The Ekofisk area lies in 70-75 metres of water at the
Ekofisk area. Map: NPD.
southern end of Norway’s North Sea sector, about 280 kilometres south-west of Stavanger. In addition to Ekofisk, it embraces Eldfisk, Embla and Tor. All four fields are operated by ConocoPhillips on behalf of the Ekofisk licensees. The area also includes the Cod, Mime, Edda, West Ekofisk, Albuskjell and Tommeliten Gamma fields, which have ceased production. It has comprised a total of 32 platforms, including the first production installation, Gulftide. Developed in a number of stages, the area has the highest concentration of offshore installations and flowlines/pipelines in the whole North Sea. Nine platforms are due to disassembled and removed up to 2013.
The discovery of Balder in 1967 and Cod in 1968 demonstrated that hydrocarbons were also present on the Norwegian side of the North Sea, although these initial finds were not commercial at the time. After a number of dry wells, the Phillips group discovered Ekofisk in the autumn of 1969. This proved to be a huge oil field, currently estimated to have originally contained more than three billion barrels of recoverable oil. Production began officially in the summer of 1971 from the Gulftide jack-up rig.
Approval in principle was given to the technical plans for developing Ekofisk in 1972. The plan for waterflooding in Ekofisk received a green light on 20 December 1983, the PDO for Ekofisk II was approved on 9 November 1994, and the PDO for Ekofisk Area Growth gained official sanction on 6 June 2003.
Bravo and Kielland
Accidents in the Ekofisk area have helped to focus attention on safety issues and the risks associated with offshore petroleum operations. The uncontrolled blowout on Ekofisk 2/4 B (Bravo) in April 1977 put pollution on the agenda, and speeded up the creation of an oil spill clean-up organisation. With 123 fatalities, the capsizing of the Alexander L Kielland accommodation rig in March 1980 was the worst industrial accident in Norway’s history. The Norwegian Maritime Directorate commanded in the autumn of 1980 that all offshore workers should be issued with a survival suit.
Subsidence and jacking up
Unlike many other fields in the North Sea, Ekofisk is a chalk structure. Declining reservoir pressure has led over the years to seabed subsidence. Work to safeguard the platforms against this phenomenon began as early as 1985. The steel jackets in the Ekofisk centre were jacked up by six metres in 1987, and a protective breakwater was installed around the Ekofisk tank two years later. The rate of seabed subsidence has slowed in recent years.
Reservoir and recovery strategy
Ekofisk produces from naturally fractured chalk belonging to the Ekofisk and Tor formations of early Palaeocene and late Cretaceous age. These reservoir rocks have high porosity but low permeability, and are fine-grained and tight. However, the fracturing allows oil and water to flow more easily. Located at a depth of 2 900-3 250 metres below sea level, the reservoir has an oil column of more than 300 metres and is 10 kilometres long by eight wide.
The field was originally developed with pressure reduction as the drive mechanism and an expected recovery factor of 17 per cent. Limited gas injection and extensive waterflooding have subsequently helped to improve oil recovery substantially. Large-scale waterflooding began in 1987, and has since been expanded in several stages. Experience shows that the water effectively displaces the oil, and the expected recovery factor for Ekofisk is now about 50 per cent. In addition, compaction of the soft chalk provides additional drive for draining the field.
Immediately after the plans to merge Conoco and Phillips became known in December 2002, the company announced the Ekofisk Area Growth project. This aims to improve oil and gas recovery while enhancing Ekofisk’s processing capacity and reliability. The field is currently expected to continue producing until 2050.
Oil and gas are piped today from Ekofisk 2/4 J to
Transport in the Ekofisk area
Teesside in the UK and Emden in Germany respectively.
Initially, oil produced from the field was loaded into tankers via two loading buoys tied back to the Gulftide jack-up. Gas was burnt off from a flare stack on the rig. The problem with this approach arose when the tankers were forced to disconnect from the loading buoys because of strong winds or high waves, and production had to cease. Ekofisk was shut down by bad weather for 20 per cent of the time during the first year.
After Gulftide had been removed in 1974 and production was under way from Ekofisk 2/4 A, B and C, the loading buoys were moved further from the platforms and Ekofisk 2/4 T (the Ekofisk tank) became operational. The latter was highly useful for oil storage, making it possible to remain on stream when bad weather prevented the tankers from connecting to the buoys. Production could thereby continue in virtually all weather conditions. The tank was used for storage for a year from the autumn of 1974.
