RU2446271C2 - Hydraulic impact device - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device includes housing, connection pipe with a seat equipped with longitudinal slots and throttle channel, pusher with perforated cage of spring-loaded ball valve relative to the seat, and annular piston with hollow stock. Housing is equipped with a shell. Annular piston is equipped with end valve with taper surface inside it, a sleeve rigidly attached to pusher by means of conical connection strap and installed in axial channel of the stock with possibility of contacting the annular piston equipped with drain holes. Annular chamber between hollow stock and shell is connected hydraulically to annular gap between a sleeve and hollow stock. Perforated cage is installed in axial channel of pusher with possibility of being moved axially and equipped with support projection and adjusting nut with longitudinal slots. Connection pipe is equipped with support seat. Sleeve is equipped with spring-loaded valve in axial channel installed with possibility of covering the drain holes in conical connection strap. Axial channel of connection pipe above the cage is hydraulically connected by means of throttle channel in the seat to annular chamber between shell and housing and radial hole in the body of hollow stock with annular gap between sleeve and shell.

EFFECT: increasing plug destruction and removal efficiency.

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Description

The invention relates to the oil and gas industry and is intended to clean the bottomhole zone of dense proppant plugs in the presence of abnormally low reservoir pressures.

A device is known for cleaning wells from sand plugs (see RF patent No. 2242585, class MKI ⁷ ЕВВ 37/00; 21/00. Publish. December 20, 2004 Bull. No. 35).

The device consists of an adapter with a saddle, a detachable hollow body connected by a sleeve to a casing provided with teeth at the end.

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 rod is spring-loaded relative to the hollow body by a return spring and is connected through a sleeve to a crown equipped with end teeth, which has an axial throttling channel. The crown on the outside has a hydraulic nozzle.

The hollow rod forms an annular chamber with the inner surface of the hollow body, which is connected by a hydraulic channel to the axial channel of the device, and the cross-sectional area of the annular chamber is equal to the cross-sectional area of the axial hydraulic channel in the hollow stem.

The disadvantage of the design of the device for cleaning sand plugs is:

- low operational reliability, consisting in the fact that during the transportation of mechanical particles along the annular gap between the device body and the inner surface of the pipe tubing, sand may enter the device, which can lead to clogging of the throttling channel of the hydraulic nozzle, jamming of the ring piston, and the process piston will stop process

- the presence of a retaining ring connecting the fracture mechanism with a hollow body requires axial forces developed on the annular piston to ensure its deformation and movement of the fracture mechanism in the direction of the surface of the tube being destroyed.

Known hydraulic hammer (see ed. St. USSR No. 1539303 Mcl 5 E21B 4/14. Publ. 30.01.90 Bull. No. 4), designed to destroy tight plugs when running into the well on drill pipes.

The device consists of a split housing, a hydraulic cylinder, a distribution chamber in the upper part. A stepped piston is placed in the cylinder, connected with the striker and thrust spring-loaded relative to the piston. The distribution chamber is equipped with inlet windows, lower and upper seats, a cover with a drain channel.

At the bottom of the lid there is a glass with drain outlet windows. The valve assembly is made in the form of a hollow sleeve with an axial hole for moving the rod. The sleeve is installed with the possibility of interaction with the lower and upper saddles and with traction.

The disadvantages of the design of the device include the following:

- there is no transfer of the shock load from the hammer to the rock cutting element due to the fact that the latter is rigidly connected to the body, which in turn is rigidly connected to the drill pipe string;

- there is no direct flow of working fluid directed at the rock cutting tool for cooling and cleaning;

- in the presence of abnormally low formation pressure (AAP) in a number of wells, it becomes necessary to carry out a backwash in order to remove mechanical particles along the axial channel of the drill pipe string (since the upward flow rate of the working fluid increases sharply).

In the opposed design, such a process is impossible.

The known design of the hydropercussion device adopted by the authors for the prototype, a description of which is set forth in the works of NPO “Drilling”, issue 15 “Modern equipment and technology for pumping wells and drilling sidetracks,” p.363-371.

A hydropercussion device consists of a housing connected through a hydraulic cylinder to a connecting pipe in which an annular piston is mounted.

The hydraulic cylinder is equipped with an annular piston with a hollow rod passed into the axial channel of the housing.

