Mafumeira Sul Project, Angola
Mafumeira Sul Project is the second-phase development of the Mafumeira Field located in Block 0, approximately 24km (15 miles) offshore Cabinda province, Angola, at a water depth of 60m.
The first phase involved the development of the field's northern section (Mafumeira Norte), which started production in July 2009 and currently produces at a rate of 40,000 barrels of oil a day.
The Mafumeira Sul project involves the development of the southern section of the Mafumeira field with an investment of $5.6bn. The front-end engineering design (FEED) studies for the project started in January 2010, and the final investment decision (FID) was made in February 2013.
First production from Mafumeira Sul was achieved in October 2016 and daily peak production from the project is estimated to reach 110,000 barrels of crude oil and 10,000 barrels of liquefied petroleum gas (LPG).
Chevron's subsidiary Cabinda Gulf Oil Company (CABGOC) is the operator with a 39.2% interest. Other partners in the project include Sonangol (41%), Total (10%) and ENI (9.8%).
Mafumeira Sul development details
The development of Mafumeira Sul primarily involves the installation of new platforms, drilling of 34 production wells and 16 water-injection wells, installation of umbilical, riser and flowline (URF) facilities, and 121km (75 miles) of subsea pipelines.
The platforms at the field comprise the central production complex (CPC) featuring three bridge-connected platforms, two 3,200t each wellhead platforms (WHPs), namely Mafumeira Centro and Mafumeira Sul, a 148-man living quarters platform (LQP), and a flare tower. The CPC started the oil and gas production in March 2017.
The project also involved making modifications to the existing Mafumeira Norte wellhead platform. The facilities are designed to accommodate production from undeveloped fields in the Southern Malongo area in the near future.
Oil and gas export facilities
The oil produced from the field is exported to the existing Malongo Oil Terminal, while the LPG is conveyed to the Sanha LPG floating production, storage and offloading (FPSO) vessel, which has a storage capacity of 135,000m³. Associated natural gas is conveyed to the onshore Angola Liquefied Natural Gas (ALNG) plant located at Soyo.
Contractors involved with the Angolan offshore field
The pre-FEED and majority of the FEED activities for the project were performed by Amec. Cronus Technology performed the FEED for the submarine pipelines and subsea tie-in spools.
Saipem has been awarded three engineering, procurement, construction and installation (EPCI) contracts for the project. The first contract is for the URF, the second contract is for the modifications on the existing Mafumeira Norte platform and tie-ins on the new platforms, while the third contract is for the onshore section of the 18in-diameter pipeline connecting the field to the Malongo Terminal.
The project involves the development of the Cabaça North and Cabaca South-East discoveries located approximately 350km north-east of Luanda.
The two WHPs were fabricated by a consortium of Daewoo Shipbuilding & Marine Engineering (DSME) and Paenal. The former, along with Wood Group, is also responsible for the fabrication of the CPC platform, whereas the EPC contract for the LQP has been awarded to McDermott.
A deck module for the CPC was supplied by Taekyung Heavy Industries. The cathodic protection works for the CPC were performed by Samgong.
The workshop and laboratory building, storage and work control building, and operation storage building for the CPC were designed by EDG Consulting Engineers.
Dimension-All Manpower (DAMI) performed the hook-up, commissioning and carryover works for the two WHPs.
Primary air, instrument air, nitrogen generator and nitrogen booster packages for one of the platforms were supplied by Generon IGS. Autronica Fire and Security provided its proprietary AutroSafe fire protection system for the production platform.
A wide range of valves, including floating ball, trunnion-mounted ball, metal-seated ball, cryogenic service ball, and gate / globe / check valves, were supplied by SWI Valve. Dual grout seals, mud diaphragms and pile centralisers were provided by Crux Products.
The shipments of the pipe components were performed by Base, a member of Project Cargo Network (PCN). Trenching of a pipeline was undertaken by Geocean using a marine autonomous excavator (MAX) system.
Integrated telecommunications systems for the project were provided by Harris CapRock. Other contractors involved in the project include Hyundae Fitting (HDFCO), Cameron Solutions, Posco Plantec, and Sail Inspection & Engineering (SIECO).