Frozen natural gas offers potential energy boon for New Zealand

New Zealand government scientists are looking at ways to extract natural gas frozen in ice beneath the seabed after finding an enormous deposit off the country's east coast.

A solid band of hydrates extending from the top of the South island to Poverty Bay in the North Island had been identified during a six-year study, the Institute of Geological and Nuclear Sciences (GNS Science), which is leading the study, announced Monday.

Gas hydrates, sometimes called "burning ice" because of the ease with which the ice burns when brought to the surface, are seen as a potential future energy source, but until recently were considered too difficult to extract to be commercially viable.

But researchers from GNS Science, the National Institute of Water and Atmospheric Research and the universities of Auckland and Otago said the deposit was "world class in its quantity and quality."

Program leader Ingo Pecher, of the University of Auckland, said engineers working in Japan had developed a way of melting the hydrates so that natural gas was released and captured.

Scientists in the New Zealand program had made steady progress in identifying hydrate accumulations with seismic data and modelling, which, together with improvements in understanding how they formed, meant they were now more confident of finding "sweet spots."

This would be a key factor in enabling the industry to evaluate the potential of developing the resource, Pecher said in a statement.

GNS Science researcher Stuart Henrys said the research was building to a point where there would be enough information to allow scientists to undertake scientific drilling off the North Island's East Coast region to learn more about the marine sediments and biological communities where hydrates occurred.

"Ground-truthing by scientific drilling will be the ultimate test of the quality of the gas hydrate deposits," Henrys said in the statement.

New Zealand had some of the most extensive deposits of the frozen form of methane in the world.

The largest gas hydrate province on the east of the North Island covered about 50,000 square kilometres.

Scientists estimated that if only a fraction of the deposit could be recovered economically, it would be the main source of natural gas for New Zealand for many decades. Endi