Galp Energia has made a major oil discovery offshore Namibia with its Mopane-1X exploration well, triggering a 6.7% jump in its stock price to €14.795 ($16.20) on the Lisbon bourse at the time of publishing.

The operator did not reveal a resource size, although Knowledge Katti, chief executive of Mopane partner Custos Energy, said previously that the prospect had the potential to house a mean, oil-in-place resource of “up to 10 billion barrels.”