVE]Fotnote: Daling, Unn Kristin, and Erlandsen, Hans Christian (1999): Offshore Kongsberg 25 år, 1974–1999, 69.

draugen under vann, illustrasjon, engelsk,
The field control station on Northeast Frigg had a concrete foundation on the seabed and a control tower without a permanent crew. floating on a horizontal plane in the sea, Northeast Frigg was linked with six subsea wellheads in a well frame with manifold systems, valve systems and pipelines for TCP2 on the Frigg field. The well frame was designed by Kongsberg Våpenfabrikk and Elf Norway, and produced by Nord Offshore. Divers were used both for installation and later for maintenance. Illustration: Robert P. Johannessen

KV also collaborated with Elf, which included delivery of engineering services and two Xmas trees for the test facility in the French oil company’s Skuld programme during the early 1980s.

That provided valuable experience, and KV had full freedom to continue using this technology. It also won an order from Elf for six subsea wellheads in a template with a manifold system to produce from North-East Frigg in 1981.[REMOVE]Fotnote: www.kulturminne-frigg.no.

In 1984, Shell involved KV in a forward-looking project to develop a subsea system which could produce oil and gas from fields in 600 metres of water and beyond.

Plans called for this solution to be tied back to a floating platform, with oil and gas being brought ashore by shuttle tankers or pipelines.

The aim was for such a system to be ready for use around 2000. Where KV was concerned, this project meant work worth NOK 20 million and further development of its expertise.[REMOVE]Fotnote: Aftenposten, 27 August 1984, “Oljeproduksjon på 600 meters dyp”.

According to Tore Halvorsen, who was then a young and promising engineer in KV’s subsea department, the company wanted to apply experience and results achieved jointly with Shell to other projects as well.

KV worked closely with Statoil, for example, and wanted to extend solutions developed for Shell to the Norwegian company as well.

Shell was initially doubtful about this plan, but it proved possible to reach an agreement.[REMOVE]Fotnote: Daling, Unn Kristin, and Erlandsen, Hans Christian (1999): Offshore Kongsberg 25 år, 1974–1999, 69. That was reflected in an advertisement later run by Shell in Norway:

Collaboration with Norwegian industry aims primarily to develop solutions which will be used specifically for Norske Shell’s involvement on the continental shelf. Once a project has been fully developed, however, our partners are also free to produce and market the specific results where and how they want.[REMOVE]Fotnote: Advertisement for Shell, about 1991.

Shell was also willing to share its know-how in other ways. In addition to technical and financial contributions to the construction and testing of prototypes by KV’s subsea department, an educational programme was developed at Kongsberg’s technical college.

With Norske Shell providing lecturers, this course contributed to good recruitment of graduates in subsea-related disciplines.

One of the lecturers, Briton Bob Frith, eventually became Shell’s technical director in the Hague with responsibility for every aspect of subsea technology.

He and Halvorsen collaborated well, and a network was created by them and others between KOS – as the department eventually became – and Shell. That helped to bring the Kongsberg technology to the wider world.[REMOVE]Fotnote: Torvald Sande in conversation with Kristin Øye Gjerde and others, 12 May 2016.

The Borgny Dolphin drilling rig struck oil for Shell on 26 June 1984 in Norwegian Sea block 6407/9, awarded in the eighth licensing round only a few months earlier in March.

According to production licence 093, Norske Shell would be operator of this Draugen field with a 30 per cent holding while Statoil had 50 per cent and BP 20 per cent.

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On June 26, 1984, the drilling rig Borgny Dolphin made discovered oil at Draugen. This picture of the rig is most likely from Valhall. Photo: Hilde Hysing-Dahl/Norwegian Petroleum Museum

The oil-bearing zone was encountered about 1 650 metres beneath the seabed. Appraisal wells in 1984-85 indicated that Draugen contained an estimated 250 million barrels (40 million cubic metres) of recoverable crude.

Draugen lies in 250-280 metres of water in an area of flat seabed covering no less than 120 square kilometres. That made it hard to optimise recovery with wells drilled from one spot.

Submitted in September 1987, the plan for development and operation (PDO) of Draugen envisaged a concrete platform with a single support shaft (monotower) and four production wells.

Oil would be recovered from a wider area by drilling two subsea producers tied back to the field centre and two water injection wells.[REMOVE]Fotnote: AS Norske Shell (September 1987): Draugen field, plan for development and operation, figure 5.3.5.

No decision had yet been taken on who should build the various components, but KOS quickly indicated its interest where the subsea modules were concerned.

The company worked in 1989-90 on submitting a bid to Shell for a complete subsea production system for both oil and gas. This was based on pumping the unprocessed wellstream to the field centre, where a simple processing took place.

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Fixed structure concept for Draugen field development. Illustration: A/S Norske Shell

Plans still called for two subsea production wells, one named Rogn and the other designated the southern oil producer (SOP).

In addition came two templates for water injection with a Shell multiphase underwater booster station (Smubs). These templates each had three slots, with three used on the northern and two on the southern.

Eventually, a well was also added for gas injection into the Husmus formation (see separate article on gas exports).

The bid from KOS was dramatically lower than others – NOK 480 million, with the nearest rival’s offer NOK 300 million higher. That worried Shell, who called the company in for several days of clarification in Stavanger.

Halvorsen recalls how unusual this was: “Everything was so secret that we participants were ordered not to fly to Stavanger on the same flight, and to register under aliases at the hotel.

“When the meeting began, we were told to remain in Stavanger for as long as it took to clarify whether a contract would be awarded.”

To ensure that KOS had not got its bid completely wrong, Shell wanted to conduct a detailed review. The two sides eventually reached agreement, and the contract was placed in 1990.[REMOVE]Fotnote: Daling, Unn Kristin, and Erlandsen, Hans Christian (1999): Offshore Kongsberg 25 år, 1974–1999, 149-150.

The most important reason why KOS could make such a low offer was that specifications for the equipment required on Draugen were prepared at the same time as the company was drawing up a similar bid for Statoil’s Statfjord satellites project.

KOS saw an opportunity to win both contracts, since it could standardise to some extent. The technical solutions were presented to Statoil and Shell without them being aware of each other.

The results were satisfactory for everyone concerned, with Shell securing subsea installations from KOS at almost half the price offered by European competitors.[REMOVE]Fotnote: Teknisk Ukeblad, 19 March 2003, “Industripolitikk – samspill eller kamp?”

Subsea expert Hans Jørgen Lindland has observed:

The subsea installations on Statfjord, of course, were actually very similar to Shell’s architecture on Draugen. Shell first awarded the world’s largest subsea contract, worth NOK 900 million, in 1989. Then Statoil placed the new contract for the Statfjord satellites, which thereby became the world’s largest at NOK 1.3 billion.[REMOVE]Fotnote: Hans Jørgen Lindland in conversation with Kristin Øye Gjerde and Arnfinn Nergaard, 1 December 2016.

KOS secured the job of turnkey supplier for the subsea modules on Draugen under an engineering, procurement and construction (EPC) contract.

It thereby had control over design, manufacturing of the subsea equipment both in its own facilities and at sub-contractors, and installation on the field.

As mentioned above, this was the biggest subsea EPC contract awarded in Norway at that time. That fitted well with industrial plans at KOS and helped to boost its reputation in the market.[REMOVE]Fotnote: Daling, Unn Kristin, and Erlandsen, Hans Christian (1999): Offshore Kongsberg 25 år, 1974–1999, 150.

