RU2586122C2 - Hydropercussion device - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: hydropercussion device for cleaning the wellbore from sand and clay tube consists of the housing assembly, the saddle with longitudinal grooves, connecting fitting with an annular piston arranged in the housing of the compensator, a spring-loaded pusher end flap with the rod and the crown, the nut on the lower end of the housing assembly. Apparatus is provided with a restrictive washer placed beneath the crown and the related nut pins freely through a hole in the crown, the body of which is made to cover the inner groove bounding the washer at the time of the stroke, the body bounding the washer central bore.

EFFECT: application of the device in the production tubing of small inner diameter of the pipes can effectively transport mechanical impurity to the surface through the annulus.

1 cl, 3 dwg

Description

The invention relates to the operation and repair of oil and gas wells and can be used to destroy and remove dense sand-clay and sand-hydrate plugs in the axial channel of the pipe tubing and the perforation interval.

A device is known for cleaning wells from sand plugs (see US Pat. RF No. 2.242.585, Mcl. E21B 37/00, publ. 12/20/2004, bull. No. 35).

The device consists of an adapter with a saddle, a detachable hollow body connected through a sleeve to a casing, on the end of which teeth are made.

The destruction mechanism consists of a detachable hollow rod associated with an annular piston.

The adapter with the destruction mechanism have a common hydraulic channel. The hollow stem is spring-loaded relative to the hollow body and is connected through a sleeve to a crown, which is equipped with a nozzle on the outside. The hollow rod together with the hollow body forms an annular chamber, hydraulically connected with the axial channel of the device, while it is assumed that the cross-sectional area of the annular chamber is equal to the cross-sectional area of the hydraulic channel in the hollow rod.

The disadvantages of the design of the device include:

- design complexity;

- the possibility of clogging the bypass holes and the throttle hole with mechanical impurities entering together with the working fluid;

- continuous supply of working fluid through the device and with the flow through the bypass and throttle openings of a part of the flow rate reduces the efficiency of hydropercussion by the teeth of the crown, since both the impact force itself and the frequency of their application are reduced;

- the inclusion of a circulation valve in the device also leads to a decrease in operating efficiency due to irrational losses of the working fluid.

A hydropercussion device is known (see the works of NPO “Drilling”, issue 15, “Modern equipment and technology for pumping wells and drilling sidetracks”, pp. 363-371, Krasnodar, 2006). The authors took this design as a prototype.

The hydropercussion device consists of a housing connected through a hydraulic cylinder with a connecting pipe, in the axial channel of which an annular piston is placed, which is connected with a hollow rod passed in the axial channel of the housing. At the lower end of the hollow rod there is a destruction mechanism including a throttle washer with an axial channel blocked in the initial position by a spring-loaded pusher.

In the middle part of the detachable body, a saddle is installed, to which the end valve connected to the nozzle, the inner crown is fixed at the lower end, is spring-loaded. An external crown is located at the lower end of the split housing. The axial channel of the pusher is equipped with a ball check valve. The axial channel of the hollow rod is constantly hydraulically connected to the throttle channel in the body of the throttle washer, with a chamber formed by the inner wall of the split housing and the pusher.

The annular chamber itself, through longitudinal grooves on the outer side surface of the saddle, is connected to the annular chamber between the detachable body and the nozzle.

The pressure of the end valve to the seat is regulated by a nut with calibrated holes that connect the annular chamber in the detachable body to the well cavity.

The axial channel of the pusher is hydraulically connected to the axial channel of the nozzle and the axial hole in the body of the inner crown.

The cavity of the annular chamber under the annular piston is constantly hydraulically connected to the cavity of the well through a radial hole in the body of the hydraulic cylinder.

The operation of the device is as follows. On the drill pipe string, the device descends into the well to the level of the proppant plug, with unloading on it part of the weight of the drill string.

To ensure the operation of the device for cleaning the wellbore from the proppant plug, it is assumed that the total cross-sectional area of the calibrated holes in the body of the adjusting nut is taken to be less than the cross-sectional area of the throttle channel in the body of the throttle washer. The total area of the calibrated holes in the body of the inner crown is taken to be larger than the cross-sectional area of the throttle channel in the body of the throttle washer.

When it is supplied from the surface of the working fluid, it enters through the axial channel of the nozzle and the hollow rod to the throttle channels in the body of the throttle washer and through the longitudinal grooves on the saddle passes to the calibrated holes in the body of the adjusting nut, through which the hydromonitor impacts on the surface of the proppant plug.

The flow rate of the working fluid supplied from the surface is taken to be greater than the total flow rate of the fluid flowing out through calibrated holes in the body of the adjusting nut, which leads to a smooth increase in pressure in the axial channel of the drill pipe string and inside the device. This pressure is perceived by the cross-sectional area of the pusher, which leaves the end contact with the throttle washer and acts on the end valve, which leads to its separation from the seat.

