In a presentation to investors, the Sydney-based mid-cap said the potential six-well drilling program at its Cabinda South Block was targeting anywhere between 344 million and 1.446 billion (P50-P10) barrels of in-place oil.

Roc managing director John Doran has been bullish about the onshore exploration program.

"Any one of those wells could change the company – that's the extent of that potential," he told a Boardroomradio interview recently.

The campaign will start with the spudding of an exploration well on the Massambala prospect, estimated to contain 33-180MMbbl of in-place oil.

Following Massambala-1 well, the Explorer rig will move on to the Cevada-1 well site, which Roc said has “big upside” with 54-157MMbbl of potential.

Next in line is Miho-1, a directional well scheduled to start being drilled in either June or July following the arrival of the Simmons rig. The prospect is estimated to contain a potential 33-129MMbbl of in-place oil.

The next well, Trigo-1, in the program is another directional one, to be drilled from the same location as Miho-1. This well is targeting a potential 78-188MMbbl.

Following these two wells, the joint venture will move on to the Soja-1 exploration well, with 54-157MMbbl.

In addition, Roc plans to undertake a 200 square kilometre 3D seismic program in the middle of the year over the Lead 113C, to determine whether or not to drill a well here.

At the end of 2006, the Cabinda joint venture formally approved an estimated $US54 million ($A68.5 million) 2007 work program.

Roc has a 60% working interest, or 75% contributing interest, in the Cabinda South Block JV. Its partners are Force Petroleum (20% working interest and 25% contributing interested) and Angolan state company Sonangol P&P (20% interest, free carried).