There are two types: one is in the rotary rotary drilling rig on the basis of the addition of impact mechanism, mainly to rotary drilling, when encountering pebble layer with impact drilling dual-purpose well drilling rig, strong adaptability to various strata; The other is the impact and rotary action combined with the well drilling rig, such as the pneumatic DTH hammer drill. The DTH hammer drill (FIG. 5) is composed of a cylinder liner and a piston that moves up and down in the cylinder liner. The lower end of the cylinder liner is connected with the drill bit, and the upper end is connected with the drill pipe through the threaded joint. The high-pressure air provided by the air compressor is 0.7~1.4 mpa through the check valve above the piston, the air distributor and the air inlet below the piston, and the impact frequency of the piston is pushed up and down as 700~1200 times/min, so that the piston frequently impacts the drill bit. To enhance the ability of the drill bit to drill rock. At the same time, the drill pipe rotates at a lower speed of 35~60 RPM. Air from the upper and lower cavities of the piston flows down into the bit to cool the bit and bring the bottom-hole cuttings out of the wellhead. The structure of the rotary and circulating well washing part is basically the same as that of the rotary rotary drill with compressed air, and the bit used is tungsten carbide ball tooth bit or roller cone bit. Pneumatic DTH hammer drill can be used for drilling deep Wells in hard rock strata. The drilling speed is high, and the drilling speed does not decrease due to the increase of drilling depth, and the drilling hole is straight.
In order to adapt to the needs of different strata drilling, improve drilling efficiency, well drilling rig is multi-purpose drilling rig and full hydraulic transmission and control of the direction of development: that is, a drilling rig with a variety of equipment and accessories, can use impact, rotary and DTH hammer and other drilling methods; Mud well washing, compressed air well washing and positive and reverse circulation well washing can also be used.
Post time: Feb-15-2022