Falklands-focused oil and gas exploration group Rockhopper disclosed that the first phase of its Sea Lion development was expected to recover 293m barrels of oil over 25 years. The announcement came ahead of the update which Premier Oil was scheduled to give at a Capital Markets Day.As per the Tension Leg Platform concept employed for the development of Sea Lion, the company further disclosed that estimated capital costs for Phase 1 of the project would total $5.2bn.Capital outlays to first oil were seen coming in at $3.8bn, with annual operating expenditure (gross) expected to average $260m, including floating storage unit rental and well interventions.Premier Oil was expecting to award the front-end engineering and design contracts in the second quarter of 2014 and to submit the draft field development plan at the end of that year, Rockhopper explained. Field sanction was anticipated for the second quarter of 2015. First oil was seen arriving 3.5 to 4 years after project sanction. As of 10:50 shares of the firm were 8.94% higher at 128p. AB