The Spanish player will spin the bit on the Welwitschia-1 wildcat on PEL 0010 in Walvis Bay off Namibia on Friday, partner Tower Resources said.
The Rowan Companies-owned newbuild drillship Rowan Renaissance was originally due to be delivered from South Korean yard Hyundai Heavy Industries by the end of December but was handed over to the US rig contractor last month.
In early March a spud date of 18 April was then set.
However, this has been pushed back due to prolonged acceptance-testing of the unit by Repsol, Tower said.
The Welwitschia prospect is believed to have multi-billion barrel upside potential, with Tower targeting net risked recoverable resources of 496 million barrels of oil equivalent based on its 30% interest in the block, held by local subsidiary Neptune Petroleum.
The well will be drilled to a total depth of 3000 metres to evaluate primary and secondary target reservoirs in both the Maastrichtian and Aptian-Albian reservoir sequences. Up to five reservoir targets will be intersected.
The ultra-deepwater Rowan Renaissance, chartered by Repsol on a three-year contract at a dayrate of $619,000, is the third in a series of four newbuilds ordered at the yard by Rowan, which has yet to line up a charter for the fourth unit, Rowan Relentless, amid a softening of the rig market.