A new generation diamond crown, developed by Boart Longyear using synthetic diamonds supplied by GE Superabrasives, has achieved impressive drilling depths in lava formation near Fochville, South Africa, reports customer Cementation Mining.

On an ultra deep exploration contract near Fochville in the Free State, two diamond crowns outstripped the average 120 - 160m lifespan by drilling 941 and 861 metres respectively.

Says Piet Olivier, Manager Surface Drilling "The exceptional metreages obtained with these crowns, on this ultra deep hole has dramatically increased productivity by reducing rod tripping time to exchange diamond crowns. The diamond crowns are also extremely versatile and are able to handle a wider range of drilling formations, allowing the driller to keep the bit in the hole for an extended period of time." When exploration drilling ultra deep holes up to 6 kilometres deep it is essential to reduce your risk on the contract by minimizing the rod tripping time. "It is not unusual when drilling through Ventersdorp lava to average between 120 - 160 metres per diamond crown." says Olivier.

Olivier went on to say "it's fine achieving great meterages, but they are meaningless if you experience an increase in deflections, we found the free cutting GE diamond in the crown kept deflections to the minimum, keeping the hole well within the clients parameters."

Not only was Cementation Mining impressed by the vastly increased productivity yielded by the crowns, but also by the significant reduction in both torque and diesel, and the minimal wear and tear on their drilling equipment. The latter a factor attributed to the free cutting action of the diamond.

The results? Cementation Mining achieved increased productivity and metreages; and minimized deflections through a new generation of high strength, free cutting diamonds.

GE Superabrasives is the inventor and is one of the world's leading supplier of manufactured diamond, cubic boron nitride (CBN) and polycrystalline products. With sales offices in more than 25 countries and state-of the art technical centers, GE Superabrasives works directly with end user's to develop product and application solutions.