Friday, 6 March 2015

How much shale gas lies beneath our feet… by Dr Clement Uguna

Dr Clement Uguna at work in the laboratory
Most people these days will have heard of shale gas.  It’s the unconventional gas stored within fine grained mud rocks and its extraction has been hitting the UK headlines over the last couple of years. Dr Clement Uguna, a new Research Fellow at the British Geological Survey and the University of Nottingham, is pioneering research into answering questions about how much gas lies beneath our feet...
My research, within the Organic Geochemistry Laboratory and Centre for Environmental Geochemistry, focuses on understanding the fundamental mechanisms through which gas is generated and retained within deeply buried rocks in the UK and overseas.
  
Although the amount of research on shale gas has vastly increased during the past decade, the mechanism of how shale gas is actually generated and how it is retained within shale is not properly understood. Shale gas is dry and composed mainly of the fossil fuel methane, and we know it is formed at high temperatures and pressures deep in the subsurface. What we really need to know though is whether the amount of methane generated is greater at particular depths (temperatures and pressures) in the Earth.

Dr Clement Uguna between his team members
(left) Prof Colin Snape (right) Dr Christopher Vane
A few studies have so far investigated the  process of gas formation by analysing natural shale rocks or used 'pyrolysis' techniques but have not replicated subsurface conditions to simulate gas generation.  I have devised a specialised experimental technique (called high water pressure pyrolysis) that does closely replicate subsurface conditions beneath us to simulate shale gas generation as a function of the temperature and depths under the Earth subsurface. I can then calculate the amounts of methane and other hydrocarbon gases generated from my experiments which will be significant in improving the assessment of gas stored at different depths across the UK (and this varies a lot).

Overall my aim is to better understand the amount of gas in the shales buried deep under the UK, and then others can decide on whether extraction is economically viable.
 
Dr Clement Uguna at work in the laboratory
By Clement

Clement is a Research Fellow within the Centre for Environmental Geochemistry at the British Geological Survey and the University of Nottingham where he is working with a team including Prof Colin Snape, Dr Christopher Vane, Dr Will Meredith and Vicky Moss-Hayes.

For more details have a look at Clements recent paper: Uguna, C.N., Carr, A.D., Snape, C.E., Meredith, W. 2015. High pressure water pyrolysis of coal to evaluate the role of pressure on hydrocarbon generation and source rock maturation at high maturities under geological conditions. Organic Geochemistry. 78, 44-51.

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