LONDON Dec 2 Oil drillers hoping pre-salt discoveries in west African waters may match the prolific finds beneath similar deposits off Brazil got a lift on Monday from the drilling results of the Lontra 1 well offshore Angola.
Cobalt International Energy said the drill stem test results were "exceptional, with excellent quality reservoirs that are better than we had expected".
Drilled to a depth of 4,195 metres (13,843 feet) and penetrating some 75 metres of net pay, Cobalt said that "while further appraisal drilling will be required to determine the ultimate size of the Lontra field, it is clear that Lontra is a discovery on a global scale.
"The exceptional reservoir system that we have discovered ranks among the best that we have seen."
The well indicated a bigger gas content than the oil-seeking partnership between operator Cobalt (40 percent), BP Plc and Angola's state company Sonangol (30 percent) had been anticipating, Cobalt said. But this was not a problem given that Lontra is offshore near the Angolan capital Luanda, where there may be an emerging market for the gas.
For Cobalt, whose stock has underperformed due to uncertainty over the drilling result, the announcement is "a clear positive relative to current share price and market sentiment", said a Deutsche Bank research note which said the field could contain 1 billion barrels of oil equivalent (boe).
Investors are stepping up the hunt for hundreds of billions of dollars worth of oil beneath a deep submerged salt crust offshore West Africa, seeking to emulate Brazil's major discoveries across the Atlantic.
Geologists have long held that Africa's western seabed mirrors that of South America. The continents were fused into a single plate nearly 200 million years ago.