Like rotary drilling machine, impact drilling machine and compound drilling machine 3 categories.
Rotary drill
By the vertical reciprocating motion of the drilling tool, the drill bit hits the bottom of the hole to break up the rock. It is simple, but does not have a circulating flushing system, so cuttings can not be removed at the same time as the rig, resulting in low efficiency. The drilling depth is generally within 250 meters, and some can reach 500~600 meters. The main types are as follows. A simple percussion drill that uses the weight of the drill string to strike the formation. Of the lower end of the drilling tool is a few can zhang pointed horn disc, when drilling tool under the action of its weight downward movement, grasp valve open, draws disc point on the circumference of the diameter of about 1 m cut into the rock, and then passed by hoist rope hoisting tool, grasp the disc in closing process debris into the pointed cone and put forward the wellhead open again after catch the cutting disc discharge. The thrust grab cone is typically drilled to depths of 40 to 50 m, with the deepest being 100 to 150 m.
Wire rope impact drill is composed of mast and its top lifting pulley, wire rope, impact mechanism, drilling tools (including drill pipe and drill bit), motor, etc. (Figure 4). During operation, the motor drives the impact mechanism through the transmission device and drives the wire rope to make the drilling tool reciprocate up and down. When moving down, the weight of the drill makes the bit cut into and break the rock, while moving up depends on the traction of the wire rope. The height of drilling tool falling, namely the stroke size, is determined according to the rock formation conditions, generally 0.5~1 m, hard rock with the maximum value; The impact frequency is usually 30~60 times/min. The cuttings are cut out of the ground with a sand pumping cylinder, and can also be used to drill a drilling tool that integrates the drill bit and the sand pumping cylinder. Drilling and removing cuttings are carried out at the same time, so that the cuttings cut directly into the pumping cylinder, and after the accumulation is full, the drilling tool is lifted and the cuttings are poured out. In order to improve the wear resistance and drilling speed of the bit, tungsten steel powder is often surfacing at the end of the bit to become alloy repair welding bit. Compound drill.
Post time: Feb-15-2022