Scientists at the British Geological Survey (BGS) have today published ground breaking research that will reduce the risk of earthquakes and borehole damage caused by fracking.
Fracking for shale gas has proven controversial in the UK. This controversy intensified after the tremors, caused by fracking, occurred near Blackpool in 2011. All rocks in the UK are under stress and when this is released it can result in an earth tremor. As a result of the tremors, the UK government ordered an expert panel from the Royal Society and Royal Academy of Engineering to investigate the safety of fracking in the UK. A key recommendation from the panel was to undertake a complete review of stress data for the UK, and the BGS was best placed to undertake this review. BGS has totally overhauled the available data for the UK, and is recommending that all new boreholes drilled for shale gas are logged by borehole imaging tools to better understand in-situ stress.
In the early 1990s mapping of the UK in-situ stress orientation, was hampered by the limited data and computing power available at that time. In the intervening period the coal and oil industries have begun collecting a new type of data called borehole imaging which scans the entire inner circumference of the borehole. This allows zones of the borehole wall that have been widened by in-situ stress (borehole breakouts) to be identified. The new data allows breakouts to be imaged much more clearly and so we can interpret much smaller features allowing breakouts to be identified in many more wells under UK stress conditions.
BGS now has access to data from over 90 of these boreholes from the coal and oil industry and has identified features in 37 of these which stretch from the Peak District to the Scottish Border. The BGS compared this new data with the 1990s data and, although we have not changed the basic stress orientation, we have massively decreased the uncertainty of borehole breakouts. This will help to assess the in-situ stress orientation, ensuring that regulators assessing well safety have the best data available to allow them to make properly informed decisions about borehole integrity. The BGS hopes this will allow the Department of Energy and Climate Change (DECC) and the Oil and Gas Authority (OGA) better information to properly assess the risks of any fracking proposed in new boreholes.
Professor Mike Stephenson, Director of Science and Technology at the BGS, commented “This research is crucial to the regulators and the oil and gas industry as it is an easily applicable technique that can highlight parts of boreholes that may contain evidence of stress that is already present in rocks before fracking.”
For further details or to arrange media interviews please contact:
Sarah Nice, BGS Press Office, Keyworth, Nottingham, NG12 5GG
Office: +44 (0)115 936 3605 Mobile: +44 (0)7989 115657
E-mail: sebr@bgs.ac.uk Twitter @Sarahnice1
The following are available for interview:
- Andy Kingdon, British Geological Survey
Link to paper: http://www.sciencedirect.com/science/article/pii/S0264817216300344
For additional information go to: www.bgs.ac.uk
Photographs are available from our ftp server: ftp://ftp.bgs.ac.uk/pubload/bgspress/In-situ%20Stress/
Free for media use with this acknowledgement: British Geological Survey © NERC
The British Geological Survey
The British Geological Survey (BGS), a component body of the Natural Environment Research Council (NERC), is the nation’s principal supplier of objective, impartial and up-to-date geological expertise and information for decision making for governmental, commercial and individual users. The BGS maintains and develops the nation’s understanding of its geology to improve policy making, enhance national wealth and reduce risk. It also collaborates with the national and international scientific community in carrying out research in strategic areas, including energy and natural resources, our vulnerability to environmental change and hazards, and our general knowledge of the Earth system. More about the BGS can be found at www.bgs.ac.uk.
The Natural Environment Research Council
The Natural Environment Research Council (NERC) is the UK’s main agency for funding and managing world-class research, training and knowledge exchange in the environmental sciences. It coordinates some of the world’s most exciting research projects, tackling major issues such as climate change, food security, environmental influences on human health, the genetic make-up of life on earth, and much more. NERC receives around £300 million a year from the government’s science budget, which it uses to fund research and training in universities and its own research centres. www.nerc.ac.uk