The explorer said the competent person’s report by SLR Consulting had pegged in-place potential of between 134 million and 691 million barrels for the prospect, which lies beneath the Kinsale Head and SW Kinsale gas fields.
Shares in the Dublin-based company were trading up 3.25% at £0.24 on London's AIM in the wake of the announcement.
Fastnet Oil & Gas secured the prospect in February under a farm