Rig: West Alpha

Name West Alpha
Owner North Atlantic Alpha Ltd.
Manager North Atlantic Drilling AS
Rig Type Semisub
Sub Type Midwater Floater
Jackup Type --
Max Water Depth (ft) 2000
Max Drill Depth (ft) 23000
Dimensions (ft) 323 x 250 x 70.5
Leg Length (ft) --
Competitive Yes

Current Location

Country --
Region --

Drilling Equipment

Drawworks Type AKMH Wirth GH 3000 EG
Drawworks HP 3000
Mud Pumps Type AKMH Wirth TPK
Top Drive Aker Maritime Hydraulics DDM-650-L-DC
Hookload Capacity (lbs) 1300000

Rig Construction Details

Rig Design Dyvi Offshore
Rig Model Ultra Yatzy
Year Built 1986
Country of Build Japan
Yard Name Tsu Shipyard
Group Yard Name Nippon Kokan Ltd.

Rig Contract Details

Operating Status Retired
Operator Rosneft

Rig Images


17 Apr 2015

Rosneft and NADL delay proposed agreement by two years

On August 22nd, 2014 North Atlantic Drilling Ltd. ("NADL") announced that it had entered into a Framework Agreement between NADL, Seadrill and Rosneft Oil Company ("Rosneft"). On November 7th, 2014, the closing of the transaction was delayed until the end of May 2015. Today, all parties have mutually agreed to extend the termination date of the Framework Agreement until May 31st, 2017, whereby any party can terminate the Framework Agreement and / or any offshore drilling contracts at any time prior to May 31st, 2017 at no cost. Additionally, the parties have agreed to use reasonable efforts to renegotiate the terms and characteristics of the transactions contemplated in the Framework Agreement and the terms of the related offshore drilling contracts. During this time, NADL is permitted to market the offshore drilling rigs subject to existing drilling contracts with Rosneft and enter into binding contracts with third parties. NADL will also be permitted to delay the construction, delivery, or shipyard stay of any of those rigs. This delay follows the decision to cancel the contracts for the ‘West Navigator’ drillship and ‘Energy Endeavour’ jackup, both of which were also due to go on contract with Rosneft in Russia.

8 Dec 2014

ExxonMobil to use 'West Alpha' on Balder field

ExxonMobil has received consent to use the West Alpha semisub drilling rig for production drilling, completion and installation of subsea equipment on the Balder field. Balder was the first oil field to be discovered on the Norwegian Continental Shelf, with Esso as the sole licensee in production licence 001. This happened as far back as 1967, more than two years before the Ekofisk field was discovered and declared viable. At the time, Balder was not assessed to be commercially interesting. Following new investigations, the Balder field was subsequently developed. Production began in 1999, still with ExxonMobil as the sole licensee and operator. The Balder field is in the central North Sea, around 213 kilometres west of Stavanger. The field has been developed using a subsea solution tied to a floating production, storage and offloading (FPSO) unit. Water depth in the area is approximately 125 metres. ExxonMobil has now received consent from the PSA to use West Alpha to drill and complete new production wells on the field. The activities also concern the installation of subsea equipment and the plugging of wells no longer in use.

