Phase 1 is designed to produce around 220 MMbbl from license PL032. Phase 2 will encompass a further 300 MMbbl from the remaining resources in this license and satellite accumulations in the north of PL004.
In addition, a further 200 MMbbl of low risk, near field exploration potential could be included in either scheme.
Phase 3 will focus on the Isobel/Elaine fan complex in the south of PL004, subject to further appraisal drilling.
Operator Premier Oil plans a conventional FPSO development with around 23 subsea wells and gross capex to first oil of $1.5 billion.
Letters of intent have been signed for the FPSO, drilling rig, well services,subsea production systems and helicopter services, and these will be converted to fully termed, executed contracts.
Front-end engineering design concluded last month. The field development plan is substantially agreed on, and this will likely be submitted in the run-up to sanction.
Premier and Rockhopper continue to engage with the Falkland Islands government on securing consents and agreements in order to reach a final investment decision.
The Sea Lion Discovery Area is due to expire on April 15, 2020, but the development plan should be submitted before that date, Rockhopper said, so an application for a further license extension should not be needed.