The company said the 36-inch surface hole had been drilled and the 30-inch well conductor was run and successfully cemented.
Nexus said it would now run and cement a 13 3/8-inch casing string, before drilling ahead to the targeted formations.
The Culverin prospect, defined by 3D seismic data at Top Latrobe level in the eastern part of the permit, has the potential to contain mean oil reserves of 97 million barrels, Nexus said.
Underlying Culverin is the Scimitar prospect at the deeper Intra Latrobe level, also defined by 3D seismic.
Nexus said this prospect, expected to contain a mixture of oil and gas, was analogous to the Basker Manta fields 10km north. Scimitar has the potential to contain mean oil reserves of 63 million barrels.
Joint venture partners in Vic/P56 and the adjacent Vic/P49 permits are: Nexus (operator and 40%), Korea National Oil Corporation (30%), Seoul City Gas Company (20%) and Anzon Australia (10%).