Definition - What does Blasthole Drilling mean?
Blasthole Drilling is a drilling technique whereby a hole is drilled in the rock surface up to certain depth, and then explosives are loaded to induce cracks on the hard surface of the inner geology formation for further deep drilling. This hole which is meant for loading explosives is known as a blasthole. Blasthole Drilling is one of the techniques of surface drilling.
Petropedia explains Blasthole Drilling
Blasthole Drilling is often used in the mining industry; however, it can also be used to create cracks in inner geological formations during oil or gas well preparation after examining the formations.
RAB (Rotary Air Blast) drilling is used frequently for Blasthole Drilling. In this type of drilling methodology, a piston driven hammer generally pneumatic reciprocating type drives heavy drill bit into the rock with a lot of force. The drill bit is a hollow solid steel material with approximately 20mm thick tungsten rods which hold the drill bits. The bit blows the rock by applying a feed force to ensure rock/bit contact. Compressed air is used to flush out the slurry, thereby advancing the wellbore depth at an efficient pace.