Small Country, Large Resource? Gas Hydrate Exploration in New Zealand

Natural gas hydrates, ice-like compounds of water and gas, are abundant in sediments on many continental margins and may constitute a significant energy resource. Several countries have embarked on research into gas hydrates aiming at developing this potential resource. Significant technological progress has been made in recent years including first production tests. New Zealand is a latecomer to focussed gas hydrate research with a first dedicated gas hydrates programme launched in 2010. Because of New Zealand’s remoteness and small population base, the economic case for gas hydrates may differ favourably from that of other countries. In this talk, we will present results from research into characterizing gas hydrate deposits offshore of New Zealand. We are taking a petroleum-system based approach by studying potential gas sources, gas migration, and reservoir quality. Key findings include evidence for a contribution of thermogenic gas in addition to microbial gas for hydrate formation, a strong link between fluid flow and gas hydrate deposits, and the need for detailed studies into reservoir quality. Seismic rock physics models allowed us to constrain gas hydrate saturation and we have identified several locations that are likely to contain concentrated hydrates. Geochemical profiles from a recent coring campaign on the other hand point towards limitations of the seismic method and emphasize the need for a multidisciplinary approach to better characterize gas hydrates in deep-sea sediments.