Research, published in Nature Communications, reports that the UK’s shale gas reserves are lower than they were previously thought to be.
Prof Stuart Haszeldine, Professor of Geology and Carbon Storage, University of Edinburgh, said:
“This laboratory study applies careful analyses of a type well established in hydrocarbon exploration, to the innovative topic of shale gas exploration. Small samples of organic shale gas source rock are heated in wet conditions where oil and gas are allowed to escape – mimicking nature.
“The existing public estimates of shale gas resource are paper estimates,
“The new study uses a different system of laboratory analyses (hydrous pyrolysis with a wet system), which better reproduces the departure of water and oil from the shale rock upon heating – leading to earlier (shallower depth / cooler temperature) oil generation and greatly improved draining of the hydrocarbons from rock. Hence the assertion that much less of the original hydrocarbon remains in the shale to be produced as an unconventional resource. A weakness is that there are still only few samples available – but those which have been used look to be selected from the most productive shales – so will be “optimistic” in oil and gas quantity.
“The new study then makes a comparison of those new analyses with real samples of core which has been drained of gas – and finds a good match, suggesting that laboratory measures do authentically represent the natural system. This is the 5x less number.
“The new study then makes a desktop evaluation of how much shale is currently buries into the correct depth/temperature window (based on the hydrous pyrolysis conditions for temperature) for generation. And finds that a much lesser volume of shale than that mapped by BGS is in that window. This is the 2x less number.
“Finally, the new study applies an arbitrary down grade from large resource to commercial reserve. This is stated to be a 10x reduction. There is no justification given, but that is a very typical reduction factor used as a rule of thumb, by commercial oil and gas exploration companies. This is the 10 years of consumption number.
“The results bring bad news to those hoping that northern England is floating on a bed of cheap and abundant gas. Abundant hydrocarbons may have been generated in the past, but have leaked away to the earths surface many millions of years ago. Not only have all those hydrocarbon horses bolted, but there is no longer a secure stable door to retain very large quantities of present-day gas in these shales. The shale rocks themselves have been fractured and leaked during oil and gas generation and are incapable of repair. If industry drillers in northern England do finally overcome the hazards of induced earthquakes, their drill pipes will reach deep down to the end of their imagined rainbow, only to find that nature has already stolen and removed the black gold.
“This study shows that 5 times less oil and gas remains in the rock than previously predicted, that the volume of useful shale buried to the correct depth with oil and gas present is also 2 times less than predicted, meaning 10 times less resource. And if conventional downgrades of commercial reserves are factored in, then the total available gas amounts to less than 10 years of UK gas consumption. UK Governments would be very unwise to rely on production of shale hydrocarbon from north England to fuel the country.”
Prof Andrew Aplin, Department of Earth Sciences, Durham University, said:
“Making accurate estimates of the amount of shale gas present under Northern England is a hugely uncertain game.
“In 2013, data from the US shale industry were used to guesstimate how much gas might be present in UK shales. Since then, results from a couple of wells have provided some very preliminary UK data.
“The approach here is different in that data from laboratory experiments are used to suggest how much gas might be present. The results suggest that there may be much less gas than the first estimates suggested. However, both laboratory and field approaches require huge extrapolations of very limited data and inevitably result in substantial uncertainty. Without a lot more field data from the UK, we just don’t know how big the resource might be.
“There are the additional uncertainties of the proportion of the total gas which might be recovered, how many wells will be needed and whether it is feasible to drill them for both societal and economic reasons. It is now almost 10 years since the first UK shale gas exploration well was drilled and we are yet to see any production. It has been a very slow journey.”
Prof Quentin Fisher, Professor of Petroleum Geoengineering, University of Leeds, said:
“The study presents some interesting experimental results but its conclusions should not be taken too seriously in terms of their implications for the volumes of gas within UK shales particularly as it only samples one core of the Bowland shale, which is known to be very heterogeneous. The only way to provide accurate estimates of how much gas is likely to be produced is to drill, hydraulically fracture and test many wells, which is exactly the intention of companies holding shale gas licences in the UK.”
Prof Mike Stephenson, Chief Scientist for Decarbonisation and Resource Management, BGS (British Geological Survey), said:
“This study uses an interesting new scientific technique, sequential high-pressure water pyrolysis, to estimate shale gas resources in the Bowland Shale Formation. This technique could help us further understand the shale gas potential of UK onshore basins.
“Early indications published today in Nature Communications, suggest that it is possible there is less shale gas resource present than previously thought, however the study considered only a very small number of rock samples from only two locations.
“BGS has continued to study resource estimation in shales over the past 16 years and further studies are still required to further refine estimates of shale gas resources.”
Prof John Ludden, Chief Executive, BGS (British Geological Survey), said:
“This study by Whitelaw et al., which was funded by a BGS PhD fellowship and involves BGS staff working with academic and industrial partners, further enhances our understanding of the shale gas potential of UK onshore basins. These data are of value for companies in helping them optimise their shale gas extraction technology and exploration. It is to be expected that shale gas reserves will vary across sedimentary basins depending on rock-composition, organic carbon contents and fracture and faulting patterns.”
‘Shale gas reserve evaluation by laboratory pyrolysis and gas holding capacity consistent with field data’ by Patrick Whitelaw et al. was published in Nature Communications at 16:00 UK time on Tuesday 20 August 2019.
Prof Stuart Haszeldine: “Stuart Haszeldine has no funding from the unconventional hydrocarbon industries, and has several independent academic publications on UK resources of fossil carbon. Stuart Haszeldine has had many years of research experience working with oil and gas companies. He is currently funded by UK research councils NERC and EPSRC to work on carbon capture and geological storage relating to industry emissions, and engineering and storage of carbon recapture from the atmosphere. He also holds funds to work on massive inter-seasonal storage of hydrogen. And is sponsored by Scottish Gas Networks, to work on conversion of methane gas networks to deliver hydrogen to domestic and business consumers.”
Prof Andrew Aplin: “I have no competing interests.”
Prof Quentin Fisher: “I conduct research and consultancy for the petroleum industry related to conventional reservoirs. I do not work on shale gas production for the petroleum industry. I believe my views on this are totally impartial and I have no financial gain to be made from supporting hydraulic fracturing.”
None others received.