Santos is participating in the well, having agreed in April to take a 37.5% interest in two Vietnam exploration permits – Block 12E and Block 12W. The farm-in will be fully effective after Santos has funded a proportion of the costs of a two-well drilling program.

Dua-4X was drilled down-flank from the 1974 Dua-1X discovery well that flowed 1500 barrels of oil per day.

Following the intersection of hydrocarbons in the Dua 4X vertical well, a side track has been drilled (Dua-4X ST1) to provide further geological information.

Wireline testing of both Dua-4X and Dua-4X ST1 recovered oil samples, core and pressure data to help define the quantity and quality of hydrocarbons within the northern flank of the Dua structure. As planned, no drill stem test was performed.

A second geological sidetrack, Dua-4X ST2, will now be drilled to evaluate potential gas and oil reservoirs in the southern fault block of the Dua structure.

Following completion of Dua-4X ST2, the 12E-CS-1X well will be drilled on the Blackbird prospect to explore a large tilted fault block up-dip of a pre-existing well (12E-LK-1X), which encountered very good oil shows, according to Santos.

On completion of the farm-in, the interests in Block 12E will be operator Premier Oil (37.5%), Santos International Holdings (37.5%) and Delek Energy (25%).