The lower end of the hollow rod is equipped with 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 a mechanical valve is connected by a spring, connected by a pipe to the inner crown. The lower end of the split housing is provided with an external crown.

The axial channel of the pusher is equipped with a ball check valve. The axial channel of the hollow rod is constantly hydraulically connected by the throttle channel in the body of the throttle washer, with an annular chamber between the wall of the split housing and the pusher.

The annular chamber itself is connected through longitudinal grooves in the body of the saddle to the annular chamber between the detachable body and the nozzle.

The pressure of the mechanical valve to the seat is regulated by a nut equipped with calibrated holes connecting the annular chamber between the wall of the split housing and the pusher with the cavity of the well.

The axial channel of the pusher is constantly 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 with a radial hole in the body of the hydraulic cylinder.

The operation of the device.

At the lower end of the drill pipe string, the complete assembly is installed and lowered into the well to the location of the proppant plug, with the unloading of part of the weight of the drill string on it. Supply a working fluid with a given flow rate and pressure.

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

When supplying the working fluid through the drill pipe string, the latter enters through the axial channel of the connecting pipe and hollow rod, and then through the throttle channels in the throttle body and longitudinal grooves in the seat body, is fed to the calibrated holes in the body of the adjusting nut, with the action of the working fluid stream on surface of dense proppant tube.

Since the flow rate of the working fluid supplied through the drill pipe string is taken to be greater than the total flow rate through calibrated holes in the body of the adjusting nut, a smooth increase in pressure occurs in the axial channel of the drill string and inside the device. With the calculated pressure difference perceived by the pusher area, the latter leaves its end contact with the throttle washer and acts on the end valve with axial force. This leads to its separation from the saddle and the formation of a hydraulic connection of the annular chamber between the body of the split housing and the pusher with the axial channel of the pipe.

The working fluid with an increased flow rate enters the axial channel of the nozzle and then through the holes in the crown is fed to the surface of the proppant plug.

When the end valve is detached from the seat, it drastically moves down, with compression of the return spring and mechanical impact of the teeth of the inner crown on the surface of the proppant plug, with its destruction.

When the end channel is open and the flow rate of the working fluid flowing from the device exceeds the flow rate of the working fluid supplied from the surface to the drill pipe string, a pressure drop occurs in the hydraulic channel of the device, and conditions arise that contribute to the return of the end valve to the seat by the force of a pre-compressed spring. The pusher enters end contact with the surface of the throttle washer.

The process of reciprocating movement of the crown by the teeth is carried out in automatic mode.

When the working fluid is absorbed by the formation, the upward flow rate in the annulus and the efficiency of transporting proppant particles to the surface are reduced. In this case, the pump unit is switched to the reverse supply of the working fluid. The working fluid with proppant particles enters through the central hole in the crown into the axial channels of the nozzle and pusher, and then with the ball valve open, it is fed into the axial channel of the connecting nozzle and is brought to the surface through the drill pipe string. After washing and removing mechanical proppant particles from the proppant tube, the pump unit is switched to direct supply of the working fluid and the hydromechanical process is applied to the next section of the proppant tube.

The disadvantages of the design of the device include the following:

- when switching from a direct supply of flushing fluid to a reverse one, in order to ensure the removal of mechanical particles from the bottomhole zone, flushing fluid with mechanical particles is fed through the axial channel of the nozzle and pusher with the opening of the check valve;

- the presence of constant hydraulic communication through the throttle hole in the crown and channels in the throttle washer with the axial channel of the shank and the pipe lift string, which, when backwashing and supplying a mixture of mechanical particles through them, leads to clogging of the throttle holes. When re-switching to a direct supply of flushing fluid for the operation of the hydraulic hammer in the mode of destruction of the dense proppant plug, the operating mode changes.

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

- increasing the efficiency of the destruction and removal of dense proppant plugs in the axial channel of the wellbore with the existence of ANPD (abnormally low reservoir pressure);

- the ability to backwash the wellbore through a hydropercussion device with protection against clogging of calibrated holes with proppant particles and ensuring the effective supply of mechanical particles with a flow of working fluid to the surface;

- the possibility of reciprocating movement of the percussion mechanism at low flow rates of the working fluid supplied through the pipe lift string;

- the ability to provide reverse flow of the working fluid through the device with an increased flow rate;

- reduction of the axial compressive load on the pusher spring due to the axial force generated from the differential pressure of the working fluid and perceived by the valve cage, with the closure of this load on the support seat.