KOS was taken over in its entirety on 30 June 1993 by the American FMC Corporation through its FMC Norway AS subsidiary. Renamed FMC Kongsberg, it made great progress and secured 40 per cent of the global subsea market during the 1990s.

The Draugen project bore fruit for a number of other companies. The work included nine subsea trees and seabed templates with manifold and control distribution system. Fabricated at Dunfermline in the UK under FMC’s control, the trees had electrohydraulic controls.

All the subsea equipment was designed for diverless installation, operation and maintenance, with great emphasis therefore placed on standardisation. Components had to be simple to connect, reducing the number of intervention tools needed.

Comex Norge had the contract to install the two templates, and used the MSV Amethyst crane ship for this job. The templates were fabricated at the Kaldnes de Groot yard in Tønsberg south of Oslo as subcontractor to KOS.[REMOVE]Fotnote: Aftenposten, 18 February 1992, “Draugenkontrakt til Comex”.

Framo and the world’s first multiphase pump

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Figure 5.3.2 from Draugen field, Plan for development and operation, 1987.

The world’s first underwater pump capable of driving an unprocessed multiphase wellstream mixing oil, gas, water and sand in the same pipeline was installed on Draugen.

This aimed to overcome one of the challenges facing subsea oil and gas production ­– the distance output can travel between well and platform is restricted by pressure and flow conditions. The problem increases as reservoir pressure declines over time.[REMOVE]Fotnote: Bergens Tidende, 1 April 1992, “Mohnpumper gir ny oljealder”.

So Framo Engineering’s technical innovation was installed to maintain pressure in the reservoir and thereby boost recovery. It was placed without diver assistance in 275 metres of water on a subsea well six kilometres from the platform.

Shell was the first customer for this new concept for water injection from the company, which was spun off in the mid-1980s from the development department at pump specialist Frank Mohn.

With Martin Sigmundstad as its first chief executive, Framo Engineering began working with Norske Shell as early as 1986 to develop various concepts for pumping multiphase wellstreams.

This groundbreaking Smubs solution was tested for the conditions prevailing on Draugen in Framo’s test facility at Fusa outside Bergen.

Performance trials were also conducted at Frank Mohn Flatøy’s test facility for multiphase pumps. System integration of the device was a technological breakthrough in Norway and worldwide.

NOK 30 million had been devoted to developing the device by 1990, while the contract for the Draugen pump system was worth NOK 15.6 million.

The pump was hydraulically driven by the pressure of the water passing through a hydroturbine before being conducted to the injection well.

This concept is based on maintaining a high rotational speed to generate pressure through the use of contra-rotating axial (CRA) technology.

draugen under vann, teknisk tegning, engelsk,
Template / manifold system for the water injection wells on Draugen. Figure 5.3.4 from Draugen field, Plan for development and operation, 1987.

Known as the high speed approach, that allows the wellstream to be compressed and pumped without having to separate its components.

The same outcome was accomplished in traditional pumps over several stages with more equipment. Framo’s pump needed less space and was lighter than conventional devices.

Statoil, Mobil, Total and the French IFP petroleum institute contributed financially to a further development of the multiphase pump.

Tore Torp from Statoil’s research centre in Trondheim said that this product created “the basis for a completely new way of thinking over oil production in the North Sea.

“Fields which are too small to warrant a platform development could now be relevant with subsea solutions which greatly reduce the investment.”

Speeding up a wellstream creates an underpressure on the pump’s suction side towards the reservoir, which means the oil flows up more readily and the recovery factor increase.

Statoil was confident many new fields would be developed with subsea solutions now that this technology was available.[REMOVE]Fotnote: Dagens Næringsliv, 31 August 1990, “Draugen får verdens første flerfase pumpe”.

Around 1990, Smubs was restricted to transport over a maximum distance of 50 kilometres. According to Shell communications manager Einar Knudsen, the goal was to carry oil and gas direct from the wellhead to a processing plant on land.

Continued research to extend the transport range was a goal not only for Shell but also for a number of oil companies who saw opportunities to save money – not least by direct landing.

Nevertheless, the Framo pump failed to live entirely up to expectations. It unfortunately transpired that the power needed reduced water injection and thereby oil recovery. The pump therefore remained in operation for no more than six months.

Shell nevertheless contributed to marketing the multiphase device on the world market. As mentioned above, Frith made a big personal contribution to establishing a KOS-Shell network.[REMOVE]Fotnote: Torvald Sande in conversation with Kristin Øye Gjerde and others, 12 May 2016.

The oil major also helped to market Framo’s pump by including it in the Shell International vendors list, exchanging press releases and so forth.

This created interest for the product in the USA. Esso, Texaco and Agip also used equipment from Framo and helped to spread sales of multiphase pumps to the UK, Australia and Malaysia.[REMOVE]Fotnote: Norsk Oljerevy no 12, 1990, “Esso/Shell klarer det: Hjelper industrien ut”.

 

Published April 27, 2018   •   Updated October 17, 2018
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Removing the rig

person Finn Harald Sandberg, Norwegian Petroleum Museum
It was decided in January 1997 to dispense with the maintenance-intensive drilling package on the Draugen platform because the well programme had been completed.
— The drilling module on Draugen is constructed and built by Hitec Dreco. Photo: A/S Norske Shell/Norwegian Petroleum Museum
© Norsk Oljemuseum

Transocean Drilling, which had taken over the Aker Drilling company, was commissioned to disassemble and remove the rig. Work began on 10 April and finished a month later.[REMOVE]Fotnote: Shell UP, no 5, June 1997.

Apart from the mud pumps, the whole package was modularised – put together from separate, relatively small units – to simplify removal and reuse.

This solution proved advantageous and meant that the whole job could be done with a limited number of people, using the platform’s own cranes to handle the modules.

No heavy-lift vessel therefore had to be chartered, which made the removal decision much easier to take from a purely financial perspective.

Nor was additional transport needed, since a recent shipping pool agreement (also covering large supply vessels) for the Halten Bank fields allowed components to be sent free as return cargo.

All the work was done without any accidents or other undesirable incidents, and production continued

boreriggen på draugen fjernes,
Draugen topside under construction at Kværner Rosenberg in Stavanger. Photo: A/S Norske Shell/Norwegian Petroleum Museum

unabated throughout the disassembly process.

After removal, the drilling rig was held in intermediate storage at Vestbase in Kristiansund before being shipped on to Forus outside Stavanger.

The package has been sold during the spring to the Stavanger-based Hitec company, which had delivered it originally in partnership with Canada’s Dreco.[REMOVE]Fotnote: Stavanger Aftenblad, 16 October 1997, “Hitec kjøper borerigg”.

Hitec had intended to use the rig for a particular project which failed to materialise. Soon after 2000, however, an inquiry was received by RC Consultants in Sandnes south of Stavanger.

Passed on by Hitec from the Norwegian agent of Russian state oil company Rosneft, this involved an invitation to tender for conversion of the Ispolin heavy-lift vessel to a drill ship.

Rosneft therefore needed a rig for the project, which was aimed at drilling the first well in the Russian sector of the Caspian, and the Sandnes company won the job.

