Pyrenees is an extensive project, involving 13 subsea wells, an extensive subsea gathering system and a Floating Production Storage and Offloading (FPSO) facility.
The project's total capacity is said to be approximately 96,000 barrels of oil, with a gas reinjection capacity of 60 million cubic feet of gas per day.
According to BHP Billiton, oil wells will be drilled as planned and brought on in phases, with approximately half the field ramping up from first oil and the other half over the coming six months.
BHP Billiton Petroleum chief executive J. Michael Yeager said the Pyrenees project has been a technically challenging development that will make a significant contribution to the company's worldwide operations and production volumes.
He said he is very pleased with the rapid pace of the project's production schedule.
"Given the complexity of the project, the early start-up of Pyrenees is an outstanding achievement," he said.
July 2007 saw BHP Billiton first enter into joint venture with major U.S. oil and gas company Apache Corporation to sanction the WA-42-L portion of the Pyrenees development at a cost of approximately US$1.7 billion. First production was planned during the first half of calendar year 2010.
Located approximately 45 kilometres off the coast of Exmouth in Western Australia, the Pyrenees oil and gas project has an estimated production life of 25 years.
The operation is also around 20 kilometres east from BHP Billiton's existing Stybarrow offshore oil project, which Yeager said will be helpful to the new operation.
"Learnings from the Stybarrow development have been incorporated into the Pyrenees development contributing to the excellent performance," he said.
The Pyrenees project is made up of the development of the Crosby, Ravensworth and Stickle oil fields, all of which the company discovered in 2003 at water depths ranging from 169 metres (555 feet) to 250 metres (820 feet.)
BHP Billiton said the fields are developed with very long horizontal wells drilled from the sea floor and then tied back to the Pyrenees FPSO via an extensive gathering system. Water injection is incorporated to enhance oil recovery.
As operator of the project, BHP Billiton has a 71.4% stake in the WA-42-L production area, valued at around US$1.2 billion, while joint venture partner Apache Corporation holds the remaining 28.6% stake.