The technical result is achieved in that the device consists of a housing, a connecting pipe with a saddle, in which longitudinal grooves are made on the inner surface and a throttle channel, a pusher with a ball valve cage, spring-loaded relative to the saddle, the housing is additionally equipped with a glass in the axial channel with the formation of an annular between them chamber and coverage of the upper end of the saddle and the formation of a movable joint with the annular piston. The annular piston is equipped with an end valve and a hollow stem. The housing is equipped with a sleeve rigidly connected to the pusher by a conical jumper equipped with drain holes and installed in the axial channel of the hollow rod, with the possibility of mechanical contact with the counter conical surface in the body of the mechanical valve, provided with drainage holes at the contact point. The annular chamber between the hollow stem and the cup is hydraulically connected by radial holes in the cup body to the annular chamber between the cup and the body and the radial holes in the hollow stem body, under the annular piston, with an annular gap between the sleeve and the hollow stem.

The ball valve cage is provided with drainage holes, a support protrusion and an adjusting nut with longitudinal grooves, mounted in the axial channel of the pusher with the possibility of axial movement. The connecting pipe is equipped with a support seat installed with the possibility of forming an annular gap with the ball valve cage and the possibility of alternating interaction with the support protrusion and the adjusting nut. The sleeve is equipped with a spring-loaded valve in the axial channel, installed with the possibility of overlapping drain holes in the conical jumper. The axial channel in the connecting pipe, above the ball valve cage, is constantly hydraulically connected to the throttle channel in the seat and the annular chamber between the cup and the body, through the annular gap between the valve cage and the supporting seat, with a hydraulic channel formed by the outer surface of the pusher and the internal connecting pipe.

An analysis of the inventive step showed the following:

A device is known for cleaning the bottom-hole zone of a well (see RF patent No. 2138617, class IPC 6 ЕВВ 37/00, published on 09/27/1999), which includes a check valve in the structure of the valve mounted on the stem. Also known is the connection of the inner cavity of the glass through the throttle with the animation chamber.

The design of the hydropercussion device is illustrated by drawings, where

figure 1 shows the design of the device in section in the initial position;

figure 2 - the design of the device in the position of hydromechanical impact on the surface of a dense proppant tube rock-cutting tool;

figure 3 - design of the device in the position of the backwash of the wellbore.

The device consists of a housing 1, with a connecting pipe 2, in the hydraulic channel 3 of which there is a saddle 4, with longitudinal grooves 5, for the passage of flushing fluid, equipped with a throttle channel 6, hydraulically connected with a groove 7 in the body of the housing 1. In the axial channel of the housing 1 a cup 8 is installed, with the formation of an annular chamber 9 between them. Inside the cup 8, an annular piston 10 is installed with an end valve 11 resting on a saddle 4, rigidly connected with the hollow rod 12, passed through the nut 13 beyond its limits.

The annular chamber 9 is hydraulically connected by a radial hole 14 in the body of the glass 8, with the annular chamber 15 and the groove 7 in the housing 1.

An annular piston 10 with an end valve 11 is pressed against the seat 4 by a spring 16. A sleeve 17 is mounted in the axial channel of the hollow rod 12, which is connected to the pusher 18 passed through the axial channel in the annular piston 10.

At the upper end of the pusher 18, a spring 19 is installed, pressed by the adjusting nut 20 to the end surface in the inner bore of the seat 4.

In the axial channel 21 of the pusher 18, a perforated cage 22 is installed with a seat 23 of the ball valve 24, having on the outer side a support protrusion 25 and an adjusting nut 26 with a number of longitudinal grooves 27 on the outer side. In the axial channel 3 of the connecting pipe 2 below the location of the connecting thread 28 mounted support seat 29 with a tapered seating surface 30 under the counter surface on the body of the support protrusion 25.