29 Sep 2014

Rosneft announces discovery with Universitetskaya-1 well

Rosneft successfully completed the drilling of the northernmost well in the world – the Universitetskaya-1 well in the Arctic. According to the results of the drilling Rosneft has made an oil discovery at the East-Prinovozemelskiy-1 license area. The drilling was completed in record-breaking time - in one and a half month - in compliance with all the technological and ecological standards and requirements. The sea depth at the drilling site is 81 m, the depth of the straight well – 2,113 m. the well was drilled in open-water conditions – at the 74th circle of longitude, 250 km clear off the inland of the Russian Federation. As a result of the drilling formation samples were obtained, a pilot borehole was drilled (diameter 8.5 inches to a depth of 600 m) and horizontal drill samples were collected. Specialists obtained substantial amount of new geological data which will be elaborated. Upon the completion of the analysis a conclusion on the resource base of the discovered field can be made. At the moment the geological data interpretation is being conducted, the field’s development model is being elaborated. The security and fail-safety of the operations of future drilling is guaranteed by the landing of 5 columns. The Universitetskaya structure covers an area of 1,200 thousand kilometers with a 550 m high hydrocarbon trap. Its resources account to more than 1.3 billion tons of oil equivalent. A total of some 30 structures were found in three East Prinovozemelskiy areas of the Kara Sea, and the entire resource base of the three areas is estimated at 87 billion barrels or 13 billion tonnes of oil equivalent. According to experts the volume of the Kara Sea oil province resources exceeds the oil and gas resources the Gulf of Mexico, the Brazilian shelf, the shelf of Alaska and Canada, and it will be comparable to the resource base of Saudi Arabia. Prior to the start of operations in the Kara Sea the ‘West Alpha’ drilling rig was heavily upgraded, which among other things was needed to guarantee ecological safety. The rig is equipped with two groups of blowout preventers and an independent submarine locking device, which in case of minor risks will seal the well. The rig is held at the drilling site by an anchoring positioning system, consisting of 8 anchors. This guarantee an elevate rig stability. Most of the platform is out of the reach of the waves, which can disturb its operations. The rig is capable of drilling to a depth of up to 7 km.

9 Aug 2014

Rosneft spuds Kara Sea well

Rosneft and ExxonMobil joint venture company Karmorneftegaz began drilling at Universitetskaya-1, the Russian Federation's northernmost well using the ‘West Alpha’ rig. The signal to begin drilling was given by Russian President Vladimir Putin in a video link to the Kara Sea with the head of Rosneft Igor Sechin and the head of ExxonMobil Russia Glenn Waller. Special representative of President of the Russian Federation on international cooperation in the Arctic and Antarctic Artur Chilingarov and North Atlantic Drilling representative Jan Tore Theimann also took part in the ceremony. “The start of exploratory drilling in the Kara Sea is the most important event of the year for the global oil and gas industry. As a result of this work we hope to discover a new Kara Sea oil-bearing province. Developing of the Arctic shelf has a huge multiplicative effect on the whole Russian economy” – said Igor Sechin. The ‘West Alpha’ rig was provided by the Norwegian company North Atlantic Drilling which signed long-term agreements with Rosneft on 30th July 2014 for the offshore drilling. ‘West Alpha’ was transported via the Barents, Pechora and Kara Seas and installed on the drilling site of the East Prinovozemelskiy-1 Licence Area in the Kara Sea. The drilling rig made the way of over 1,900 nautical miles to reach its destination. The rig is 30,700 tons in deadweight, 70 m long, 66 m wide, the derrick hangs 108.5 meters over the main deck, and it drafts during drilling for 21.5 m. The rig is held on the drilling site by an 8-anchor positioning system, which provides advanced stability for the rig. Most of the platform is outside the reach of waves, which are no impediment for the rig's operation. The drilling will continue for two months.

3 Jan 2012

West Alpha returns to Ølensvåg

Westcon Yard has received a Letter of Intent from North Atlantic Drilling (a company partially owned by Seadrill) for work on the submersible rig West Alpha, in the third quarter of 2012. The work includes intermediate inspection and various modification works to prepare the rig for a new contract with ExxonMobil on the Balder field. West Alpha will bore two wells, a job which has an anticipated value of US$100 million, and will have an option for drilling a further four wells.

11 Feb 2011

West Alpha arrives at Westcon

West Alpha arrived at Westcon on the 7th of February; it was also in for a major yard stay in autumn 2009. The main job this time will be to install third party equipment required for the rig’s next task which is involves the drilling and completion of well 6507/3-L-4 AH on the Alve field and the intervention of well. While this work is in progress there will also be a new Gantry Crane installed in addition to various minor works. The rig is expected to remain in the yard for a period of one week.

