Thu 3 Mar 2005 at 18:30 PM
Natural Methane Hydrates - Their Future Effect on The World
David Long, Researcher, British Geological Survey
Sponsorship is provided by Wood Mackenzie.
This event occurred on: Thursday, 03 March 2005, 6:30 p.m.
The pressure and temperature conditions that cause hydrates to form in pipelines also occur naturally. These conditions are found in two main areas, in areas of permafrost and in deep water. Natural occurrences of hydrates have been found or inferred for most of the world's continental slopes and onshore in the Arctic where there is extensive permafrost. Hydrates are a potential resource because up to 164 cubic metres of methane is held in 1 cubic metre of methane hydrate. It has been claimed that globally hydrates contain twice as much carbon as all other fossil fuels combined. Therefore methane hydrates an important aspect to bear in mind when considering a country's Exclusive Economic Zone. However, they also pose a hazard to hydrocarbon operations in deepwater and they may be an important contributor to global climate change. Hazards include the de-stabilisation of existing hydrate due to warming induced by drilling or pumping of fluids, and the puncturing of a hydrate cap rock of a gas pocket below the zone where hydrate is stable. Also the hazards are due to drilling providing a conduit for deep gas to migrate to seabed through the hydrate stability zone forming hydrate around the riser or at the seabed interfering with the blow-out preventer. Because of their large volumes any release of methane (a greenhouse gas) from natural hydrates, by human activity or caused by climate change, may modify the atmosphere and cause further climate change. Also the destabilization of methane hydrates has been linked with many of the major submarine slides around the world. Therefore even if they are not exploited as a resource, naturally occurring methane hydrates can impact on all of us.
Following a degree in Geology from Leicester University and a degree in Engineering Geology and Geotechnics at Leeds, David Long joined the British Geological Survey more than 25 years ago--initially as a member of the Engineering Geology group working onshore, but was soon involved in looking at geohazards offshore. David has spent extensive time mapping the shallow geology of the North Sea and in the deeper water west of the UK, in addition to short periods overseas. David has participated in many international cruises including the ODP drilling of the Amazon Fan. David is member of the Offshore Site Investigation and Geotechnics committee of the Society of Underwater Technology holding several positions.