As Operator of Angola Block 15, Esso has completed several projects since November 2003, with production capacity totaling 590,000 barrels of oil per day. This paper will provide an overview of the projects from their development planning stages through start-up. Both the Kizomba A and B projects incorporate a surface wellhead, tension-leg platform that is close-moored to a floating production, storage, and offloading vessel (FPSO) in more than 1,100 m of water. Each project also includes offloading facilities and subsea wells and equipment. The FPSOs set records for size, each with processing facilities for 250,000 barrels per day throughput and more than 2.2 million barrels of storage. The Xikomba project, which incorporated an FPSO converted from a trading tanker, will also be described. The paper will address project management aspects of the various projects and highlight some of the unique aspects and challenges of these developments.
In August 1994 Esso Exploration Angola (Block 15), Ltd. (Esso) and its Coventurers acquired the rights to explore offshore Angola Block 15. Block 15 encompasses an area of 4,200 km2 in water depths ranging from 200 m in the east to over 1,600 m in the west. The Angolan national oil company, Sonangol, is the concessionaire of the block, which is approximately 370 km northwest of Luanda, Angola and 145 km west of Soyo, a coastal town at the mouth of the Congo River.
Under a Production Sharing Agreement with Sonangol, Esso is the operator of Block 15 and holds a 40% interest. The other Block 15 Coventurers are BP with a 26.7% interest, ENI with a 20% interest, and Statoil with a 13.3% interest.
The Kizomba developments, which comprise several reservoirs, are named for a popular Angolan dance. Each of the Block 15 reservoirs has been named for Angolan musical instruments.
The initial exploration well on Block 15, Kissanje #1, was drilled in early 1998 to test three objectives in Middle and Lower Miocene age reservoirs. Results from this well confirmed oil in each of the objectives. In parallel to Kissanje #1, a second rig was employed to drill the Marimba #1 wildcat. This well, located 13 km west of Kissanje, also yielded a successful Miocene test. By the third quarter of 1998, two additional successful exploration wells had been drilled in the Hungo and Dikanza reservoirs, and in 1999 discoveries were made in the Chocalho and Xikomba reservoirs.