RU2533514C1 - Slot perforator - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: slot perforator for pipes comprises a body with power piston and puncher, barrel with a hollow plunger inside, connected with a stem entering the oil chamber. The cylinder is fitted with screw stopper and sub interconnected with each other by a calibrated shear tie. The sub is fitted with a bush with an internal ring lug. The hollow plunger is fitted with the extender installed inside a bush with forming of telescopic connection. The axial channel of the sub is hydraulically connected through holes with the axial channel of the cylinder. The axial channel of the hollow plunger is connected through circulating holes in its housing with bypass holes of the cylinder. The axial channel of the extender is connected by radial holes in its housing with the ring chamber between a bush and extender and is fitted with a seat with a ball valve connected to it through the shear tie. The bush is fitted with hydraulic channels designed with a possibility of connection of the ring chamber with the axial channel of the cylinder. The ring chamber under the hollow plunger is hydraulically connected through channels with annular space. The housing is fitted with a barrel with a restrictive lug, and the power piston is installed inside with a possibility of axial movement and interaction with the restrictive lug in a boundary position.

EFFECT: free lowering of the device into a well with crossflow of formation fluid from annular space inside the device and axial channel of a flexible pipe string, possibility of the termination of hydraulic connection of the axial channel of the flexible pipe string with annular space during perforation and possibility of returning of the power piston of punchers into transportation position.

3 dwg

Description

The invention relates to the mining industry and is intended for perforating pipes in oil and gas wells.

Known hydraulic rotary hammer (see AS No. 757692, M. class. E21B 43/114, publ. 23.08.80, bull. No. 33).

The hydraulic hammer drill consists of a housing with a feed channel. A punch is installed on the outer side of the housing, in which a channel is made that is hydraulically connected to the supply channel. In the case below the installation site of the punch, on the opposite side is a cylindrical bore provided with a piston and connected by a channel to the axial channel of the case. The piston stroke in the cylindrical bore is limited by a stopper. A hydraulic hammer drill descends into the borehole on a tubing string.

Device operation

In the axial channel of the tubing is supplied under excess pressure and with a sufficiently large flow rate of the working fluid. Thus, under the influence of excessive pressure, the piston moves inside the cylindrical bore of the housing, with the action of the housing with a punch in the opposite direction. The punch is introduced into the pipe material with its destruction and the creation of a perforation hole through which the jet of working fluid flowing from the nozzle onto the rock is exposed.

- Such a constructive solution can be implemented in wells with a large diameter of the casing string;

- to create axial force on the punch, it is necessary to have pumping units with a large flow rate and high working pressure, of the order of Q = 10 ÷ 12 l / s and ΔР≈70 ÷ 100 MPa.

This requires the use of high-strength tubing capable of withstanding such pressure.

A known method of perforation of wells and a device for its implementation (see AS No. 1352042, M. class. E21B 43/114, publ. 15.11.87, bull. No. 42). The hammer drill consists of a housing in which several horizontal chambers are made, with punches placed in them, the cavities of which are hydraulically connected by channels to the lower chamber. A plunger connected to the piston is introduced into the lower chamber, the cavity above which is filled with liquid. The axial channel is blocked by a second plunger with a piston acting as a multiplier. During the descent of the perforator on the tubing, its axial channel is filled with a liquid whose density is less than the density of the kill fluid. By creating a pressure of the working fluid in the axial channel of the pipe tubing string, transferring it to punches that move in horizontal chambers and penetrate the pipe body, with the formation of perforation holes.

When the pressure in the tubing string, or in the tubing string, is depressurized, due to the difference in the specific gravity of the fluid in the tubing and the annulus, the pistons and punches are introduced into the horizontal chambers, which serves as a signal about the operation of the perforator and the possibility of its extraction from the well.

Design disadvantages:

- design complexity;

- the need to fill the axial channel of the tubing string with a special fluid with a lower specific gravity than the fluid with which the well is filled;

- it is not possible to provide a hydraulic connection between the axial channel of the pipe tubing string and the annular space of the well, which causes certain difficulties when removing the device from the well.

Known borehole punch for pipes (see AS No. 673724, M. class E21B 43/00, publ. 07/15/79, bull. No. 26), which is intended for use in the process of repairing wells, adopted by the authors for the prototype.