30 Apr 2009

Gas condensate find at Veslefrikk

A small gas condensate discovery has been made by StatoilHydro in the Canon prospect, about 11 kilometres west of the Veslefrikk field in the North Sea. The purpose of the exploration well was to prove petroleum in a fault block between the Huldra and Oseberg fields. The well tested two reservoir levels – an upper one belonging to the Brent group and a deeper level in the Statfjord group. "The exploration well struck gas condensate in the Brent group but the reservoir was thinner than expected and the find is probably not commercial," says Tom Dreyer, StatoilHydro's vice president for infrastructure exploration in the North Sea. Deeper in the structure, the well struck sandstone belonging to the Statfjord group. Data gathered from this interval showed that the reservoir consisted of tight sand and was probably full of water. Drilled by the West Alpha semi-submersible, the well will now be permanently plugged and abandoned. The rig's charter with StatoilHydro will terminate once the well is completed. This is the second well to be tested in the Canon structure. An exploration well drilled in 2000 provided inconclusive results about the economic potential of the structure. The licensees in production licence 052 are: operator StatoilHydro (18%), Petoro (37.0%), RWE Dea Norge (13.5%), Revus Energy (4.5%) and Talisman Resources Norge (27.0%).

5 Feb 2009

Discovery at Fulla

StatoilHydro has made a gas and condensate discovery in North Sea license 035b on the Fulla prospect with well 30/11-7. Det norske oljeselskap ASA has an ownership stake of 15 percent in the license. The well is located about 40 kilometers north of the Heimdal Field. The well encountered gas and condensate in Middle Jurassic reservoir rocks of the lower Brent Group. Testing and extensive data sampling has been carried out. Proven volumes are estimated between one and three million standard cubic metres of oil equivalents (6 to 19 million boe). An appraisal well is being planned drilled in the spring to help decide the size of the discovery. It is positive that hydrocarbons have been proven in this area, Det norske Vice President for reserves and area development Odd Ragnar Heum noted. The well was drilled to a vertical depth of 4067 meters below the seabed and ended in rocks of Lower Jurassic age. Water depth in the area is 111 meters. The well, which was drilled on a cost sharing basis between license 035b and 362, is currently being temporarily plugged and abandoned. Det norske holds a 15 percent stake also in license 362.

14 Nov 2008

Well spudding on Fulla

Drilling operations at the Fulla Field started 12 November. The field is operated by StatoilHydro, and Det norske has a 15 percent interest in the license. Fulla is located in licenses 035 and 362, and the drilling operations are carried out by the semi-submersible rig West Alpha. The recoverable volumes are estimated at 63 MBOE (P50), while Det norske`s share is 11 MBOE. Oil, gas, and condensate are expected.The drilling operation is expected to last about 80 days. The water depth on Fulla is 114 meters. The nearest installation is Heimdal, located 36 kilometers away. The well, 30/11-7, has a reservoir of late Jurassic age in the Brent formation.

23 Oct 2008

Possible tie-back of Noatun to Njord

Recoverable reserves of the Noatun discovery have been estimated to be between five and eight million standard cubic metres of oil equivalent following the drilling of an appraisal well. A tie-back to the Njord field is being considered. In September gas and condensate were confirmed at Noatun, which lies 16 kilometres north of the Njord field in the Norwegian Sea. StatoilHydro is currently concluding the drilling of a sidetrack well from the original well. The purpose of the well was to confirm the size of a gas/condensate discovery in reservoir rocks of middle to lower Jurassic age. The data gathered in connection with the sidetrack drilling have confirmed recoverable volumes of between five and eight million standard cubic metres of oil equivalent according to a preliminary estimate. The well was drilled to a vertical depth of 5050 metres below sea level and was completed in the lower Jurassic Åre formation. ”The Noatun find proves that it is still possible to make considerable finds in established exploration models in this area, also at water depths of up to 5000 metres,” says Sivert Jørgenvåg, head of exploration activities close to existing fields on the Halten Bank. ”It is encouraging that we make discoveries which can prolong the lifetime of the Njord field.” The well was drilled by the semi-submersible West Alpha drilling rig, which is proceeding to the North Sea to drill the Fulla prospect.

