The UK is rapidly coming to a pivotal point in its engineering policies. Will it exploit its massive potential of shale gas or will it let itself be steered away from a new gas revolution out of environmental fears? At a recent special summit organised by the UK Institution of Mechanical Engineers (IMechE), engineers explained why the fears are overblown. They argued strongly that fracking can be done safely and with minimal impact on the environment.
In his budget speech in March, the UK’s Chancellor of the Exchequer, George Osborne, spoke of the “need to cut energy costs” and said the government would be “investing” in “a shale gas revolution” (as well as nuclear power and renewables). The Ukraine crisis has added another dimension to the debate. Michael Fallon, the Energy Minister, said in a TV debate that “shale gas is important to the UK’s energy security of supply. Russia’s dealings with the Ukraine have exacerbated this.”
The prize offered by the UK’s shale gas resources could well be huge. Indications so far are that the country has enough recoverable shale gas to completely replace its gas imports for more than a century. (See below.)
However, investment has so far been modest, despite the Chancellor’s upbeat words. For example, in February this year, Lord Browne, former Chairman of BP and now Chairman of Cuadrilla Resources, an independent UK company specialised in shale gas exploitation, indicated that £100 million is currently being spent on shale gas exploration in the UK. This is a very small amount compared with the £2 billion a year subsidies for renewable electricity in the UK and the £1billion one off programme for two Carbon Capture and Storage (CCS) demonstrations.
“Safety is all about well design and construction”
Total, the French oil giant, announced £30M investment in shale gas in the East Midlands and Centrica is reported to have taken a 25% stake Cuadrilla’s Bowland activities. Over the last four years, smaller companies such as Cuadrilla and IGas have been investing in drilling in the Blackpool and West Sussex areas and the Midlands. These are exploratory drillings regulated by UK Onshore Operators Group (UKOOG) under strict UK government Department of Energy and Climate Change (DECC) rules.
BP and Shell have ruled out activity in UK shale gas development for the moment. It has been said about the US shale gas revolution that smaller more agile players have outmanoeuvred the big guns on projects calling for rapid decision-making and low costs. Gas prices in the US are so low as to make shale gas production barely profitable.
Two million wells
Probably the main reason why activity has been restrained so far is resistance from local populations and policymakers. People are afraid that fracking will destroy the landscape, pollute drinking water aquifers and cause earthquakes. At a recent Summit on Shale Gas organised by the Institution of Mechanical Engineers (IMechE) in London, leading operators from the UK and elsewhere made it clear that they believe shale gas exploitation and production can be done safely.
According John Blaymires, chief operating officer of IGas Energy – a company carrying out drilling at a site in Barton Moss near Manchester which is permanently besieged by protesters – fracking is not even the issue. “Safety is all about well design and construction”, he says.
At the ImechE conference in London Blaymires, along with other speakers, said that, when shale gas drilling and extraction are carried out in compliance with the regulations, they are as safe as any other form of hydrocarbon recovery.
“Fracking has been carried out in more than two million wells worldwide without a single instance of contamination of drinking water”
More fundamentally, he argued that the case against shale gas extraction made by its opponents is simply wrong. For instance, he said that fracking has been carried out in more than two million wells worldwide without a single instance of contamination of drinking water traceable to the technique. Where the procedure has caused tremors, these have been of low intensity and associated with pre-existing geological conditions.
In a balanced energy generation scenario, he said, shale gas will tend to displace the use of coal and as it has done in the US, can therefore contribute to reduced carbon dioxide emissions. And once drilling and fracking have been carried out, the surface installations required for shale gas extraction are minimal and do not ‘industrialise’ the landscape.
In the UK, the situation has been bedevilled by the fact that the one instance in which fracking has been carried out did cause two small earth tremors. These occurred in 2011, following operations carried out by another company, Cuadrilla, at Preese Hall near Blackpool. An analysis commissioned by the Department of Energy and Climate
Change, however, recommended that with safeguards – including the initial injection of smaller amounts of fluid and a lower threshold at which operations would be suspended if tremors were to be detected – there was no reason to suspend frackingat that site or elsewhere.
Combination of techniques
The contrast with the situation in the US is stark. There, exploitation of shale gas resources has grown to become a significant industry that could turn the country into a net exporter of liquid natural gas before this decade is out. That reminder was delivered to the symposium by Chris Poole, head of engineering and technology development for Weir Group, which has been supplying wellhead equipment to the US industry for six years.
