The company said the hydrocarbon-bearing sand would be production tested after drilling and completion of the horizontal section of the well.

Currently, Nexus is setting casing after the well reached a depth of 2600m.

Once casing is set, the West Triton Jack-up rig will drill a pilot hole to intersect the deeper section of the Longtom field, which is anticipated to contain the major portion of gas reserves, the company said.

Following the pilot hole, the horizontal section would be drilled to intersect the two deepest sands within the field.

Nexus is planning to suspend Longtom-4 is as a future gas producer once production testing of the horizontal section is completed.

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

The results from Longtom-4, together with the field's production performance over time, will determine when a third development well would be drilled, according to the company.

Nexus Energy owns 100% of VIC/L29.