Shale gas or oil is trapped within impermeable shale rock, as opposed to conventional natural gas deposits such as those under the North Sea, which are trapped below impermeable rock. Therefore simply drilling down to it is not enough. The rock has to be fractured at high pressure or to get the gas or oil out.
Fracking techniques have for some years been used in the UK in conventional deposits, but mainly offshore. However, the Government is now backing a big push to extract gas and oil from the shale rock onshore to increase UK production of gas and oil. The Government says that this would reduce reliance on imports and generate economic benefits. The largest expanses of shale rock are situated in the countryside, and this is where the majority of economically viable sites are likely to be. Little exploratory drilling has occurred to date in the UK’s shale deposits and it is not yet known how much gas or oil will be commercially recoverable. The USA has been developing shale gas rapidly over the past 10 years now has several hundred thousand shale gas wells. Experience from the USA shows fracking can be a substantial environmental hazard. The robustness of the safeguards put in place through regulation of shale gas and oil development is critical if environmental harm is to be prevented.
Fracking involves drilling down to over 2km vertically, then laterally outwards for as much as 3km. The gap between the lining of the borehole that has been drilled and the surrounding rock is then sealed up with concrete. The well casing is perforated to allow fracking fluid to get into the rock, and gas to get out. Then, on a typical well, up to 10 million litres of water containing sand, lubricating fluids and other additives are pumped into the borehole under extremely high pressures. This opens up cracks in the shale for up to 50 metres. The cracks are kept open by the sand particles when the pressure is released, so the shale gas can escape. A well head is then installed to capture the released gas. The drilling and fracking equipment is then taken away.
We all have a role to play to reduce our energy consumption, but we are realistic and recognise there are no easy solutions to our energy mix. However, we rapidly need to move away from fossil fuels towards low carbon energy.
The Government’s Strategic Environmental Assessment (SEA) process highlighted significant uncertainties associated with the impacts of shale gas. The impacts of shale oil are even more uncertain – the SEA did not adequately cover shale oil. We believe that the Government needs to do more to tighten the safeguards to adequately protect the countryside and climate, and reassure the public. We also believe the shale gas and oil operators need to do more to demonstrate that they are following the very best practice. We would like to see a more precautionary approach given the major uncertainties, and the potential cumulative impact on the landscape and climate change.
Based on current information, we do not oppose exploration for shale gas in principle, provided it meets certain conditions. Our Policy Guidance Note sets out those conditions and how we are trying to secure them. We will oppose proposals which fail to meet these conditions. The conditions are that shale gas development should not:
- Harm the beauty and tranquillity of the countryside; in particular vehicle movements to transport the large volumes of water needed for fracking have the potential to significantly reduce tranquillity
- Pollute or natural resources unsustainably, especially water
- Undermine meeting the country’s climate change commitments.
The Government argues that shale gas is consistent with the transition to a low carbon energy system, but this is only the case if it replaces a higher carbon energy source. An example of a relatively higher carbon option is coal power without measures to capture and store greenhouse gases, which are not yet available anyway. The carbon benefits of shale gas are not certain, but it is even more unclear how shale oil exploitation can fit with an overall reduction in carbon given that it is a relatively high carbon fuel.
Without effective global agreements to reduce greenhouse gas emissions, new fossil fuel exploitation − including shale gas and oil − will increase overall emissions and the risk of climate change.