Belmont Offshore - Thums Long Beach

Belmont Offshore Field

Location and Discovery

The Belmont Offshore Field is located approximately 1.6 miles off the shore of Seal Beach, California.

Development

• The field was discovered in 1948, but oil production did not begin until 1954.
• To facilitate drilling and production, a man-made island was built in 40 feet of water in 1953.

Significance

• The Belmont Offshore Field is notable as the first strictly offshore oil field in California.
• The construction of this man-made island marked an early example of offshore oil production in the state.

Current Status

• The first artificial offshore island built for the Belmont Offshore Field was removed in 1999, indicating that the field is no longer in active production.

THUMS Long Beach Oil Project

Location and Structure

• The THUMS Long Beach oil project is part of the larger Wilmington Oil Field, which extends from onshore San Pedro to offshore Seal Beach.
• The project involves four artificial islands located in Long Beach Harbor, approximately 1.25 miles offshore from Long Beach.

History and Development

• The islands were built in 1964 following a U.S. Supreme Court ruling that allowed offshore drilling along the California coast.
• The construction involved massive engineering efforts, using 640,000 tons of boulders mined from Catalina Island and 3.2 million cubic yards of sand dredged from the area.

Operators and Contractors

• The THUMS Islands are operated by California Resources Corporation (CRC), with THUMS Long Beach Company acting as the agent. THUMS is an acronym for the original field contractors: Texaco (now Chevron), Humble (now ExxonMobil), Union Oil (now Chevron), Mobil (now ExxonMobil), and Shell Oil Company.

Production and Operations

• The four islands (named Grissom, White, Chaffee, and Freeman after astronauts) house over 1,000 active wells.
• These wells produce approximately 46,000 barrels of oil and 9 million cubic feet of natural gas per day.
• Production methods include primary production, secondary water flooding, and steam flooding to maintain reservoir pressure and prevent subsidence.

Environmental and Aesthetic Considerations

• The islands were designed to be aesthetically pleasing, with landscaping and architectural features such as palm trees, curved walls, towers, and waterfalls. This was done to hide the oil derricks and make the islands blend in with the surrounding environment.
• The design was led by the architecture firm Linesch and Reynolds, which had previously worked on projects at Disneyland. Sculptor Herbert J. Goldman and horticulturalist Morgan “Bill” Evans also contributed to the landscaping.

Future Plans and Decommissioning

• Long Beach plans to end all oil production and abandon the oil fields by 2035, ahead of the state's plan to end petroleum production by 2045.
• The decommissioning process is expected to be costly, with estimates ranging from $768 million to $1.07 billion, depending on whether the THUMS Islands are left intact or removed. The State Lands Commission retains significant liability for the decommissioning costs.

Economic and Environmental Impact

• The oil production from the THUMS Islands has been significant, but it has also raised environmental concerns and issues related to subsidence. The city has had to continue pumping water into the reservoir to maintain pressure and prevent further subsidence.

In summary, the Belmont Offshore Field and the THUMS Long Beach oil project represent key milestones in California's offshore oil and gas history, with the THUMS project being a notable example of both engineering and aesthetic innovation in oil production.