12 Sep 2008

Sidetrack to be drilled at Noatun prospect

Drilling of an exploration well in the Noatun prospect 16 kilometres north of the Njord field in the Norwegian Sea has struck gas and condensate. A sidetrack is to be drilled in the well to assess whether the find is worth exploiting. The objective of exploration well 6407/7-8 was to prove gas/condensate in the middle/lower Jurassic reservoirs in the Noatun prospect. The well struck gas/condensates at the prospective Jurassic range, although the size of the find is as yet unconfirmed. The well has been formation tested using mini-DST, and extensive data and samples have been collected. A flank sidetrack will be drilled to confirm gas/water contact and the size of the find. "We are delighted to have found hydrocarbons which can contribute to the extended lifetime of the Njord field, but we need more information before we can say anything about the size of the find, and any possible extraction methods," says Sivert Jørgenvåg, exploration manager for the Halten Bank. This is the eighth exploration well drilled in production licence 107. The licence was awarded during the ninth concession round in 1985. The well was drilled to a vertical depth of 5,110 metres under the sea surface, and terminated at the Åre formation in the lower Jurassic level. Sea depth is 293 metres. The well will be permanently plugged and abandoned. The well was drilled by the semi-submersible drilling rig West Alpha, which will now continue operations in production licence 107 by drilling sidetrack 6407/7-8A. Licensees for production licence 107 are: StatoilHydro (20%), E.ON Ruhrgas (30%), ExxonMobil (20%), Gaz de France (20%), Petoro (7.5%) and Endeavour Energy (2.5%).

21 May 2008

Gas discovery in the Norwegian Sea

StatoilHydro has struck gas during exploration drilling in the Norwegian Sea north-west of Kristiansund and will drill a sidetrack well to further identify the area. StatoilHydro, the operator of production licence 348, now completes the drilling of exploration well 6407/8-4 S. The well is located 30 kilometres north-east of the Njord field and 9 kilometres north-west of the Draugen field. "The purpose of the well was to confirm the existence of hydrocarbons in mid/lower Jurassic rocks in the southern segment of the Galtvort prospect. It is very positive that we again strike hydrocarbons in these areas where finds can quickly be put on stream,” says StatoilHydro’s vice president for infrastructure-led exploration in the North, Ørjan Birkeland. The well has confirmed the existence of gas in Jurassic sandstone. The size of the discovery is so far not determined, and a sidetrack well will be drilled right after the current well has been completed. . This is the first exploration well in production licence 348, which was awarded in TFO 2004 (awards in pre-defined areas). No formation leak-off test has been conducted in the well, but extensive data acquisition and sampling have been performed in the reservoir. The exploration well was drilled to a vertical depth of 2632.3 metres below the sea surface and completed in rocks belonging to the lower Jurassic Åre formation. The well, located in 266 metres of water, will now be permanently plugged and abandoned. The well was drilled by the West Alpha drilling rig, which will now drill sidetrack well 6407/8-4 A on the Galtvort prospect. The licensees in production licence 348 are: StatoilHydro (30.0 percent), Gaz de France Norge (20.0), Norwegian Energy Company (17.5), E.ON Ruhrgas Norge (17.5), Endeavour Energy Norge (7.5) and Petoro (7.5).

14 Apr 2008

New discovery on the Halten Bank

StatoilHydro has made a gas discovery in the Natalia prospect in the Norwegian Sea. According to preliminary calculations the discovery could contain around 1.5 billion cubic metres of recoverable gas. Natalia is located five kilometres north-west of the Midgard structure on the Åsgard field on the Halten Bank and adds to the many finds in this area. Exploration activities in the area have so far this year given good results, such as the Natalia, Gamma and Marulk (partner-operated) finds. Positive results in Gamma and Natalia are also important contributions in evaluating the potential of equivalent structures in the area.

