Boart Longyear recently introduced the LS250 MiniSonic, a compact track-powered drill rig suitable for a wide variety of environmental, geotechnical, water and mining projects. Capable of drilling to depths of up to 250 ft (78 m) when used with 4.75-in. (121-mm) casing, its low-ground-pressure rubber tracks and smaller overall footprint are well suited for operating in fragile terrain, hard to reach areas and at sites that necessitate small drill pads.
According to the company, the LS250 MiniSonic rig offers several advantages over conventional rigs. It provides a relatively undisturbed core sample through any type of formation, with minimal deviation. When using the iso-flow groundwater profiling system, hydrogeological and geochemical data can be easily obtained. Sonic drilling is faster than conventional overburden drilling methods and greatly reduces the risk of future problems due to unknown or difficult subsurface conditions.
Safety features of the rig include an interlocked rotation barrier, reduced noise levels, a dump mast and wiggle tail, and a rod presenter. The interlocked rotation barrier automatically slows head rotation when the barrier is open. The articulated mast and wiggle tail allow the mast to shift from left to right and front to back for precise positioning over the hole, eliminating time-consuming rig movements. The dump mast allows the crew to work from the ground, enhancing safety by avoiding stairs and safety rails often required when working from a platform. The rod presenter allows the rod and casing to be loaded horizontally, with an actuator that then presents the rod and casing vertically to the head. The head rotates 28° to the side for sample extraction, while the head slide shift allows for unobstructed winch use down the hole.