Petroleo Brasileiro SA expects by early November to deploy its Petrobras XXIV floating production unit (FPU) in about 900 ft of water in Albacora field off Brazil.
The FPU was scheduled to depart Galveston, Tex., this month, following completion of modifications and upgrades under a turnkey contract with Chiles Offshore International Inc.
Chiles began modifying Petrobras XXIV about 1 year ago as part of a deal closed in October 1991 in which Chiles Offshore Corp. sold the vessel, then known as Intrepid, to Brasoil, the international subsidiary of Petrobras. To work in Albacora, Chiles removed all drilling systems and equipment and installed:
- A 60,000 b/d processing plant, hot oil treaters, chemical injection systems, and other units to handle Albacora's high paraffin crude.
- A computer based supervisory, control, and data acquisition system for the processing plant.
- Two 50% turbocompressors to power a 35 MMcfd gas export system.
- Gas injection capacity of 5 MMcfd for gas lift operations.
Petrobras XXIV was outfitted to handle a total of 24 flexible risers at three locations. The unit's mooring system also was modified to use single riser wire instead of spring buoys.
The vessel's transformation to pure FPU did not include installation of a water treating system. Petrobras decided not to include a water handling system because it is yet to produce a significant volume of water from Albacora wells. Other than a 500 bbl surge tank, Petrobras XXIV has no onboard oil storage capacity.
REUSABLE PRODUCTION SYSTEM
The FPU's deployment to Albacora will mark its third assignment as a mobile production unit and its second production assignment off Brazil.
The vessel was built at Marathon Le Tourneau's Brownsville, Tex., shipyard and in 1975 was christened Penrod 72, a semisubmersible drilling rig. One of its early assignments was to serve as a temporary production facility off Brazil.
The first major modification of Penrod 72 occurred in 1986, when Placid Oil Co. chose it as the centerpiece of its Gulf of Mexico development in 1,530 ft of water on Green Canyon Block 29. In 1987, it became the first semisubmersible FPU to produce oil in the gulf.
For that project, Placid added a mooring system capable of coping with hurricane conditions, a 20,000 b/d oil processing system on the aft main deck, and a top drive drilling system.
Placid abandoned the Green Canyon Block 29 field after 2 years of operations with the unit. In October 1990, Chiles bought seven Penrod mobile offshore rigs, including Penrod 72, and renamed the unit Intrepid.
Petrobras has been producing wells in Albacora field for about 7 years. Current Alabcora flow is about 35,000 b/d of oil and 20 MMcfd of gas.
Petrobras XXIV will replace a drillship that is ending a temporary production assignment for other duty. Petrobras XXIV is expected to stay on location in 908 ft of water for 3 years until Phase II Albacora development begins in 1995.
Copyright 1992 Oil & Gas Journal. All Rights Reserved.
