Seismic survey of Pegasus Basin to begin within days

20:53, Jan 22 2014

Giant American oil and gas exploration company Anadarko's first round of seismic exploration in the Pegasus Basin off the Wellington coast is about to kick off.

Contracted seismic testing ship the MV Duke arrived in Wellington harbour yesterday before heading out to the Pegasus Basin on Friday to run 4500kms of test lines over about 40 days, till the end of February. It is in Wellington for final project planning, health and safety checks, and fuelling and provisioning.

Anadarko is looking for "large" oil or gas formations in the Pegasus Basin, but doesn't yet know what is more likely in the area.

Earlier reports suggested Anadarko was hoping to find about 150 million barrels of oil and drilling rigs could be between 25 and 100km from the coast, if the company moves to that phase.

Anadarko won the five-year permit to explore the Pegasus Basin, off the Wellington and Wairarapa coasts, more than a year ago. It has already carried out seafloor mapping of the area, with water depths averaging about 2200 metres and going as deep as 3000m.

After the first round of 2D-seismic testing, the results will be analysed back at head office in Houston to identify areas which may be looked at more closely. The company could then drop the permit if it finds nothing of interest or move on to more detailed 3D seismic test, possibly next summer. After that an exploration well could be possible at the end of the five year permit period.


Anadarko presently holds 100 per cent of the two adjoining permits, but in future may seek to "farm out" a part share in the area, to spread the costs and risks of exploration.

Opponents of deep sea drilling, Oil Free Wellington, plan a protest march in Wellington on Friday, to mark the departure of the MV Duke. The group says the water depth in the Pegasus Basin is twice that of the Deepwater Horizon rig, responsible for the "catastrophic" Gulf of Mexico oil spill. Meanwhile, Anadarko's exploration well in deep water off the Taranaki Coast has completed drilling after about 70 days on the job. It was the first of possibly three deep water wells to be drilled off the New Zealand coast, at a cost of up to US$250 million.

"It went very well, with no days lost to bad weather," Anadarko spokesman Alan Seay said. The well is about 200km off the North Island, west of Raglan.

Anadarko was "very pleased" with the drilling, though would give no indication of what they had found. A firm decision on what happens next could be some time off. The exploration well would tell Anadarko if they had struck oil or gas. But a second or third "appraisal" well would then be needed to see how big the potential field was and if it would be commercially viable to develop into production.

That could be years away.

The new ship, the Noble Bob Douglas was a "piece of awesome technology" and had drilled to a total depth of 4600m, including 1500m of water.

The ship will remain in place for a few more days while results of the well are analysed. Then the Noble Bob Douglas will move down to the Canterbury Basin to drill one and perhaps two more exploration wells about 60km off the coast from Dunedin. Drilling may start early next month.