Sociedade Nacional de Combust’veis de Angola (Sonangol E.P.), BP Angola (Block 18) BV, and Sonangol Sinopec International Limited (SSI) started production at the Greater Plutonio development area in Block 18, offshore Angola, on October 1. Greater Plutonio consists of five distinct fields discovered in 1999-2001 in water depths of up to 1,450 meters and is the first BP-operated asset in Angola.
The Greater Plutonio offshore development area is located 160 kilometres northwest of Luanda and is comprised of the Galio, Cromio, Paladio, Plutonio and Cobalto fields in water depths varying from 1200 to 1450 metres. It will contain 43 wells: 20 producers, 20 water injectors, and 3 gas injectors. The development utilizes a floating, production, storage and offloading vessel (FPSO) to process produced fluids and export crude. The FPSO is connected to the wells by a large subsea system.
The FPSO is 310 metres in length and has an oil storage capacity of 1.77 million barrels, oil processing of up to 240,000 barrels of oil per day, produced and treated water injection rate of 450,000 barrels per day, and gas handling of up to 400 million standard cubic feet per day. It is held in position by 12 mooring lines connected to anchor piles on the seabed.
The heart of the Greater Plutonio subsea system is the longest single riser tower system of its kind in the world, according to BP. At some 1,258 m, it connects the FPSO to a network of subsea flowline and control systems that include 150 km of flowlines, 9 manifolds and 110 km of instrument and control umbilicals. Many components of the subsea systems, including the riser tower, were constructed and assembled in Angola, including six of the subsea manifolds along with the worlds largest CALM (Catenary Anchor Leg Mooring) offloading buoy and the first ever Angolan assembled and tested subsea trees.
Many Angolan technicians and engineers have been trained to operate and support the Greater Plutonio development area in an ongoing five-year development program, according to BP.
Several elements of the project were manufactured in Angola, namely the riser tower and six manifolds, including support structure, tees, flowline termination assemblies, installation and mooring piles and the CALM offloading buoy (SBM) all manufactured at the Sonamet yard in Lobito. Algoa (FMC) manufactured 45 permanent guide bases in Luanda and FMC are now assembling most of the subsea trees from “superkits” manufactured abroad. Some of the umbilicals were manufactured by Angoflex in Lobito and the water injection lines were laid by Technip using the new spoolbase in Dande, Bengo province.
BP has a 50 percent interest in Block 18, which was acquired by Amoco in 1996, prior to its merger with BP. The other 50 percent is held by Sonangol Sinopec International (SSI). The block has an area of approximately 5,000 sq km, and water depths vary from 500 metres to 1,500 metres.
The five fields – Galio, Cromio, Paladio, Plutonio and Cobalto – were all discovered between 1999 and 2001.
Greater Plutonio is a low sulphur, medium gravity crude oil.
BP”s involvement with Angola goes back to the mid 1970s. During the 1990s, BP made very substantial investments in Angola”s offshore oil and it is now an important part of the company”s upstream portfolio. BP has interests in four blocks with operated interests in two.
Operatorship of Block 18 was transferred to BP Angola (Block 18) BV in May 1999.
BP has non-operated interests in Block 15, operated by Esso (Block 15) Limited (BP 26.67 percent equity) and in Block 17 operated by Total (BP 16.67 percent equity).
BP also has a 13.6 percent interest in the Angola LNG project.