Endeavour Funding

Gas Hydrates: Economic Opportunities and Environmental Implications

What are gas hydrates?

Gas hydrates (white, ice-like material) within submarine sediments (photo credit: GEOMAR, Germany).

Gas hydrates (white, ice-like material) within submarine sediments (photo credit: GEOMAR, Germany).

Gas hydrates are ice-like substances that contain natural gas (usually methane) that is surrounded by water molecules. They occur in conditions where temperature is relatively low and pressure is relatively high. In nature, this means they are common in marine sediments beneath the ocean at water depths over about 700 m, as well as in frozen soils (permafrost) in the Arctic.

Why study gas hydrates?

A future energy resource?
On the global stage, the main reason for studying gas hydrates is to understand the role they could play as an alternative energy resource. Gas hydrates are sometimes viewed as a ‘bridging fuel’ that could assist in the important transition from a carbon-dominated energy landscape, to one of cleaner, renewable energy resources. Gas hydrates are a type of fossil fuel, but they have the advantage that they are cleaner-burning than coal and oil. Countries like Japan, the U.S. and India have advanced government-funded research programmes that are investigating the energy potential of gas hydrates and a range of issues that would be involved in exploiting the resource. In the last decade, the New Zealand Government has also funded research programmes to investigate the potential gas hydrate energy resource in our offshore estate.

Global climate and ocean chemistry
The energy question is just one reason to study gas hydrates. There are several other major reasons to be interested in gas hydrates. One of these is the role that gas hydrates play in global climate and ocean chemistry, both in the past and in the future. For example, changes in ocean temperature can cause gas hydrates to break down, a process that can release methane gas into the oceans and have ‘flow on’ effects for ocean chemistry.

A species of ampharetid or ‘bristle worm’ that is extending into the ocean from the seafloor in an area of gas hydrate occurrence. Photo credit: Stefan Sommer, GEOMAR, Germany.

A species of ampharetid or ‘bristle worm’ that is extending into the ocean from the seafloor in an area of gas hydrate occurrence. Photo credit: Stefan Sommer, GEOMAR, Germany.

Seafloor ecology
Another reason for studying gas hydrates is to understand how they interact with biological communities on the seafloor. Gas hydrates influence the flow of methane through the seafloor, which is important for sustaining these so-called ‘chemosynthetic biological communities’ that live off the methane.

Submarine landslides
It is known that parts of the seafloor can collapse and cause enormous underwater landslides. These slides are typically much larger than ones on land and can generate devastating tsunamis. It has been suggested that the breakdown of gas hydrates could cause widespread sediment weakening, thereby contributing to the hazard of submarine landslides.

Opportunities and implications of energy extraction from gas hydrates

A submarine landslide off the coast of Gisborne occurs above gas hydrate-bearing sediments. Image credit: Joshu Mountjoy, NIWA, New Zealand.

A submarine landslide off the coast of Gisborne occurs above gas hydrate-bearing sediments. Image credit: Joshu Mountjoy, NIWA, New Zealand.

The background:
Gas hydrates exist beneath large areas of New Zealand’s seafloor. They present an unconventional energy resource for the country and if only a small fraction of the potentially huge resource can be commercially recovered, it would prove a major boost to our economy and energy security. The increasing national and global demand for energy is driving commercial exploration for oil and gas, and in New Zealand exploration in deep water off the East Coast may require drilling through gas hydrates. There is a need to assess the potential of the gas hydrates resource in terms of economic viability, production hazard, and environmental implications, contributing base-line evidence for informed decision-making on future development.

The implications:
Because gas hydrates are an important part of the natural marine environment, these recent developments highlight a need for: (1) an assessment of the potential environmental impacts of producing natural gas from (or beneath) gas hydrates, and (2) a better understanding of the role that gas hydrates could play in New Zealand’s future energy demand. There is also a need to understand socioeconomic implications of developing the gas hydrate energy resource.

The approximate distribution of gas hydrates in New Zealand’s offshore East Coast

The approximate distribution of gas hydrates in New Zealand’s offshore East Coast

Our research:
By undertaking marine, economic and social science research, our team will investigate the balance between economic opportunities, cultural values and environmental risks associated with extracting gas hydrates. We aim to determine where and how gas hydrates could be produced economically, while also investigating whether production would be socially and environmentally acceptable. Our social engagement strategy will encourage informed discussion between scientists, government, industry and the public about the role of gas hydrates in New Zealand’s future energy landscape and our responsibilities for the natural environment, both locally and globally. In our research programme we pose two high level questions:

  • Will feasible hydrocarbon production scenarios, either directly from gas hydrates or through gas hydrates, significantly impact seafloor stability, ecology or ocean biogeochemistry?
  • What are the likely socioeconomic implications of gas hydrate production in New Zealand?

Contact:

Dr. Jess Hillman (GNS Science)
Phone +64 4 570 4207

Dr. Ingo Pecher (University of Auckland)
Tel: +64 9 373 7599
Email: Ingo Pecher