A multifunctional NSU (N surface and underground) core barrel system for core drilling applications — said to be the first of its kind to feature interchangeable components, along with standard and pump-in applications in a single system — has been introduced by Sandvik.
The NSU core barrel system features an innovative new design that the company says increases productivity and safety, and reduces net working capital and spare parts inventory.
“Our newly patented iQ-FCV valve provides and maintains a constant alert via sustained high water pressure, assuring the operator that the inner tube assembly has positively latched into the core barrel, eliminating mislatches and ensuring valuable time is not lost,” Sandvik Mining Core Drilling Product Line Manager Chris Daws says.
“For better water efficiency,” he adds, “the iQ-FCV has been designed to always retain the volume of water in the drill string even in broken ground or dry holes — an important benefit in core drilling.”
Other features are:
- The overshot attachment to the wireline no longer requires cable eyes or cable splicing, enabling easier maintenance and repair in the field.
- A newly-designed logic tip on the overshot allows for in-hole dry releasing of the inner tube assembly once the water level has been reached, shortening the release time.
- The pump-in overshot features a ball valve indicator which alerts the operator of positive latching onto the core barrel’s back end.
Daws says the system is safer as the ‘intelligent’ overshot design is automatically latch-locking, while latches can be released without operators having to use fingers in potentially high-risk areas. In addition, a knuckle joint on the overshot ensures easier handling, particularly in confined underground drilling conditions, while load-rated breakaway safety pins also provide a safer way to release the overshot from stuck inner tubes.
“The Sandvik NSU — along with our forthcoming HSU (H surface and underground) — core barrel systems have a high commonality of components used in the core barrel head assembly,” Daws says. “With this interchangeable design for both systems, the NSU core barrel head assembly can easily be converted into an HSU core barrel head assembly, and vice versa. This will significantly reduce parts and spare parts inventory.
“Furthermore,” he adds, “our new core barrel system is designed for both standard and pump-in applications, so there is no longer a need to keep different coring tools systems on the shelf, reducing net working capital requirements for owners.”