"New work to define the feature has shown that while some uncertainty still exists about the potential oil volumes which can be attributed to Wardie, the prospect is seen to be comparable in size to the West Seahorse field," 3D said.

West Seahorse oil field, containing proved and probable reserves of 5.8 million barrels and contingent resources of another 4.5MMbbl totalling up to 10.3MMbbl.

The Wardie prospect's potential hydrocarbon volumes are categorised as undiscovered resources unlike those in the West Seahorse complex, which is a combination of proven reserves and contingent resources.

3D Oil has chosen to drill a well on the Wardie prospect ahead of an earlier planned well on the Sea Lion prospect.

"While Wardie has lower associated risk than the Sea Lion prospect, there is still considerable associated risk but its proximity to West Seahorse, makes it more economically viable in the event of a discovery," the company said.

"If commercial volumes of oil were present in Wardie it is feasible the field could be linked, for production purposes, to the proposed West Seahorse development."

Planning for the drilling the West Seahorse-3 appraisal well and the Wardie-1 wildcat exploration well is continuing, based around the preferred option of drilling both wells from the same surface location, 3D said. Deviated wells would then be drilled into each feature.

3D Oil plans to spud these two wells in March next year following the completion of a drilling program by Apache Oil.

The newly constructed drilling rig, West Triton, which will be modified to allow the drilling of deviated wells, will be used for the two-well program.

Oil production from West Seahorse could start as early as 2010, according to 3D.