This was accordingly a story of exporting Norwegian petroleum expertise, reusing offshore equipment from Norway and Russia’s commitment to increasing its oil production at the time.

RC Consultants’ contract was originally worth NOK 120 million, including the drilling module and engineering services related to its testing, transporting, installing and commissioning.[REMOVE]Fotnote: Stavanger Aftenblad, 4 February 2003, “Russisk borerigg gir kontrakt til Sandnes”.

“This rig only drilled five wells on Draugen from 1993, so I regard it as almost brand new,” Egil Tjelta, CEO of RC Consultants, told local daily Stavanger Aftenblad.

Trial assembly and testing of the package took place at Offshore Marine in Sandnes during the spring of 2003 under the supervision of five Russian engineers.

It was then broken down into two parts and transported to the port of Astrakhan on the Caspian in April. All this work was carried out with no problems of any kind.

Different routes were taken by the rig sections, with one travelling by barge through the Straits of Gibraltar and via the Mediterranean, the Black Sea and canals.

The other was carried by a specially adapted river boat via St Petersburg, the Russian canal system and the Volga, which empties into the Caspian.

Installation on the ship occurred in Astrakhan, which is where the problems started. Nobody had told the Norwegian engineers that drilling would take place in very shallow water.

The ship was actually due to sit in the seabed, because the Caspian in this area is only about five to 10 metres deep. Drawing on experience from Norwegian conditions and international safety standards, all warning lights flashed.

Installing the derrick and equipment presented no difficulties, but the fact that operational safety was not approved meant that a drilling permit could not be obtained.

The drill ship was admittedly renamed by President Vladimir Putin, but that carried no weight with the regulators. The project was shelved, but Ispolin was later used for other drilling jobs in the Caspian.

Published July 2, 2018   •   Updated October 9, 2018
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Squaring the circle

person Finn Harald Sandberg, Norwegian Petroleum Museum
The Draugen platform comprises a round concrete monotower and an almost square steel topside. Putting drilling and oil transport functions in a single shaft posed a range of safety challenges. Moving from circular to square cross-section also proved testing.
— Top of the shaft with gliding formwork. Photo: Eivind Wolff/Norwegian Petroleum Museum
© Norsk Oljemuseum

A technique known as “gliding formwork” or “slipforming” was used to construct the vertical sections of the concrete gravity base structures (GBSs) built in Stavanger and elsewhere. This was a special form of a “climbing formwork”, where a form is constructed and then disassembled once casting has been completed. It can then be reinstalled to cast the next section. That approach is preferred when constructing vertical sections of limited height, such as in residential properties or foundations.

Such cases involve a limited number of disassembly/reassembly operations. The method is advantageous where many cutouts – such as windows – are involved. Slipforming was the best approach for the big concrete GBSs because it permitted continuous construction with few joints and cost-efficient working.

Figure 2 shows how this is typically built up. The actual formwork comprises a vertical sheet installed to ensure that wall thickness and shape meet the design specifications.

Gangways are installed on both sides of the wall around the whole circumference to provide a work space and access for such jobs as installing reinforcement bars (rebars) and cutouts. Other tasks here include pouring concrete into the forms, applying epoxy, inspecting the finished result and repairing possible surface blemishes.

Formwork and gangways are attached to frames hung from hydraulic jacks, which move up as the structure rises. If the design requires changes in diameter, the formwork radius can be adjusted with a horizontal jacking system.

sirkelens kvadratur, engelsk
Sketch showing the principle of "slipforming". Illustration: Norwegian Contractors

As concrete is cast, the whole formwork get raised by activating the jacks simultaneously. Adjusted to the curing time of the concrete, the speed of the glide will vary with complexity and volume and is normally 1.5 to four metres per day.

The jacks are constantly adjusted to adapt the formwork to the desired shape of the concrete wall and to correct possible variations without exceeding tolerances specified in the chosen building standard.

Careful control of shaft geometry is exercised with the aid of laser measurements to ensure that all dimensions meet the tolerances throughout.

The conical shaft in the Draugen GBS has its narrowest diameter at the sea surface, where it measures just over 15 metres compared with more than 22 metres down at the storage cells.

That reduces wave forces acting on the platform and thereby allows its base section to be reduced, as well as securing a more efficient design.

However, a circular cross-section with a relatively small diameter was not the optimal solution for the transition to the square topside.

The top of the shaft was accordingly designed as a box structure with a square cross-section measuring 22 metres to a side.

Designing and operating a slipforming process where the cross-section gradually changed from circle to square therefore presented a challenge in construction terms.

This required both a variation in wall thickness and an increase in external dimensions – squaring the circle in practice.[REMOVE]Fotnote: Tegning GS D 2001-001 GENERAL VIEW

The solution involved a system which made it possible to add additional formwork sheets as the slipformed area increased, and creating a frame with arms which stuck out from the centre.

A horizontal jacking system controlled the distance from the centre to the formwork, and this approach provided a successful outcome.

The formwork could be raised so that the shaft wall became a double arc with its external dimensions tailored to a favourable solution for designing and attaching the topsides.

One result of this building technique was that a checked pattern emerged on the transition piece, which gives the Draugen platform a characteristic appearance.

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The Draugen platform. Photo: Heine Schjølberg/A/S Norske Shell

Based on an e-mail from Dag N Jensen, former head of engineering design at Norwegian Contractors.

Published July 2, 2018   •   Updated October 2, 2018
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Subsea wells extend producing life

person Kristin Øye Gjerde, Norwegian Petroleum Museum
The plan for development and operation (PDO) of Draugen submitted to the Storting (parliament) in 1988 gave the field a producing life until 2012 and a recovery factor of 37 per cent. When it came on stream in 1993, however, operator Shell was already working to both extend and increase output.
— Draugen field layout. Illustration: A/S Norske Shell/Norwegian Petroleum Museum
© Norsk Oljemuseum

By 2017, Draugen’s producing life had been extended to 9 March 2024 and its expected recovery factor was put at 75 per cent. These forecasts have changed gradually, as technological advances in the oil industry permitted production improvements.

But the reservoir has nevertheless yielded surprises along the way.

Reserves up, producing life and recovery factor extended

Havbunnsbrønner forlenger produksjonen, kart, illustrasjon, engelsk
Illustration from Draugen development status, July 1999

Shell could report in 2001 that recoverable reserves in Draugen were larger than earlier thought.

Use of four-dimensional seismic surveys improved geological understanding of the reservoir, which was also behaving better than expected. A number of the wells were producing very well.

Draugen’s producing life was extended to 2016 and the expected recovery factor increased to 67 per cent. In the longer term, the goal was to recover at least 70 per cent – assuming that the field remained commercial beyond 2016.[REMOVE]Fotnote: Adresseavisen, 5 February 2001, “Draugen leverer olje helt til 2016”.

New subsea wells in south and west

To increase production from and producing life for the Draugen area even further, Shell now planned development of the Garn West and Rogn South subsea wells.

These would be tied back to the Draugen platform and increase reserves by about 81 million barrels or 13 million standard cubic metres (scm) of oil. That was nine per cent of the field’s 144.2 million scm in recoverable oil.[REMOVE]Fotnote: http://factpages.npd.no/factpages, 26 October 2017.

This decision built on rapid improvements during the 1990s in the methods for tying subsea wells back to fixed and floating offshore installations.

