by Michael Edmund, Editor
Shale Gas: Separating fracked from fiction
There have been suggestions that America's development of shale gas offers a model for investment in renewable technologies elsewhere. Sensitive ears may have detected a whiff of triumphant jingoism in an election year; others may have heard the grating sound of slick Industry PR machinery and determined journalism rubbing against each other. Meanwhile in Europe, hope has been expressed in Poland that her shale gas reserves might finally decouple economic growth from pollution. And, it must be said, at the same time reduce her dependence upon energy imported from Russia. Elsewhere, tremors beneath England forced a temporary halt to prospecting, while France has outlawed it altogether.
Confident assertions have also been made that the US will be completely independent of imported oil by 2030; these have been amplified by extravagant claims of an energy resource that is "effectively infinite". One European commentator has observed that we may not actually be running out of oil at all: "the problem facing us", he sorrowfully states, "may not be that there is too little oil, but that there is too much". Meanwhile, talk of "enough oil to deep-fry humanity"; of poisoned drinking water; and of "much of the Earth becoming uninhabitable and billions of people displaced" together offer a much less optimistic vision of the future. YouTube videos of flames shooting out of kitchen taps do little to dispel this apocalyptic image.
What implications are there for Europe's carefully-constructed energy strategies? And for her still-fragile economies? Does shale represent a new era of cheap, plentiful energy, a Promised Land if you will; or is it the gateway to Armageddon?
Energy and climate are clearly both too important as issues to be dominated by incendiary rhetoric. Truth invariably lies somewhere between two extreme positions, and we thought it was time to examine some of the facts.
What is it and how much is there?
At the centre of the debate is shale, the commonest sedimentary rock on Earth. Shale is composed originally of mud, deposited over millions of years in very slow moving waters such as lakes, lagoons or river deltas. Normally grey, the rock may be black where significant quantities of organic matter have also been deposited; this of course may offer a clue to the presence of economically-useful hydrocarbons. An important physical characteristic of shale is that it may break along parallel planes within the structure, a property known as fissility. These so-called bedding planes arise from the orientation of the mineral flakes within the rock, and from the existence of layers whose composition differs slightly according to variations in the mud originally deposited.
Hydraulic fracturing, or fracking, uses pressurised fluid to create and propagate fractures in the bedding planes to allow the release of trapped hydrocarbons. The new technology unlocks enormous quantities of gas, and makes shale one of the most important natural resources upon the planet. This is no exaggeration: there are over 6,500 trillion cubic feet of shale gas on the planet, according to the best current estimates. China's shales alone are thought to contain some 1,275 trillion cubic feet; those in America over 850 trillion cubic feet; according to one estimate, this could supply the US for over a century. For comparison, Russia possesses the largest known conventional reserves of natural gas, some 45 trillion cubic feet.
If these figures are impressive, those for oil are truly staggering. A great deal of the current American enthusiasm stems from the oil being extracted from the Bakken Shale in North Dakota and the Eagle Ford Shale in Texas: there may be in excess of 400 billion barrels there, though the amount recoverable with current technology may be less than 10 billion barrels. However, these figures are dwarfed by those for the Green River formation in Wyoming. It is estimated to contain about 3 trillion barrels of oil, of which half may be recoverable, depending on available technology and economic conditions. Saudi Arabia currently holds the largest known conventional reserves of crude oil, some 263 billion barrels. However, although Green River is a shale formation, the oil it contains is not amenable to fracking. It must instead be pyrolysed: in effect to be "cooked", to release it.
Clearly, there are considerable economic and geopolitical implications of a possible shift in hydrocarbon production from the Middle East and Russia to the United States.
How clean is it?
There are environmental implications too: gas is a 'cleaner' fuel. According to figures from the US EPA, generating electricity from gas produces less than half the CO2, while reducing SO2 emissions by over 99% and NOx emissions by two thirds. However, these advantages must be balanced against other potential environmental issues associated with the production of shale gas. The fracturing wells require large amounts of water, which may affect availability for other uses, particularly in relatively dry regions. It may also affect aquatic habitats, while both the gas that is not collected for consumption and the chemicals used in the process may leak into the surrounding rocks, or even affect the water table.
Does fracking cause earthquakes?
38 seismic events associated with fracking in British Columbia were detected by Natural Resources Canada. They ranged between magnitudes 2.2 and 3.8 on the Richter scale. In an area being test drilled in England, one event of magnitude 2.3 was followed 7 weeks later by a second of magnitude 1.4.
Globally, there are over one million naturally-occurring events in the Richter range 2.0 - 2.9 per year. They are classed as minor, and may be felt by few to many persons up to several miles or kilometers from the epicentre. There are over 100,000 natural events in the range 3.0 - 3.9; they are also classed as minor, and are likely to be felt by many to all persons in the area, but very rarely cause damage.
Behind all this is one overarching observation. Apart possibly from the odd atom in nuclear reactors, there is exactly as much carbon on the planet today as there has always been: fossil fuels comprise a colossal natural carbon capture and storage system. And in the case of the Bakken Shales, that carbon has been sequestered away for over 350 million years, since the Devonian Period. The earth's average temperature during that time was approximately 6 degrees higher than the pre-industrial period, atmospheric CO2, at 2200ppm was 8 times the pre-industrial level, and mean sea level was over 100 metres above that of today.
Shale Gas may well offer short-term economic advantages, while its exploitation probably causes no more environmental damage than current mining technologies. But burning it will surely exacerbate long-term anthropogenic climate change. When looking into our Devonian past, we surely do not wish to see a reflection of our future. For climate change is surely more than fiction.