Big Foot (WR029) - Chevron

Big Foot (WR029) - Chevron Oil and Gas Asset Profile

Location

The Big Foot oil field is located in the Walker Ridge Block 29, approximately 225 miles (360 km) south of New Orleans, Louisiana, in the deep waters of the Gulf of Mexico. It operates at a water depth of around 5,200 feet (1,584 meters).

Discovery and Appraisal

• The Big Foot field was discovered by Chevron in January 2006 through the Big Foot No. 2 well, drilled by the Cajun Express semi-submersible rig to a depth of 1,524 meters. The well encountered more than 91 meters of net oil pay.
• Further appraisal was conducted through three additional wells, including Big Foot No. 2 Sidetrack No. 3 and Big Foot No. 3 Sidetrack No. 2, drilled in 2007 and 2008, respectively. These wells helped define the structure of the field reservoir.

Ownership and Operator

• Chevron is the operator of the Big Foot field, holding a 60% working interest.
• The other development partners include Equinor (formerly Statoil) with a 27.5% stake and Marubeni Oil and Gas with a 12.5% stake.

Development and Facilities

• The field development involves an extended tension-leg platform (ETLP) with dry trees and top-tensioned risers. This platform is considered the world’s deepest of its kind, operating at a depth of 1,615 meters.
• The ETLP features a full-capacity onboard drilling rig for development well drilling and future interventions. The platform includes oil and gas processing systems, such as gas compression, oil and water treatment, and export and utility systems. It also has living quarters for on-board personnel.
• The hull of the ETLP was fabricated in South Korea (or Singapore, according to some sources), while the topsides were fabricated in Aransas Pass, Texas. Integration and onshore commissioning were carried out at Kiewit’s yard in Ingleside, Texas.

Production Capacity

• The production facilities are designed for a capacity of 75,000 barrels of crude oil and 25 million cubic feet of natural gas per day.

Pipeline and Transportation

• The oil produced from the Big Foot field is transported through a 64 km-long, 20-inch diameter pipeline built by Enbridge. This pipeline is part of the Walker Ridge Gas Gathering System project and has the capacity to transport up to 100,000 barrels of crude oil per day to an onshore gathering system in Louisiana.

Investment and Timeline

• The project was sanctioned by Chevron in December 2010, with construction works commencing in 2011. The initial estimated cost was $4 billion, but it exceeded $5.1 billion due to delays, including a technical failure in tethering the platform to the seabed in June 2015.
• The Big Foot field began producing oil in November 2018.

Reserves and Production Life

• The Big Foot field is estimated to contain total recoverable resources in excess of 200 million oil-equivalent barrels.
• The field is expected to have a production life of approximately 35 years.

Contractors and Suppliers

• Several contractors were involved in the project, including INTEC Engineering for subsea systems, Foster Wheeler for the detailed design of the oil pipeline, Wood Group for ETLP commissioning, and Mietec for electrical and instrumentation hook-up and commissioning services. Baker Hughes supplied the electrical submersible pumping (ESP) systems, and Nabros provided the deepwater drilling rigs.

Technical Specifications

• The ETLP has push-up type tensioner systems to withstand harsh conditions and is designed to survive a 1,000-year hurricane.
• The platform supports 15 drilling slots and includes water injection capability. The production wells are equipped with electrical submersible pumps.