The Adelaide-based company today said the intervals had encountered a total net oil pay in excess of 70m.

Managing director John Ellice-Flint said the discovery was an “encouraging” step towards the company’s growing operations in Vietnam.

“The discovery of oil at Blackbird is very encouraging, and we await the results of testing to provide additional clarity on the likely resources,” Ellice-Flint said.

“The success at Dua and now Blackbird in the Nam Con Son Basin, plus the recent signing of a production sharing contract in northern Vietnam’s Song Hong Basin, are encouraging steps towards our plans to grow Santos operations in Vietnam.”

Blackbird has been drilled to a total depth of 4058m and is about 21km to the southwest of the recent successful wells in the Dua field.

The well drilled a large tilted fault block and discovered four oil-bearing intervals in the main Middle Dua target, up-dip of a previous well that encountered good oil shows.

These intervals have been wireline logged with oil samples recovered for further evaluation, Santos said.

Santos holds a 37.5% stake in the block where the well is, with Premier Oil holding 37.5% and Delek Energy holding the other 25%.