Drilling rock with small or large rigs requires better tooling, bits and power.
Rock drilling in most cases people use DTH hammer and air. The DTH hammer is like a mini Jack hammer that operates off of air
pressure. The deeper you drill and the larger the bore hole the more CFM's of air is required.
When drilling with air and a DTH hammer, some people use a injection system. The injection system injects foam. The drilling foam injected helps stabilize rock cuttings and dust, so when air is turned off to connect another drill pipe the cuttings are stabilized and do not fall and stick to the drill pipe.
The nice thing about drilling with air, is when you hit water you know right away. Once you hit water it is known because water will blow out and your injection foam will thin down.
Drilling with air is also a plus in northern areas where temps stay below freezing for months at a time. Below freezing weather makes using rotary mud with water nearly impossible.
The good of rock drilling
-Drilling rock, the bore hole walls are stable, so you do not have to all the trip pipe out at the end of every days drilling.
-When you hit water it is easy to know. Water formations evidence is not covered up by thick drilling muds. While air is blowing up rock chips and cuttings , if there is water there it is blown up too.
-Hard rock is much slower than soft formations drilling.
-Better bits and DTH hammers are required.
-You will need a large CFM air compressor to run DTH hammer.
-Large CFM air compressors use lots of fuel.
-Drilling rock, drillers charge more and don't like using there equipment on hard formations.
When looking to buy a drilling rig for rock, remember to look for these options. Swivel must be rated for Air
to run DTH hammer and also have high heat seals for the extreme temps large compressors put off.
Drilling rock require better pipe and flush joint or smooth connections. Mayhew Jr is not air or rock pipe. the large shoulder tool joint hurts air flow and much easier to loose pipe or get stuck. Also the DTH hammer is really hard of pipe connections. some connections fail prematurely. Email us for correct connectiona nd pipe you need.
When drilling hard rock some time small or large rock above bit can fall down and lock your pipe down. There is not easy fix, this could take days or just minites to dis-lodge and free pipe again. This is where drilling steady and slow are a blessing. Getting in a hurry gets you in trouble. also better DTH hammers help by drilling straighter.
Rotarty Mud rock drilling
This can be done, but not as fadt results are DTH hammer, but much cheaper and lower overhead. Rotarty mud uses cheap drilling mud and water pumps. The DTh hammer requires lot of CFMS, which equals large diesel engines to drive compressor which equals lots of diesel fuel @ 4 bucks per gallon x 200 gallons per day = 800.00 per day over head just to run compressor. Fast DTH hammers do have a price to pay.