Firstly, the first kind of percussive water well drilling rig, which mainly relies on the vertical reciprocating motion of the drilling tool, causes the drill bit to impact the bottom of the well to break the rock formation. Its structure is simple, there is no circulating well washing system, cuttings removal and drilling rig can not be carried out at the same time, so the efficiency is low. Drilling depth is generally less than 250 meters, sometimes up to 500-600 meters. There are two main types:
The punch and grab cone. Use the weight of the drilling tool itself to impact the formation. The lower end of the drill tool is several sharp angle grab flaps which can be opened. When the drill tool moves downward under its own weight, the grab flaps open and cut into the rock stratum. Then the hoist lifts the drill tool through the wire rope. The grab flaps grab the cuttings into the cone body during the closing process, and put forward that the cuttings are discharged from the wellhead. Drilling depth is usually 40 to 50 meters, up to 100 to 150 meters.
(2) Steel wire rope percussion drill. The utility model is composed of a mast and a lifting pulley installed at the top, a steel wire rope, an impact mechanism, a drilling tool, a motor, etc. During the operation, the motor drives the impact mechanism through the transmission device, drives the wire rope to make the drill tool move up and down, and breaks the rock stratum by the weight of the drill bit itself when moving downward, and moves upward by the wire rope traction. The bit stroke is 0.5-1 m and the impact frequency is 30-60 times per minute. The cuttings are cleared out of the ground by the sand extraction cylinder, and drilling and debris removal are carried out simultaneously.