“The joint venture partners expect to review log data and then decide to either continue drilling at reduced mud weights to the prognosed total depth of 4300 metres or commence production testing,” MEO said.

A reduction in mud weights is being considered because the well has sustained significant mud losses from increased permeability, possibly due to fracture/fault development in the section. The losses have been controlled loss circulation material treatment and mud weight reduction.

With Heron-2, MEO is aiming to find enough gas to underpin an LNG project. The company already has approvals in place for an LNG project to be sited on an artificial concrete gravity structure near Tassie Shoal in the Timor Sea north of Darwin. It also has a 50:50 partnership in the proposed facility with LNG technology giant Air Products.

The well is being drilled by Seadrill’s West Atlas jack-up rig contracted to MEO for two firm wells and one option well. The well is aimed at penetrating and production testing the Epenarra Darwin Formation and the deeper Elang/Plover Formation of the Heron North structure.

The Heron-1 well drilled by ARCO in 1972 intersected a 52m gas bearing column in the Darwin Formation (a fractured carbonate reservoir) within the 1200 square kilometres mapped closure of the large Epenarra structure. Heron-1 also reached a gas charged zone in the deeper underlying Elang/Plover horizon, which is a secondary objective for the Heron-2 well.

The participants in Heron-2 are two MEO subsidiaries TSP Arafura Petroleum and Oz-Exoil (both 45%) and Petrofac Energy (10%).