Oil giant Anadarko Petroleum has raised the prospect several oil and gas explorers will share costs of leasing an oil rig for exploration off Dunedin and in the Great South Basin, as a decision looms whether to commit to drilling or drop exploration permits in the area.
At present Anadarko and Australian-listed Origin Energy have permits for exploration in the Canterbury Basin, about 65km off the coast from Dunedin, while Exxon Mobil and Austrian-based OMV each have separate exploration permits for drilling in the Great South Basin - all having undertaken ship-borne seismic hydrographic studies.
Industry sources believe given the permit time-frames, a rig could be used in the Canterbury Basin in spring 2011 and in the frontier Great South Basin over summer, when calmer weather would prevail in what is acknowledged by mariners as one of the roughest seaways in the world.
Cost estimates for a one-hole deepwater drilling programme in the Canterbury Basin lie between $US75 million and $US100 million ($NZ103.7 million and $NZ138.3 million).
Origin and Anadarko have until August 21 to make a commitment to test drilling within the following year, with an Origin spokeswoman this week referring all comment to Anadarko, as the operator in the joint venture.
Anadarko's senior public affairs representative Matt Carmichael said from the United States following "informal discussions with key players", Anadarko was aware of when and where other New Zealand operators had upcoming drilling commitments.
"We believe the timing of our drilling commitments could dovetail well with those of other operators, to the point where it makes sense to share the mobilisation costs involved with importing a rig to New Zealand," Mr Carmichael said, when contacted.
"These permits have different requirements related to our exploration commitments, and we are evaluating the best and next course of action for each with our partners," he said.
Anadarko is a minority partner with BP in the blown-out Gulf well which has spewed more than five million barrels of oil into the ocean, with clean-up, compensation and asset sales totalling more than $US60 billion announced by BP this week.
Mr Carmichael was asked if the Gulf incident had affected any decision-making on its proposed New Zealand work programme.
"Anadarko is committed to safely exploring, developing, and producing vital energy resources, in an environmentally sound manner."
Anadarko executes budgets to "appropriately high-grade" multiple prospects of an exploration programme, which often includes 2-D semi-regional seismic, 3-D detailed seismic and the appropriate environmental assessment work, prior to identifying, proposing, and drilling a well location, he said.
In the other separate southern proposals in the Great South Basin, Exxon Mobil was granted an extension last October on its "drop or drill" decision, until October 10 this year, while the OMV-led joint venture proposal, within the same basin, also received an extension, in January, with drill-or-drop deferred until January 10 next year.
In July 2007, Exxon (90%) and Todd Exploration (10%) made up one consortium, with the other headed by Austrian-based OMV New Zealand Ltd.
They announced separate five-year permits for nine of a total of 40 Great South Basin blocks, touting up to $1.2 billion in potential spending on exploration during the five-year period between the pair.
• Rigs were last in southern waters off Oamaru in 2006, for Tap Oil and Australian Worldwide Exploration's Ocean Patriot, and in 1985, with BP Shell Todd's Zapata Arctic.
In the Great South Basin eight test holes were drilled from 1976 through to 1984 by Hunt, Phillips, Placid, Occidental, Husky and Ultramar.
All the drilled holes were capped, the majority of them then being uneconomic.