Artificially stimulating the flow of hydrocarbons from a well is not new, said Poole. The earliest attempts to do so in the US date back to the 1860s, and involved lowering explosive charges down the boreholes of oil wells. The fracking technique itself, though more recent, is alsowell-established in the US. Initial experiments took place in Kansas in 1947. Just two years later, the first commercial applications of the technique were carried out for oil exploration in Texas and Oklahoma by Halliburton.
Fracking for shale gas, however, did not take place in the US until the mid-1990s, and even then was initially inconsequential, he said. What made the US shale gas ‘revolution’ was its coupling with the technique of horizontal boring – making boreholes run out at angles of up to 90° from the initial vertical shaft – which was perfected during that decade.
What made the US shale gas ‘revolution’ was its coupling with the technique of horizontal boring
A consequence of that combination of techniques, said Poole, has been pad-drilling – packing a series of vertical boreholes into a single, compact area at the surface, each borehole perhaps as little as 10m from its neighbours, and each also supporting horizontal extensions in different directions. That way, a wide underground volume can be exploited with little surface structure. Once the boreholes have been drilled, the subsequent fracking involves no permanent structures but only portable, or easily removable, equipment, he said.
Typically, this process will involve tanks for the water and chemicals, with all the other equipment being truck-mounted.
If the US experience were to be repeated on this side of the Atlantic, just how much shale gas is there underneath the UK’s landmass?
Analysis of the available data is likely to come up with only an approximation, said Mike Stephenson, director of science and technology for the British Geological Survey (BGS), part of the UK’s Natural Environment Research Council, which last year published probably the most detailed attempt to estimate shale gas resources in a particular area yet carried out in Europe.
The report, commissioned from the BGS by the Department of Energy and Climate Change, focused on one of the UK’s primary areas for prospective shale gas exploitation – the Bowland-Hodder shale formation that lies under an area encompassing much of Lancashire and Yorkshire and, at its southern fringe, parts of Cheshire, Derbyshire, Nottinghamshire and Lincolnshire.
The study is based on information derived from seismic and geological testing in the past and on core samples extracted from the boreholes that have been drilled in the area previously, says Stephenson. The resulting data was then loaded into a 3D computer model to produce what he said is an accurate representation of shale formations in the area.
Nevertheless, the study provides only a broad estimate of the region’s potential. The reason for this involves an understanding of the distinction between the terms ‘resources’ and ‘reserves’, he said. The first refers to the total shale gas that may exist in an area, whereas the second is the proportion of that amount that may be practicably recoverable. The amount of reserves depends on geology and technology but also political and social aspects. Whatever the amount of shale gas that may exist, public opinion must accept that it can be extracted safely as well as economically.
A potentially massive resource exists that can be exploited without the need for any great technological innovation
As for resources, not only is it necessary to know the extent of the shales involved but also the actual concentration of hydrocarbons they may contain. Ultimately, the only way to discover that is to drill into them, said Stephenson. So until targeted exploratory drilling takes place, only estimates based on likely concentrations can be hazarded.
Nevertheless, even this one area could offer substantial prospective resources – the report estimates that at least 23.28 trillion m3 of shale gas are likely to be in place and possibly as much as 64.62 trillion m3. To put those figures in context, UK imports of natural gas in 2013 were some 56 billion m3. So if 10% of the lower estimate of these resources were recovered, just this one area would be equivalent to 41 years of gas imports.
And the Bowland region is just one of several areas in the UK that include shale formations likely to contain recoverable gas. Others are the central Lowlands of Scotland, Hampshire, South Wales and the Weald area in southern England. In the last-mentioned area, the BGS has been carrying out a similar exercise to estimate resources, and the resulting report is due for publication soon.
The UK is coming to a pivotal decision-making point in its energy policies. A potentially massive resource exists that can be exploited without the need for any great technological innovation. Instead, the battle will most likely involve fears of environmental degradation and prejudice against the use of hydrocarbon fuels.
Michael Knowles was a Member of the IMechE energy and power committees variously from 1980 to 2006. After 50+ years of experience in the UK energy industry, including as Energy Sales and Marketing Manager at Babcock. See also his earlier article for Energy Post: “UK electricity market: financiers are holding the government over a barrel”.
Part of this article was written by Mike Farish for the IMechE Members’ magazine Professional Engineering in April under the title “Untapped resources”. It is gratefully republished here with permission from the publisher.