Methane hydrate - natural gas frozen into the sea bed – has recently been announced by scientists employed by some of the world’s major IOCs as a new energy source, with the potential to contain more energy than all the world’s known coal, oil and gas reserves combined (although only a limited proportion of this is expected to be harvested economically based on current technology and gas prices).
Research into the viability into methane hydrates has been ongoing for some years, with US funding into the study of methane hydrate as a viable fuel source being authorised during the Clinton Administration under the Methane Hydrate Research and Development Act of 2000. It wasn’t until 2003 that geologists announced that they had successfully tapped into the resource in the Mackenzie River delta in the Canadian Northwest Territories. The limitations of drilling & processing technology and viability of extraction meant that further methane hydrate drilling was limited. Recent advances in both the understanding of the extent of reserves and in the technology required to extract the energy have brought methane hydrates back onto the energy agenda.
Until recently, methane hydrate has been seen by upstream operators as a nuisance to be overcome in the process of drilling new wells. It forms at low temperatures and high pressures and can be found in sea-floor sediments and the arctic permafrost. The deposits are stable in the extreme cold and the crushing weight of deep water, but are extremely dangerous when they build up inside the drill column of a well. It is these characteristics that led methane hydrates to be assessed by the US Oil Spill Commission[1] as a possible factor in the BP Deepwater Horizon disaster in the Gulf of Mexico in 2010.
Statoil, the Norwegian state oil company, has recently suggested that methane hydrates be reclassified from a nuisance blocking agent to a potentially significant fuel resource. Other major energy sector players are also involved in the exploration of methane hydrates. JOGMEC expects to be extracting gas from this source as early as 2013 from wells lying off Japan’s south-west coastline, with an expectation that this new source of gas could supply Japan’s energy needs for anywhere from 100 to 300 years (depending on recoverable quantities and future gas usage).
There are environmental concerns that temper the enthusiasm for offshore methane hydrate extraction. Fears of a repeat of the GoM disaster are at the forefront of these concerns, along with worries that melting hydrate can cause landslides as it decomposes, resulting in tsunamis which can cause untold damage to coastal communities. Additionally, methane is a highly potent greenhouse gas, and unexpected releases from the deposits under the sea bed or permafrost could cause additional damage to the ozone layer.
Whether or not methane hydrates will supply a large part of our energy needs in the future is still dependent on the existing technology, the availability of easy-source free natural gas, the environmental concerns, and on current and predicted future gas prices. With global gas usage expected to continue to rise, it will certainly remain on the agenda.
[1] Full report can be found at: http://www.oilspillcommission.gov/sites/default/files/documents/DEEPWATER_ReporttothePresident_FINAL.pdf
Posted by David Balchin on the 15th of February 2012