The adjusting nut 26 is located above the support seat 23 and is installed with the possibility of mechanical interaction with his body. The perforated cage 22 with the seat 23 of the ball valve 24 with its lower end enters the axial channel 21 of the pusher 18 with the formation of a movable connection between them. An annular gap 31 is formed between the outer surface of the perforated cage 22 and the inner surface of the support seat 29, which is hydraulically connected with the axial channel 3 between the body of the pusher 18 and the inner surface of the connecting pipe 2, and then with the annular gap between the saddle 4 and the pusher 18, above the location of the annular piston 10. In the body of the mechanical valve 11 of the annular piston 10, a series of drainage holes 32 are made, extending into the axial channel 33 above the point of contact of the sleeve 17 with the inner conical surface of the mechanical valve 11. At the junction of the pusher 18 with the sleeve 17, there are drain holes 34 hydraulically connected through an annular gap between the outer surface of the sleeve 17 and the inner surface of the hollow rod 12 with radial holes 35 in the body of the hollow rod 12 and the annular chamber 15 under the annular piston 10.

At the junction of the pusher 18 and the sleeve 17, a conical surface 36 is formed, to which the valve 38 is pressed by the spring 37. The spring 39 is pressed by the nut 39.

The annular gap between the annular piston 10 and the cup 8 is closed by the sealing ring 40. The annular gap between the cup 8 and the housing 1 is closed by the sealing ring 41.

The annular chamber 15 under the annular piston 10 is isolated from the external environment by the sealing rings 42 mounted in the bores of the nut 13, covering the hollow stem 12, which is provided with an internal connecting thread 43, for installing a rock cutting element, for example, a crown with teeth, as in the prototype.

The annular gap between the annular piston 10 and the inner surface of the glass 8 is closed by a sealing ring 44.

The throttle channel 6 in the body of the saddle 4 constantly hydraulically connects the annular space 45, under the longitudinal grooves 5 in the body of the saddle 4 with the groove 7.

Hammer device operation

By connecting thread 28, the complete assembly is fixed at the lower end of the drill pipe string and lowered into the well to the depth of the proppant plug.

The pumping unit is connected to the drill pipe string and fed under pressure and at a given flow rate to the device.

Through the longitudinal grooves 27 in the adjusting nut 26, the working fluid enters the axial channel 3 of the connecting pipe 2 and then through the longitudinal grooves 5 in the saddle 4 is fed into the annular space 45, from where through the throttle channel 6, the groove 7 enters the annular chamber 9. Through the radial holes 14, the working fluid passes into the annular chamber 15, connected by radial holes 35 in the body of the hollow rod 12, with an annular gap between the body of the sleeve 17 and the hollow rod 12 and is supplied to the drain holes 34, blocked by the valve 36.

Since the flow rate of the working fluid through the throttle channel 6 exceeds the flow rate in the annular gap between the body of the sleeve 17 and the hollow stem 12, then the pressure increases in the axial channel of the drill pipe string and the axial channel 3 of the connecting pipe 2. The excess pressure of the working fluid is sensed by a ball valve 24 on the saddle 23, which leads to the suspension of the perforated cage 22 through the adjusting nut 26 at the end of the supporting seat 29. The excess pressure of the working fluid is perceived as the cross-sectional area of the pushed For 18. The force from the perception of the pressure drop through the adjusting nut 20 is communicated to the spring 19 and leads to the movement of the pusher 18 relative to the connecting pipe 2 with the seat 4. This leads to a departure from the contact sleeve 17 with the body of the mechanical valve 11 and the free hydraulic connection of the annular chamber 15 through radial holes 35 and drain holes 34, with the axial channel 33 of the sleeve 17. This leads to a sharp drop in pressure of the working fluid in the annular chamber 15 under the annular piston 10, while maintaining the impact of excess pressure on the annular area of the mechanical valve 11, from the side of the annular space 45.

This leads to a sharp movement of the annular piston 11 with the hollow rod 12 down relative to the cup 8 with compression of the spring 16 and the impact of the rock cutting element on the surface of the proppant plug. This creates a free hydraulic connection of the axial channel 3 through the longitudinal grooves 5 and the annular space 45 with drainage holes 32 in the body of the mechanical valve 11 and drain holes 34 in the body of the sleeve 17, with its axial channel 33. The valve 38 tilts down with compression of the spring 37 and working fluid with an increased flow rate is ejected into the well, also affecting the surface of the proppant plug. The pressure in the axial channel 3 decreases and, by the force of the compressed spring 16, the end valve 11 interacts with the seat 4 and blocks the direct supply of working fluid to the drain holes 32.

