REUTERS
Smoke billows from a controlled burn of spilled oil after the Deepwater Horizon rig explosion at BP's Macondo undersea well in the Gulf of Mexico.
Your ship is floating in water so deep that if it were ashore, its height above sea level would place it in snow at the very top of the mountain's Manganui skifield.
Because of that water depth, it is impossible for the drillship to be anchored, so it is being held exactly in place by a highly sophisticated dynamic positioning system which uses satellite positioning and sonar beacons to constantly monitor its position, and several powerful thrusters that can swivel 360 degrees to keep it there.
And the ship is drilling for oil or gas. A string of pipe as large as 53 centimetres in diameter, called a riser, is snaking its way down to the seafloor 1.6km below and is connected to a heavy piece of equipment called a blowout preventer that is sitting on the top of the wellhead. Inside that riser is the drillpipe itself, which is operating the drill bit that is eating its way thousands of metres under the sea floor to geological formations the explorers hope will contain hydrocarbons.
Drilling fluid, known as "mud", is pouring down the drillpipe to help act as lubricant for the drill bit. And the riser is also being used as the means to return the fluid back up to the surface again - only this time the mud is carrying cuttings from the borehole to the drillship for processing and disposal.
It's all highly advanced stuff, and it's coming to an area near you.
Well, not exactly. While it is almost certain that this summer New Zealand will be introduced to the technological wonders of deepwater drilling, it will all be happening so far out to sea that nobody on the shore will be aware of it.
The location of the country's first truly deepwater exploration well will be in what is officially known as the Deepwater Taranaki Basin, a giant area northwest of existing production oil and gas fields and which is 60,000 square kilometres in size - equivalent to half the North Island.
Within that basin there is a petroleum exploration permit area officially known as PEP 38451, which is owned by a joint venture headed by Texas-based Anadarko Petroleum Corporation, one of the world's largest independent oil and gas exploration and production companies and a recognised proponent of deepwater drilling.
This permit area is seriously isolated. Its eastern boundary is 140km out to sea from New Plymouth, and water depths range from 200m on the edge of the continental shelf down to 1800m at its northern and western boundaries.
This means that no matter where Anadarko chooses to drill, it will take place in water deeper than any of the oil and gas fields currently producing off Taranaki.
For example, the Maui gasfield is in 110m of water. The Maari oilfield sits under 101m of water, and Tui is 123m deep. Closer to shore, the Pohokura field is in just 50m of water, and Kupe is even shallower at 35m.
But in PEP 38451, depending on what prospect the Anadarko joint venture chooses to target, the drilling rig and its crew will be parked above water depths of up to 1600m.
It's all part of an international trend which is seeing the explorers head further out to sea in their efforts to find new supplies of oil and gas. Those in the know believe all of the big fields in so-called "easy" territory have already been found, and that 90 per cent of the world's undiscovered offshore hydrocarbon reserves lie in ocean depths of more than 1000m.
And experts say the Deepwater Taranaki Basin looks particularly prospective. Surveys conducted thus far over the area have identified a giant delta - where ancient river systems and the sea met millions of years ago - that is 130km long, 100km wide, and up to 3km thick. This has led the Institute of Geological and Nuclear Sciences (GNS) to speculate that the basin may contain as much as 20 billion barrels of trapped oil.
No information has yet been made public as to which prospects within the basin Anadarko plans to target this summer, but it is likely to be one of three - Romney, which the experts estimate may contain up to 1.6 million barrels of oil, Coopworth, which may hold up to 540 million barrels, or Corriedale further to the south- east and in shallower water on the top of the continental shelf.
All that is known at this stage, via Anadarko external communications director John Christiansen, is confirmation the explorer is already evaluating the offshore rig market with the aim of bringing a semi-submersible rig or drill ship to New Zealand for the summer, probably as part of a consortium to share the costs of bringing rigs to this country.
Those costs will be very high. There's an international shortage of big drilling rigs anyway, and that will combine with the extra cost of drilling way out to sea to take the total charge for the drilling operation to potentially more than US$1 million a day.
And then there are the potential environmental costs if things go wrong.
The oil industry argues that deepwater drilling is environmentally safe, with the only real differences between drilling in shallow and deep water being that the deepwater operations are invariably further out to sea and in greater water depths.
But environmentalists counter that by arguing that the very fact the drilling is in hundreds of metres of water means it will always be much more difficult to fix things if they go wrong. They point to the Deepwater Horizon catastrophe in the Gulf of Mexico in 2010 as proof of that - when the well the rig was drilling blew out, it gushed close to five million barrels of crude oil into the gulf and took three months to bring under control.
Anadarko held a 25 per cent interest in that well, and already environmentalists in New Zealand are taking full political advantage of that with some very tricky questions to the Government.
Just this week, Green Party co- leader Metiria Turei pinned acting Minister of Energy and Resources Hekia Parata over the issue when, during oral questions in the House, she asked what emergency response, safety and environmental protection provisions were included in Anadarko's permit to undertake the deepwater drilling - and was told the company was required to develop a discharge management plan.
And when Turei asked what assurances the Government could give that the same catastrophe as the Deepwater Horizon spill won't happen in New Zealand, all Parata could reply was: "The latter hasn't been drilled yet."
Naturally the Green Party has now come out strongly, savaging the Government for allowing drilling to take place in water five times deeper than any well has ever been drilled in New Zealand waters, with no environmental permitting regime in place, or infrastructure to respond if there is a spill.
All this means that the prospect of deepwater drilling taking place off New Zealand is almost certain to ramp up public speculation and interest as the 2011-12 summer draws near.
It might start as early as next month when the big ENEX oil and gas conference is held in New Plymouth. A keynote speaker will be Jeff Oslund, the Asia exploration manager for Anadarko, who will travel from Houston for the event and will share his company's experience in deepwater drilling around the world.
And that's an important point - deepwater drilling is now commonplace, with dozens of big semi- submersible rigs and drillships operating in waters up to thousands of metres deep.
For the vast majority of time this drilling is without incident, thanks to strict industry-led procedures and regulations and the use of powerful and hi-tech equipment. But it's just that if things do go wrong, the isolation of these wells mean chances are things will go catastrophically wrong.
- Taranaki Daily News
No comments:
Post a Comment