Vic student uses ultrasound technology in oil hunt

Victoria University geophysics student Mike Stevens is using sophisticated ultrasound-type technology to help oil company Indo-Pacific Energy explore the Canterbury plains.

Mike, who has been awarded a $23,000 Graduates in Industry Fellowship by the Foundation for Research, Science and Technology, says the 2.7 million acre plains are virtually unexplored.

“If the Canterbury plains were in America, they’d be covered in hundreds of wells,” he says. “It’s virgin territory with great potential.”

Mike’s project results from the discovery of a major sedimentary basin that had been hidden under the gravel of the Canterbury plains.

“The gravel has been shed by the Southern Alps, which are lifting upwards, over the last five million years,” says Mike. “Geologically, that’s young. But the gravel is around two kilometres thick and forms a formidable layer for oil explorers to deal with.”

“We want to get a better picture of structures that appear to be a series of sedimentary basins similar to those in Taranaki, where oil production is well proven.”

Mike’s fieldwork involves using dynamite to send sound waves into the earth. The sound waves reflect back and are recorded by a series of listening devices on the earth’s surface.

“By measuring the time the sound waves take to get back to you, you can work out the depth to the different layers. I then use a computer to organise the signals and construct a picture of the geological structure. It’s a bit like an ultrasound.”

The gravel sucks up the sound energy, making it harder to picture the sediments below. However, Mike says advances in the seismic recording technology mean it’s now possible to get a good picture of what’s beneath the gravel.

As part of his research, Mike is comparing data from Indo-Pacific Energy and from a joint New Zealand and United States project for which Victoria University’s Institute of Geophysics was one of the principal partners. Although they used different techniques, both projects found that the sedimentary basins under the Canterbury plains were, at three to four kilometres, thicker than the two kilometres previously estimated.

“This makes them a more exciting prospect for oil and gas exploration than previously thought,” says Mike.

Mike worked for seismic company Schlumberger for three years after he finished his BSc at Victoria University. He completed his honours year in Geology in 1999 and his current research is part of a MSc in Geophysics. He is supervised by Associate Professor Tim Stern of Victoria University’s School of Earth Sciences and Dr David Bennett, Chief Executive of Indo-Pacific Energy Ltd.

Mike, who lives in Island Bay, Wellington, will be doing fieldwork in Canterbury, near Darfield and Hinds, in the first week of July.

New Zealand has won the World Bank’s highest rating for attractiveness to oil and gas explorers.

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