Perth-based Tap said that Johnson-1 had reached a depth of about 1680m by 9am yesterday and that the well could take another 10-14 days to reach the total depth of about 3200m.

Johnson-1 is targeting an oil prospect at the Top Barrow Objective, a formation that has proven successful in the nearby Woollybutt, Griffin and Chinook/Scindian fields.

Located 15km west of Woollybutt and 20km north of Griffin, Johnson-1 is only the second well drilled in the permit, even though about 200 million barrels of oil have been discovered in the adjacent licences.

The WA-285-P participants are operator Santos (37.5%), Tap (Shelfal) with 12.5%, OMV Australia (25%) and Nippon Oil Exploration (25%).