The Holstein field is located 200 miles (322 kilometers) south of New Orleans, La. in 4,300 feet of water (1,311 meters) on Green Canyon Block 645. BP operates this oil and gas development with a 50% working interest; Shell owns the remaining 50%.

Discovered and appraised in 1999 and sanctioned in 2001, Holstein's reservoir is located completely above a salt level. The field consists of stacked sheet sands varying in thickness from 15 to 150 feet (5 to 46 meters) separated by shale layers of similar thickness.

The Ocean America semisubmersible drilled the Holstein discovery. A 3-D seismic program and a 4-D seismic baseline survey enhanced the recovery of available reserves, which helped the field to be developed in 42 months. Field development included production and water injection wells, a truss spar, two risers and two pipelines.

Field Development

The field is developed through 12 production wells and three water injection wells. An industry first, Holstein's high angle, open-hole gravel pack completions for production and injection wells; novel multi-zone well completions; and dynamic formation testing and surveillance improved the production and recovery of the Holstein field.

The Holstein development consists of a truss spar equipped for production and drilling operations, as well as two steel catenary risers for oil and gas export. At the time of construction, the Holstein truss spar was the largest of its kind in the world.

The truss is 430 feet (131 meters) long and weighs 6,600 tons (5,987 tonnes); the spar is 745 feet (227 meters) long and 145 feet (44 meters) in diameter. The truss spar has wells for production and water injection, and a drilling rig capable of reaching 25,000 feet (7,620 meters). Technip fabricated the Holstein spar.

The 148-foot-diameter (45-meter-diameter) hull of the truss spar is the first to be built in South Korea by Samsung, under subcontract to CSO Aker Maritime. The spar is also the first to be supported by a vertical riser system, the first to use feathered heave plates and access shafts, and the first to use the largest suction anchors ever constructed.

The 29,762-ton (27,000-tonne) topsides for the truss spar consist of four levels to accommodate production, compressors, generators and living quarters. J. Ray McDermott fabricated the topsides in three major components: the north module, which houses the drilling and processing facilities; the south module, which houses the quarters and utilities; and the frame, which supports the structure. The entire structure is moored by 16 chain, wire and suction-pile anchors.

Heerema Marine Contractors was chosen to install facilities, associated pipelines and gathering lines. Installation of these facilities commenced in 2002 and was completed in 2003.

Baker Energy was contracted to develop operating procedures, and implement a computerized maintenance management system for the truss spar.

Production and Pipelines

Production began Dec. 9, 2004 and the facility is expected to reach peak production of 100,000 bopd and 90 MMcf/d (2.5 MMcm/d).

FMC Energy Systems signed a three-year strategic sourcing agreement with BP to transfer oil or gas from the Holstein wells to the Cameron Highway pipeline. This pipeline has a contract with Shell to transport 50% of Holstein's production.

Cameron is a 390-mile (2-kilometer), 24-inch to 30-inch pipeline with the capacity to deliver up to 500,000 bopd from the Holstein field to refining markets along the Texas Gulf Coast. Enterprise and Valero Energy Corporation jointly own Cameron Highway pipeline.

Another oil pipeline, Caesar, moves oil from Holstein to Ship Shoal Block 332. The 120-mile (193-kilometer) pipeline is 28-inches in diameter and has a capacity of 450,000 barrels per day. Caesar is the first of its kind to be installed in water depths of 5,000 feet (1,524 meters) in the Gulf of Mexico. It is owned by Caesar Oil Pipeline Company, LLC, and its affiliates are BP (56%), BHP Billiton (25%), Equilon Pipeline Company LLC (15%) and Unocal (4%).

Holstein's natural gas production, roughly 100 million cubic feet per day, is transported to Ship Shoal 332A, where it connects with Manta Ray Gathering System and then to the 101-mile (163-kilometer), 30-inch Nautilus Gas Transportation System. Enterprise, Marathon Oil and Enbridge Inc. jointly own these pipelines. The gas is processed at Enterprise's Neptune natural gas processing plant.