Coro Energy pleased with latest progress at Duyung

The AIM-traded firm said the Tambak-1 well was designed to both appraise the Mako gas field and test the underlying Tambak exploration prospect.

Following the drill stem test at Tambak-1, which flowed dry gas at a maximum flow rate of 11.4 million standard cubic feet per day, operations had now concluded, resulting in the “highly successful” appraisal of the Mako gas field.

The Tambak-1 well encountered 24 metres of intra-Muda reservoir sandstones at a depth of 389 metres true vertical depth subsea, confirmed a common gas-water contact across the field and culminated in a drill stem test reflecting the potential deliverability of the Mako reservoir.

Coro said the well was deepened beneath the Mako field to a depth of 1,543 metres true vertical depth subsea, to test the Tambak exploration prospect.

The well encountered multiple sandstone intervals in the Lower Gabus section as predicted, with corresponding hydrocarbon shows seen while drilling.

However, petrophysical interpretation of wireline log data has concluded that those sandstones had low gas saturations and attempts to collect fluid samples and pressure data demonstrated low permeabilities.

The well was currently being plugged and abandoned as planned, prior to the Asian Endeavour 1 rig being demobilised.

Overall, the drilling campaign had been completed within the expected time frame and within budget.

“We are very pleased with the flow test results announced today and the appraisal results overall from this drilling campaign, which confirms the Mako field as being a very valuable gas resource,” said chief executive officer James Menzies.

“The data demonstrates the excellent reservoir characteristics across a huge areal extent, with good porosity, high permeability and the drill stem test has again demonstrated the deliverability of the Mako reservoir.

“The drill stem test is particularly significant as the test was conducted through cased hole and less than two metres of reservoir section perforated.”

That, Menzies said, was in contrast to the previous drill stem test at Mako South-1, which saw a substantially larger section tested in open hole, and he added that it provided a “valid completion alternative” for field development.

“We are delighted with the additional resource that has been proved up in the Mako field as a result of this campaign which we believe enhances the commercial attractiveness of the project.

“Coro management estimate that the campaign has demonstrated a gross resource addition of at least 100 billion cubic feet, and we look forward to the independent assessment of field resources which will follow.”

At 1449 GMT, shares in Coro Energy were down 4.52% at 2.15p.