Terra Drill, Inc. offers Wire-Line rock coring. This is a high speed method of collecting actual cores of the bed rock for engineering and geological studies.
A diamond bit is attached to a core barrel which consists of the inner barrel, the outer barrel, quad latch and swivel. The core barrel is lowered into the hole and core rods of the same size are attached to reach the starting point in the bed rock. The drill rod acts as a casing for the borehole and provides a controlled environment to efficiently retrieve the rock core from the borehole.
The entire assembly is rotated at high speed and weigh from the drill rig is added to force the diamond bit into the rock formation. The type of bit, speed in which it is turned and amount of weigh on the bit is determined by the type of rock that is being cut. During the entire process, water is being pumped into the drill rods to cool the diamond bit and remove the cuttings from the borehole.
Rock core samples are obtained by removing the inner barrel assembly from the core barrel portion of the drill rod by using an overshot retriever attached to a Wire-line on one of the drill rigs winches. The overshot is lowered into the drill rod and engages the quad latch on top of the core barrel. Once engaged, the inner barrel is raised to the surface and the rock is removed. Once the rock is removed, the inner barrel can be lowered back into the core barrel and the process continued to the desired depth by added additional drill rods.
This is an efficient method of recovering core samples of rock. Typical uses include foundation investigations, material sources, rock cut investigation and general rock coring when an actual core of the rock is desired.
