Bonga

Bonga Oil and Gas Field Profile

Location and Geology

• The Bonga Oil and Gas Field is located in the Niger Delta, approximately 120 km offshore, in a water depth of around 1,000 to 1,125 meters.
• It is situated in Oil Mining Lease (OML) 118, specifically in block OPL 212.
• The field covers an area of approximately 60 km².
• The geology of the area involves Tertiary-age sediments, including the Akata Formation (source rocks), Agbada Formation (reservoirs), and Benin Formation (overlying alluvial sands).

Discovery and Development

• The Bonga field was discovered in 1993, with the first exploratory well drilled between September 1995 and January 1996.
• Appraisal wells were drilled in 1997 and 1998, confirming significant hydrocarbon reserves.
• The field is operated by Shell Nigeria Exploration and Production Company (SNEPCo) under a production sharing contract with the Nigerian National Petroleum Corporation (NNPC) and partners including Total, Eni (previously Agip), and Exxon-Mobil (previously Esso).

Production

• Production from the Bonga field began in November 2005, with the first oil shipment made in February 2006.
• The field has produced over 819 million barrels of oil by the end of 2018.
• The Bonga FPSO is capable of processing up to 225,000 barrels of oil per day and 150 million standard cubic feet of gas per day.

Infrastructure

• FPSO Vessel:
  • The Bonga FPSO was constructed by Samsung Heavy Industries in Korea and outfitted with topsides by AMEC at their Wallsend facility in the UK.
  • The FPSO measures 305.1 meters long, 58 meters wide, and has a design draft of 23.4 meters. It has a storage capacity of 2 million barrels of crude oil and can store 10,970 m³ of diesel oil and 138,131 m³ of water ballast.
  • The vessel is connected to 16 subsea oil production and water injection wells using Steel Catenary Risers (SCRs).

Subsea and Pipeline Infrastructure

• The field includes 16 subsea oil-producing and water injection wells tied back to the FPSO.
• Additional infrastructure includes 92 km of 16-inch diameter gas-export pipeline, 25 km of 12-inch diameter water-injection flowlines, and other subsea facilities installed by contractors such as Subsea 7, Saipem, and Seaway Polaris.

Expansion and Phases

• Bonga North-West:
  • Located in water depths ranging from 900 to 1,200 meters, this extension was developed with 12 subsea wells tied back to the Bonga main infrastructure. First oil from this project was produced in August 2014.
• Bonga Phase 3:
  • This phase is an expansion of the Bonga Main development, with peak production expected to be around 50,000 barrels of oil equivalent per day. Production from this phase started in 2015.

Contractors and Suppliers

• Key contractors involved in the project include:
  • Samsung Heavy Industries (FPSO hull construction)
  • AMEC (FPSO engineering, procurement, construction)
  • Saipem (subsea flowlines and production facilities)
  • Subsea 7 (subsea flowlines and Steel Catenary Risers)
  • Aker Solutions (umbilicals)
  • ABB (subsea equipment and gas-lift risers)
  • Stolt Offshore (subsea construction)
  • Seaway Polaris and Seaway Kestrel (pipeline installation)
  • Nakakita Siesa Kusho (cargo and ballast control system)
  • Wartsila (propulsion systems)
  • Invsat (satellite communication systems).

Economic and Social Impact

• The Bonga project has been significant for Nigeria, contributing to nearly one-third of the country's deep-water oil production.
• It has created jobs, training, and business opportunities for local people, helping to develop the first generation of Nigerian oil and gas engineers with deep-water experience.

Environmental and Operational Notes

• The field underwent its fourth turnaround maintenance (TAM) in 2017.
• There was a temporary shutdown in 2011 due to a leak, highlighting the importance of maintenance and safety measures.
• The project has incorporated various safety systems, including fire detection and extinguishing systems supplied by NK Fire Protection.

The Bonga Oil and Gas Field is a landmark project in Nigeria's deep-water oil and gas sector, showcasing advanced technology and significant economic impact.