Geocore was contracted by fellow RSK company Ecologia to undertake a drilling project at Barking Power Station.

The City of London was the main Client, with the principal contractor on site being Cognition. Our sister company, CJ Associates, drilled boreholes using cable percussion techniques, boring down to 20 metres for contamination assessment purposes. Geocore was then contracted for the rotary follow-on drilling.

The power plant houses two coolant tunnels -an outlet and an inlet. The tunnels at the power station are three metres in diameter, have a combined volume of 16-17 million meters squared and are linked up to the Thames.

The project was split into four phases. Over the four phases, 21No. holes were drilled in total, to a depth of 44 – 48metres. All boreholes were verticality tested afterwards to be within a 0.5 degree tolerance. The holes were left on casing clamps, holding the casing just inside the crown of the tunnel.

Two of the holes in the last phase were over water, on a 100-tonne jack-up barge, which was supplied by Red7Marine. Our 30-tonne Comacchio 909GT drilling rig was used for this project and was driven onto the barge.

Geocore’s GT900 drilling rigs have the unique ability to simultaneously drill and case using mud/water flush. This helps to eliminate obstacles of challenging ground conditions. The rig boasts a carousel of 128m of 150mm (casing with rods) and a high torque dual drilling head. The automated system allows for rapid penetration and simultaneous casing in even the most challenging of ground conditions. All drilling fluids and drill cuttings return to the surface directly through the inside of the casing and are fully contained in the recirculation system. The rapid case and drill method also seals the formation during drilling, protects the borehole from the surrounding strata and prevents the downward migration of any materials from the surface.