Shallow drilling refers to the process of drilling relatively shallow boreholes into the earth’s surface to explore and extract valuable resources, assess geological conditions, or perform environmental studies.
There are several methods of shallow drilling, each with its own advantages and suited to different applications:
Auger drilling
Auger drilling utilises a hand-held power auger or a small vehicle-mounted auger, similar to the post hole diggers used in farming. This method is effective for drilling shallow holes and is particularly useful for soil sampling, environmental testing, and geotechnical investigations.
Air drilling
Air drilling comprises three primary shallow drilling techniques: air core, reverse circulation (RC), and rotary air blast (RAB). These methods typically employ a utility, track, or small truck-mounted rig with an onboard or towed air compressor.
Air drilling generates rock chips by forcing compressed air down the drill hole, lifting the chips to the surface. This method is efficient and minimally invasive, requiring minimal site preparation and rehabilitation, making it well suited to early-stage mineral exploration drilling programs.
Diamond drilling
Exploration diamond drilling uses a truck-mounted or track rig with support vehicles to extract a continuous cylinder of rock, known as core. The method involves water and drilling fluids, which are either stored in an in-ground sump or above-ground tanks.
Exploration core drilling demands significant site preparation and rehabilitation, but it provides accurate and continuous core samples of exceptional quality. It is commonly used in combination with reverse circulation drilling for mineral and coal exploration drilling programs where precise sample recovery is critical.