19 Sep 2006

Duster on Antares

Exploration well 6406/3-7 has been completed by operator Statoil on the Antares prospect in production licence 314 in the Norwegian Sea without encountering mobile hydrocarbons. The group now plans to drill three further exploration wells in this part of the Halten Bank area, which lies south of the Åsgard field. Drilled from the West Alpha semi-submersible in 275 metres of water, the 6406/3-7 well was intended to probe for oil and gas in Jurassic sands. “We’re naturally disappointed that the well turned out to be dry, but it was important for clarifying the potential of this area,” says Tim Dodson, Statoil’s senior vice president for exploration on the Norwegian continental shelf. Drilled to a total depth of 4,502 metres below sea level, the well terminated in early Jurassic sediments. It has now been permanently plugged and abandoned. Mr Dodson says that the three other interesting projects available in the area are due to be drilled this year and in 2007. “These operations will be carried out in quick succession, and will be important for clarifying the potential of the area,” he reports. Since Antares lies in a different geological area from the new wells, it has no significance for the probability of discoveries with them or the estimated resources they might contain. Statoil has a 45% interest in PL 314, with Hydro holding 35% and ExxonMobil 20%. West Alpha is now due to spud an exploration well in PL 255, operated by Shell.

15 Jun 2006

Finds on Valemon and Morvin

Gas and condensate have been proven by Statoil on Valemon near the Kvitebjørn field in the North Sea and oil has been proven on Morvin on the Halten Bank north of the Kristin field. The finds were made during drilling of appraisal wells 34/11-5S (Valemon) and 6506/11-8 (Morvin). "Developing fields near areas where we already play a leading role is essential to us," says Tim Dodson, senior vice president for the exploration cluster in the Exploration & Production Norway (UPN) business area. "Even if it is too early to determine the size of the reserves on Valemon and Morvin, these finds support the group's high ambitions for the Norwegian continental shelf." The appraisal well on Valemon was drilled from the Statoil-operated Kvitebjørn platform. With a total length of 7,380 metres this well is the longest high pressure/high temperature (HPHT) well ever drilled by the group. "This drilling operation has been highly cost-effective as the well is later to be converted to a production well for Kvitebjørn," says Astrid Sørensen, senior vice president for the Troll/Sleipner business cluster. "Field development studies of Valemon are currently being made, however, it is too early to say anything about any development of this gas/condensate find. We will look at alternatives involving a separate development and hook-up to another infrastructure," Ms Sørensen says. The appraisal well on Morvin was drilled from the West Alpha rig. "The oil find is interesting and confirms the large potential in the Halten Bank area. Morvin will most likely be developed as a satellite to the Kristin or the Åsgard field," Mr Dodson notes. The Kvitebjørn (production licence 193) licensees are Statoil with 43.55%, Petoro 30%, Hydro 15%, Enterprise Oil Norge 6.45% and Total with 5%. The Morvin licensees (production licence 134B) are Statoil with 50%, ENI 30%, Hydro 14% and total with 6%.

24 Mar 2006

Drilling on Morvin

The West Alpha rig has started drilling an appraisal well for operator Statoil in the Morvin structure in the Norwegian Sea. The drilling operation began on 24 March and is expected to take just over four months. Kjell Martin Edin, senior geologist in the Halten/Nordland area and project manager for well 6506/11-8, reports that Morvin is an oil discovery on the Halten Terrace. Morvin lies in production licence 134b, about 10 kilometres from the Statoil-operated Kristin field. Like Kristin, Morvin is challenging owing to high pressure and high temperature in the reservoir. In 2001, Statoil drilled an exploration well on Morvin and found light crude. The well where the find was made was drilled at the top of the structure. The purpose of the new well is to appraise the extent of the find and clarify whether the resources are sufficient to justify a development. "If oil is proven in the well, it is likely that Morvin will be a subsea development phased in to Kristin or Åsgard," says Mr Edin. The well is set to be drilled to a depth of about 4,800 metres below sea level. Water depth in the area is 380 metres. Statoil has a 50 per cent interest in production licence 134b. The other licensees are Eni (30), Hydro (14) and Total (6).

