The report “First Studies on the separation of the Bowland-Hodder shale unit from coal mining activity in the East Midlands” was tasked to take the existing available data from the Coal Authority, borehole data and existing seismic surveys as a first step to looking at the separation distances between old coal workings and the two borehole sites at Tinker lane and Springs Road. “This is to be used for public engagement purposes”.
The conclusions from the report are less than surprising and are pretty much what our Tinker Lane communities already know of the relationship between the old coal workings and the Tinker Lane wellpad.
That in the ground between the Tinker lane and Springs Road sites and to the west, these coals have been mined.
That no coal mines exist immediately beneath either of the proposed IGas sites at Tinker Lane or Springs Road
There are vertical separation distances quoted in the report between shale and coal workings that vary across the area from 310 metres to the south and 1,300 metres to the northwest. On BGS calculations the Tinker lane site is somewhat closer (horizontal separation) to the Harworth workings than we had calculated (we thought 1,000 metres or so) at approx 800 metres. Springs Road is 2,700 metres away from old coal workings. One figure in the report actually shows Tinker lane 700-800 metres and Springs Road 1,700 metres away.
The report mentions that there are 3D seismic data available, this must be a reference to Springs road where 3D seismic was undertaken by IGas a few years ago. However this data was not included in the study and one wonders if it were made availabe to BGS. No 3D data is of course available for Tinker lane as no contemporary surveys either of 2D or 3D have been undertaken. Indeed the report candidly states that the seismic interpretation is based on 2D exploration lines of varying vintage (1982-1987).
On first reading, and there is a lot of technical stuff but there is no mention of the issue that consumes us and that is that the vintage seismic dataset predates the nearest coal working activity of 2002-2003 at Tinker lane. Have the mining activities had an impact upon the geology of the Tinker lane site (mining induced faulting)?
The data that is missing from the report is shown on the annotated map of the old coal workings closest to Tinker lane attached BGS_Map.jpg. This map by courtesy of Torworth Parish Council who bought a set of the maps from the Coal Authority clearly shows the dates that mining took place.
What is now required is for OGA to commission the second phase study, a more rigorous study as described by BGS to add base mine workings to the existing 3D model and hydrocarbons database. Presumably BGS are fully aware that no 3D exists for Tinker lane?
We therefore look forward to hearing that OGA are committed to making a proper assessment on the separation of shale activities from old coal workings by making a prompt committment to getting this work underway as soon as possible.