The North Sea's Piper oil field resumed production Feb. 3, almost 5 years after its original platform was damaged beyond repair in an explosion and fire that killed 167 men.
Elf Enterprise Caledonia Ltd.'s Piper Bravo platform lies about 1 mile from where the original Piper Alpha platform stood on U.K. Block 15/17. Piper Alpha operator and majority interest owner at the time of the accident was Occidental Petroleum (Caledonia) Ltd.
Elf Enterprise's new platform is regarded as an example for offshore safety, based on lessons learned from the July 6, 1988, Piper Alpha blast.
All oil and gas pipelines to and from Piper Bravo are fitted with emergency shutdown valves on the seabed and platform deck.
Crew members can evacuate from their living quarters to the sea without exposure to the atmosphere. Freefall lifeboats are the main means of escape. There are two routes of escape from every point on the platform.
A major feature of the design, arising from the recommendations of Lord Cullen's 1990 report on an inquiry into the Piper Alpha disaster, is the separation of production and accomodation modules.
Piper Bravo's redevelopment is part of a El.5 billion ($2.3 billion) program to develop three fields: Piper, Saltire, and Chanter. Partners are operator Elf Enterprise 36.5%, Texaco Britain Ltd. 23.5%, Lasmo plc 20%, and Union Texas Petroleum Ltd. 20%.
Elf Enterprise was formed in 1991 to acquire for $1.35 billion in cash the North Sea assets of Occidental Petroleum Corp., parent of Occidental Petroleum (Caledonia). Elf Enterprise is owned two thirds by Ste. Nationale Elf Aquitaine, Paris, and one third by Enterprise Oil plc, London.
Piper field lies in 475 ft of water, 120 miles northeast of Aberdeen. Remaining reserves are 172 million bbl of oil and 14 bcf of gas. The oil is 37 gravity, containing 1 wt % sulfur.
Original reserves were 1 billion bbl of oil and 120 bcf of gas. Production start-up occurred in December 1976.
Average production rates from Piper Bravo are expected to be 75,000 b/d of oil and 34 MMcfd of gas. Peak production from Piper Alpha was 274,000 b/d of oil in 1979, while gas flow reached 34 MMcfd in 1985.
The new platform weighs 55,000 metric tons, of which 22,700 metric tons is the jacket, while the deck and modules weigh 25,300 metric tons. The platform has 24 slots, through which eight wells were predrilled.
Oil moves 21 miles through a 30 in. pipeline to join the Flotta pipeline 2/2 miles north of the Claymore platform on Block 14/19. Gas travels almost 1 mile through a 16 in. pipeline to join the existing route to Claymore for transport to St. Fergus, Scotland, terminal.
Copyright 1993 Oil & Gas Journal. All Rights Reserved.
