As of 6am this morning (Perth time) Woollybutt-5A, located about four kilometres south of the Woollybutt-3A well, had drilled to 512 metres measured depth where casing was run and cemented.

The original Woollybutt-5 well, which spudded on November 26, had reached 1377m when well-bore instability resulted in the collapse of part of the rock formation, requiring the surface hole to be re-drilled from a new location, junior partner Tap Oil reported.

“The subsurface zone which created drilling problems in the initial well is now behind casing,” Tap said.

“The well will drill ahead to the next casing point at around 1350 metres. It is expected to take approximately 18 more days to reach total depth.”

Meanwhile, the tie-in of the Scalybutt-1H well is continuing.

“Flowlines and control cables have been laid and work is proceeding on completing the tie-in,” Tap said.

“The Scalybutt connection is now expected to be completed within the next 10 days.”

But unseasonable weather and equipment commissioning delays have been experienced in connecting the Scalybutt-1H production well, according to Tap.

“This has required that Woollybutt-2H be shut in longer than expected and consequently, production from the Woollybutt field is expected to average around 10,000 to 11,000 barrels per day for December – about 50% of previously budgeted production,” the company said.

“Upon completion of the connection of the tie-in works and initial well testing, all three wells – Woollybutt-1 and 2 and Scalybutt-1 – will be on production at an expected combined rate in excess of 20,000 bopd.”

Despite these delays, Tap’s total production for the year is expected to be in excess of previous guidance at around 2.5 million barrels of oil equivalent, the company said.

WA-25-L joint venture participants are Eni Australia Ltd (operator) 65%, Mobil Australia Resource Co Pty Ltd 20% and Tap West Pty Ltd 15%.