31 Aug 2005

Charters awarded for 10 rig-years

Three rigs owned by two drilling contractors have been chartered by Statoil on behalf of a partnership which also includes Eni Norge, Norsk Hydro and Norske Shell. Confirming earlier letters of intent, these contracts relate to Smedvig’s West Alpha unit and the Transocean Arctic and Polar Pioneer vessels owned by Transocean. The three-year charter for West Alpha starts in the first quarter of 2006, and this rig will primarily be used for exploration. It is currently drilling production wells on Statoil’s Kristin development in the Norwegian Sea. Transocean Arctic has been chartered for about four years from the second half of 2006, and will be used for exploration drilling by the partners. Currently doing field drilling for Statoil on Norne and the Norne satellites in the Norwegian Sea, it is also due to work on Statoil’s Tyrihans project in the same waters. The charter for Polar Pioneer, currently drilling production wells on Statoil’s Snøhvit field in the Barents Sea, will run for about three years from the second quarter of 2006. This rig will primarily be used for exploration work on the Norwegian continental shelf, including the Barents Sea. The collaboration between the four partners is forward-looking and a milestone for operator cooperation on the NCS, according to Arne Tillerli Statoil’s manager for the partnership. He notes that these waters are currently characterised by a tight rig market for exploration and production drilling as well as for well workovers. The partnership model also represents a crucial step towards achieving the industry’s chosen solution for broad operator cooperation. This approach is supported by the Norwegian government through the Kon-Kraft industrial collaboration. “Our rig cooperation will be highly significant for exploration on the NCS over the next two-three years,” says Tim Dodson, senior vice president for NCS exploration at Statoil. “It ensures that the four companies involved have the rig capacity they need for a large part of their drilling programmes.”

28 Aug 2001

Find in Gudrun well

Statoil has proven hydrocarbons in an exploration and appraisal well in the Gudrun structure in the Sleipner area of the North Sea. Well 15/3-7 was drilled in the eastern section of the structure. Hydrocarbons were encountered in Middle and Upper Jurassic sandstone intervals. The well was not production tested, but core samples were retrieved and extensive information was collected. “The results of the drilling will now be evaluated in terms of the potential reserves in Gudrun and in the rest of block 15/3,” reports Kjersti Seim, acting exploration manager for the area. Gudrun was found through two exploration wells drilled in 1975 and 1979, when oil, gas and condensate were proven. The reservoir turned out to be complicated with high pressure and high temperature, and the reserves were not sufficiently quantified. Well 15/3-7 has been a cooperation project between the licensees in production licences 025 and 187. BP is operator in 187 and Statoil in 025. Statoil has also been operator for the drilling. The licensees in licence 025 are Statoil with 46.8 per cent, BP (25 per cent), TotalFinaElf (18.2 per cent) and Norsk Hydro (10 per cent). The allocation in licence 187 is BP (25 per cent), Statoil (65 per cent) and Norsk Hydro (10 per cent).

10 May 2001

Drilling on Gudrun

The West Alpha drilling rig has started drilling an exploration and appraisal well on the Gudrun field in the North Sea. “The purpose is to prove sufficient amounts of oil, gas and condensate to develop the Gudrun find,” says Lars Jan Jaarvik, exploration manager for the Troll/Sleipner area. The find has been localised in block 15/3, about 45 kilometres north of the Sleipner East field. Gudrun was found through two exploration wells drilled in 1975 and 1979, when oil, gas and condensate were proven. The reservoir turned out to be complicated with high pressure and high temperature, and the reserves were not sufficiently quantified. Well 15/3-7 is a project in cooperation between the licensees in production licences 025 and 187. Statoil is the operator in PL 025, and is also operator for the drilling. BP has joined as a new partner in PL 025 and it is also the operator in PL 187. The well is to be drilled to a total depth of 4,800 metres. Middle and Upper Jurassic sandstone intervals will be assessed. The operations are planned to be completed at the beginning of August. Statoil has a 46.8 per cent share in PL 025, BP has 25 per cent, TotalFinaElf has 18.2 per cent and Norsk Hydro has 10 per cent.

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