Library Alwyn Brochure


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North Alwyn NAA and NAB Platforms

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Library Alwyn Brochure

  1. 1. A LW Y N / D U N B A R Alwyn Area
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  3. 3. 3 The Company TOTAL E&P UK PLC is one of the largest oil and gas operators in the North Sea. It is a subsidiary of the TOTAL Group, an international energy company, which is headquartered in Paris and has operations in 130 countries. The Group’s operations cover the entire oil and gas chain – oil and gas exploration and production, trading and shipping, refining and marketing, as well as chemicals. It employs more than 110,000 people worldwide. The UK upstream subsidiary, TOTAL E&P UK, which has its headquarters in Europe’s oil capital, Aberdeen, is one of the largest operators in the UK sector of the North Sea in terms of production and reserves. The company employs some 600 people. As an international business, TOTAL E&P UK adds value through a mix of both local and expatriate staff. TOTAL E&P UK owns and operates the Alwyn North, Dunbar, Ellon, Grant, Nuggets and Otter Fields in the Northern North Sea. In addition, it is operator of the Elgin and Franklin Fields in the Central Graben Area. The company has a number of non-operated interests in the Central and Northern North Sea including Bruce, ETAP Alba, Armada and Nelson and , has an interest in the Sullom Voe Oil Terminal in Shetland. Onshore, TOTAL E&P UK operates the St Fergus Gas Terminal on the northeast coast of Scotland, which receives and processes up to 15 per cent of the UK's natural gas requirements from some 20 fields in the UK and Norway. It owns 100 per cent of the terminal’s UK facilities and 50 per cent of its Common Facilities including those on the MCP-01 platform; the remainder of the plant is owned by the Norwegian association, Gassled. The company (and/or its affiliate) has a 100 per cent interest in the UK Frigg pipeline. It also has an interest in the SEAL (Shearwater Elgin Area Line) pipeline through E.F Oil and Gas Limited (EFOG), owned 77.5 per cent by . Elf Exploration UK PLC and 22.5 per cent by Gaz de France; EFOG has a 25.73 per cent share in SEAL. The TOTAL Group has a 10 per cent shareholding in Interconnector (UK) Limited, the company which owns and operates the Gas Interconnector between Bacton and Zeebrugge.
  4. 4. 4 Safety, Health and Environment TOTAL E&P UK conducts all its activities taking into account the safety of people and property, the preservation of natural resources and the protection of the environment. Our objective is an accident-free workplace and ‘Think Safety First’ is the watchword for all our operations, both onshore and offshore. We set measurable safety, health and environmental objectives and continually strive to improve our performance, taking steps to make certain all employees and contractors are equipped to do so. We develop, maintain and test emergency plans and help raise industry standards by consulting and working with partners, suppliers, competitors, regulators and the public. We endeavour to create a positive culture for the advancement of safety, health and environmental issues by encouraging a spirit of openness and co-operation. Our performance is reviewed and audited. Those who contribute to improvement are recognised and it is an important element of performance evaluation for all employees, particularly those with management responsibilities. In 2002 TOTAL E&P UK was awarded company-wide registration to ISO 14001, the international Environmental Management System standard. This is recognised throughout the world as a mark of ‘good business practice’ and as a genuine commitment to sustainable development. TOTAL is proud of this achievement, and through the maintenance of its management system, aims to continue to improve its environmental performance.
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  6. 6. 6 Alwyn Area The Alwyn Area lies in the UK sector of the North Sea 160 kilometres east of the Shetland Islands and 440 kilometres north-east of Aberdeen. It comprises five fields – Alwyn North, Dunbar, Ellon, Grant and Nuggets. Collectively the fields produce some 150,000 barrels of oil equivalent a day. Alwyn North is the hub of the Alwyn Area and the support centre for the neighbouring fields. It supplies them with power and water while simultaneously receiving water and gas via a network of subsea cables and pipelines. The Alwyn Area typifies how, through innovation and technological developments, North Sea oil and gas fields can be extended far beyond original estimates. Technological developments are making it viable to develop small, previously uneconomic accumulations, often discovered decades ago, through the infrastructure of long-established fields. The fields developed around Alwyn North have made maximum use of the existing infrastructure – the Alwyn North platform, the Frigg Transportation System and the St Fergus Gas Terminal.