Submarine pipelines provided the permanent solution for transporting oil and gas to land.
Running for 354 kilometres, the Norpipe oil pipeline to the receiving terminal in Teesside became operational in October 1975. The oil and natural gas liquids (NGL) were pressurised by pumps on Ekofisk 2/4 P. Two pumping stations – Ekofisk 36/22 A and 37/4 A – were originally installed along the pipeline to maintain pressure, but were disconnected in 1983 and 1987 respectively. Both stood on the UK continental shelf (UKCS).
Ekofisk 2/4 T. Photo: ConocoPhillips
The Norpipe gas pipeline became operational in September 1976, with the gas initially pressurised by compressors at the Ekofisk centre. Two compressor platforms – B-11 and H-7 – are located along the 443-kilometre pipeline to Emden. Both stand on the German continental shelf, while the pipeline also crosses the Danish sector. H-7 was shut down in 2007.
Since the Ekofisk centre was strategically located in the centre of the North Sea basin, using the existing platforms and pipelines to transport other oil and gas to land was a natural solution. Transport of the field’s own production was supplemented with output from Cod, Albuskjell, West Ekofisk, Tommeliten, Edda, Tor, Embla, Eldfisk, Valhall, Hod, Ula and Statpipe. The first five of these fields have now ceased production.
The Ekofisk centre. Photo: Kjetil Alsvik/ConocoPhillips
Phase one of development and production in the Ekofisk area began with the first oil produced by the Gulftide jack-up in 1971, and ended with the shut-down of Ekofisk I in 1998. A new PDO for the field – Ekofisk II – was approved in 1994, at the same time as the production licence was extended until 2028. This led to large parts of the Ekofisk area being converted in 1998.
The installations located centrally on the field and linked by bridges are termed the Ekofisk centre, and this consisted until 1998 of eight platforms and two flare stacks. In addition came the 2/4 G and 2/4 S platforms owned by Amoco (later BP) and Statoil respectively.
A reconstructed Ekofisk centre is now in place on the field, including the 2/4 X wellhead platform positioned in the autumn of 1996. The 2/4 J structure for processing and transport followed in 1997, and Ekofisk 2/4 M – a steel wellhead and processing platform – was installed in the summer of 2005. Ekofisk, Eldfisk, Embla and Tor are now tied back to the new centre.
Platforms outside the Ekofisk centre are 2/4 A to the south as well as 2/4 B and 2/4 K to the north.
Year Overview of developments in the Ekofisk area
1971 Gulftide begins production from Ekofisk, with the oil loaded into tankers.
1973 Ekofisk 2/4 Q comes into use as a quarters platform.
1974 Ekofisk 2/4 A, B and C come on stream. Ekofisk 2/4 FTP and the southern flare stack become operational. Gulftide ceases production and is removed.
1975 The Ekofisk 2/4 P pumping platform and the Norpipe pipeline to the UK, with the 36/22 A and 36/4 A pumping platforms, become operational. Offshore loading ceases.
1977 The processing facilities on the Ekofisk tank and the northern flare stack start operation. The tank is no longer used as an oil store. Tor, West Ekofisk and Cod are tied back to the new Ekofisk 2/4 R platform. Gas is piped through a new Norpipe line via the B-11 and H-7 compressor platforms to Emden in Germany.
1978 The Ekofisk 2/4 H hotel platform becomes operational.
1979 Albuskjell, Edda and Eldfisk are tied back to the Ekofisk centre.
1981 Valhall produces to a new platform, Ekofisk 2/4 G, which is linked by a bridge to the Ekofisk tank.
1983 The Ekofisk 36/22 A pumping platform is shut down.
1985 The Statpipe line is tied to the Ekofisk centre via the 2/4 S platform.
1987 The Ekofisk 2/4 K waterflood platform comes on stream. It is linked by a bridge to Ekofisk 2/4 B. Tommeliten starts production through a tie-in to Ekofisk via Edda. The Ekofisk 37/4 A pumping platform is shut down.
