But the significance of these shows will not be known until the sidetrack well, known as Drakea-2, reaches a total depth of 2850m and wireline logging is completed, it said.
Yesterday afternoon, the well was at a depth of 2773m.
Arc and partner Origin Energy decided to sidetrack the well after it was found to have intersected a 3-5m oil column in the High Cliff Sandstone.
Drakea-2 is designed to penetrate the High Cliff Sandstone in a more crestal location, where the partners believe a larger hydrocarbon column could be encountered.
The two wells, which are targeting a potential 15 million barrels of oil reserves, are about 19km southeast of the Dongara township in production licence L1, where Origin and Arc are 50:50 partners.
