Project Profile
Value: US$500 million
Location: Viosca Knoll, block 786, 130 miles (208km) south-east of New Orleans
Reserves: 80-100 million barrels of oil
Water depth: 535m
Start-up Year: 1995
The Petronius oil field and platform is located in Viosca Knoll, block 786, approximately 130 miles (208km) south-east of New Orleans. It lies in water depths of 535m. The field was discovered in 1995 and contains estimated recoverable reserves of 80-100 million barrels of oil equivalent. Petronius has been developed by a compliant tower - the largest free-standing structure in the world. The cost of the project has been put at US$500 million. Texaco (the operator) owns 50% of the field and the remaining 50% is owned by Marathon. The field is being depleted by 17 wells including ten producing wells and seven water-injection wells. The estimated peak injection is 72,000 barrels of water per day. The design specified a height of 1,870ft and a weight (including two tower sections, a foundation template, piles and conductors) of 43,000t. The tower accommodates 21 well slots. The jacket supports topsides of 7,500t. This houses the necessary process equipment for a production capacity of 60,000 barrels of oil per day and 100 million ft³ of gas per day.
CONTRACTS:
The US$140 million contract for construction of the compliant tower was awarded to J Ray McDermott. McDermott also handled the installation of the entire structure, while the McDermott Engineering performed engineering design work. Gulf Island Fabrication, based in Houma, won a US$50 million deck fabrication and integration contract, while WH Linder & Associates won the US$10 million contract for engineering design work of the topsides and the procurement support. The topsides are 210ftx140ftx60ft-tall and contain all processing equipment, water-injection facilities, export pipeline pumps and miscellaneous utilities for the platform operation. The topsides also support a full drilling-rig spread.
Operators:
Texaco: Operator with 50% interest
Marathon: 50% interest
Contractors:
J Ray McDermott: Contract for construction of the compliant tower and installation of the entire structure
McDermott Engineering: Engineering design work
Gulf Island Fabrication: Deck fabrication and integration contract
WH Linder & Associates: Contract for engineering design work of the topsides and the procurement support.
Saipem: Installation contractor