The company said yesterday the West Triton jack-up rig began drilling on Saturday and to date the pilot hole has reached 755m.

Drilling of the well's pilot hole and horizontal production section is expected to take about seven weeks to complete.

According to the company, the horizontal section would be drilled to intersect the two deepest sands within the Longtom field.

Nexus also said the results from Longtom-4 together with the field's production performance over time will determine when a third development well would be drilled.

"The current plan assumes this well will be drilled two to three years after project start-up," the company said.

The Longtom field is expected to start first commercial production in April next year.

The gas from the field will be transported via a new Nexus built pipeline to the end of Santos' existing Patricia-Baleen pipeline, 19km away.

The raw gas would then continue along the Patricia-Baleen pipeline to shore where it would be processed at Santos' existing onshore gas plant.

Nexus Energy owns 100% of VIC/L29.