Thus, a hydraulic connection of the annular chamber in the detachable housing with the axial channel of the pipe arises. The working fluid along the axial channel of the nozzle and the holes in the crown is fed to the surface of the proppant plug. When the end valve is torn from the seat, an additional area is included, which is affected by the pressure of the working fluid, which leads to its sharp movement downward with compression of the spring and the impact of the crown on the surface of the proppant plug with its destruction. With an increased flow rate of the working fluid flowing out of the device during this process, a pressure drop occurs inside the latter, which contributes to the return of the pusher and the end valve by the springs to their original position, with the cessation of the flow of working fluid through the axial channel of the nozzle. There is a set of pressure in the axial channel of the drill pipe string and the process of the impact of the crown on the surface of the proppant plug is repeated. Mechanical particles are transported to the surface by the flow of working fluid along the annulus. In case of insufficient speed of the outgoing flow of the working fluid, it is possible to use foam systems with foam generation at the bottom of the well, with variable supply of packs of working fluid and gas in the axial channel of the flexible pipe string of the coiled tubing installation.

The disadvantages of the installation design include the following:

- the need to measure the diametrical dimensions of all throttling channels in the adjusting nut and throttle washer. In the process of work, it is possible to clog them with mechanical particles, with a change in the cross section and their total area, which can lead to a change in the operating mode for the worse;

- during prolonged use of the device, erosion of the throttling channels is also possible, with an increase in their diametrical dimensions, which can also lead to a change in the operating mode of the device;

- the constant supply of working fluid through the device, even with a lower flow rate, is a decrease in the efficiency of the device.

The technical result that can be obtained by implementing the proposed invention:

- the ability to support the device on the surface of the sand-clay cork with the loaded weight of the device;

- the possibility of stopping the flow of working fluid into the cavity of the well after stopping the flow of working fluid into the axial channel of the pipe tubing from the pump unit located on the surface;

- the possibility of full use of the energy of the compressed working fluid with a pulsed flow of the working fluid with an increased flow rate, with the impact of the rock cutting tool on the surface of the sand-clay cork;

- the exception of the termination of the device due to the ingress of mechanical impurities into the axial channel of the hollow rod.

The technical result is achieved by the fact that the hydropercussion device consists of a detachable housing with a saddle in place of the connector provided with longitudinal grooves, a connecting pipe with an annular piston installed in the housing of the compensator, a spring-loaded follower, an end valve with a stem and a crown forming a movable connection with a nut on the bottom end of split housing provided with threaded holes. The device is equipped with a restrictive washer mounted under the crown and associated with a nut with studs freely passing through the holes in the crown, in the body of which an internal groove is made to cover the restrictive washer at the time of the stroke.

The design of the hydropercussion device is shown in the drawings, where:

- FIG. 1 - the device in the context in the initial transport position of the parts;

- FIG. 2 - the design of the device when resting on the surface of the sand-clay cork restrictive washer;

- FIG. 3 is a sectional view of a device during impact. The inventive device consists of a housing 1, at the junction of parts 2 and 3 of which a saddle 4 is installed. The upper part 2 of the detachable housing 1 is connected to the connecting pipe 5, and a seat plate 6 is installed at their junction 6. In the axial channel 7 of the detachable housing 1 at the bottom 3, a spring-loaded end valve 8 with a hollow stem 9 is installed, pressed by a spring 10 to the seat 4. In the axial channel 11 of the upper part 2 of the detachable housing 1, a spring-loaded pusher 12 is installed, which rests on the seat plate 6, the lower end of which is missing through Without the axial channel of the seat 4, resting on the end of the end valve 8 with the location inside its landing protrusion 13. At the end of the detachable body 1, a nut 14 is installed, covering the hollow stem 9 of the end valve 8. The end valve 8 is equipped with a crown 15 with teeth 16 facing side of the destructible barrier.

The device is equipped with a restrictive washer 17 with a central hole rigidly connected through studs 18 with a nut 14 located in the axial channel 7 of the detachable housing 1. The crown 15 is provided with an internal groove 19, the diameter and depth of which are larger than the overall dimensions of the restrictive washer 17. Connecting pipe 5 is equipped with an annular piston 20 located in the axial channel 21 of the compensator body 22, connected through a sub 23 with a flexible pipe string. The stroke of the connecting pipe 5 by means of an annular piston 20 inside the axial channel 21 of the compensator housing 22 is limited by the screw 24. The assembly including the detachable housing 1 with parts in the axial channels 11 and 7 in the upper 2 and lower 3 parts is connected with the connecting pipe 5, a spring-loaded spring 25 mounted on the outside of this nozzle 5. The pusher 12, with its end 26, enters the axial channel of the seat plate 6 and has a number of longitudinal grooves 27 on the outer surface. The saddle 4 on the outer surface also contains a number of longitudinal grooves 28, hydra connecting the axial channel 11 in the upper part 2 of the detachable housing 1 with the axial channel 7 of the lower part 3 of the detachable housing 1. from the known sizes of the landing protrusion 13 and the outer diameter of the hollow rod 9. The resulting cross-sectional area is taken to be less than the cross-sectional area of the spring-loaded pusher 12.

