Hole bottom annular spacing strong suction device of through type down-the-hole hammer

Abstract

The invention relates to an oil-gas well hard rock drilling tool and other drilling and tunneling tools, in particular to a through-type pneumatic down-the-hole hammer hole-bottom circular space powerful suction device. A reverse circulation drill bit is provided with a drill bit accepting cavity and a drill bit mixing spray nozzle; re-absorption spacing is arranged between a spline housing and the reverse circulation drill bit; the spline housing is provided with a spline housing injection spray nozzle; the spline housing injection spray nozzle is communicated with an air exhaust channel between the reverse circulation drill bit and the spline housing; the drill bit accepting cavity is communicated with the drill bit mixing spray nozzle. According to the injection principle, because of the entrainment of high-speed fluid, the waste gas and the rock powder returning to the circular spacing between the drill bit and the hole wall is entrained from the re-absorption spacing to the drill bit accepting cavity, and is mixed with the high-speed air flow from the spline housing injection spray nozzle in the drill bit mixing spray nozzle, to form the mixed jet fluid. The invention improves the through-type down-the-hole hammer reverse circulation forming capability, and solves the problems of hole shrinkage, sticking and the loss of partial ore samples caused by escaping of partial gas with small particles of rock debris and rock powder from the circular spacing of a drill hole.

Description

technical field [0001] The invention relates to a hard rock drilling and other drilling equipment for oil and gas wells, especially a through-type pneumatic down-the-hole hammer hole bottom annular space powerful suction device. Background technique [0002] The reverse circulation continuous coring technology of through-type down-the-hole hammer is an advanced drilling technology. Its working principle is: compressed air enters the down-the-hole hammer through the outer ring channel of the double-wall drill pipe to drive the piston to do work, and the exhaust gas after the work passes through the reverse circulation drill bit of the multi-nozzle principle to generate a negative pressure area at the bottom of the hole, forming a full hole reverse circulation . Due to the high rate of core recovery, full-hole reverse circulation and little disturbance to the formation, this process has great advantages in solving drilling problems in complex formations. In recent years, tes...

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Problems solved by technology

[0005] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art, and provide a method to solve the problems of diameter reduction, drill pinching and partial ore sample loss caused by a part of the gas carrying small particles of cuttings and rock powder escaping from the annular gap outside the borehole. The powerful suction device for the annular space at the bottom of the through-type down-the-hole hammer hole

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