Usan

Usan Oil Field Profile

Location and Geology

• The Usan Oil Field is located approximately 100 kilometers off the coast of the Niger Delta in Nigeria, specifically in licence block OML 138 (also referred to as OPL 222).
• The field is situated in water depths ranging from 750 to 850 meters.

Discovery and Development

• The Usan field was discovered in 2002. Subsequent appraisal wells, including Usan-2, Usan-3, Usan-4, Usan-5, and Usan-6, further defined the field's extent and potential.
• In 2005, the eastern extension of the Usan field was confirmed by wells Usan-7 and Usan-8.
• Development approval was granted by the Nigerian Government in February 2008.

Operator and Partners

• The field is operated by Total E&P Nigeria Limited, a wholly-owned subsidiary of TotalEnergies.
• The partners in the project include:
  • TotalEnergies: 20% interest
  • Chevron Petroleum Nigeria Ltd.: 30% interest
  • Esso Exploration and Production Nigeria (Offshore East) Ltd.: 30% interest
  • China National Petroleum Corporation (CNPC), which acquired a 20% interest from Total in 2012.

Production and Reserves

• The field began production in February 2012.
• The estimated proven and probable reserves of the Usan field are in excess of 500 million barrels of oil.
• As of 2022, the remaining recoverable reserves were estimated at 184.9 million barrels of crude oil and condensate.

Production Capacity and Infrastructure

• The development involves 23 subsea production wells and 19 water and gas injection wells connected to a Floating Production, Storage, and Offloading (FPSO) vessel.
• The FPSO, built by Hyundai Heavy Industries (HHI), measures 320 meters in length, 61 meters in width, and weighs approximately 116,000 metric tons. It has a storage capacity of 2 million barrels of oil and a maximum daily production capacity of 180,000 barrels of crude oil.
• The FPSO also processes 5 million cubic meters per day (176.6 million cubic feet per day) of gas, which is primarily re-injected into the reservoir to minimize gas flaring.

Contractors and Subcontractors

• Hyundai Heavy Industries (HHI): Constructed the FPSO on a turnkey basis, including engineering, procurement, and construction.
• Saipem: Responsible for the engineering, procurement, construction, installation, pre-commissioning, and assistance to commissioning and start-up of the subsea umbilicals, flowlines, risers, and the oil loading terminal. They also handled part of the FPSO anchoring system.
• Acergy: Fabricated, assembled, and tested subsea structures including manifolds, suction piles, and well jumpers at their Globestar Yard in Warri, Nigeria.
• Nexans: Supplied umbilicals and associated equipment, as well as power, control, instrumentation, and telecommunications cables for the FPSO.
• Cameron: Provided subsea systems, including subsea Xmas trees, production and intervention control systems, manifolds, and flowline connection systems.

Local Content and Environmental Impact

• The project involved a significant level of local content, with over 500,000 engineering man-hours and 14 million construction and installation man-hours performed in Nigeria. The FPSO construction included the offshore integration of 3,500 tons of locally fabricated structures.
• Total introduced technological innovations to reduce gas flaring, minimizing the project’s environmental impact. Large-scale training and capacity-building programs were also implemented to enhance the skills of the local workforce.

Historical Milestones

• 2002: Usan Oil field discovered.
• 2005: Western extension discovered.
• 2008: Development approval given for the Usan Project; Acergy awarded fabrication contract for subsea structures; HHI began building the FPSO.
• 2009: West Capella drilling rig positioned at the field.
• 2010: FPSO launched in November.
• 2011: FPSO arrived at the field in July.
• 2012: First oil produced in February; Total announces sale of 20% stake to Sinopec.