Discoveries too small to justify their own process platform could use relatively cheap, standardised subsea systems tied back to a fixed platform, a floater or even land. And unprocessed wellstreams could be sent over ever longer distances with advanced multiphase flow technology.

Development of small satellite fields had become a profitable business, which proved a boon for oil companies around 2000 when oil prices slumped towards USD 10 per barrel. An advantage of subsea wells was that they were quick to install and start up.

Located at the westernmost edge of the Draugen area, Garn West was the first to be tapped with the aid of two seabed wells tied back by a 3.3-kilometre pipeline in the summer of 2001.[REMOVE]Fotnote: Adresseavisen, 5 February 2001, “Draugen leverer olje helt til 2016”.

The Rogn South development was approved in the spring of that year, and Transocean Winner drilled and installed two subsea wells in 2002 so that they could come on stream the following January. Their wellstreams are routed via Garn West (see map).

These satellites helped to increase and extend oil production from Draugen – which was advantageous as oil prices staged yet another recovery after 2002.

Norske Shell could report in 2001 that it was investing NOK 1.5 billion in developing Garn West and Rogn South.[REMOVE]Fotnote: Adresseavisen, 30 May 2001, “Draugen større”. Among those winning contracts were Kværner Oilfield Products AS at Lysaker outside Oslo, which delivered the subsea systems.[REMOVE]Fotnote: NTB, 6 June 2000, “Draugen utvides for 130 millioner kroner”.

The Kristiansund business community also did well, with Aker Møre Montasje and Vestbase – the biggest local suppliers – securing work in the order of NOK 70-90 million.

Coflexip Stena Offshore won the pipelaying job, while the new water treatment system on Draugen was produced by Aker Offshore Partner at Stord.[REMOVE]Fotnote: Adresseavisen, 30 May 2001, “Draugen større”.

Water, water and more water

Production from Draugen was highly promising in 2001. It was at its highest-ever level of 12.87 million scm of oil equivalent (oe) per year – almost too good to be true.

This annual output of oil, gas and condensate equalled as much as the total expected recovery from Garn West and Rogn South combined.

Annual production from Draugen measured in oil equivalent (oe). The latter is a measure of energy which corresponds to burning a specified amount of oil. One oe equals the amount of energy released when one cubic metre of crude oil is burnt. It is used by Norway’s petroleum administration to specify the total energy content of all types of petroleum in a deposit or field by summing equivalent quantities of oil, gas, natural gas liquids (NGL) and condensate. Oil equivalent – saleable (mill scm) The annual production from Draugen measured in oil equivalent (oe). The latter is a measure of energy which corresponds to burning a specified amount of oil. One oe equals the amount of energy released when one cubic metre of crude oil is burnt. It is used by Norway’s petroleum administration to specify the total energy content of all types of petroleum in a deposit or field by summing equivalent quantities of oil, gas, natural gas liquids (NGL) and condensate. Source: PD
Oil equivalent – saleable (mill scm) Annual production from Draugen measured in oil equivalent (oe). The latter is a measure of energy which corresponds to burning a specified amount of oil. One oe equals the amount of energy released when one cubic metre of crude oil is burnt. It is used by Norway’s petroleum administration to specify the total energy content of all types of petroleum in a deposit or field by summing equivalent quantities of oil, gas, natural gas liquids (NGL) and condensate.

The field nevertheless showed some signs of production weaknesses. As the oil was produced, the level of water in the reservoir rose and its proportion of output (or cut) increased. In June 2002, Shell reported that the water cut had risen to 35 000 cubic metres per month – a trebling from six months earlier.

Well A1, which only contained 10 per cent water in its oil output at 30 March 2002, increased this cut to 30 per cent over a three-month period.

With a record output of 77 000 barrels of oil per day (bod) making it the best of Draugen’s wells, A4 had to be shut down because of the salts being precipitated. These threatened to block the pores in its walls – a sign that the area being produced was approaching depletion. Production from the field was nevertheless not particularly reduced, since the other wells were increasing their output.[REMOVE]Fotnote: Adresseavisen, 11 June 2002, “…mens vannet stiger i Draugen”.

Water produced at Draugen. Source: PD
Water wellpaths

All the same, it transpired over the years which followed that the amount of oil and gas produced went down as the water cut rose.

By 2010, production had fallen 20 per cent or 2.6 million scm oe from the peak year of 2001 and water output was approaching eight million scm.

New boost

Something had to be done if Draugen was to stay on stream. As part of Shell’s environmental improvement programme, a project for produced water and reinjection on the field had been launched. The reinjected fluid would be used for pressure support.

Advanced new seismic surveys identified a number of oil pockets in the area. That led in 2012 to a plan for drilling a further four new wells.

These would help to produce fuel gas for power generation on the platform, operations head Ervik explained.[REMOVE]Fotnote: Tidens Krav, 3 February 2012, “Langt liv for Draugen”. The electricity was intended partly to drive a new pressure support pump.

Shell contracted with Seadrill to use West Navigator for the subsea wells in this Draugen infill drilling programme to help boost oil production from the field.

These wells were due to come on stream at the same time as a subsea boosting pump was installed in 2017.[REMOVE]Fotnote: http://petro.no/far-bruke-havbunnsbronn-pa-draugen/2235 05.09.2014. The project also covered a subsea tee manifold on Rogn South.

In addition came 19 kilometres of new production flowline, 11 kilometres of umbilical cables and 52 tie-ins. See the next figure.

illustration: Shell
Boosting pump system to increase the production of oil. Illustration: A/S Norske Shell/Norwegian Petroleum Museum

Installing a boosting pump system in the pipeline flow from the subsea templates was expected to improve recovery, and initially involved installing a protective structure.

This was followed a manifold and two 3 000 hp pumps operating in parallel. The latter units are not especially large.

Each compressor has two vertically positioned motors which rotate in separate directions to increase pressure in the wellstream from the pump up to the platform’s process plant.

The pumps create a vacuum in the direction of the reservoir, which means in theory that the formation will release more oil (and water).

Illustration: Shell
Illustration from "Draugen subsea boosting" a presentation by Jan-Olav Hallset/ A/S Norske Shell

Output in 2016 was 1.35 million scm oe, a slight decline from 1.72 million in 2015. But oil production from Draugen had visibly increased in 2017 as a result of the new pump system.

This successful result means that Shell now intends to try out similar technology on other fields elsewhere around the world.

 

Published April 27, 2018   •   Updated October 2, 2018
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Working life on Draugen

person by Gunleiv Hadland, Norwegian Petroleum Museum
The Draugen platform stands by itself out in the Norwegian Sea, with no other fixed facilities close by. Those who work there have been concentrated together in a confined space.
— Gas measurement at Draugen (2012). Photo: A/S Norske Shell/Norwegian Petroleum Museum
© Norsk Oljemuseum
arbeidslivet på draugen, engelsk,
Work at Draugen. Photo: Jan Soppeland/Norwegian Petroleum Museum

Many of the field’s personnel have worked there for many years, making them thoroughly familiar with the installation and allowing close ties to be developed between colleagues.
When Draugen came on stream in 1993, 43 people per shift were expected to be sufficient for normal operation. Their jobs covered managing the process, maintenance, catering and cleaning, medical care and safety.
Most of these personnel are employed by Norske Shell or the catering company. The workforce can expand considerably when major maintenance or conversion work is underway.

