The shale gas company, Cuadrilla, has announced plans to carry out seismic surveys in a field next to its Preston New Road site near Blackpool.
In an email to the site’s community liaison group, the company said the work would help to establish the best locations underground to drill the two planned horizontal wells.
It said the work was expected to be done late this month (December) or early in 2018 and would take two to three days.
Cuadrilla said it would use what’s known as an articulated hydrostatic vehicle, equipped with a seismic vibroseis unit (see picture above).
The vehicle creates sound waves underground. They are reflected back from different rock layers. The company said it could build up an accurate picture of the subsurface at the exploration site by measuring how long it took for the sound waves to be reflected back.
“This helps us in positioning the horizontal exploration wells some 2km underground. This is a standard practice used in seismic surveys across the country.”
Cuadrilla said the vibroseis unit would be positioned above the bottom of the pilot hole currently being drilled from the Preston New Road site (marked on the image below by Expected Well TD).
The email said:
“The information on the shale rock from this survey at this single point above the pilot hole will be matched with the wider data obtained from Cuadrilla’s seismic survey of the Fylde carried out in 2012.
“Together this combined information will be used to inform the optimum subsurface locations for drilling of two horizontal wells in the shale rock from the Preston New Road site.”
Cuadrilla said the work was not expected to exceed the noise limits set in the planning condition for Preston New Road.