RU2495233C1 - Hydromechanical slot-type rock drilling machine - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: rock-drilling machine includes a body with ejector piston and cutting unit installed in it; at that the latter is made retractable from the body when ejector piston moves; at least one jet nozzle and flushing unit consisting of filter connected to the body of flushing unit that has operating channels and axial channel with landing saddle for a ball. Operating channels unite cavity between filter and the body of flushing unit with cavity over the piston in the body of rock-drilling machine. The body of flushing unit has radial channels connected to axial channel and united with tubular annulus by a circular groove at outside surface of the body of flushing unit and radial channels united with it and made in the body of rock-drilling machine and covering the body of flushing unit.

EFFECT: improvement of quality in process of rock-drilling machine washing, exclusion of impurities entrapped into the flushing channel and thus into structure of rock-drilling machine.

2 dwg

Description

The invention relates to the field of drilling and operation of oil, gas and injection wells, and in particular to a device for the secondary opening of formations by creating longitudinal perforation slots in production columns and forming filter channels in the bottomhole formation zone.

The prior art devices for slotted perforation of casing strings based on the use of a cutting tool in the form of a retractable rolling roller. Such devices are disclosed, for example, in patents RU 2182221 C1, 05/10/2002; RU 2151858 C1, 06/27/2000; RU 2087683 C1, 08.20.1997; RU 2030563 C1, 03/10/1995; RU 2007549 C1, 02.15.1994; US 4119151 A, 10/10/1978; US 4220201 A, 09/02/1980. The described devices differ mainly in the design of the mechanism of attachment and extension of the cutting tool.

One of the disadvantages of the above devices is the rapid wear of working parts, including the cutting unit, the difficulty of replacing and repairing them, as This requires complete disassembly of the device. Another disadvantage is the possibility of contamination and clogging of the perforator with mechanical impurities of the working fluid (scale, dirt, rust, pieces of rubber seals, etc.).

Currently, all models of hydromechanical perforators, after being installed in place of the beginning of the perforated interval, are pre-washed with technical fluid through the tubing elevator before using the perforator. The technical fluid is passed under overpressure through the tubing and practically through the perforator, where sedimentation and accumulation of dirt occurs on the working surfaces of the perforator. This leads to the impossibility of carrying out work and the need to lift the tool to the surface, disassemble it, clean and, accordingly, lose time during this type of work.

Closest to the proposed is a slotted hydromechanical punch (RU 2393341, published 06/27/2010).

In the known perforator there is one flushing channel of a limited diameter, passing through the entire structure in the area of placement of hydraulic monitors. In practice, the channel is quickly clogged with mechanical impurities brought by the working fluid (scale, rust, pieces of rubber seals, etc.), reducing the quality of washing the perforator.

The objective of the invention is to improve the quality of washing the hammer.

The technical result of the invention is the elimination of the possibility of mechanical impurities entering the washing channel, and, consequently, into the design of the perforator.

The specified technical result was obtained due to the fact that in the hydromechanical slotted punch, which includes: a housing, a piston-pusher located therein and a cutting unit installed with the possibility of extending from the housing when moving the piston of the pusher, at least one hydraulic nozzle and a flushing unit, including a filter connected to the housing of the washing unit having working channels and an axial channel with a seat for the ball, the working channels communicating a cavity between the filter and the housing of the washing unit with piston cavity of the punch body. According to the invention, the body of the washing unit is made with radial channels connected to the axial channel and communicating with the annular space by means of an annular groove on the outer surface of the body of the washing unit and communicated with it radial channels made in the body of the perforator covering the body of the washing unit.

Figure 1 shows an axial section of the upper part of the proposed perforator, figure 2 is a section along aa in figure 1.

The drill includes: a housing 1, in one part of which a piston-pusher is installed, a cutting unit with one or two cutting disks and one or more hydraulic nozzles mounted at the outlet of the channels made in the piston-pusher (not shown); a valve 2 for discharging a working fluid with a seat socket 3 on a shear saddle, for a ball of large diameter; and a flushing unit 4 installed in another part of the housing 1 between the plunger piston and the valve 2.

The valve 2 discharge of the working fluid has a thread for screwing the column tubing (tubing).

The washing unit 4 includes a housing 5 with a seating socket 6 for a small-diameter ball, with an axial channel 7 and radial channels 8. The seating socket 6 is located at the entrance to the axial channel 7 connected to the radial channels 8, the outlet openings of which are connected by an annular channel 9 formed by annular groove on the surface of the housing 5 of the washing unit, which in turn is connected by radial channels 11 in the housing 1 of the perforator, with the annulus (Fig. 4 shows four channels 7 and four channels 11). A filter 10 is connected to the housing 5 of the washing unit with filter holes in the walls of the cylinder connected to the seat 6. In the housing 5 of the washing unit there are also working channels 12 connecting the cavity of the washing unit 4 between the filter 10 and the housing 5 with the over-piston cavity of the perforator.

The punch works as follows.

On the tubing string, the perforator descends into the production casing of the well at a predetermined perforation interval. Having installed a perforator in the well, the tubing cavity is directly flushed through the central channel of the fluid discharge valve 2, through the axial channel 7 and large diameter radial channels 8 and 11 with minimal fluid resistance with mechanical impurities falling into the pipe cavity during geophysical work on the perforator to a given interval, in the annulus. This completely eliminates clogging of the punch.

Then, a small diameter ball 13 is thrown into the tubing cavity, which, passing through the tubing string and the working fluid discharge valve 2, is lowered into the seat 6 and closes the axial channel 7. In this case, the working fluid is passed through the filtering holes of the filter 10 and through the working channels 12.

Further, the perforator works similarly to the known hydromechanical slotted perforators. In the tubing create working pressure, which begins to act on the piston-pusher, which, moving translationally along the axis of the punch, pushes the cutting unit with one or two cutting discs.

By gradually creating a pressure of 1.0 to 8.0 MPa in the tubing cavity, the puncher is moved up and down and the cutting discs (or disc) are gradually pressed into the wall of the production string.

After the formation of a perforation gap in the production string, the pressure in the tubing cavity is raised to 15.0 MPa. The jets of fluid flowing out of the hydraulic nozzles with great speed, destroy the cement stone and rock behind the production string, forming filter channels. After washing the cavity, the pressure in the pipes is reduced to atmospheric, the cutting unit is pulled into the perforator under the action of a return spring. After that, a large diameter ball (not shown) is lowered into the tubing cavity, which sits in the seat socket 3 of the shear seat 14 of the valve 2 for discharging the working fluid.

The shear seat 14 under pressure of the working fluid moves inside the valve 2 discharge of the working fluid and cuts off the plugs 15 installed in the valve 2, thereby opening the drain holes in the annulus.

Thus, when lifting the suspension with a perforator, the spill of the working fluid at the wellhead is excluded.

The proposed invention improves the quality of washing the perforator by eliminating the clogging of the perforator due to flushing of the washing fluid through a large cross-section drainage into the annulus.

Claims (1)

A hydromechanical slotted puncher comprising a housing, a pusher-piston disposed therein and a cutting unit mounted to extend from the housing when moving the pusher-piston at least one hydraulic nozzle and a washing unit comprising a filter connected to the washing unit body, having working channels and an axial channel with a seat socket for the ball, the working channels communicating a cavity between the filter and the housing of the washing unit with a supra-piston cavity of the perforator body, characterized in that a washing assembly housing is configured with radial channels connected to an axial passage and communicating with the annular space by an annular groove on the outer surface of the washing unit of the housing and communicated with its radial channels made in the gun body covering assembly body wash.

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