Rotation

arbeidslivet på draugen, engelsk,
Maintenance work on Draugen. Photo: Jan Soppeland/Norwegian Petroleum Museum

Draugen employees work offshore for two weeks, followed by four weeks off on land. They do 12-hour shifts, either day or night, and their working hours over a year compare with those of an industrial worker on land.

Generally speaking, a shift runs from 07.00 to 19.00, and from 19.00 to 07.00. Work is planned so that as much as possible is done by the day shifts. Three shifts, each working two weeks at a time, are needed to get the tour rotation to work.
Since a new team takes over responsibility and jobs every other week, logging and documentation of work done, irregularities and plans are crucial.

arbeidslivet på draugen, engelsk,
Photo: Jan Soppeland/Norwegian Petroleum Museum

When a different person comes out to work, they need to know what has happened over the four weeks since their last tour. So time was devoted to recording and reporting.
During the early years on stream, this could take the form of logbooks kept on the platform. Logs have subsequently become computerised, making them also available to the land organisation.
As communication via radio links and data transfer has improved, computerisation has provided enhanced support in ensuring the continuity of work at shift changes.
The team on land has access to the same computer systems used offshore, and follow up activities on the platform through such technologies as videoconferencing.

arbeidslivet på draugen, fritid, engelsk,
Leisure fishing can give a great catch. Nurse, Vidar Hoem, has gotten common lings on the hook. Photo: A/S Norske Shell/Norwegian Petroleum Museum

During their offshore tours, employees are part of a community which lives and works in one place. Draugen is a 24-hour society, in that workers also spend their leisure hours there.
The latter are largely devoted to eating meals and getting enough sleep. But some time is available for talking with colleagues and reading the papers.
A number of leisure activities are also provided on the installation, with a welfare committee made up of enthusiasts elected by the workforce.
This organises film shows, golf in a simulator, computer games, song and music, arts and crafts and angling.[REMOVE]Fotnote: A/S Norske Shell (2005) Shell Drift Draugen, brochure. The gym is the most popular leisure provision on Draugen.

arbeidslivet på draugen, engelsk,
Leisure time in the gym at Draugen. Photo: Jan Soppeland/Norwegian Petroleum Museum

Personnel travelling out to the platform are now allowed to bring their mobile phone. This can only be used in the living quarters, but has made it easier to keep in touch with family and friends on land. A dedicated wireless network has been installed to cover the living quarters.[REMOVE]Fotnote: http://www.draugen.in/velferdsnett/
At one time, mobile phones were prohibited on all Norway’s offshore facilities because they could interfere with helicopters, or exploding batteries could serve as an ignition source.
Control of the information flow provided another important reason for the restriction. The company was concerned about what information – or disinformation – could be sent ashore and create uncertainty and needless fears.
Mobile phones are still banned from the production area, precisely because of concern about possible battery explosions and disruption of electronic instrumentation.[REMOVE]Fotnote: Teknisk Ukeblad 7 November 2013, Derfor må mobilene bo på hotell,.  https://www.tu.no/artikler/derfor-ma-mobilene-bo-pa-hotell/233850.

Under control

det er ikke lett med sommertid, forsidebilde, engelsk,
Draugen control room. Photo: Shadé Barka Martins/Norwegian Petroleum Museum

The central control room (CCR) is the platform’s heart and nervous system, and can monitor, govern and regulate the whole production process with the aid of a comprehensive computer system.
It runs the process and safety systems, which involves continuous supervision of operational equipment – including fire and gas detection as well as safety systems such as fire pumps and emergency power.
A minimum of two operators must be in the CCR at all times to facilitate planned work on the production facilities as well as responding to messages and alarms.
These personnel are also responsible for monitoring and controlling the loading of oil into shuttle tankers.
The CCR has a number of work stations, allowing operators to monitor and work on several systems simultaneously. More than two of them can be on duty when things get hectic.

Handover procedures between day and night shifts are just as important as they are when tours are being rotated offshore and to land. When the night shift is due to take over, meetings are held with the day shift before it stands down. Held in a room adjacent of the CCR, these review jobs done and planned, and the work permits (WPs). The WP represents an important document on offshore facilities. They are designed to ensure that all risk-related aspects have been taken into account. That covers the planning, approval, preparations, execution and completion phases. All activities are thereby coordinated, with information given on hot work or closed areas/equipment and taken into account when doing other types of jobs.
All WPs must be approved by the operations supervisor or the offshore installation manager (OIM).

Most of the process on the platform is automated – not least shutdowns. If abnormal values are measured by the detectors, the whole process plant will automatically cease running.
If such an emergency shutdown (ESD) or other crisis occurs, the CCR operators are trained to handle them. That plays an important role in safety and risk management work on Draugen.
A number of closed-circuit TV (CCTV) cameras are installed on the platform, allowing the CCR operators to follow physical events out in the process.
Since the platform came on stream, the CCR has been converted and upgraded a number of times. Bigger computer monitors and newer control software have been installed.
These upgrades have been carried out in consultation with the CCR operators in order to ensure that they provide the best possible workflow.[REMOVE]Fotnote: Raaen, Stine N (2015), Team Situation Awareness in Practice, MSc theses in cybernetics and robotics, Norwegian University of Science and Technology (NTNU): 60.

Arbeidslivet på Draugen, engelsk,
Work in the CCR in connection with the upgrading which occurred in 2013. Photo: A/S Norske Shell/Norwegian Petroleum Museum
Arbeidslivet på Draugen, engelsk,
The Draugen CCR in 2000. Photo: A/S Norske Shell/Norwegian Petroleum Museum

The meeting room is linked to the CCR, and contains systems for videoconferencing and collaboration with the land organisation. It also serves as an emergency response centre.

(pic)
Screen capture from the film 1-2-3 Vi er med! produced for a campaign launched by the Draugen operations organisation in 1994.

Land organisation

arbeidslivet på draugen,
Operations organization at Råket in Kristiansund. Photo: A/S Norske Shell/Norwegian Petroleum Museum

The operations team on land is structured to support work on the platform, and performs the administrative duties which do not need to be done offshore.
It includes experts on the various activities pursued on the field, and additional capabilities can be acquired as and when required. The specialists on land can decide on the action to be taken in meetings with the offshore organisation.

