Gas pressure

With global oil prices soaring and continued concerns over the security of gas supplies, the need to exploit alternative sources of fossil fuels has never been greater.

The US Geological Survey estimates that the amount of organic carbon stored as frozen natural gas under the Earth’s surface is greater than the world’s oil, coal and non-frozen, free gas reserves combined. Large reserves are thought to exist under the oceans off the coasts of Japan, China, India, Canada and Russia.

Like conventional natural gas, the methane held within these reserves was formed as a by-product by microbes feasting on organic matter trapped in sediment. In cold, high-pressure environments, water molecules form open solid lattices that trap methane molecules without chemical bonding — methane hydrates. It is thought that around 55 million years ago some event caused vast quantities of gas to be released from these structures, causing abrupt global warming.

Methane from hydrates is more environmentally friendly than normal natural gas as it produces less carbon dioxide when burned. However, accidental creation of a large uncontrollable leak could be catastrophic. Identifying and extracting methane from hydrates for commercial use thus presents an enormous technical challenge that has swallowed millions of research dollars in countries including Japan, Canada and the US.