Chevron has sanctioned a third phase of development at the Jack-St Malo project in the US Gulf, its flagship Lower Tertiary development, as it looks to take advantage of pleasant surprises in reservoir performance to date.

The US supermajor acknowledges that the $8 billion development, which came online on time and under budget in late 2014, remains in the early stages of what is planned to be a 30-year life for the 175,000 barrels per day semi-submersible, Jack St Malo asset manager Travis Flowers told an industry luncheon last week.