Deepwater: The Gulf of Mexico’s deepest offshore oil and gas rigs4 July 2012 Elisabeth Fischer
The US Government’s offshore leasing plan 2012-2017 will once again open up the deepest areas of the Gulf of Mexico. In the run-up to the first sale of leases, Offshore-technology.com profiles some of the region’s biggest and most promising deepwater drilling projects.
On Thursday, 28 June 2012 the Obama Administration finalised a proposed offshore oil and gas leasing programme for 2012-2017 that focuses on areas with the highest-known resource potential, and aims to reduce US dependence on foreign oil. The main focus of the plan, besides opening up areas in the Alaska Arctic, is on allowing development in already-explored deepwater areas of the Gulf of Mexico.
Infographic showing some of the deepest oil and gas drilling operations in the Gulf of Mexico.
At the first sale of leases set to take place in autumn 2012, several deepwater areas in the western Gulf of Mexico will be up for grabs, only a little over two years after the disastrous Deepwater Horizon oil spill. As major oil and gas companies prepare for a competitive bidding process, Offshore-technology.com rounds up some of the deepest drilling projects in operation or underway today.
BP's Atlantis - the deepest moored floating oil and gas production facility
The Atlantis platform is the deepest moored floating dual oil and gas production facility in the world.
One of BP's technically most challenging projects ever and the deepest moored floating dual oil and gas production facility in the world is the Atlantis platform in the Gulf of Mexico. Located 306km (190ml) south of New Orleans, the field is 2,150m (7,100ft) deep. Atlantis produced its first oil in October 2007 and reached full commission and a ramp up in production in mid-December of the same year. The plateau, which weighs 58,700t, achieved full production by the end of 2008. It has a production capacity of 200,000 barrels of oil and 180 million cubic feet of gas a day, with an estimated life of 15 years.
BHP Billiton's Shenzi oil and gas field
Shenzi oil and gas field lies in the Gulf of Mexico in Green Canyon blocks 609, 610, 653, and 654.
Located about 193km (120ml) off the coast of Louisiana, US, BHP Billiton's deepwater Shenzi oil and gas field is about 1,311m (4,300ft) deep. It is estimated that it holds recoverable reserves of 350-400 million barrels of oil, even though additional potential reserves will be targeted of a follow-up development. Cost for the full field development until 2015, which includes 15 wells, have been put at $4.4bn. Its main operator is BHP Billiton, who owns a 44% stake in the field, while Repsol and Hess hold a share 28% each.
Chevron's Jack / St Malo deepwater project
The Jack / St Malo deepwater fields are estimated at over 500m oil-equivalent barrels.
The Jack / St Malo deepwater project is a joint development of the Jack and St Malo oilfields, which are 40km located from each other in the Walker Ridge blocks. The Jack field lies in the Blocks 758 and 759 at a water depth of 2133.6m (7,000ft), while the St Malo field is located Block 678 at a water depth of 640m (2,100ft). The project was approved by the partners Chevron, Statoil, Maersk, Petrobas, ExxonMobil and ENI in October 2010, with an investment of $7.5bn in the initial development phase. Production start-up is expected in 2014 and Chevron, who owns the majority interest in both fields, will also be the sole operator.
Anadarko Petroleum's Lucius deepwater oil and gas project
Lucius will produce oil and gas through a truss spar floating production facility.
Located in the Keathley Canyon block, the Lucius deepwater field contains high-quality crude oil and associated gas. Field development is estimated to cost about $2bn and the first oil is expected in 2014. Anadarko Petroleum operates the field with a 35% working interest with co-owners including Plains Exploration & Production, ExxonMobil, Apache Deepwater, Petrobas and ENI Petroleum. The field is located at 2,164m (7,100ft) and is expected to produce 80,000 barrels of oil and 450 million cubic feet of gas a day.
Anadarko's Nansen and Boomvang oil and gas fields
The Nansen and Boomvang fields lie in the East Breaks area of the Gulf of Mexico.
Positioned in the East Breaks area about 241km (150ml) south of Houston, the Nansen and Boomvang fields are 1,121m (3,678ft) and 1,054m (3,453ft) deep, respectively. Anadarko operates the Boomvang field with a 30% working interest and the Nansen field with a 50% working interest. The other partners in Boomvang are Shell (50%) and Ocean Energy (20%), who also holds the remaining 50% interest in the Nansen field.
Both fields have been developed by the world's first truss spars, which replaced the lower cylindrical hull in order to reduce weight and cost as well as to lessen movement. Air chambers in the upper hull provide buoyancy for the floating structures.
ConocoPhillips' Magnolia oil field
The Magnolia field in Garden Banks blocks 783 and 784 in the Gulf of Mexico.
The Magnolia field began production in 2004 with initial development completed in 2006, as part of a five-year $400m deepwater drilling programme. Located 289km (180ml) south of Cameron, Louisiana in the Garden Banks blocks of the Gulf of Mexico, the field reports an average production of five million barrels of crude oil, ten million cubic feet of natural gas and one million barrels of natural gas liquids per day. ConocoPhillips is the operator and holds a 75% working interest, with Devon Energy (former Ocean Energy) owning the rest. It is the deepest extended tension leg platform at 1,432m (4,698ft). The discovery well was drilled to a depth of 5,141m (16,868ft).
Shell Deepwater Production's Mars oil and gas field
The Mars tension leg platform on location in Mississippi Canyon block 807.
Discovered in April 1989, Shell Deepwater Production's Mars field is one of the oldest deepwater developments in the Gulf of Mexico. Located about 209km (130ml) south-east of New Orleans in the Mississippi Canyon block, the discovery well was drilled using the drillship Discoverer Seven Seas. Production started in July 1996 and the initial development was designed to recover about 500 million barrels of oil with the cost of the first project phase coming to $1bn. Shell Deepwater Production is the field's operator and has a 71.5% interest, while the remaining 28.5% interest is held by BP.