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  8. 8. 8 The History Exploration licences for the Alwyn Area were granted in 1965 and drilling started in 1971. Within a year the Dunbar, Ellon and Grant fields had been discovered but at that time they were not economic prospects. Four years later the Alwyn North Field was discovered. Its complex geological structure meant that extensive and expensive evaluation was required. Five separate compartments were found – Statfjord containing gas with condensate, and Brent North, Brent North West, Brent East and Brent South West with oil. In 1980 technological advances made a three-dimensional seismic survey possible and provided the additional information to allow the completion, in 1982, of a £1,500 million plan to develop Alwyn North including the Brent and Statfjord reservoirs. Production started in 1987. The most southerly reservoir, Brent South West, was developed independently as a subsea satellite – the Alwyn North Extension – and was brought onstream in 1992. A year later the Alwyn North Triassic reservoir was discovered beneath the original discoveries. Around £700 million was then spent on developing the Dunbar Field to make maximum use of the Alwyn North platforms, the Frigg Transportation System and the St Fergus Gas Terminal to which gas is exported. Dunbar came onstream in 1994 and in turn made its satellite fields, Ellon and Grant economically viable. They started production in 1995 and 1998 respectively. In 1999 improvements to the gas plant on Alwyn North were completed. This increased processing capacity on the platform and enabled the development of the nearby Nuggets Fields. N20 N37 3/9a-2 N10 3/9a-5 N22 N33 3/10b-1 P&A P&A P&A P&A West East 3000 3000 Upper Cretaceous . B.C.U . OWC OWC y Fm Tarbert . Cla Kimm eather H Ness t Ta rber Dunlin 3500 Dunlin 3500 s Nes GWC Statfjord Upper Cretaceous Dunlin Shetland Group Statfjord 4000 4000 Triassic GDT Lower Cretaceous Depth (metres) Cromer Knoll Group Triassic 4500 4500 Kimm. Clay Fm. 5000 Heather 5000 BRENT NORTH WEST PANEL BRENT EAST PANEL STATFJORD PANEL 5500 OWC Oil Water Contact 5500 GDT Gas Down To 0 Kms 10 TRIASSIC MAIN PANEL GWC Gas Water Contact Dunlin
  9. 9. 9 Alwyn North Alwyn North consists of two platforms linked by a 73-metre bridge, which sits 31 metres above the water. The platforms stand in 126 metres of water. North Alwyn A (NAA) is the drilling and accommodation platform. North Alwyn B (NAB) houses the processing facilities. Separating the drilling and treatment facilities offered numerous advantages with safety the most important consideration. However it also allowed NAA, with its four-legged steel jacket, to be installed and to begin drilling operations in 1986. This was a full year before NAB, which has an eight-legged steel jacket, was ready. The bridge is the passage for the crew to walk between the two installations and the link between the drilling and well facilities on NAA and the process facilities on NAB. Untreated oil and gas cross the bridge from NAA to be processed ready for export by pipeline. It also carries the links for the systems that are common to both platforms – electrical power, fire and gas control, emergency shut-down system, process control and telecommunications. Alwyn North was innovative in that two platforms were built for greater safety. A further key safety feature on NAA is a thick blast wall protecting the high pressure module from the accommodation area. There are seven 58-man lifeboats on NAA and four 58-man lifeboats on NAB, more than enough to cope with the maximum number onboard. The platform has been designed to withstand winds of more than 160 kilometres an hour and 30 metre waves, the kind of conditions it may occasionally have to face in the hostile North Sea.