The device consists of a housing, in the bore of which a piston with a punch is installed. The space under the piston through the channel communicates with the high-pressure chamber, filled with oil and pressed by the rod. The latter is connected to a hollow plunger of large diameter by means of a pin. The cylinder cavity through the seal of the plunger divides it into two parts - the chamber. The chamber on the side of the rod in the initial position is filled with air. The lower chamber is also filled with air and isolated from the environment with a needle check valve.

To open the needle valve, a lever and a pre-thrown load-stop are used, with the upper beveled surface facing the punch.

The device is used to create a hydraulic connection of the axial channel of the pipe tubing with the annulus, for example, in the case of a sand-clay plug stuck.

After opening the needle valve, a hydraulic connection is formed between the chamber under the plunger and the cavity of the well. The reservoir fluid under the influence of hydrostatic pressure acts on the end face of the plunger, with its movement inside the cylinder along with the rod. In this case, oil from the chamber enters under the piston, with its movement towards the pipe wall. The pin connecting the plunger to the rod is designed for the force required to create oil pressure above the piston, at which the pipe wall is punched. After abutment of the stem collar at the end of the chamber, the pin collapses and further movement of the plunger stops. The pressure in the cavity of the plunger and the chamber is equalized, which leads to the return of the piston into the cylinder, with pulling out the punch from the formed hole.

Design disadvantages:

- the reliability of the device depends on the reliability of the sealing elements of the plunger and rod, which allows penetration of formation fluid into the device, with a corresponding failure in operation;

- the use of the device is limited, since for its operation it is necessary to first drop the stop-load, which should rest on a sufficiently strong surface in the axial channel of the pipes.

It is known that to obtain holes in the wall of the pipe, for industrial needs, it is possible at any distance from the bottom of the well. It is impossible to do this with this device, since it is problematic to open the check valve when the lever interacts with the load-stop, since the force by which the needle valve is pressed to the seat due to the hydrostatic pressure from the fluid column in the well can far exceed the force from the interaction of the lever with emphasis load.

The technical result that can be obtained by implementing the invention is reduced to the following:

- the possibility of free descent into the well, with the flow of formation fluid from the annulus, into the device and the axial channel of the flexible pipe string;

- the possibility of terminating the hydraulic connection of the axial channel of the flexible pipe string with the annulus during the formation of the perforation hole due to the creation of excess pressure;

- the ability to return the power piston with the punch to the transport position, with the formation of hydraulic connection of the axial channel of the flexible pipe string with the annulus of the well and, if necessary, the possibility of damping the reservoir.

The technical result is achieved by the fact that the downhole punch for pipes contains a housing with a power piston equipped with a punch, a cylinder with a hollow plunger inside, connected with a rod entering the oil chamber.

The cylinder is equipped with a screwdriver and an adapter passed through its axial channel, connected with each other by a calibrated shear element. The adapter is equipped with a sleeve with an annular protrusion inside. The hollow plunger is equipped with an extension extending inside the sleeve, with the formation of a telescopic connection between them. The axial channel of the adapter is hydraulically connected by openings to the axial channel of the cylinder, the axial channel of the hollow plunger is connected by circulation holes in its body to the bypass openings of the cylinder.

The extension cord is equipped with a seat with a ball valve in the axial channel, which is connected by radial holes with an annular chamber between the extension cord and a sleeve provided with hydraulic channels connecting the annular chamber to the axial channel of the cylinder. The annular chamber under the hollow plunger is hydraulically connected by channels with the annulus. The housing is equipped with a glass, inside of which there is a power piston with a punch, with the possibility of axial movement and interaction with the restrictive protrusion in the extreme position.

The drawings show in section a design of a downhole drill, where:

- figure 1 - the device in the context, in the initial position of the parts, before lowering into the well;

- figure 2 is a device in section, in the position of the parts when creating a perforation hole in the wall of the tubing;

- figure 3 - the relative position of the parts of the device when it is removed from the axial channel of the pipe riser.

The device consists of a housing 1 connected to a cylinder 2, in the axial channel 3 of which a hollow plunger 4 is installed with a stem 5 entering a chamber 6 filled with oil. The axial channel 3 of the cylinder 2 in the upper part is blocked by a screw-up 7, in the axial channel of which an adapter 8 is placed, provided with a sleeve 9 with an inner annular protrusion 10 at the lower end, inside of which there is an extension 11, which forms a movable connection with its upper end.

An extension cord 11 is mounted on a hollow plunger 4 and comprises a seat 14 in the axial channel 13 with a ball 15 connected with it by a shear element 16. An annular chamber 17 is formed between the sleeve 9 and the extension 11, hydraulically connected with the holes 18, with the axial channel 13 of the extension 11 and radial holes 19 with the axial channel 3 of the cylinder 2.

