What is down-the-hole (DTH) drilling?

Down-the-hole (DTH) drilling has made it easier for contractors to drill wells faster and more efficiently, and to transition from dirt boring to rock boring just by adding a compressor and hammer to the drill bit.

What is a DTH drill rig?

A down-the-hole drill, usually called DTH Drilling Rig, is basically a mini jackhammer screwed on the bottom of a drill string. The speedy hammer activity breaks hard stone into little flakes and dust and can be dismissed evident by the air exhaust in the DTH hammer.

What is a down-the-hole drilling system?

It is a cost-efficient system that leaves less material behind in the hole. Down-the-hole drilling pipes are engineered with cold-drawn seamless tubing material N80 to ensure straightness, thickness and high strength for a smoother drilling process and longer service life.

How long did it take to drill a 12,000 ft hole?

The original estimate for completion of a 12,000-foot hole was 30 days using the conventional rotary technique, which was reduced to 13 days using the DTH method. Before DTH was used, drillers would typically case the vertical portion of the well and convert to rotary drilling to drill at a tangent.

How do you flush a borehole?

The flushing medium (in some cases, water is also used) is pressed down through the drill pipes, down-the-hole hammer and the drill bit. It is then forced back out of the borehole along with the cuttings through the annular gap between the drill pipe and the borehole.

How fast can you drill a well with DTH?

With DTH, it was now possible to turn 2-4 degrees curves and drill the well’s tangent up to 30 degrees or greater averaging 300 feet per hour, where rotary drilling would progress 30-40 feet per hour.