Reverse Circulation Drilling (also referred as dual-wall drilling, and RC Drilling for short) is a method used in investigation and exploration drilling to find out if the bedrock is strong enough to support construction or if people can extract materials from it. It helps to gain fast and reliable results about what is hidden down there in the bedrock. This method makes use of both percussion and rotation movements.
The RC Drilling is done with a RC down-the-hole hammer, uses dual-wall rods with inner and outer tubes, the drill cuttings are returned to surface inside the rods. It ideally produces dry rock chips, as large air compressors dry the rock out ahead of the advancing drill bit. RC Drilling is used to retrieve continuous samples from the ground where a solid core is not needed. Samples are taken continuously during drilling, with around 12% of the cuttings going for analysis.
RC Drilling is considerably faster than core drilling because it eliminates the problems that water can cause with coring and eliminates the time spent recovering core barrel samples to the surface as they are instant even through broken or fractured ground. RC Drilling is cheaper than diamond core drilling and has additional advantage that all the drilled rock is collected making it the most viable option when it comes to mineral exploration and site investigation. However, RC Drilling only produces fragments and chips of broken rock, so there is less geological information available than would be obtained from core.
Advantages of Reverse Circulation Well Drilling:
Mitigates air loss into sensitive formations
Requires less air to evacuate cuttings
Efficient removal of larger cuttings cause less wear on tooling and faster penetration rates
Ultimate control of cuttings when discharged at surface
Energy efficient and environmentally less impactful to site
Acedrills offers full range of RC drilling tools, including RC hammers, RC bits, dual-wall drill rods (RC Drill Pipes) and so on, some of which is compatible with most others on the market.