Drilling is a process of the cylindrical form mine working — well, hole (artificial cylindrical deepening in solid medium (rock, concrete) with diameter of up to 75 mm and depth of up to 5 m. They are used for blast placing in case of blasting, for roof bolting, water or cement injection into the circumfluent rock mass etc. In shot-hole or shaft drilling jackhammers, electric drills and other light drilling machines are used for rock failure at bottomhole.

Generally, drilling is done in earth crust and occasionally it is done in manufactured materials (concrete, asphalt and others). In some cases drilling involves lining with casing and cement grouting in annular clearance between casing and hole walls (generally in case of longhole drilling).

Application is comprehensive: minerals exploration and prospecting; rock formation property investigation; liquid, gaseous and solid mineral deposits mining (with leaching and melting) via operating holes; blasting; solid minerals extraction (see Augering machine); artificial rock formations gripping (rock freezing, bituminous or cement grouting etc.); minerals watered fields and water-logged areas drainage; development; subsurface utility engineering: pile foundation construction and others.

By the nature of rock breaking the applied drilling methods are divided into: mechanical, when drilling tool directly has an effect on rock formation and breaks it and non-mechanical when at breaking there is no direct contact between rock and source of effect (thermal, blasting and others).

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