Unique core drilling project
Deep core sampling in ancient rock may help scientists to discover one of the biggest mysteries of evolution – when and how life on land first began.
Contractors at the drilling site in the UK were faced with the challenge of recovering cores, perfectly intact, at depths of 500 m. They exceeded all expectations with their equipment of choice – Atlas Copco’s S Geobor drill system.
At a remote site near Berwick-on-Tweed, a town in The Borders region between England and Scotland, drilling and sampling has been carried out by Drilcorp Ltd, of Seaham, County Durham, experts in exploratory, geotechnical and deep hole drilling using Atlas Copco’s S Geobor coring equipment.
The unique S Geobor wireline, triple tube core barrel system is part of the extensive Atlas Copco Terracore range of core drilling tools. It was developed specifically to cope with site investigations requiring high quality, cost-effective production coring in difficult situations. It is a highly flexible system offering large core drilling and sampling in the 146 –150 mm range in soft to medium hard formations, both consolidated and fragmented, using all common coring methods. The triple core barrel assembly consists of three tubes – an outer tube fitted with a set bit, a middle tube, and a plastic liner which is used to cover and protect the core. Among the many advantages of this design is that the non-coring pilot bit can be easily removed and replaced and cores can be extracted continuously and efficiently while leaving the outer coring equipment in place in the hole. Using this system, together with its own drilling equipment, Drilcorp achieved an average drilling rate of 25–30 meter per day through shales, sandstones, cemented bands and beds of evaporates. And despite the delicate strata and the presence of two geological faults, the S Geobor recovered an almost perfect 102 mm diameter core throughout the length of the 500 m deep borehole.