The Melbourne-based company today said that the PGS Australia vessel, M/V Orient Explorer, has acquired about 19% of 3D seismic data covering 500 square kilometres since September 27 and is ahead of schedule.

“The results of specific basin modelling have supported the view that Epenarra consist of a contingent resource having a condensate to gas ratio of between 120 and 30 barrels of condensate per million standard cubic feet (MMscf) of gas,” Methanol Australia said.

“Based on 120bbl/MMscf and a most likely contingent resource of 5620 billion cubic feet, Epenarra could contain in-place condensate (light oil) of approximately 675 million barrels.”

Earlier this month, a study undertaken by IPSA Consulting found the Epenarra structure could contain up to 800 million barrels of in-place condensate.

The structure is a broad, low relief anticline at the Darwin Formation level with a mapped closure of about 1200sq.km.

It is designed to identify the density, distribution and orientation of faults and fracturing in the 50m gas-bearing zone intersected 34 years ago by the nearby Heron-1 exploration well.

The survey will also determine the best place to drill an appraisal well, planned for late next year, to test the productivity of this interval.

Methanol Australia said the expanded survey would improve the imaging of the deeper Heron North and South Plover Formation structures. Subject to confirmation by appraisal drilling, the potential gas resource could underpin the company’s proposed liquefied natural gas and methanol projects.

Heron-1, drilled by ARCO in 1972, recorded several interpreted gas-bearing zones, including a 50m fractured carbonate interval in the lower section of the Darwin Formation. Studies indicate that the gas quality at this level may be low in carbon dioxide with the possibility for attractive levels of associated condensate, the company said.

Epenarra lies immediately west of Tassie Shoals and is 100% owned by Methanol Australia.