1990 Albuskjell 2/4 F ceases production.
1991 The Ekofisk 2/4 W water injection platform is placed on the bridge support to the southern flare stack.
1993 Embla starts production through a tie-in to the Ekofisk centre via Eldfisk.
1995 Norpipe is re-routed to bypass the 36/22 and 37/4 A pumping platforms.
1996 The new Ekofisk 2/4 X drilling and wellhead platform comes on stream.
1997 Cod ceased production.
1998 The Ekofisk 2/4 J processing platform comes on stream. Ekofisk 2/4 G, 2/4 P, 2/4 R and 2/4 S, Albuskjell 1/6 A, West Ekofisk 2/4 D, the process plant on the Ekofisk tank, and production from Edda 2/7 C and Tommeliten ceases. Large parts of the pipelines around the Ekofisk centre are relaid.
2000 Eldfisk 2/7 E comes on stream.
2005 Ekofisk 2/4 M is installed.
This four-leg jack-up rig was built in Glasgow in 1967 for Ocean Drilling & Exploration Co, and converted in 1971 to serve as a production platform. It produced on Ekofisk from 1971 to 1974, when the first well on the fixed 2/4 A platform came on stream. To win time, it was resolved that the three wells drilled by Ocean Viking to delineate Ekofisk as well as the discovery well would be converted for production. The statistics show that each of these wells flowed 10 000 barrels of oil per day. Oil and gas were dewatered on the platform, with the gas burnt off from a flare boom on the drilling derrick. The oil was piped through flowlines to two loading buoys which linked the platform with tankers.
Ekofisk 2/4 A
Originally a combined production, drilling and quarters platform, Ekofisk 2/4 A serves today as a pure wellhead structure. It stands in 74 metres of water, 2.9 kilometres south of the Ekofisk centre. It was installed in 1972 and came on stream in April 1974.
Production was processed in the platform’s separators and piped to Ekofisk 2/4 FTP for further separation. Ekofisk 2/4 A has 11 producing wells with gas lift from 2/4 C.
Gulftide. Photo: Terje Tveit/Norwegian Petroleum Museum
Ekofisk 2/4 A. Photo: Husmo Foto/Norwegian Petroleum Museum
The quarters module originally provided 42 berths, but new accommodation was installed in 1984 with two-berth, en-suite cabins. Drilling equipment was upgraded to the top drive system in 1991.
Personnel moved from the platform in 1993, and it was remotely operated from Ekofisk 2/4 K (and could also be controlled from 2/4 FTP) and from 2/4 J after 1997. The derrick and drilling equipment were removed in the latter year.
A breach in the riser on the pipeline to Ekofisk 2/4 FTP led to ignition of the gas on 1 November 1975 and a big fire. Crew had to be evacuated, with the loss of three lives. The downhole safety valve functioned as intended and production was automatically halted, but the gas pack in the 2.9-kilometre pipeline fed the flames until this fuel has been exhausted and the fire died of its own accord. The cause of the fire was corrosion of the riser in the wave zone beneath the platform.
Ekofisk 2/4 B
This is a combined production, drilling and quarters platform standing in 70 metres of water, 2.3 kilometres north of the Ekofisk centre. Installed in 1972, it came on stream two years later.
The processing equipment comprises two identical parallel separators and a test separator. Of the 24 platform well slots allocated to production, 22 were completed as producers and two held in reserve. The production wells delivered a mix of oil and gas, which was piped to Ekofisk 2/4 FTP.
Ekofisk 2/4 B carried two derricks for a time, but both are now removed. The 68-berth quarters model was removed after the installation of the neighbouring 2/4 K platform, which is connected to 2/4 B by a bridge.
An uncontrolled blowout of oil and gas occurred from this platform in April 1977. Well B-14 needed a workover, which required the 3 000 metres of production tubing to be pulled. The blowout preventer failed during this operation, and it took a week to bring the well back under control.
Ekofisk 2/4 B. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 C
This PDQ platform is linked by bridges to Ekofisk 2/4 P, 2/4 Q and 2/4 H. Installed in 1972, it stands in 70 metres of water and has 12 wells. Nine of these are used for gas injection and the other three produce oil, gas and condensate, which are piped via the bridges to 2/4 FTP for separation and processing.
The platform came on stream in 1974.
