Equinor on Aug. 27 increased its resource estimate for the Johan Sverdrup oil field, the North Sea’s largest discovery in more than three decades, while cutting the cost of development.

The field is believed to hold 2.2 to 3.2 billion barrels of oil equivalent (Bboe), up from a previous forecast of 2.1-3.1 Bboe.

The overall cost of developing the field has been cut to 127 billion Norwegian crowns (US$15 billion), down some 6 billion crowns since February, Equinor said, as it presented its investment plans for the field’s second phase.

“Johan Sverdrup is on track to deliver vast volumes of energy with high profitability and low emissions for many decades to come,” CEO Eldar Saetre said.

At its peak, the field will produce up to 660,000 barrels per day, with a breakeven price of less than $20 per barrel. The Brent North Sea benchmark currently trades at about $75 per barrel.

While the first phase of the development is on track to start production in November 2019, the second phase is planned to begin pumping in the fourth quarter of 2022.

“Full field development of Johan Sverdrup is projected to contribute more than 900 billion (crowns) in income to the Norwegian state over the lifetime of the field,” Equinor said.

The operator and its partners will invest 41 billion crowns in the second phase, four billion less than an estimate made in February. It will put 86 billion into the first phase, a reduction of 2 billion crowns.

Since announcing its initial plans for the field in 2015, Equinor has cut the investment cost by more than 80 billion crowns, it said.

Equinor operates the field and holds a 40% stake. Lundin Petroleum has 22.6%, Petoro 17.36%, Aker BP 11.57% and Total 8.44%.

($1 = 8.4525 Norwegian crowns)