OTC: Petrobras emphasizes safety in FPSO design, operation in gulf

May 13, 2013
Safety was a priority for engineers planning the first floating production, storage, and offloading vessel installed in the Gulf of Mexico, Petrobras America Inc. executives told a May 6 technical session of the Offshore Technology Conference in Houston.

Safety was a priority for engineers planning the first floating production, storage, and offloading vessel installed in the Gulf of Mexico, Petrobras America Inc. executives told a May 6 technical session of the Offshore Technology Conference in Houston.

The BW Pioneer FPSO, owned by BW Offshore, has a capacity to process 80,000 b/d of oil and 17.6 MMcfd of gas (OGJ Online, Mar. 17, 2011).

The FPSO was installed for production from Cascade-Chinook fields on Walker Ridge Block 249 about 165 miles off Louisiana. The project is in about 8,200 ft of water. Shuttle tankers take oil from the FPSO to shore using a deepwater offloading concept that Petrobras developed for the gulf.

In 2006, Petrobras held an innovative design competition for any type of vessel that could offload from the FPSO while complying with Petrobras safety requirements. The shuttle tanks comply with the Jones Act and the Oil Pollution Act requirements and are US Coast Guard approved double-hulled vessels.

USCG also approved an offloading manual for gulf operations. The primary offloading operation involves the transfer of crude oil by a reel-mounted floating hose on the FPSO to a dedicated shuttle tanker.

In April 2010, Petrobras conducted an offloading workshop to ensure crew competence on the procedure by everyone involved. One of the Petrobras shuttle tankers was subleased to BP PLC to assist in the deepwater Macondo blowout incident. BP used that shuttle tanker for 3 months.

Cesar Palagi, Petrobras America's manager for the Cascade-Chinook project, said the BW Pioneer FPSO uses a mooring design that ensures the FPSO can be moved if the need arises.

"If there is a hurricane, for example, the FPSO can be disconnected," Palagi said. A detachable anchoring system enables the FPSO to go into sheltered waters during hurricanes and tropical storms.

The US Bureau of Ocean Energy Management, Regulation, and Enforcement approved Petrobras America's application to use an FPSO (OGJ Online, Mar. 17, 2011).

Palagi said the first Cascade-Chinook offloading operations were done on June 8, 2012. As of Dec. 31, 2012, eight tandem offloading operations had been executed, and the frequency of offloading operations will continuously increase as production ramps up.

"The proactive steps taken by Petrobras, very early in the project, have produced positive results," Petrobras executives wrote in an OTC technical paper. "Continued safe and efficient offloading operations…has raised confidence" in the use of offloading procedures, they said.

During OTC, Petrobras executives made a series of technical presentations on Cascade and Chinook subsea development, the FPSO, and the shuttle tankers.

Petrobras owns 100% of Cascade field, which started production in February 2012, and 66.67% of Chinook field, which started production in September 2012. Total E&P USA Inc. holds 33.33% of Chinook.