Radial channels 20 are made in the body of adapter 8, connecting its axial channel 21 with axial channel 3 of cylinder 2. In the initial position, adapter 8 is connected to screwdriver 7 by a calibrated shear element 22.

The hollow plunger 4 is made with an internal bore 23, hydraulically connected through holes 24 in its body, and holes 25 in the body of the cylinder 2 with the external environment.

The annular gap between the hollow plunger 4 and the cylinder 2 is insulated by seals 26. The rod 5 is provided with o-rings 27.

An annular chamber 28 is formed under the hollow plunger 4, which is hydraulically connected by the channel 29 to the external environment. A radial bore is made in the body of the housing 1, in which a glass 30 with a restrictive protrusion 31 is installed, in the axial channel of which a power piston 32 with a punch 33 is installed. The cavity of the chamber 6 in the body of the cylinder 2 is constantly hydraulically connected by the channel 34 with the cavity of the glass 30 in front of the power piston 32 The lower end of the housing 1 is provided with a plug 35.

Device operation

The downhole drill through an adapter 8 is connected to a flexible pipe string of the coiled tubing installation and is inserted into the axial pipe channel of the lift string, with a location at a given depth.

When the device is lowered into the well, the formation fluid through the openings 25 in the body of the cylinder 2 and the openings 24 in the hollow plunger 4 freely enters the inner bore 23 and through the axial channel of the seat 14 into the axial channel 21 of the adapter 8 and then into the pipe lift string.

Supply under pressure of the working fluid in the axial channel 21 of the adapter 8.

Under the action of a differential pressure, the seat 14 with the ball 15 destroys the shear element 16 and moves in the axial channel 13 of the extension 11 with a passage into the inner bore 23 of the hollow cylinder 4, with the section of the holes 24 overlapping and the hydraulic connection with the annulus ceased. The hollow plunger 4 moves downward in the axial channel 3 with the rod 5 entering the chamber 6, transferring pressure to the cross section of the power piston 32 through the channel 34. The power piston 32 moves in the axial channel of the cup 30 until it contacts the inner surface of the pipe and stops against the restrictive protrusion 31.

When the calculated pressure drop acting on the power piston 32, the punch 33 is introduced into the wall of the pipe with the formation of a perforation hole. When moving the hollow plunger 4 together with the rod 5 down, the extension 11 moves relative to the sleeve 9 against the stop in the inner annular protrusion 10. Stop the flow of pressure of the working fluid into the device. The tension of the flexible pipe, communicated to the adapter 8, destroys the calibrated shear element 22 and, through the extension 11, imparts axial force to the hollow plunger 4, which moves inside the cylinder 2 together with the rod 5 upwards to create a vacuum in the cavity of the glass 30. Thus, under the action excess pressure acting on the power piston 32 from the side of the annulus, the latter moves inside the cup 30. Further tension up to the stop with the sleeve 9 at the end of the screw-up 7, with the location of the radial channels 2 0 beyond, a hydraulic connection is formed between the axial channel of the flexible pipe string and the annulus.

This allows you to drain the fluid from the axial channel of the flexible pipe string, or, if necessary, to supply the working fluid in the annulus, for example, to kill the well.

After rising to the surface, the device can be prepared for reuse.

Claims (1)

A hydromechanical puncher for pipes, comprising a housing with a power piston and a punch, a cylinder with a hollow plunger inside, connected with a rod entering the oil chamber, characterized in that the cylinder is equipped with a screwdriver and an adapter, connected with each other by a calibrated shear element, the adapter is equipped with a sleeve with an internal annular protrusion, the hollow plunger is equipped with an extension installed inside the sleeve with the formation of a telescopic connection, the axial channel of the adapter is hydraulically connected by holes to the axial channel cylinder, the axial channel of the hollow plunger is connected by circulation holes in its body to the bypass holes of the cylinder, the axial channel of the extender is connected by radial holes in its body with an annular chamber between the sleeve and the extension and is equipped with a seat with a ball valve, an associated shear element, the sleeve is equipped with hydraulic channels made with the possibility of communication of the annular chamber with the axial channel of the cylinder, and the annular chamber under the hollow plunger is hydraulically connected by channels with the annulus, the housing with It is stuffed with a glass with a restrictive protrusion, and the power piston is installed inside with the possibility of axial movement and interaction with the restrictive protrusion in the extreme position.

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