by injecting into the borehole a liquid, either initially at high pressure or subsequently subjected to high pressure, e.g. by pulses, by explosive cartridges acting on the liquid (slitting by jets of water E21C25/60; blasting by explosives F42D)

Full Title

Other methods or devices for dislodging with or without loading (breaking-down by means inserted in slits E21C27/14) > by making use of hydraulic or pneumatic pressure in a borehole > by injecting into the borehole a liquid, either initially at high pressure or subsequently subjected to high pressure, e.g. by pulses, by explosive cartridges acting on the liquid (slitting by jets of water E21C25/60; blasting by explosives F42D)