Ekofisk 2/4 C. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 FTP
This riser (formerly production) platform was installed in 1972 and became operational in 1974. Until the Norpipe oil pipeline to Teesside was installed, oil was shipped from two loading buoys tied back to 2/4 FTP by 30-inch flowlines. The platform is linked by bridges to Ekofisk 2/4 Q on the northern side and Ekofisk 2/4 W to the south.
Its original function was to process oil and gas from the 2/4 A and 2/4 B platforms, and later also 2/4 C. The processing equipment comprised separators for oil, water and gas as well as two compressors for pressurising the gas and sending it on – first to Ekofisk 2/4 C for injection into the reservoir and later to 2/4 T when that unit became operational. Peak flow via 2/4 FTP was 420 000 barrels per day.
For many years, the platform had its own management and staffing on a par with other installations in the Ekofisk centre. It also has a helideck, which was in use for many years. After 28 years of operation, control room staff were withdrawn from 2/4 FTP in September 2001. All shutdown signals and safety systems were transferred to the Ekofisk 2/4 J control room.
Ekofisk 2/4 FTP is to be regarded today as a riser platform for a production flowline from 2/4 A, and also supplies the latter with power.
Ekofisk 2/4 FTP. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 G
Owned by the Valhall licence, this was a riser platform which tied Valhall to Ekofisk. The fields were connected by two 20-inch pipelines, for oil and gas respectively. Oil was piped on to Teesside and gas to Emden.
A bridge with piping systems linked Ekofisk 2/4 G to the 2/4 T tank. Installed and operational in 1981, the platform was shut down in 1998 when a new 24-kilometre gas pipeline from Valhall was tied directly into the Norpipe line to Emden. The oil pipeline was re-routed to Ekofisk 2/4 J for continued transmission to Teesside.
Ekofisk 2/4 G. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 H
This is a specialised service platform for accommodation and administrative functions. Providing 212 berths in double cabins, it is linked to Ekofisk 2/4 C by a bridge.
The platform is equipped with all the facilities required by the personnel quartered on it, including its own generator and water production as well as full catering provision. In addition come a cinema, gym, games and reading rooms, chapel, coffee lounge, sick bay, equipment for technical education and storage capacity for a number of technical functions, a helideck, a hangar and a control centre for sea and air traffic. The top management for the whole Ekofisk field and offices for a number of shared services are also located there.
Installed in 1977, Ekofisk 2/4 H became operational in 1979 and functions as the main accommodation installation for the Ekofisk centre until a new quarters platform is built.
Ekofisk 2/4 H. Photo: Jan A Tjemsland/Norwegian Petroleum Museum
Ekofisk 2/4 J
All production from the Ekofisk centre and the field’s satellite platforms goes to this processing and transport platform before gas is piped to Emden and oil to Teesside.
Large parts of the Ekofisk centre were reorganised in 1998, with 2/4 J as the key installation in these changes. In addition to production from the main Ekofisk field, it receives oil and gas from Eldfisk, Embla, Tor and Valhall. Gas and oil also arrive from Gyda and Ula respectively for onward transmission to Emden and Teesside.
Oil, gas and water are separated on Ekofisk 2/4 J, with the hydrocarbons pressurised at the start of their journey to Emden and Teesside. On stream since 1998, the platform also has equipment for gas injection into the reservoir.
Ekofisk 2/4 J. Photo: Jan A Tjemsland/Norwegian Petroleum Museum
Ekofisk 2/4 K
This combined water injection, drilling and quarters platform stands three kilometres north of the Ekofisk centre and is linked by a bridge to the adjacent Ekofisk 2/4 B installation. With the quarters module providing 182 berths over six stories, Ekofisk 2/4 K became operational in 1987.
To boost pressure and improve production, waterflooding of the reservoir was initiated from the platform in 1987 in order to replace the oil and gas as they are produced. Injection water is filtered and has chemicals added. Ekofisk 2/4 K has also supplied the 2/4 W platform with water since 1990 for pressure maintenance in the southern part of the reservoir. Ekofisk 2/4 K was later supplied with additional injection water from Eldfisk 2/7 E.
Operations on 2/4 B were run by the 2/4 K control room from 1995. The latter also took over remote monitoring of Edda 2/7 C and Albuskjell 1/6 A in May 1999. These installations then shut down and, rather than leaving them staffed until the wells were permanently plugged, a solution was introduced based on remote operation of such functions as emergency shutdown, fire and gas systems, ventilation, power supply and well status.
