Capping a major oil leak off NZ coast could take 14 days - Shell

The disaster at BP's Deepwater Horizon oil rig in the Gulf of Mexico has brought new regulations. Photo / AP

Shell said it would take the company about 14 days to respond to a major deepwater drilling accident off the New Zealand coast.

Rob Jager, who is chairman of the Shell companies in New Zealand, told the Advantage NZ Petroleum Conference that the company was going through a process of evaluating the equipment required and the time it would take to respond to a major drilling incident.

Oil explorers often use a so-called "capping stack" device to stem the flow of hydrocarbons when things go wrong.

"We have our own capping stack which we would deploy, but I would expect that it would certainly be within that 14-day period," he said.

"It is first and foremost about preventing things from occurring and that's where a large amount of the focus is, but in the unlikely event of things going wrong, we would work through the scenarios, identify the equipment - including relief drilling facilities - to be able to respond to a disaster," he said during a question and answer session at the conference.

Shell has interests in the Maui, Kapuni and Pohukura gas fields, which represent about 70 per cent of New Zealand's gas supply.

The 2010 Deepwater Horizon oil spill in the Gulf of Mexico - also referred to as the Macondo blowout - took 87 days to contain.

Jeff Burns, the Asia and Australia sales representative Helix Energy Solutions - which specialises in containing subsea oil spills - sent three specialist vessels to Macondo.

He said the gulf's industry's response time had been substantially reduced to 14 days because of the lessons learned from the disaster. The reduction had been achieved through increased level of readiness, investment in people, equipment and planning.

Burns said the Macondo incident mirrored the Montara oil spill and gas leak in the Timor Sea, off the northern coast of Western Australia, just eight months beforehand.

Montara, one of Australia's worst ever oil disasters, took 74 days to contain.

Burns said New Zealand and Australia were similar because their remoteness. They had relatively few wells and correspondingly minimal support infrastructure.

"Although we have active oil and gas developments, our infrastructure is reasonably minimal and our ability to access equipment is difficult, and we are a long way away," he said.

He said the Macondo incident happened under a prescriptive regulatory regime and Montara under a non-prescriptive regime, yet both had similar, disastrous, outcomes.