  10. 10. 10 1 Life Offshore Alwyn TOTAL E&P UK makes every effort to ensure that those who live and work on the Alwyn North platform are as safe and comfortable as possible during their stay. There are 108 cabins on NAA, each with two or three beds. Each cabin has its own toilet and shower facilities and a TV with satellite channels. All the accommodation is contained within a safe refuge area, which has been designed to withstand every sort of emergency to allow the crew time to reach the lifeboats and safety. The platform has a 70-seat cinema, a gymnasium, an open recreation area and a quiet room. In addition to the communication systems that allow operational staff to contact the team onshore, there are public telephones for the crew to keep in touch with their families. Mail and newspapers are sent on days when there are helicopter flights. Other supplies and equipment are normally dispatched by boat from Aberdeen, a journey that takes around a day. The restaurant, with a plentiful supply of good food, is a lively and sociable centre of life onboard the platform
  11. 11. 11 Dunbar/Ellon/Grant The Dunbar Field is situated around 22 kilometres south of Alwyn North. It was discovered in 1973 and came onstream in 1994 as production from Alwyn North reached its plateau. The field produces around 70,000 barrels of oil equivalent per day. The Dunbar platform sits in 145 metres of water. It has a four-legged jacket 167 metres high and safety was the primary concern when it was designed. Its two 45-man freefall lifeboats are located in the protected environment of a safe refuge area, which also contains the control room. They are as far as possible from the platform’s hazardous areas and are protected by blast walls. The platform is manned by a core crew of 21 although a new accommodation module, installed in 2002, provides bed space for up to 60 persons. The development of Dunbar made the Ellon and Grant satellite fields, discovered in 1973 and 1977 respectively, viable. These subsea developments, located around nine kilometres from Dunbar are linked to the Dunbar platform by flowlines and control umbilicals. Ellon was started up in 1994 and Grant four years later. When at plateau production the fields produce around 17,000 barrels of oil equivalent per day.
  12. 12. 12 Dunbar Innovation Keeping costs to the minimum safe level has been crucial in the development of Dunbar and innovative ways have had to be found to maintain production. Two multiphase pumps are examples of such innovation. Housed in a 650-tonne module on Dunbar and installed at a cost of £54.5 million, they are the biggest pumps of their kind in the world. As the field matures and the well pressure drops, increasing quantities of water have to be pumped into the well to maintain pressure. The pumps boost production for Dunbar, and its two satellites Ellon and Grant, by keeping the pressure of the oil, water and gas consistent without the need for the three being separated for treatment. Each pump can accommodate around 40,000 barrels of liquid and 1.5 to 3.5 million cubic metres of gas per day. The oil and gas from the two subsea satellites Ellon and Grant arrive at Dunbar through six-inch flowlines with all operations at the subsea wellheads controlled through two umbilicals. The gas from Dunbar, Ellon and Grant goes to Alwyn North for processing before joining the Frigg Transportation System and being sent onto the St Fergus Gas Terminal near Peterhead. Oil is exported to the Sullom Voe Oil Terminal in Shetland.
