"At the time they arrived [on Tuesday] they said they intended to commence drilling operations imminently but they haven't.
"Our understanding is that the presence of the Vega is stopping them from drilling and we don't believe they're going to drill while the Vega is there."
Mr Abel said neither police nor Maritime New Zealand had contacted Greenpeace about the Vega being within the exclusion zone.
Anadarko New Zealand corporate affairs manager Alan Seay said last week that the Bob Douglas was on track to begin drilling, despite the presence of the protest vessels.
Today Mr Seay told TVNZ's Breakfast the drilling was set to be under way by midday.
Protesters had stayed inside the safety zone and had yet to have an impact on the company's drilling operations but drilling would go ahead regardless.
"There's always a risk of something going wrong if somebody goes into a safety zone - it's like having an unauthorised person walking into a construction site," he said.
"We understand there are views right across the spectrum, there are people who are deeply opposed and there are times for those views, but there are also people who are very supportive of the potential economic uplift," he said.
More than 3000 people turned up at beaches from Muriwai to Wanganui at the weekend to oppose deep-sea oil drilling in New Zealand waters.