Kizomba Deepwater Project, Angola

Kizomba lies in Block 15, marking one of the first tranches of deepwater acreage offered by the Angolan Government. The development consortium is operated by ExxonMobil's subsidiary, Esso Exploration Angola, which has a 40% stake in the field.

The partners also include Agip Angola (with a 20% share), BP Exploration (with a 26.67% share) and Statoil (with a 13.33% share). Sonangol, the Angolan State oil company, is the concessionaire.

Discovery

Over 2,500km² of high-quality 3D seismic data was acquired by the joint-venture partners. This was followed during 1997-99 by the first wildcat drilling programme to take place in 1,000m to 1,400m of water, which resulted in six discoveries. Four of the discoveries announced in 1998 (Hungo, Chocalho, Kissanje and Dikanza) make up the giant Kizomba field complex.

The reservoirs are middle to lower-Miocene in age. They consist of turbiditie debris flows deposited along the upper / mid slope. The structural trap configuration is controlled by early-Aptian salt movement as well as lateral channel seals. The wells penetrated multiple high-quality reservoirs, giving an oil column exceeding 1,000m.

Kizomba has recoverable reserves approaching two billion oil-equivalent barrels.

Other nearby fields are also planned to be tied into the Kizombo infrastructure. In 1999, two more fields, Chocalho and Xicomba, were discovered or reappraised.

In July 2000, Esso Exploration Angola discovered another oil field named Mondo, 370km west of Luanda. The discovery well drilled in 740m of water and encountered an oil-bearing interval which flowed at a test rate of 4,200bpd. The well was drilled in 2,400ft of water, down to a total depth of 8,200ft.

Kizomba A deepwater development

In 2001, the company started construction on the Kizomba A deepwater development. Kizomba A is expected to recover approximately one billion barrels of oil from the Hungo and Chocalho fields at a target production rate of 250,000bpd. The project first began producing oil in August 2005 at a rate of more than 130,000bpd.

The field is operated by a combination of an ABB-designed 58,000t dry tree TLP and subsea completions tied back to an FPSO. The dry tree unit is based on ABB's ETLP design.

The FPSO was built at a cost of over $800m by Hyundai Heavy Industries, and the target production will require a $3.2bn investment.

In June 2002 Esso began construction of the Xikomba deepwater development, also on block 15. Xikomba is expected to recover approximately 100 million barrels of oil with a target production rate of 80,000bpd. First oil from Xikomba was produced in late 2003, making it the first oil production on Esso-operated block 15.

By the end of 2008, Kizomba A had 29 production wells and one development well.

Kizomba B – Kissanje and Dikanza

In early 2003 Esso started construction of the $3bn Kizomba B project which is also expected to recover nearly one billion barrels of oil, also at a target production rate of 250,000bpd. First oil for Kizomba B was reached in July 2005.

Kizomba B has developed the Kissanje and Dikanza discoveries in water depths of 3,300ft to 3,400ft. The project will include the combination of a surface wellhead platform and subsea wells tied back to an FPSO vessel.

The design for Kizomba B essentially duplicates Kizomba A, thus reducing costs and cycle time.

ExxonMobil earmarked $750m for the FPSO unit which has a storage capacity of 2.2 million barrels of oil. The unit measures 285m by 63m and stands 32m tall with a weight of 81,000t and accommodation for 100 personnel.

By the end of 2008, Kizomba B had 22 production wells.

Kizomba C – Mondo, Saxi and Batuque

The third phase, Kizomba C, is designed to develop 600 million barrels of oil from the Mondo, Saxi and Batuque fields in approximately 2,400ft of water. Located 145km off the coast of Angola, the Mondo field start producing oil in January 2008, while the other two fields, Saxi and Batuque, started production in August 2008.

Saxi and Batuque started production in August 2008, and between them are expected to contribute another 100,000 bpd.

The Kizomba C development features two FPSO vessels and 36 subsea wells making it the largest subsea development operated by ExxonMobil affiliates worldwide.

According to ExxonMobil, nearly $1.5bn has been spent on local goods and services for Kizomba C including contracts for in-country fabrication, logistics support, training, and development of Angolan personnel. It says Angolan suppliers played an instrumental role in the implementation of the project by providing subsea manifolds, helidecks, laydown modules, umbilicals, anchor piles and specialised turret components that were successfully fabricated in Angola. The fabrication of the turret components was the first of its kind in Angola.

Contractors

The contract for the design, procurement logistics and providing the support services for Kizomba project was awarded to AMEC on 3 September 2009. The company will execute the project in conjunction with Paragon Angola, AMEC's joint venture with Prodiaman in Luanda.

To provide subsea production equipment for Kizomba fields, Esso Exploration Angola selected GE Oil & Gas on 8 September 2009. According to the terms of the contract, GE will provide a range of topside and subsea equipment including subsea trees, deepwater tree connectors, jumpers, manifolds, controls equipment; umbilical termination assemblies, subsea distribution units and flying leads. The equipment will be installed at the FPSOs of Kizomba A and B fields. A large proportion of the equipment will be produced and assembled in the Angola manufacturing and service facility of GE.