According to a Bloomberg report, Apache’s Theo-1 wildcat in WA-155-P found 19m of gas and 14m of oil.

Apache’s Australian unit managing director Tim Wall told Bloomberg that while these volumes were a little less than hoped for, the discovery could potentially mark an extension of the Vincent field, lying within Apache’s permit.

If this is the case, Wall indicated Apache’s section of the field could hold 60-70 million barrels of oil equivalent (MMboe), allowing it to negotiate a stake in the Vincent project.

The Apache permit is immediately north of the Woodside and Mitsui-held WA 28L lease and the Vincent field is on the boundary of the two fields.

In April, Woodside and Mitsui committed to the $A1 billion-plus Vincent project, 50km northwest of Exmouth in about 350m of water.

The two companies are also partners in the nearby Enfield development, which is being developed at a cost of $1.5 billion and due to begin production later this year.

In both projects, Woodside is the operator with a 60% stake, while Mitsui holds the remaining interest.

Vincent, which is believed to contain about 73MMboe, was discovered in 1998 but has lagged behind other developments in the area because of the technical nature of the reservoir.

First oil from Vincent is planned for 2008, at an initial rate of 100,000 barrels per day.

Eight production wells are planned for the first phase of the project. The oil will be processed and stored using a floating production, storage and offtake (FPSO) vessel.

The success of the initial phase will determine whether and how the project is expanded.

The Exmouth sub-basin is characterised by heavy oil, with most discoveries being between 19 and 22 degrees API.

Woodside's Laminaria/Corollina fields in the Timor Sea are declining rapidly and production from the Exmouth sub-basin will progressively add about 150,000bpd of oil to Woodside's output during the next three years.

Previously, it was not economical to develop such offshore heavy oil discoveries but the region has come into its own as reserves in other areas continue to decline.