What do the industry’s words and phrases really mean?
‘Conventional’ gas or oil is held between layers of rock and can be extracted quite easily by drilling a normal well.
‘Unconventional’ gas or oil is trapped tight in small holes and cracks inside certain rocks, so it can’t be extracted by ordinary drilling. To get at the gas or oil the drilling companies have to shatter the rock.
Shale is a sedimentary rock which contains this ‘unconventional’ gas (methane). In Fermanagh the shale layer is quite close to the surface, at around 500 – 1200 metres underground. In other countries, shale containing gas tends to be much deeper, e.g. in the USA it is usually between 2500 and 4000 metres below the surface.
Traditional fracking is a technique used since the 1940s to flush out conventional gas and oil, typically using around 80,000 gallons of water per ‘frack’. It was used in Fermanagh in the 1980s and in 2001 on a few test wells.
High volume hydraulic fracturing (HVHF) is a new technique for extracting
‘unconventional’ oil and gas. It was first used in the early 2000s but has only been commonly used in the USA since 2005. Unlike traditional fracking, it uses immense quantities of water (usually at least a million gallons per ‘frack’ and often very much more) and very high pressure. This is the technique proposed for extracting shale gas in Fermanagh.
Slickwater or fracking fluid is the mixture of water, sand and chemicals pumped at high pressure down well bores (pipes) to shatter the rock beneath. Some of the methane inside the rock will escape into these pipes and up to the surface.
Horizontal drilling is used with HVHF to allow operators to frack large underground areas.
Multi-well pads allow the operators to drill several wells on a single site, with horizontal bores extending in all directions. The plan for Fermanagh is to have at least sixty of these sites, each with twenty-four wells.
Flowback fluid is the liquid left after the fracking process – a mixture of fracking fluid, high concentrations of salt and other substances such as heavy metals and benzene. Some of this will stay underground and some will return to the surface.
Remember: Fracking in Fermanagh will be HVHF, using high volumes of fracking fluid at high pressure, drilling horizontally from multi-well pads, shattering the shale rock layer relatively near the surface, and producing large quantities of toxic flowback fluid.
Can they really frack without using chemicals?
When most of us talk about fracking, we mean the whole process of shale gas extraction, from start to finish. This includes preparation, drilling, pumping the fluid, shattering the rock, extracting the gas, processing and transporting it and maintaining the site and equipment. But when the industry talks about fracking, it only means the pumping, shattering and extraction stage. So, when operators say, for example, that they will not use chemicals, they are not talking about the whole process.
Is fracking and extraction possible without chemicals? There is little, if any, evidence to support the reality of chemical-free fracking. Even if it is possible, there is still a huge risk of soil, water and air contamination. Deep underground is a cocktail of toxic chemicals, harmless to us if undisturbed. HVHF will bring these to the surface in the millions of gallons of flowback fluid. The rest of the flowback fluid will lie underground, between two aquifers which provide the sources for Fermanagh’s and Donegal’s fresh drinking water. This fluid will contain high volumes of salt, heavy metals and benzene, all tragically toxic to humans and animals.
How will fracking be regulated?
The basic UK law which governs gas and oil licensing dates from the 1960s and has not kept pace with advances in scientific understanding and
technology. Even the most recent environmental laws do not specifically cover HVHF, which has moved so quickly in the last ten years and is still largely experimental.
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