Ekofisk 2/4 K and 2/4 B. Photo: ConocoPhillips
Ekofisk 2/4 M
This steel wellhead and processing platform was installed in the summer of 2005 south-east of Ekofisk 2/4 J and tied to the latter by a bridge. The installation was constructed as part of the Ekofisk Area Growth project, which aims to improve oil and gas recovery as well as increasing processing capacity and reliability at the Ekofisk centre.
In addition to 30 well slots, the platform has a high-pressure separator, equipment for handling produced water, and risers for use in future projects. It does not have its own drilling rig, and wells are drilled by a chartered jack-up. However, arrangements are made for coiled tubing operations.
Ekofisk 2/4 M (left). Photo: Kjetil Alsvik/ConocoPhillips
Ekofisk 2/4 P
Ekofisk 2/4 P pumped oil from the field through a 34-inch pipeline running for 350 kilometres to Teesside. Three turbine-driven centrifugal pumps provided a total capacity of one million barrels per day.
Oil from the Ekofisk area is very clean in terms of sediment and water content. Its wax content can nevertheless create problems for efficient flow through the pipeline. Ekofisk 2/4 P was accordingly equipped with a pig launcher as well as equipment for injecting chemical corrosion inhibitor. Warehousing was another important function of this platform, which held more than 5 500 spare parts in its central stockroom.
Installed in 1974, 2/4 P became operational in 1975. It was shut down in 1998, and the topside was removed in 2009.
Ekofisk 2/4 P. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 Q
This is a pure quarters platform with 68 berths in double cabins as well as a canteen, lounge and offices. Linked by bridges to 2/4 C and 2/4 FTP, it was installed in March 1972 and the first residents moved in during 1973. The quarters module was replaced in 1981.
Ekofisk 2/4 Q. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 R
This riser platform tied Cod, Albuskjell, West Ekofisk, Edda, Eldfisk, Ula, Gyda and Tor to the Ekofisk centre. It was also tied to the Statpipe system via a pipeline bridge to Ekofisk 2/4 S.
The processing facilities comprised a one-stage, two-phase gas/condensate separator for output from Tommeliten, Albuskjell, Gyda and Eldfisk. Oil was transferred directly to Ekofisk 2/4 T. Processed gas was returned from 2/4 T to 2/4 R, where it entered the pipeline to Emden. Ekofisk 2/4 R had pig traps for the incoming pipelines, and a pig launcher for the Emden line.
Installed in 1975, the platform became operational in 1977. It was shut down and the pipelines disconnected in 1998, and removed in 2009.
Pipelines tied into Ekofisk 2/4 R
From Tor 2/4 E 12-inch oil
From Tor 2/4 E 14-inch gas
From Cod 7/11 A 16-inch oil/gas
From Edda 2/7 C 10-inch oil
From Edda 2/7 C 12-inch gas
From Albuskjell 2/4 F 18-inch oil
From Albuskjell 2/4 F 24-inch gas
From Eldfisk 2/7 B 24-inch oil
From Eldfisk 2/7 B 30-inch gas
From West Ekofisk 2/4 D 24-inch oil/gas
From Ula 20-inch oil
From Gyda 12-inch gas
From Ekofisk 2/4 S via bridge, gas
To Norpipe B-11 36-inch gas
Ekofisk 2/4 R. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 S
Ekofisk 2/4 S was a riser platform which tied the Statpipe line into the Ekofisk system.
The Statpipe transport system comprises 880 kilometres of pipelines, with two riser platforms and a terminal at Kårstø. Rich gas from fields in the northern North Sea (the Gullfaks, Statfjord and Oseberg areas) is piped to Kårstø, where the NGLs are removed and fractionated to commercial products for onward transport as liquefied ship cargoes. The dry gas was carried in a 28-inch pipeline via the Draupner S riser platform in block 16/11 and Ekofisk 2/4 S to tie into the Norpipe line to Emden. Statpipe now bypasses the Ekofisk platforms to tie directly into Norpipe.
Installed in 1984, Ekofisk 2/4 S became operational the following year. It was shut down in 1998 and its whole topside removed in 2001. The jacket and bridge foundation remain, and will be taken away later. Statoil was the owner of the platform.
