The rig has drilled out the cement plugs and is drilling the Woollybutt-4H sidetrack, which will be completed as a horizontal well in the Top Barrow Sandstones, joint venture partner Tap Oil said.

The Woollybutt South Lobe was originally discovered by the Woollybutt-3A well in 1999 and subsequently appraised by the Woollybutt-4 and Woollybutt-5A wells.

With completion of the Woollybutt-4 well and a successful appraisal at the Woollybutt-6 well, additional reserves of roughly 10 million barrels of light, sweet crude would be expected from the greater Woollybutt development, Tap said.

“Preparations are on schedule for an early 2008 tie-in of the two wells by subsea flowlines to the Woollybutt Four Vanguard FPSO which will increase production to approximately 14,000 barrels of oil per day,” Tap said.

This includes drilling and completing the two wells; FPSO modifications; subsea Christmas trees, flowlines, manifolds and control systems; and installing and transporting necessary equipment.

Following completion of the Woollybutt-4 well, the rig will move to the Woollybutt-6 appraisal well.

Interests in WA-25-L are Eni Australia (operator – 65%), Mobil Australia Resources (20%) and Tap Oil (15%).