Project Profile
Location: Garden Banks (GB) block 260, 120 miles off the Louisiana coast, USA
Production: 50,000b/d and 150,000MMSCFD
Reserves: 104 million barrels of oil equivalent (MMBOE)
Water Depth: 1,650ft
Baldpate is located in 1,650ft of water, in Garden Banks (GB) block 260, 120 miles off the Louisiana coast. This is the first free-standing offshore compliant tower ever, as well as one of the tallest free-standing structures in the world. The tip of the flare boom extends 1,902ft above the seafloor. The discovery well was drilled by the semisubmersible Ocean Rover in late 1991, revealing 180ft of net pay. Total output from seven planned production wells exceeds 50,000b/d and 150,000MMSCFD. Anticipated recoverable reserves from Baldpate and Baldpate North total 104 million barrels of oil equivalent (MMBOE), of which 60% is oil and the remainder is gas. Production from the platform reached its peak in the first half of 1999, at rates approaching facility oil and gas capacities. Due to the high pressures associated with the main Baldpate reservoirs, surface producing and shut-in pressures are well above 10,000psi, necessitating 15,000psi working-pressure wellhead equipment. Amerada Hess has a 50% interest in the field and ORYX Energy Company the remaining 50%.
PIPELINE
The 12in gas line is comprised of 13.2 miles of 0.5in and 0.625in-wall API Grade-B pipe, provided by Sumitomo, coated with fusion bond epoxy (FBE). The GB 260 end of the gasline is attached to the tower with a steel catenary riser (SCR). The 16in oil pipeline is comprised of 17 miles of 0.625in and 0.75in-wall API Grade B pipe, both FBE coated and protected with anodes. There is a 16in SCR at GB 260 for the oil line, much like that for the gasline, which is neoprene coated and outfitted with strakes. The other end the oil line ties into Mobil’s SMI 205 A platform.
Operators:
Amerada Hess: Operator with 50% interest
ORYX Energy Company: 50% interest
Contractors:
Diamond Offshore: Drilling contract
McDermott Engineering: Engineering and design of Baldpate-compliant tower structure and jacket-base section
Aker Gulf Marine: Construction of the jacket-tower section
Sumitomo: Pipes
Wood Group PSN (WGPSN): Operations & maintenance services