One factor which attracted particular attention in the first phase after the field came on stream was the challenges faced in getting sea and shore to collaborate.
These problems could be related to the slow performance of computer systems and lines of communication, and inappropriate reporting structures.
One approach to improving collaboration and understanding between the two sides has been to post offshore personnel to the operations office on land for periods.[REMOVE]Fotnote: Conversation between production technician and acting chief safety delegate Jan Atle Johansen and Gunleiv Hadland from the petroleum museum on the Draugen platform, 7 March 2017.This means staff in Kristiansund have practical experience of working conditions on the platform, allowing them to conduct planning and administration related to work offshore.
Since the operations centre on land was opened in 2007, provision has been made for monitoring Draugen production from there – particularly on the night shift.
Should unusual incidents occur on the platform during these hours, key personnel from the day shift are called out until the position has been clarified.[REMOVE]Fotnote: A/S Norske Shell, 10 April 2003, Draugen organisasjonsendring. Konsekvensvurdering – Produksjonsleder Natt.
The land organisation has departments for logistics, contracts and procurement, human resources, maintenance, production support, and filing and document management.[REMOVE]Fotnote: A/S Norske Shell (2005) “Driftsavdelingen i Kristiansund”, Shell Drift Draugen brochure.
One example of a function which has been transferred from field to land is the switchboard for handling external telephone calls to the platform.
The work of planning personnel resources in connection with sickness, leave of absence and extra activities has also been moved ashore.
Sea-shore collaboration has been boosted by the process simulator at the Kristiansund office, which was included in the development plans as early as 1987 for personnel training.[REMOVE]Fotnote: Draugen impact assessment, September 1987: 22.
This facility was constructed with control systems which mimicked those in Draugen’s CCR, and it could be used before the field came on stream to test management of the process.[REMOVE]Fotnote: Draugen magasinet, no 2 1993, “Simulatoren brukt som testverktøy”, A/S Norske Shell E&P operations department.
Everyone employed as a production operator was trained in the simulator, and had to demonstrate at the end of the course that they could shut down and restart the wells.
A training plan was tailored for each person. Using the simulator, they could make mistakes and practise until they were proficient.
Operators could only start working on the platform after their competence had been approved by the instructors attached to the simulator.
Day courses have also been organised so that operators on their way out to the platform can be informed about updates since they were last at work.
When changes were made out on Draugen, the simulator was updated accordingly and, if necessary, the alterations could be tested before being introduced offshore.[REMOVE]Fotnote: Interviews between Nils Gunnar Gundersen and Gunleiv Hadland from the Norwegian Petroleum Museum, 27 October 2016 and 1 November 2017.

Training in this facility has played an important role in educating the production operators, and has been extended through their work out on the platform.

(pic)
Reviewing the process on the platform in the simulator at Råket in Kristiansund. Training supervisor Geir Solberg is in the foreground. Photo: Engvik/Norske Shell/Norwegian Petroleum Museum NOM (NOMF-02784.046)

Maintenance and turnarounds

arbeidslivet på draugen, engelsk
Maintenance work in the Draugen process facility. Photo: A/S Norske Shell/Norwegian Petroleum Museum

As much maintenance work as possible on a platform like Draugen is preventive, and planned to avoid the need to take corrective action – in other words, repair a fault after it has occurred.
Maintenance based on fixed intervals includes such activities as replacing seals, filters and other components exposed to wear and tear.[REMOVE]Fotnote: Pedersen, Vikse and Tingvold (2017): Vedlikeholdsanalyse RCM hos Shell, BSc thesis, Molde University College: 9.

This is the same approach as the one taken with a car which gets serviced at regular points, where parts are replaced after a specified number of kilometres driven or time passed.
Roughly 150 different safety valves are in use on Draugen, for example, tailored to various sizes and pressures. These get replaced during production shutdowns or maintenance campaigns.[REMOVE]Fotnote: Pettersen, Victoria C F and Sæter, Karina L, 1 July 2014, RFID-merking av sikkerhetsventiler: Forbedring av informasjonsflyt i vedlikeholdsprosesser på Nyhamna, BSc thesis in petroleum logistics, Molde University College.

arbeidslivet på draugen,
Wellhead at Draugen photographed 09.11.2001. Photo: A/S Norske Shell/Norwegian Petroleum Museum

Maintenance work on Draugen is organised on the basis of an inspection programme which specifies equipment checks at certain intervals and is coordinated by computer systems.
The programme lists components where critical faults could arise and which must receive particular attention during maintenance. Other items can be assessed as safe to leave until they fail, and are only replaced then.
An initial version of the inspection programme was established in the spring of 1993, even before the field came on stream, in a collaboration between Møre Engineering, Liaaen and CorrOcean.[REMOVE]Fotnote: Tidens Krav 12 May 1993. “Møre Engineering: Fra bygging til drift”. Supplement on industry in Nordmøre.

Much of the equipment is continuously supervised by a computerised condition monitoring system (CMS). Analysing data from the process plant can detect whether something is wrong.
Also set up to notify abnormal temperatures, this condition-based maintenance (CBM) solution avoids having to open up the equipment to check for faults.
Once the CMS has provided such notification, the load on the relevant component can be reduced until it can conveniently be replaced.
The operator on the platform reports to the technical supervisor, who contacts the responsible manager on land in turn.[REMOVE]Fotnote: A/S Norske Shell (2005) Shell Drift Draugen, brochure. They can then jointly assess the action to be taken.
Production operators on Draugen routinely tour the process areas with the emphasis on identifying anything abnormal, and experienced people can detect leaks early simply by the smell.[REMOVE]Fotnote: Werner Frøland, team coordinator at Draugen in film Norske Shell 100 years. 1912 -2012

Arbeidslivet på Draugen, engelsk,
Equipment on Draugen labelled for an annual check. Photo: Jan Soppeland/Norwegian Petroleum Museum

Planning maintenance tasks has made it possible to concentrate such work at times when production from Draugen is shut down. These periods are known as “turnarounds”.
Production from the platform has been suspended for roughly 14 days every other year – or once a year in the event of major projects.
This shutdown is partly intended to make it possible to perform inspection and maintenance in areas of the platform which are difficult to access during production.[REMOVE]Fotnote: NRK Møre og Romsdal (Bruker milliarder på produksjons-stans https://www.nrk.no/mr/draugen-stenger-i-19-dager-1.7626438
A dedicated team in the operations organisation on land will have been responsible for planning the work to be carried out during a turnaround. Equipment, extra personnel and required materials need to be ordered well in advance in order to be available at the right time.[REMOVE]Fotnote: Shell Drift Info Draugen and Ormen Lange no 5, 2006, “Vedlikeholdsstans krever ett års forberedelse”: 9.

Arbeidslivet på Draugen, engelsk,
Maintenance work on Draugen in 2008. Photo: A/S Norske Shell/Norwegian Petroleum Museum

A turnaround is usually scheduled for the summer season so that weather conditions are as good as possible during this period of concentrated work.

The scope of maintenance grows as a platform ages, and doing it takes longer. Wear and tear can lead to failures and faults, and cause accidents or unwanted shutdowns if not detected in time.
With the need to replace all or part of equipment items increasing over time, the attention devoted to continuous improvement and maintenance efficiency also rises.
Contracts have been awarded to Aker Solutions and Aibel for work on maintenance and modifications, and these companies provide additional personnel to help carry out such work.

Catering

arbeidslivet på draugen, engelsk,
Catering staff at Draugen provide clean towels. Photo: A/S Norske Shell/Norwegian Petroleum Museum

The platform’s catering personnel are responsible for such activities as food preparation and cleaning, and are employed by external contractors. Nevertheless, they have been incorporated in the permanent offshore organisation, shown on organograms and included in presentations of the workforce.
That has reflected a desire to minimise the distinction between Shell employees and catering personnel,[REMOVE]Fotnote: Interviews between Nils Gunnar Gundersen and Gunleiv Hadland from the Norwegian Petroleum Museum, 27 October 2016 and 1 November 2017.and the latter have felt an integrated part of the team from the start.[REMOVE]Fotnote: SSP.OKS’EN no 3, 1994, “Draugen- Min Arbeidsplass”, Mai Breivik, catering assistant
In collaboration with the platform nurse, catering staff also have roles in first aid, emergency response and drills for this.[REMOVE]Fotnote: Conversation with nurse Carina Løvgren on the Draugen platform, 7 March 2017. A small organisation means people have supplementary duties, particularly if a crisis occurs.
Once a year, personnel practise establishing an emergency sick bay in the mess. Installed in cooperation with the nurse, this facility is dimensioned for up to seven injured people.

