The Wei-6-12S-1Sa sidetrack well, which is about 50m from the original discovery, was drilled to further delineate and core the relevant reservoirs.

Roc said five core samples successfully cut achieved a 100% recovery. The Perth-based company said initial analysis indicated these core samples were similar to the reservoir character and quality found in the discovery well.

“With the first sidetrack operations completed without any surprises, Roc and its co-venturers will continue with their two-pronged approach to appraising this field: do it methodically and do it quickly,” Roc managing director John Doran said.

After reaching total depth of 2530m, the sidetrack well was plugged and abandoned after logging in-line with the pre-drill program.

Later this week, Roc expects to start drilling the second Wei-6-12S-1Sb sidetrack well, designed to intersect the various reservoir sands down-dip of the discovery well.

This sidetrack well, expected to be completed next month, is aimed at better delineating the likely multiple oil-water contacts in the field and test the possible thicker down-dip development of thin sands intersected in the discovery well.

Roc is the operator and owns 40% of the Wei-6-12S-1 well. Other partners in the Australian joint venture are Horizon Oil, which holds a 30% stake, Petsec Energy (25%) and First Australian Resources (5%).