Dual-controlling-channel impulse jet ball-tooth bit

Abstract

The invention relates to a pulse jet button drill with double control channels, which is composed of a pressure head, a monostable jet element with double control channels, a drill body and an internal flow channel. The monostable jet element with double control channels, the upper end pressure head and the peripheral drill body form a whole by welding. Two control channels, one large and one small, and two fluid outlets, one large and one small, are provided inside the bistable jet element with two control channels, which are respectively connected with nozzles of different sizes. During the collision-separation process of the hammer and the drill bit, one of the dual control channels opens and closes periodically, and the high-frequency switching of the fluid inside the jet element produces a pulsed jet, which strengthens the cleaning effect of the nozzle hole bottom. The surge of pressure after the impact of the invention not only does not bring negative impact on the impact process of the hammer, but also facilitates the start of the return stroke of the hammer, increases the impact frequency to a certain extent, and improves the rock breaking efficiency.

Description

technical field [0001] The invention relates to a drilling tool, in particular to a double control channel pulse jet button drill bit. Background technique [0002] Rapid drilling of deep and ultra-deep wells in hard rock formations has always been a research hotspot, and it is also a development direction in the future. The holding effect caused by the large hydrostatic column pressure in deep wells often makes it difficult to remove the cuttings at the bottom of the hole. Especially for down-the-hole hammer drilling technology. In order to ensure that the impact energy of the hammer can be transmitted to the bottom of the well, the pressure at the entrance of the button bit of the down-the-hole hammer is usually small to avoid the adverse effect of the fluid back pressure on the impact movement of the hammer. The low nozzle inlet pressure combined with the leakage in the spline fitting part of the drill bit makes the fluid ejected from the nozzle of the DTH button bit le...

AI Technical Summary

Problems solved by technology

Low nozzle inlet pressure combined with leakage from the spline fit of the drill bit makes the fluid sprayed by the DTH button bit nozzle less effective in removing cuttings

In addition, the rotation speed of DTH hammer drilling is much lower than that of conventional rotary drilling technology, which results in a relatively fixed nozzle position covering a small area at the bottom of the hole in the same time, which intensifies the lack of power of the flushing medium at the bottom of the hole and causes rock formation. Chips accumulate, which in turn causes a series of problems such as repeated crushing, excessive local temperature, and increased wear of the drill bit, which ultimately manifests as a decrease in drilling efficiency and an increase in cost

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