By the force of the compressed spring 19, the pusher 18 together with the sleeve 17 are returned to their original position and press the mechanical valve 11 against the seat 4 even more due to the perception of the pressure of the working fluid.

The pressure increases again in the axial channel 3 of the connecting pipe 2. The working fluid through the throttle channel 6 is again supplied to the annular chamber 9 and the annular chamber 15 with a set of pressure in the entire system.

It should be noted that the cross-sectional area of the annular piston 10 from the side of the annular chamber 15 is taken to be larger than the cross-sectional area of the end valve 11, which receives the pressure of the working fluid from the side of the annular space 45. The flow rate of the working fluid through the throttle channel 6 exceeds the flow rate of the working fluid in the annular gap between the sleeve 17 and hollow stem 12.

The proppant tube destruction process is carried out with a smooth movement of the drill pipe string with the device down, while maintaining an upward flow of flushing fluid with proppant particles along the annulus of the well.

With a decrease in the flow rate of the working fluid leaving the annulus, which serves as a signal about its absorption by the partially productive formation, the supply of the working fluid to the annulus of the well is switched over to ensure a predetermined upward velocity in the axial channel of the pipe drill string.

The flow of the working fluid captures the mechanical proppant particles destroyed in the previous cycle, transports along the axial channel of the sleeve 17 and the axial channel 21 of the pusher 18 to the ball valve 24 and opening the flow through the perforated cage 22 into the axial channel of the drill pipe string. In this case, the perforated cage 22 of the ball valve 24 moves upward in the axial channel 21 of the pusher 18 until the end contact of the support protrusion 25 with the conical seating surface 30 of the support seat 29.

This prevents the unauthorized supply of a mixture of working fluid with proppant inside the channel 3 under the support seat 29 and the ingress of mechanical particles into the throttle channel 6 and to the landing site of the end valve 11 with the seat 4. The valve 38 is pressed against the conical surface 36 by the force of a compressed spring 37 36 , with additional preload by differential pressure, which also eliminates the ingress of mechanical particles into the device.

After conducting a backwash, the flow of working fluid is switched from back to direct and the proppant tube is destroyed again.

Information sources

1. RF patent No. 2242585, Cl. MKI 7 Е21В 37/00; 21/00, publ. December 20, 2004 Bull. Number 35.

2. Auto USSR No. 1539303, Cl. MKI 5 Е21В 4/14, publ. 01/30/90, Bull. Number 4.

3. "Hydropercussion device" (prototype) Tr. NGO Drilling. Issue 15. “Modern equipment and technology for pumping wells and drilling sidetracks”, p.363-371.

Claims (1)

A hydropercussion device for cleaning a well from a proppant plug, consisting of a housing, a connecting pipe with a saddle equipped with longitudinal grooves and a throttle channel, a pusher with a perforated ball valve cage, spring-loaded relative to the saddle, an annular piston with a hollow rod, characterized in that the housing is equipped with a glass, installed with the possibility of the formation of an annular chamber with a housing and coverage of the seat, the annular piston is equipped with an end valve with a conical surface inside, a sleeve, rigidly connected with a cone jumper pusher and a hollow rod installed in the axial channel with the possibility of end contact with an annular piston equipped with drainage holes, the annular chamber between the hollow rod and the nozzle is hydraulically connected by radial holes in the nozzle body, with the annular chamber between the nozzle and the sleeve, and radial holes the body of the hollow stem, with an annular gap between the sleeve and the hollow stem, and the perforated ball valve cage is mounted in the axial channel of the pusher with the possibility of axial movement oia and is equipped with a support protrusion and an adjusting nut with longitudinal grooves; the connecting pipe is additionally equipped with a support seat installed to form an annular gap with a perforated ball valve cage and the possibility of alternating interaction with its support protrusion and an adjusting nut; the sleeve is equipped with a spring-loaded valve in the axial channel, installed with the possibility of blocking the drain holes in the conical jumper, the axial channel of the connecting pipe above the ball valve cage is constantly hydraulically connected by a throttle channel in the seat with an annular chamber between the glass and the body and the radial hole in the body of the hollow rod with an annular gap between the sleeve and the glass.

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