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The Issue

  • Deep sea oil drilling

    In 2010, the Deepwater Horizon disaster in the Gulf of Mexico focussed the world’s attention on the catastrophic environmental and economic consequences of a deep sea oil well blowout.

    “The cost of drilling in deeper water is not linear with depth; it increases exponentially. The risk also increases significantly. The challenges faced are significant and complex: from the rig to the deepest section of the well.”
    Rees & Sharp, 2013. Drilling in extreme environments. Lloyds, London.

    In New Zealand, the current deepest production well is only 125 meters below sea level. However, plans are in place to drill at water depths of well over 1000m.

    Source: GNS, Petroleum Basin Explorer

    Left: After Muehlenbachs et al (2011), Preliminary Empirical Assessment of Offshore Production Platforms in the Gulf of Mexico, Figure 3

  • What is exploratory drilling?

    Seismic surveying gives oil companies some indication of what might lie beneath the seafloor. Exploratory drilling is required to precisely determine whether there really are any hydrocarbons such as oil, condensate and gas contained within a prospect.

    Very little is certain about the type of hydrocarbons present and the pressure of a potential reservoir prior to the first well being drilled. It is for this reason that exploratory drilling is the riskiest phase of oil production (OGP, 2010). The source of the Deepwater Horizon disaster was an exploratory well.

    Source: International Association of Oil & Gas Producers (OGP, March 2010). Blowout Frequencies. Risk Assessment Data Directory No. 434

    Who is deep sea exploratory drilling in NZ?

    Several oil companies are planning to start deep sea exploratory drilling in New Zealand:

    • Anadarko: This Texan company was a co-owner of the Macondo Prospect, which was the site of the Deepwater Horizon disaster. They were found jointly liable for worst oil spill in history, having previously paid $4 billion to BP as indemnity against liability.
    • Shell: Shell Oil holds permits for drilling in the Great South Basin and may be exploratory drilling by the summer of 2014/15.
    • OMV: OMV holds permits in the Great South Basin and has been undertaking seismic surveying there.

  • NZ spill response capability

    • Maritime New Zealand maintains the capacity to respond to spills of up to 3,500 tonnes
    • NZ has a total of three Oil Response Vehicles (pictured at left). These are located in Northland, Auckland and Wellington
    • Chemical dispersants would be used to disperse the spill into finer droplets so that it mixes into the water column
    • The dispersants stocked in New Zealand include Corexit, which has been shown to greatly increase the toxicity of oil

    Sources: Maritime NZ, Responding to oil spills and pollution; Rico-Martinez et al. 2013. Synergistic toxicity of Macondo crude oil and dispersant Corexit 9500A® to the Brachionus plicatilis species complex (Rotifera). Environmental Pollution: 173, 5-10.

    Image credit: Maritime NZ

  • "The deepwater environment is cold, dark, distant, and under high pressures—and the oil and gas reservoirs, when found, exist at even higher pressures (thousands of pounds per square inch), compounding the risks if a well gets out of control. The Deepwater Horizon and Macondo well vividly illustrated all of those very real risks.

    When a failure happens at such depths, regaining control is a formidable engineering challenge—and the costs of failure, we now know, can be catastrophically high."

    National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, Report to the President

  • “Our exhaustive investigation finds that none of the major aspects of offshore drilling safety - not the regulatory oversight, not the industry safety standards, not the spill response practices - kept pace with the push into deepwater. In effect, our nation was entirely unprepared for an inevitable disaster.”

    William K. Reilly, Co-Chair of the US Presidential Oil Spill Commission on the Deepwater Horizon disaster

  • “A couple of years ago when the Rena spill occurred, with those 350 tonnes of oil, what we saw was New Zealand woefully unprepared to deal with a spill. Yet the Government still nominated its oil spill capacity to be only 5,500 tonnes. What we know is that a deep-sea well blowout could release 600,000 tonnes.

    "In America they had 40,000 people working on a spill. We have got 400 trained responders. In America they had 1,000 vessels. In New Zealand we have got three dinghies. In America they had everything in place, but it was still catastrophic and cost $40 billion. Yet this Government says that the maximum penalties are only $10 million and a company has to have insurance of only $30 million.”

    Gareth Hughes, Green MP

  • “New Zealand’s worst nightmare - the worst nightmare of all New Zealanders - would be a Gulf of Mexico-like disaster, with oil continually gushing for weeks and weeks and weeks, without the ability to stop it.

    Think of the damage that would do to New Zealand. Our tourism industry would be down the drain overnight - one of the biggest industries in New Zealand and one that we rely on. It is our bread and butter. We rely on it to make our living as a country, and yet a massive oil spill would wipe out our tourism industry overnight because of the damage it would do to our clean, green economy. A lot of our primary exporting industries also rely on our clean, green image for their access to overseas markets.”

    Chris Hipkins, Labour MP

Model scenario

  • Drilling locations

    The drilling locations for Romney and Caravel were estimated from statements made by Anadarko to its investors. The precise drilling locations were only publicly released after our study was complete.

    Although our location estimate is not exact, we tested whether varying the precise release site would change the probabilistic maps. Shifting the release site resulted minimal alteration to the overall impacts.

  • Spill duration

    The 76 day duration estimate for a New Zealand spill was based on past blowout events, including Deepwater Horizon disaster in the Gulf of Mexico in 2010 and the Montara well blowout in the Timor Sea in 2009. Our duration estimate is much shorter than typical industry estimates for New Zealand (120-130 days).

  • Spill flow rate & volume

    The blowout flow rate was set at 10,000 barrels per day. This flow rate is similar to natural flow rates recorded for previously drilled oil reservoirs in New Zealand.

    With a duration of 76 days, the total spill volume for our scenario is therefore 760,000 barrels.

  • Level of concern

    The level of concern is the minimum threshold that the density of an oil spill must reach when calculating the probability map.

    In the maps, the percentages refer to the likelihood of an area being impacted by at least 1 g/m2 of oil, however the density may be much higher than this.

    Image credits: 1,3: Greenpeace / Dean Sewell / Oculi;2: Greenpeace / Simon Grant;4: Greenpeace / Dom Zapata

Find out more about our assumptions and model parameters and download the full report here

The Science

What is at risk

The 2010 Deepwater Horizon Disaster has been described as the worst environmental disaster in the history of the United States. The spill clean up has so far cost in excess of US$42 billion. In New Zealand, a spill even a fraction of this scale has the potential to devastate our environment and economy.

  • Annually, New Zealand fisheries and aquaculture exports are worth between $1.2 - 1.5 billion, which consistently makes them our fourth or fifth largest export earner

    Source: MPI, Commercial Fishing

    Image credit: Phillip Capper at Flickr

    70% of our export revenue is directly attributable to NZ's clean green reputation, worth $36.7 billion to our economy each year

    Source: Greenpeace NZ, The Future is Here

    Image credit: Christopher Michel at Flickr

  • New Zealand and its offshore islands are home to 25% of the world's breeding seabird populations.

    Source:

    Source: NIWA, Seabird Diversity in the Southern Ocean

    Image credit: Greenpeace / Dave Hansford

    An estimated 80% of New Zealand's native biodiversity is found in the sea

    Source: NZ Biodiversity, Coastal and Marine Biodiversity

    Image credit: Greenpeace / Dave Hansford

  • 75% of New Zealanders live within 10km of the coast

    Source: Statistics NZ, Are New Zealanders living closer to the coast?

    Image credit: Ari Bakker at Flickr

    1 in 5 kiwis participate in recreational fishing activities

    Source: Active NZ Survey, Sport and Recreation Profile: Fishing

    Image credit: Neil Blazey at Flickr