What is RC drilling?
Reverse circulation (RC) drilling employs the use of a bit installed on a down-hole hammer that drills a hole. Unlike diamond drilling, reverse circulation drilling produces rock cuttings instead of a sample of rock core. The compressed air, which also serves as a medium of throwing the drill cuttings to the surface powers the down-hole hummer. With reverse circulation drilling, the bulky and big nature of the work is completely done away with as was the case with traditional drilling. Today, this type of drilling brings a number of benefits to the drilling firms and they include the following:
In the past, RC drill rigs were known to feature big and powerful heavy trucks mounted with sophisticated machines for drilling. However, such machines became inappropriate for remote exploration work due to the challenges and the cost of moving these heavy drills to and from the drilling site. RC drill machines can be moved easily to remote sites with aircrafts, making it the best in the industry today.
Reliable samples
Today, reverse circulation produces samples that are of high quality and which are very reliable. Dual-pipe RC drilling uses double drill rods that pass the air down the hole towards the hummer. The air clears the drill cuttings before being moved upwards to the surface through the centre tube. This way, the drill rods are not affected by the friction or contamination from the drill cuttings.
Two main types of RC Drilling Australia systems exist today namely: the centre-sample system and the conventional cross-over system. Using the former, drill cuttings are forced to move up directly through the holes in the bit and then through the center tubes. This technique is capable of producing samples that are free from contamination. This is the reason why RC drilling results are popularly used in compliant resource calculations.
On the other hand, conventional cross-over system works by allowing the drill cuttings to first travel up around the bit before they enter the center tube through the cross-over slots.
Why Go for Reverse Circulation Drilling?
This technique is fast, cost effective and is appropriate for first pass explorations drilling.
The biggest advantage of reverse circulation Australia is perhaps its high rate of penetration that go beyond 80 meters per shift depending on the conditions of the ground. The fact that this method is fast means savings on the drilling cost.
Since RC drill cuttings are moved the surface through the centre tubes, the samples have high recoveries of high quality clays.
Reverse circulation drilling come with myriad environmental advantages. First, RC does not require water to facilitate rock drilling. This is a huge advantage especially in areas with water shortages.
In addition, the winter can prove problematic to perform drilling. The process will be far costly and tricky if not difficult. Light-weight RC makes winter drilling less costly and effective in the arctic and other cold areas.
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