Arbeidslivet på Draugen, engelsk,
First-aid drill carried out jointly between catering personnel and the nurse. Photo: Shadé Barka Martins/Norwegian Petroleum Museum

From offshore to onshore

The operations organisation has been split between platform and land, but a trend in working life on Draugen is the transfer of jobs to the onshore team. This has meant a gradual reduction in permanent staffing offshore. Heavy-duty maintenance and major projects are assigned to limited periods during the summer, when extra personnel and specialists on the relevant work are sent offshore.

Photo: Working at Draugen

Photo: Leisure time at Draugen

Published October 10, 2018   •   Updated October 18, 2018
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Draugen gas exports – arrived late but going strong

person Kristin Øye Gjerde, Norwegian Petroleum Museum
Draugen was the first field to begin production on the Halten Bank in the Norwegian Sea. Its oil could be loaded into shuttle tankers and shipped to refineries, but finding a commercial solution for the gas was less simple.
Kjappe fakta:
  • When the field came on stream in 1993, it was estimated to contain a lot of oil (575 million barrels or 92 million cubic metres)
  • and small quantities of natural gas (three billion cubic metres)
— Map of Haltenbanken.
© Norsk Oljemuseum

No export infrastructure for gas was immediately available. Shell’s proposal to flare the gas in situ was rejected by the government on resource management and environmental grounds.

Injecting the gas into Husmus, a satellite reservoir, offered a temporary solution. This was permitted for six years while a permanent export system was put in place.[REMOVE]Fotnote: Norsk Oljerevy, no 11, 1993, “Draugen-prosjektet vekket Midt-Norge”.

Haltenpipe right past

draugen gasseksport sent men godt, engelsk
Through the Haltenpipe from the shelf to Tjeldbergodden.

Problems with gas were not confined to Shell and Draugen. After exploration drilling was permitted above the 62nd parallel (the northern limit of the North Sea) in 1980, a number of discoveries were made on the Halten Bank.

Saga Petroleum found gas in the Midgard field in 1981 with its third well in the area, while Statoil and Shell discovered Smørbukk and Draugen respectively in 1984.

Statoil then proved Smørbukk South in 1985, when Conoco also found Heidrun. And Norsk Hydro discovered the Njord field the following year.

Success on the Halten Bank accordingly came quickly. All three Norwegian oil companies and international operators Shell and Conoco became involved in development assignments there.

Several of these fields contained natural gas in addition to oil, and opportunities for shared pipelines to bring this ashore were discussed on several occasions.

Heidrun’s gas reserves were larger than those in Draugen, and flaring these was again excluded by Norwegian emission standards. Nor was injection relevant.

Since no gas transport network existed this far north, Statoil and operator Conoco resolved to lay the Haltenpipe gas line to Tjeldbergodden and to build a methanol plant there.

As the state oil company, Statoil was particularly concerned to meet the political goal that Norway’s petroleum production should create spin-offs and jobs on land.

Haltenpipe would pass within a few kilometres of Draugen, so a gas tie-in from that field seemed sensible. Statoil/Conoco therefore proposed that the Draugen partners should become co-owners of both pipeline and methanol plant.

Negotiations were pursued in 1992 between Shell/BP for Draugen and the methanol group on delivering gas to Tjeldbergodden. But the former felt the methanol project was too expensive. Nor were they interested in producing this chemical.

They offered their gas free of charge, but Statoil/Conoco declined.[REMOVE]Fotnote: Lerøen, Bjørn Vidar (2012): Energi til å bygge et land. Norske Shell gjennom 100 år, 177–78. The negotiations accordingly foundered, and Haltenpipe passed Draugen without a tie-in.

Natural gas is used at Tjeldbergodden in northern Møre og Romsdal county to produce methanol products, air gases and some liquefied natural gas (LNG)
,
Tjeldbergodden. Photo: Statoil ASA/Norwegian Petroleum Museum

Draugen Gas Export

As noted above, permission to inject Draugen gas in Husmus was limited in duration. Offshore could announce in March 1998 that Norske Shell had finally found a buyer for the gas.

Development of fields and transport solutions from the Norwegian Sea had now made several strides. In connection with its Åsgard development, Statoil was planning a new gas pipeline to Kårstø north of Stavanger.

This would pass within 78 kilometres of Draugen and laying a spur from that field to a T-joint on the Åsgard line would allow its gas to be sent to Kårstø.

There it could be processed and transported on to consumers in continental Europe.[REMOVE]Fotnote: Offshore, 1 March 1998, “Offshore Europe”.

This solution was fully in line with what Shell wanted.

A plan for installation and operation (PIO) of a pipeline to link Draugen with the Åsgard Transport system was submitted to the Ministry of Petroleum and Energy in May 1999.

In the consultation process on this Draugen Gas Export facility, politicians in Møre og Romsdal county council expressed some dissatisfaction.

They wanted clarification of the regional spin-offs from this project, and called for measures to secure more work for mid-Norwegian players in all new Norwegian Sea developments.[REMOVE]Fotnote: Møre og Romsdal county executive board, 16 September 1999, item U-162/99 A: Konsekvensutgreiing for Draugen Gasseksport.

That demand fell on stony ground. The priority was to ensure that Norwegian Sea gas reached the market, and calls for local jobs took second place. The PIO was approved in April 2000.

Draugen Gas Export became operational in November 2000.[REMOVE]Fotnote: Norwegian Petroleum Directorate, 1 October 2007: Helhetlig forvaltningsplan for Norskehavet. Statusbeskrivelse for petroleumsvirksomhet i Norskehavet. Its diameter of 16 inches offered opportunities to tie in several other discoveries in the area.

Once the pipeline was in place, therefore, surplus gas was no longer a challenge for Draugen and new satellite fields were developed.

The Garn West discovery came on stream in December 2001, while Rogn South was approved in the spring of 2001 and began production in January 2003.[REMOVE]Fotnote: Norwegian Petroleum Directorate, 1 October 2007: Helhetlig forvaltningsplan for Norskehavet. Statusbeskrivelse for petroleumsvirksomhet i Norskehavet.

Draugen Gas Export

Operator: Gassco
Total investment: NOK 1.15 bn (2007 value)
Technical operating life: 50 years
Capacity: about two bn standard cubic metres (scm) per annum
Operations organisation: Kristiansund

Åsgard Transport

Operator: Gassco
From: Åsgard
To: Gassco
Length: 707 kilometres
Diameter: 42 inches
Available technical capacity (ATV): 70 million scm/day
Technical service provider: Statoil

 

Åsgard Transport and connected fields

Statoil was accustomed to taking a leading role in the development of the pipeline network on Norway’s continental shelf (NCS), and did so again when the Norwegian Sea-North Sea link was realised. Growing demand for gas in continental Europe made it possible.

The Midgard discovery operated by Saga and the Statoil-operated Smørbukk/Smørbukk South finds were unitised in 1995 to create a new licensee structure with Statoil in the driving seat.

