Operator Bass Strait Oil Company (BSOC) restarted drilling 10 metres away from the original top hole.
Surface casing has now been successfully run in the new hole, named Gilbert-1A, to a depth of 107 metres, said the company.
The company said the next step was to complete setting the surface casing before drilling ahead in a 17.5 inch hole.
Gilbert-1A is expected to take five days to reach a total depth of 910 metres. It will initially target the top of the Gurnard Formation, before evaluating the Latrobe and Strzelecki Formations.
The well is being drilled by the Ocean Patriot rig.
Participants in Gilbert-1 are: Gippsland Offshore Petroleum (51%); Lakes Oil NL (26%); Eagle Bay Resources NL (10%); Moby Oil & Gas (10%); Stellar Resources (3%); and Bass Strait Oil Company Ltd (operator, no equity).
