Reverse Circulation - (RC) - Drilling Technique

Reverse circulation (RC) drilling uses a dual-walled drill pipe (rod) with a solid drill bit to produce a hole in a formation and delivers rock chips (cuttings) to the surface for a subsequent analysis. Technical Data used in the field explained in drilling courses in Rawalpindi. The drilling mechanism is a pneumatic reciprocating piston (hammer) driving a tungsten-steel drill bit and a compressor to blow the cuttings, created by the drilling operation, to the surface. Reverse circulation is achieved by blowing air down the rods; the differential pressure creates air lift of the cuttings up the inner tube which is inside each rod. Normally the air exhausts through a centrifugal classifier so that the rock chips and dust will be captured in a sampler.

The most commonly used RC drill bits are 5-8 inches (12.7-20.32 cm) in diameter and have round metal "knobs" that protrude from the bit, which are required to drill through rock and shale. As the knobs wear down, drilling becomes slower and the rod string can potentially become bogged in the hole, therefore RC drill rigs must have a high pullback capacity and hydraulic power, otherwise trying to recover the rods may take hours and in some cases days. Some more details of drilling courses in Rawalpindi are as under.

While operating in remote sites or areas, Reverse Circulation drilling setup usually consists of several support vehicles, as well as the rig itself. The support vehicles hold the drilling rods (dual tube RC pipe), spare parts, diesel and water tanks, as well as any other tools and equipment required for resupplying and rig maintenance.

Most of the RC drill rigs have their own compressor to generate the air pressure needed to extract the cuttings. However, generally these compressors do not have the power for deeper drilling, due to lack of space on the rig itself for the larger, more powerful units. Alternatively, companies like Drilling Supply, are offering compressor free setup, which enables the driller to use a compressors with various power rated outputs to accommodate their particular project, while using the same RC Drilling Rig for all of them. As a consequence, even a broken air compressor will not cause disruption in the drilling operations. While a malfunctioning compressor is being repaired, a backup unit can be rapidly deployed to continue the drilling operation, saving the drilling contractor valuable time and money. TSK Training for Skills and Knowledge is the best institute in Rawalpindi Islamabad for Pakistani Students who wants to join drilling courses in Islamabad.