28th February 2014
A freedom of information request has confirmed that Cuadrilla carried out no seismic surveys in the Balcombe area and is relying on data from the 1990s, which one geologist has said is inadequate.
Last year, Cuadrilla drilled a vertical and a horizontal oil exploration well at Lower Stumble in Balcombe. It is currently applying for planning permission to flow test the horizontal well. It wrote to Balcombe villagers last month confirming that the horizontal well had been drilled through an oil-bearing layer of micrite limestone and it had no plans to carrying out fracking at Balcombe because the micrite was naturally fractured.
The FOI request asked the Department of Energy and Climate Change (DECC):
- Whether Cuadrilla had obtained any new 2d or 3d seismic data within the licensed area round Balcombe?
- Was it commissioned by Cuadrilla or was it obtained elsewhere?
- If it was obtained elsewhere, where was it from, what date was the survey and was it possible to see this data?
DECC responded to the request today saying the latest seismic data for the area was on the UK Onshore Geophysical Library http://maps.lynxinfo.co.uk/ukogl_new/
[Unfortunately this link doesn’t work and should be http://maps.lynxinfo.co.uk/webmap/index.html# ].
The response continued: “Once the map comes up on the screen, if you zoom in on the area of interest and click on the green lines (which show seismic information) you will be able to view the seismic data for that area.
“DECC can confirm that Cuadrilla have not carried out any seismic surveys in the Balcombe area subsequent to the data available via UKOGL.”
The map shows two sets of data, both 2d seismic surveys, which appear to have been conducted in 1990 and 1980.
David Smythe, emeritus professor of geophysics at the University of Glasgow, wrote a critique of Cuadrilla’s drilling last year. He said the only available data, the 2d seismic profiles referred to by DECC, was “inadequate for the purpose required”.
He said: “Before any horizontal drilling was permitted, a full 3D seismic survey should have been carried out, as Cuadrilla has already done in Lancashire.”
The micrite layer that Cuadrilla is targeting is only 33 m thick. Professor Smythe said: “Horizontal drilling cannot reasonably be carried out without a 3d seismic survey of the district”. He predicted that the horizontal well would probably stray into the Kimmeridge Clay, which, he said, “has been identified by DECC as the most important shale gas resource in the UK, after the Bowland Shale in north west England.”
The full response to the FOI request can be read here: https://www.whatdotheyknow.com/request/geophysical_survey#incoming-488076