Ekofisk 2/4 S. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 T – the Ekofisk tank
Built in Stavanger in 1971-73 as a storage tank for oil when bad weather prevented offshore loading, this was the first concrete structure on the NCS. It was installed on the field in the summer of 1973, and became operational the following year. Ekofisk 2/4 T was eventually linked by bridges with 2/4 R to the north, 2/4 G to the west and 2/4 P to the south.
After oil began to be exported by pipeline to Teesside in 1975, the tank lost its original storage role. It nevertheless continued to be used for intermediate storage of oil waiting to be piped to the UK, thereby allowing residual water to be removed.
A new deck was installed on the tank in 1977 to carry a large processing plant, making this structure the most important hub for oil/gas production and processing in the North Sea. The facility included systems for separating water, oil and gas, as well as equipment to dewater and compress the separated gas.
Completion of the processing plant on the tank was complicated by delays to finalising the NGL terminal at Teesside. This meant that the system had to be modified so that NGLs produced with the dry gas and oil could be injected back into the reservoir with the aid of dedicated pumps on Ekofisk 2/4 C. That solution persisted until the spring of 1979, when the NGL could be received together with the oil at the UK terminal.
The plant on the tank almost doubled processing capacity for oil and gas at the Ekofisk centre. That also created a need for a second flare stack as a safety precaution, and this was positioned north of the tank. Seabed subsidence on the field prompted the installation of an additional concrete breakwater around the tank in 1989.
Ekofisk 2/4 T was shut down in 1998 and the systems cleaned. The topside has now been removed, while the tank will be left in place.
Ekofisk 2/4 T with breakwater. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 T. Photo: ConocoPhillips/Norwegian Petroleum Museum
Ekofisk 2/4 W
Originally a bridge support, Ekofisk 2/4 W was converted to a water injection platform in 1989 and stands between the southern flare stack and Ekofisk 2/4 FTP. It was shut down in 2009.
The topside equipment comprised a riser and six water injection wells with wellheads.
Waterflooding was used to improve the recovery of oil and gas. Its function is to maintain pressure by replacing hydrocarbons in the reservoir as these are produced. The water used was carried in a dedicated flowline from Ekofisk 2/4 K, which maintains pressure in the northern part of the reservoir while 2/4 W does the same for the southern area. With the platform unstaffed, waterflooding was initially controlled from 2/4 FTP and later by 2/4 K.
A leak was discovered in the flowline from the latter platform in 1993. It had been damaged by an anchor chain from Safe Lancia while this flotel was moored alongside Ekofisk 2/4 S. The damage was located and repaired.
The Big Orange VIII well stimulation vessel collided with 2/4 W in June 2009. This powerful impact caused extensive damage to both platform and wells, and operator ConocoPhillips is now removing the whole installation and permanently plugging the wells.
This means that the original removal plans for 2/4 W have been brought forward by the collision.
Ekofisk 2/4 W. Photo: Husmo Foto/Norwegian Petroleum Museum
Ekofisk 2/4 X
Ekofisk 2/4 X is a compact drilling and wellhead platform with 50 well slots. Oil and gas are piped to the other new platform in the Ekofisk II development – 2/4 J. Over time, the wells on 2/4 X are intended to replace those on the 2/4 A, 2/4 B and 2/4 C platforms. The installation has been built to cope with up to 20 metres of seabed subsidence.
Operational since 1996, Ekofisk 2/4 X is linked with the 2/4 C and 2/4 J platforms.
Ekofisk 2/4 X. Photo: Jan A Tjemsland/Norwegian Petroleum Museum
See also the Norwegian Petroleum Museum’s petroleum map: http://www.petroleummap.no
|Total recoverable reserves|
|544.70 mill scm oil|
|158.90 bn scm gas|
|16.10 mill tonnes NGL|
|Remaining reserves||at 31 Dec 2016|
|79.50 mill scm oil|
|13.60 bn scm gas|
|2.70 mil tonnes NGL|
|Approved for development||1 Mar 1972|
|On stream||15 Jun 1971|
|Main supply base||Tananger|
|Total E&P Norge||39.90%|
Ekofisk is an invented name, created by an American geophysicist. “Fisk” means fish in Norwegian. At the time, the Phillips group named all promising structures on the NCS after fish. These names were grouped by area, and began with the same letter in each area to aid identification.