  13. 13. 13 The Nuggets Cluster The Nuggets Field lies around 20 kilometres south of Dunbar and Dunbar Alwyn North was discovered between 1972 and 1991. It is a development of four gas-bearing accumulations – N1 with two wells and N2, N3 and N4 Ellon with one well each. The five wells produce around 36,600 barrels of oil equivalent per day. Grant The five isolated subsea wells that make up the Nuggets cluster are Nuggets N1 Nuggets N1 tied back via subsea pipelines to the Alwyn North platform, but NGB controlled via the Dunbar platform. From Alwyn North, Nuggets’ gas NGA Nuggets N1 Manifold is exported via the Frigg line to the St Fergus Gas Terminal for processing and distribution. Nuggets N2 Nuggets N3 Manifold Nuggets N3 N1, N2 and N3 began production in November 2001. N4, which is NGC tied back via a 13-kilometre subsea pipeline to the N3 manifold, NGD came onstream in October 2003. At a total length of 67 km, the Nuggets N4 tieback is the longest in the UK sector of the North Sea. Nuggets N4 NGE The Otter Field Eider Cormorant North Tern The Otter Field lies 150 kilometres north east of Shetland, in a ble o t ca e t an er lin or water depth of 182 metres making it one of the most northerly and yp ow tion orm c th C 2 wa u odNor Pr deepest subsea tiebacks in the North Sea. First oil flowed in jection from Tern Water In October 2002; the plateau production rate is around 30,000 barrels of oil per day. Pipeline 20'' EOR Magnus The development, which is tied back to Shell’s Eider platform, Um 10 Inj rodu bi '' P SP Po 10 ion ec lic comprises five subsea wells – three oil producers and two water '' W Pip 3E t al ate cti injectors. Oil is exported to the Sullom Voe Oil Terminal in Shetland r ne on eli wer Pip via the Brent system while gas is exported to the St Fergus Gas eli Cab ne Terminal via the FLAGS pipeline system. Otter les Template Manifold (4 well) Otter is a prime example of how technical innovation and commercial effectiveness within the oil and gas industry can unlock the stranded reserves of the UK Continental Shelf (UKCS). The development of Otter not only adds new reserves but also extends Water Injection Well (EOR – Enhanced Oil Recovery) the life of field of Eider.
  14. 14. 14 60° 50’N Total 3/9c ALWYN NORTH Total 3/10c 60° 40’N Total DUNBAR ELLON Total GRANT 29/6a Total 30/4a Total FORVIE HILD Total NORTH Total 29/9a 7 7b 30/7 Total 30/7a N1 Total Total Total NUGGETS 60° 20’N N2 Total N3 LEGEND Total Operated Block Oil Field Gas Field Total Total Condensate Field 30/10a Oil Pipeline Gas Pipeline 0 Kms 5 N4 01° 36’E 02° 00’E
  15. 15. 15 The Future An exploration well spudded in February 2002 led to a new discovery in the Alwyn Area – Forvie North in Block 3/15, 440 kilometres north-east of Aberdeen. The gas and condensate find lies 16 kilometres from the Dunbar platform and 33 kilometres from the Alwyn North platform. This discovery strengthens the company’s activities in the Northern North Sea and endorses TOTAL’s strategy to apply selective criteria to exploration prospects in the mature UKCS. Studies are underway to develop Forvie North, which in tests showed the well to flow at a rate of one million cubic metres of gas and 1,400 barrels of condensate per day. TOTAL E&P UK continues to prolong the life of field and maximise ultimate recovery of oil and gas reserves in the Alwyn Area by investing in new technology. For example, the multiphase pumps on Dunbar, miscible gas injection and infill drilling on Alwyn North, and the development of the cluster of Nuggets Fields. Such initiatives are helping to extend the life of the Alwyn Area far beyond original estimates. In addition, TOTAL E&P UK’s discovery of Forvie North in 2002 assures further development of the Alwyn Area and maximum use of the existing infrastructure. Ownership Interests ALWYN AREA TOTAL E&P UK PLC 100% OTTER TOTAL E&P UK PLC (operator) 54.296% Dana Petroleum (E & P) Ltd 19.004% Esso Exploration and Production UK Limited 13.350% Shell UK Ltd 13.350% FORVIE NORTH TOTAL E&P UK PLC 100%
  16. 16. TOTAL E&P UK PLC Crawpeel Road, Altens, Aberdeen AB12 3FG Tel: +44 (0) 1224 297000 Fax: +44 (0) 1224 298999 Photography by Borowski Photography Ltd Design by Mearns & Gill, Aberdeen Copyright © TOTAL E&P UK PLC 2004. All rights reserved, no part of this publication may be reproduced, stored in a retrieval system or transmitted in any form by any means, electronic, mechanical, photocopying, recording or otherwise without the permission of the copyright holder. Printed on Revive Silk paper, a recyclable, bio-degradable and NAPM approved recycled grade.