Of this amount, 43.3m is gas sand. Between 23.2m and 32m is oil sand, compared with 16m at the Basker-2 production and 20m at Basker-5, the Sydney-based company said.

After operator Beach Petroleum cases the well, the rig will drill the Basker-4 well to a planned total depth of 3636m.

The Basker 3, 4 and 5 wells are being drilled using a batch drilling process. Once all three wells are drilled, Beach plans to sequentially install production tubing and perforate the wells. This is expected to start early next month.

Meanwhile, Anzon said total cumulative production from the Basker-2 well to date had reached 820,706 barrels of oil. Production for the month of April was 89,455bbls at an average of 3000bbls of oil per day.

“Effective May 14, the extended production test will cease, following the invaluable and safe gathering of production data,” Anzon executive director Andrew Young said.

“Subsequently the two vessels Crystal Ocean and the Basker Spirit will sail to Singapore where they will both undergo major facility upgrades and inspections in readiness for the connection to the newly laid pipelines, umbilicals and manifold.”

The $A304 million full field development is forecast to produce an average of 25,000bopd.

Anzon and Beach are 50:50 joint venture partners in the project.