"Exploratory wells may sound harmless, but the Gulf of Mexico spill was from an exploratory well of 1500m '', Greens energy spokesman Gareth Hughes said.
"Drillers here face greater earthquake risks and wilder seas than in the Gulf of Mexico and handle much heavier oils, yet we have fewer resources to deal with a spill.''
Mr Heatley said New Zealanders wanted jobs and economic growth "but want to be sure that any development of our oil and gas resources is done in a safe and environmentally responsible way''.
"Alongside the exploration permit process we are making big improvements to the wider regime. These include environmental legislation for the Exclusive Economic Zone, now in Parliament; reviewing the Crown Minerals Act and health and safety regulations for petroleum operations; and a new code of conduct for minimising disturbance to marine mammals from acoustic survey work.''
David Binnie, general manager of New Zealand Petroleum & Minerals which is managing the tender process, said the blocks had been selected because of the likelihood they contained significant quantities of oil and gas.
The areas were finalised for the tender after consultation with iwi and local authorities.
A number of submitters emphasised the need to ensure stringent health, safety and environmental controls on exploration activity; and for ongoing engagement on the block offer and resource development more generally, Mr Binnie said.
"It was encouraging to see submissions that sought practical solutions to local concerns, without being overly restrictive to impede responsible resource development.''