Private-equity-backed Neptune Energy Group Ltd. said March 28 it had agreed with partners on a final investment decision for the Seagull oil and gas field in the British North Sea.

Partners of the Seagull Field include BP Plc and Japan Petroleum Exploration Co. (Japex).

"Seagull is expected to initially produce around 50,000 barrels of oil equivalent per day [80% oil] across its 10-year design life. Proved plus probable gross reserves are estimated at 50 million boe," Neptune said.

The Seagull Field will be developed with up to four subsea wells drilled from a new four-slot manifold 17 km south of the BP-operated ETAP Central Processing Facility, according to Neptune's website.

First production is expected by late 2021. Neptune operates Seagull and owns 35%, BP 50% and Japex the remaining 15% of the project.