Environmental factors associated with hydrates extraction; physical and chemical mitigation and a marine consent

Abstract

Gas Hydrate is a valuable potential alternative energy resource, but exploration of this resource faces significant environmental risk. This paper will discuss the fact that hydrates likely play a role in stabilising the sea floor, and drilling therefore has the potential to destabilise this environment, causing sediment to be disturbed on varying scales and with varying impact on marine life. This impact may range from suspended sediment in the water column and associated effects on marine life, through to extensive slumping of the marine shelf and associated generation of tsunamis. There are also chemo-synthetic bio-organism colonies associated with gas hydrate deposits that are not well understood or researched. This lack of information is likely to have a bearing on the ability to secure resource consents under the New Zealand EEZ Act. This paper discusses some mitigation options available for consideration during the resource consent process, using international examples, including from Japan. Japan is investigating methane-hydrate development, but is concentrating its efforts on relatively flat stretches of the seafloor off its coast. This acts to minimise the chances of a landslide, according to the Research Consortium for Methane Hydrate Resources. This paper does not consider the role of methane in climate change, as this debate is well covered in other fora, but we discuss the options for recovery of natural gas from CH4-hydrate deposits in sub-marine environments using injection of CO2 as a suitable strategy towards net-zero emissions energy production.

AAPG Datapages/Search and Discovery Article #90348 © 2019 AAPG Asia Pacific Region Geosciences Technology Workshop, Gas Hydrates – From Potential Geohazard to Carbon-Efficient Fuel?, Auckland, New Zealand, April 15-17, 2019