Okwori

Okwori Oil and Gas Field Profile

Location and Geology

• The Okwori Oil and Gas Field is located offshore in Nigeria, specifically within the Oil Prospecting Licence (OPL) 90 area.
• The field is situated in medium water depth of approximately 440 feet (140 meters).

Operator and Ownership

• The field is operated by Antan Producing Limited, although the ownership is held by the Nigerian National Petroleum Corporation (NNPC) with a 100% stake.

Discovery and Development

• The exact discovery year is not specified, but significant developments were undertaken in the late 1990s and early 2000s. Ashland Oil Inc. drilled the Okwori South-1 well in 1994, which flowed 6,184 barrels per day from the Agbada formation sands.
• The development of the Okwori field was notable for its use of advanced subsea technologies, including horizontal subsea trees, flexible subsea flowlines, and risers, to develop a small and geologically complex offshore field.

Production

• Production at the Okwori field began in 2005.
• The field has produced various quantities of oil and gas over the years:
  • In 2015, the field produced 5.45 million barrels of oil per year and 240.18 million cubic meters of gas per year.
  • In 2020, oil production was 1.43 million barrels per year, and in 2021 and 2022, it was 1.29 million barrels per year and 1.32 million barrels per year, respectively.

Infrastructure

• The production facilities include a leased spread-moored Floating Production Storage and Offloading (FPSO) vessel named Sendje Berge. This FPSO had a production capacity of up to 50,000 barrels of oil per day and a gas handling capacity of 55 million cubic feet per day, along with an oil storage capacity of 2 million barrels.
• The FPSO was operated by BW Offshore until its sale to Century Group in July 2023, after which Century Group assumed responsibility for operations.

Technological Innovations

• The Okwori project was a technological milestone in Nigeria, using subsea technologies traditionally reserved for larger fields. It included multiple selective completions hydraulically controlled from the surface and expandable sand screens for downhole sand exclusion.
• The development plan allowed for additional tiebacks, such as the Nda oil field, which was completed in October 2006.

Challenges and Learning Curve

• The project faced a steep learning curve in areas such as completion design, completion fluids, stimulation, downhole sand exclusion systems, and bean-up/bean-down procedures.

Reserves

• The Okwori field had median technical reserves of less than 50 million barrels at the time of project sanction.

In summary, the Okwori Oil and Gas Field is a significant offshore project in Nigeria, marked by its innovative use of subsea technologies and its ability to develop small, complex fields in medium water depths. The field has been in operation since 2005 and has undergone several changes in operational management, including the recent sale of the FPSO Sendje Berge.