The annular gap between the seat 4 and the pusher 12 is insulated by a sealing ring 29, the annular gap between the nut 14 and the hollow stem 9 is insulated by a ring 30. The annular piston 20 in the compensator housing 22 is provided with a sealing ring 31.

The operation of the hydropercussion device.

The device assembly through sub 23 is connected to a flexible pipe string of the coiled tubing installation and is introduced into the well through the axial pipe channel of the elevator string to bring the sand-clay or proppant plug to the location.

The restriction washer 17 comes into contact with the sand-clay plug by moving the connecting pipe 5 with the help of the annular piston 20 into the axial channel 21 of the compensator body 22 and compressing the spring 25.

In this position, the device is launched into the well with the connection at the wellhead to a flexible pipe string of the pump unit with the supply of working fluid under pressure, with a given flow rate into the flexible pipe string. As practice shows, the flow rate of the working fluid is within Q≈5 l / s at ΔP = 20 ... 25 MPa.

With an increase in these parameters and a small internal diameter of the flexible pipe, the hydraulic resistance to the flow of the working fluid sharply increases, which accordingly reduces the efficiency of the process of removing sand and clay cork.

With increasing pressure of the working fluid in the axial channel of the flexible pipe string and inside the device, the latter is perceived by the cross-sectional area of the pusher 26, which begins to move in the axial channel of the seat 4, with compression of the spring 10 and end interaction with the surface of the end valve 8 located inside the landing protrusion 13.

Overcoming the resistance of the spring 10 and the force with which the end valve 8 is pressed against the seat 4 by the spring 10 and the pressure of the working fluid acting from the side of the axial channel 7, the pusher 12 tears the landing protrusion 13 from the seat 4. Thus, the working fluid from the axial channel of the connecting pipe 5 along the longitudinal grooves 27 in the body of the pusher 12 is fed into the axial channel 11 of the upper part 2 of the detachable housing 1. Then, through the longitudinal grooves 28 in the body of the seat 4, the working fluid enters the axial channel 7 of the detachable housing 1, from where it enters the axial channel la hollow rod 3, with the impact on the additional area of the end valve 8 inside the location of the landing protrusion 13. This leads to a sharp movement of the end valve 8 together with the hollow rod 9, equipped with a crown 15, down in the direction of the sand-clay tube and the impact on its surface with teeth 16. The flow rate of the working fluid through the device, the Central hole of the restrictive washer 17 and the axial channel of the hollow rod 9 exceeds the flow rate of the working fluid supplied from the surface of the pump unit. This leads to a pressure drop inside the device and the mechanical valve 8 returns to its original position with the landing lug 13 landing on the seat 4. The pusher 12 returns to its original position with the force of the compressed spring and engages with the landing washer 6.

With the destruction of the sand-clay cork, with repeated repetition of the cycles of the reciprocating movement of the end valve 8 with the hollow stem 9 and the impact of the crown 15 on its surface, the device is moved down by twisting the flexible pipe from the drum of the coiled tubing installation.

The use of such a device in an elevator string of pipes of small internal diameter, for example, composed of tubing Du = 73 mm, allows efficient transport of mechanical impurities to the surface along the annulus formed by the inner wall of the elevator column pipe and the outer surface of the flexible pipe of the coiled tubing installation.

The use of this device in an elevator pipe string composed of large diameter tubing requires the use of new technological methods aimed at ensuring the removal of mechanical particles to the surface, for example, the use of aerated liquids or foam systems.

Information sources

1. RF patent No. 2.242.585, Mcl. E21B 37/00, publ. 12/20/2004, bull. Number 35.

2. Proceedings of the NGO Drilling, vol. 15, “Modern equipment and technology for pumping wells and sidetracking”, p. 363-371, Krasnodar, 2006.

Claims (1)

A hydropercussion device for cleaning a wellbore from a sand-clay plug, consisting of a detachable body, a saddle with longitudinal grooves, a connecting pipe with an annular piston located in the compensator body, a spring-loaded end valve pusher with a stem and a crown, nuts on the lower end of the detachable body, characterized the fact that the device is equipped with a restrictive washer installed under the crown and connected to the nut with studs freely passed through the holes in the crown, in the body of which the inner Thread groove to cover bounding the washer at the time of the stroke, in which the body bounding a washer provided with a central hole.

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