Darby said in Wellington earlier this week that New Zealand’s sustainable energy future would depend, in part, on successful carbon capture and storage projects.

“New Zealand’s energy usage will continue to increase,” he said. “I believe this must be accompanied by geosequestration.”

Carbon capture and storage was already happening in different parts of the world, such as at the Norwegian North Sea Sleipner field, where natural gas was extracted and the associated carbon dioxide re-injected.

In New Zealand, it was also happening with the onshore Taranaki Kapuni gas field, where CO2 re-injection had been occurring for several years.

CO2 disposal options included using depleted oil and gas reservoirs, deep coal seams, large underground voids and cavities, or deep unused saline water-saturated reservoirs.

CO2 disposal could enhance oil and conventional gas recovery, as well as coal seam methane production.

Darby said any geosequestration projects needed to be near existing infrastructure, particularly pipelines “which are found largely in Taranaki”.

The Maui field could potentially store up to 300 million tonnes of CO2, while Kapuni could hold up to 84MMt at Kapuni.

“That is total potential of 100 years of carbon,” Darby said.

But New Zealand was different from other geosequestration regions because of its active tectonics, challenging subsurface structure, complex reservoirs, leaky seals and high anisotropic stress.

GNS Science, Genesis Energy and Solid Energy are partners in Australia’s CO2CRC, which is supported through the Australian Government’s Cooperative Research Centre Program.

Darby said understanding New Zealand’s petroleum systems would be key to applying CO2CRC technology in a New Zealand setting.

Current work included developing an inventory of possible storage sites, studying the effect of CO2 on reservoirs, fault studies and monitoring of CO2 flux.