Darius V. Snieckus
OGJ Online
LONDON, May 21 -- Texaco Inc. plans to begin appraisal drilling later this year to evaluate gas reserves on three of Angola's most prospective offshore blocks that are expected to drive its liquefied natural gas joint venture with state oil company Sonangol.
Bill Hauhe, Texaco's project manager, said Monday the early estimates of gas volumes to be exploited from deepwater Blocks 15, 17, and 18, along with non-associated gas concessions on shallow water Blocks 1, 2, and 3, are 9.5-25 tcf. He spoke at the Angola Oil & Gas Summit in London.
Texaco and Sonangol are selecting appraisal well locations to tap nonassociated gas in Block 2 as a backup to associated gas production, he said, in time with jointly evaluating bids for drilling rig and services contracts for the project.
UK consultant Gaffney Cline & Associates is reassessing reserves on Blocks 2 and 17, while establishing new certification for reserves on Blocks 15 and 18.
Production of the Angola LNG project will involve a fixed offshore gas gathering hub -- based around four 4, 6, or 8-legged structures -- which will tie-in pipelines from fields in waters of up to 1,500 m and connect back to the onshore LNG terminal via a 260 km trunkline.
Plans are for a 400-tonne/day onshore LNG plant near Luanda with one train, to be followed "immediately or as dictated by market demand" by a second, he said.
Last week, Texaco named the four industry consortia that would be bidding for the integrated onshore/offshore front-end engineering and design (FEED) contracts (OGJ Online, May 15, 2001). The FEED contracts will be awarded on July 1, said Hauhe.
Shipping of the first LNG cargo is scheduled for mid-2005, subject to government approval next year.
Hauhe emphasized that Texaco and Sonangol would set specifications for the hub development, but leave the choice of LNG technology to the contractor.
Because of safety concerns raised by the onshore storage of LNG and, more centrally, LPG, Hauhe said the JV has opted to use a concrete gravity-based storage and offloading system. He said the "dock in the box" system would use a 300 m long structure containing both LNG and LPG tanks located 200-300 m offshore.
Carriers would dock along either side of the storage structure, which could hold 200,000 cu m of LNG, 80,000 cu m of propane, and 35,000 cu m of butane for offloading. The JV plans to order as many as five carriers, at $170 million each, for the development on either a charter or project-owned basis.
Hauhe said new partners, "large, multinational operators with experience in Angola or expertise in LNG," are being added to the venture through participation agreements.