Renamed Åsgard, this area became the subject of the biggest single development on NCS, which made extensive use of increasingly tested and reliable subsea technology.

An oil production ship, Åsgard A, and the floating Åsgard B gas/condensate platform were tied to 63 subsea-completed production and injection wells split between 19 seabed templates.

The gas/condensate satellites Mikkel and Yttergryta were also tied back to Åsgard B through seabed templates and associated flowlines.

With water depths of 240-310 metres across the area, plans called for oil from Åsgard A to be shipped ashore by shuttle tankers.

The big reserves discovered in the Norwegian Sea created the basis for tying this area to Norway’s existing gas transport system in the North Sea.

Operational in 2000, the 42-inch Åsgard Transport pipeline is 707 kilometres long from a starting point on the seabed beneath Åsgard B to the Kårstø processing plant.

Gassco is the operator of this system today, with Statoil as the technical service provider. Åsgard Transport can carry 25 billion cubic metres of gas per annum.

All the fields in the Norwegian Sea except Ormen Lange and Heidrun (part) export their gas through the pipeline. In addition to Åsgard, that includes Statoil-operated Njord, Heidrun (part), Kristin and Norne, BP-operated Skarv, and Draugen.

The Njord oil field lies due west of Draugen and came on stream in 1997. Associated gas was initially injected in parts of the reservoir to maintain its pressure.

Gas exports began from Njord in 2007, reducing the quantity available for injection. The gas travels through the 40-kilometre Njord export pipeline, which is tied into Åsgard Transport.

Heidrun, on stream since 1993, still sends the bulk of its associated gas to Tjeldbergodden. Opening Åsgard Transport also made it possible to transport part of the gas to Kårstø, but little use is made of this opportunity.

Like Njord, the Norne oil field came on stream in 1997 and its associated gas was injected as pressure support until 2005. Part of the gas was exported via Åsgard Transport from 2001, and all this output from 2005 when gas injection ceased.

The Alve gas/condensate and Urd oil fields pipe their production to Norne for processing and onward transport.

Kristin is a gas/condensate field just to the south-west of Åsgard, which came on stream with a tie-in to Åsgard Transport in 2005.

Tyrihans was tied back to Kristin as a subsea development in 2009. Some gas from Åsgard is injected into this field to improve oil recovery.[REMOVE]Fotnote: Kristoffer Evensen, Kjetil Nøkling, Martin Richardsen, Kamil Martin Sagberg and Marius Haara Tjemsland (2011): Gasstransportkapasitet fra Haltenbanken til Europa. Project assignment in subject area TPG4140 natural gas, Norwegian University of Science and Technology (NTNU)

draugen gasseksport sent men godt, engelsk

 

Published April 27, 2018   •   Updated October 2, 2018
© Norsk Oljemuseum
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Subsea work on Draugen

person Kristin Øye Gjerde, Norwegian Petroleum Museum
When Shell planned the Draugen development, the project included the installation of various subsea facilities and other work in 250 metres of water.
— Signing the Draugen underwater installation services (DUIS) contract on 30 April 1992. Seated from left: Per Olaf Hustad from Shell and Stolt Nielsen Seaway’s Kåre Johannes Lie. Standing from left: Jim Seavar, David Cooke and an unidentified person (all Shell), and Arnfinn Vika, Joar Gangenes and Magne Vågslid (all Stolt Nielsen Seaway). Photo: A/S Norske Shell/Norwegian Petroluem Museum
© Norsk Oljemuseum

This included positioning a subsea pump and manifold as well as modules from Kongsberg Offshore, opening and shutting valves in deep water, connections and maintenance jobs of various kinds.

The Draugen underwater installation services (DUIS) contract was won in 1992 by Stolt-Nielsen Seaway, a specialist with diving and remotely operated vehicles (ROVs).

Based in Haugesund north of Stavanger, this company had to make a rather unusual acquisition in order to satisfy Shell’s technical specifications for the work.

Plans called for ROVs to be used to carry out subsea work for the platform, since saturation diving by humans was not feasible at these water depths.

Several types of such vehicles were relevant, including crewed systems which kept the person doing the seabed job under atmospheric pressure no matter how far down they were.

The other principal solution was an ROV operated from a control room on a rig or ship without any people needing to go underwater.

Stolt-Nielsen Seaway had an ROV on its diving support vessel (DSV), but Shell wanted a back-up in case this vehicle ran into problems.

Eric Lutzi is trying an ADS – an armoured diving suit which is suspended from a cable and provided with lifting equipment on the DSV. The operative stand inside it like an astronaut, with a transparent dome for vision. Photo: Eric Lutzi / NOM.
Erich Luzi from Statoil trying a Newtsuit on the diving vessel "Seaway Condor". Photo: Unknown/Norwegian Petroleum Museum

Diving could be an option, and successful test dives had already been conducted down to 250 metres and beyond. But demonstrating (qualifying) that descents to these depths could be conducted safely was both expensive and very demanding.[REMOVE]Fotnote: Joar Gangenes by email to Kristin Øye Gjerde, 13 October 2017.

Instead, Shell specified that the company must have an atmospheric diving suit (ADS) available as a back-up in order to secure the contract.

An ADS was an armoured diving suit suspended from a cable and provided with lifting equipment on the DSV. The operative/diver stood inside it like an astronaut, with a transparent dome for vision. Although able to walk on the seabed, he lacked the mobility of a diver.

Having won the job, Stolt-Nielsen Seaway had to invest in this system. It was purchased from a Canada-based company via Draeger and proved extremely expensive.[REMOVE]Fotnote: Joar Gangenes by email to Kristin Øye Gjerde, 13 October 2017.

A test programme established that getting a person inside this suit to do effective work was almost impossible. It was accordingly never used.

Fortunately for Stolt-Nielsen Seaway, Shell proved willing to bear the whole cost of both investment and testing. It regard this as research and development work.

Kåre Johannes Lie, who followed up this acquisition from the contractor’s side, found the whole business unfortunate and felt spending money on an unnecessary system was a bit of a waste.[REMOVE]Fotnote: Kåre Johannes Lie in an interview with Kristin Øye Gjerde and Arnfinn Nergaard, 9 August 2017.

Subsea installation work was performed with the aid of the module handling system on the DSV, which had been developed earlier by Stolt-Nielsen Seaway in collaboration with Elf.

During the 1990s, the contractor also used the newly developed and powerful Perry Tritec Triton ROV from Oceana Subsea Ltd Perry Inc in Florida.

The most popular ROV on the Norwegian continental shelf in the 1990s, this unit could descend to 1 000 metres and perform subsea observation, sonar searches, seabed surveys and mechanical jobs.

With a deployment cable (umbilical) which incorporated the necessary communication lines, the Triton was able to remove and replace components on the seabed.

It featured two powerful manipulator arms developed by Shilling in the USA and remotely operated via a fibreoptic cable in the umbilical.

The package also included a cable drum, winch, power transmission unit and control room. Its control system ran an electric pump which drove the propellers and other gear.

Hydraulically powered thrusters provided propulsion in the sea. In addition came dedicated systems for lifting the ROV and its basket from the deck and into the sea.

Triton ROV was used at Subsea work near Draugen. Photo: NOM.
Photo: NUI/Norwegian Petroleum Museum

 

Published April 27, 2018   •   Updated July 5, 2018
© Norsk Oljemuseum
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