Santos (ASX:STO) started continuous production at its Pikka phase one oil development on Alaska's North Slope, with initial flow from the first wells averaging around 20,000 barrels per day, according to a Tuesday filing with the Australian bourse.

The company plans to begin seawater injection in the coming weeks to support reservoir pressure, followed by the commissioning of additional production wells, per the filing.

The company said production is expected to ramp up toward a plateau of about 80,000 barrels per day in the third quarter.

The project is expected to produce around 400 million barrels of gross 2P reserves, with an additional 600 million barrels of gross 2C resources in the Pikka unit supporting phased development beyond phase one, the filing added.