RU2382872C1 - Hydraulic pulser - Google Patents

Abstract

FIELD: oil-and-gas industry.

SUBSTANCE: invention related to oil-and-gas industry and can be used for oil and gas wells operation efficiency increase. Device consists of a case, a barrel with a seat, and an end valve in its axial channel. At the barrels end installed a bolster with a longitude cuttings along its perimetre from external side, pressed from the top with a screw spiral string with a adjusting nut. The barrel executed with figure cylindrical boring and equipped with a seat with a figure piston and the end valve, equipped with a pull, going though the axial channel in a perforated wall and pressed with the string. The figure piston contains stepped boring with a changeable nozzle and screwed barrel, installed in it with ability of creation a movable connection with the support nut and end interconnection with the figure piston. The stepped boring constantly connected hydraulically via radial holes with case under the barrel axial channel.

EFFECT: ability of hydrodynamic impulses application on the produced formation fluid, with formation fluid flow total impulse increase in tubing string axial channel.

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Description

The invention relates to the oil and gas industry and may find application in the operation of fountain wells with a variable mode of production or for influencing the bottom-hole zone of a well with an increase in its permeability and injectivity of the formation. Known hydraulic vibrator [1], designed to create a hydraulic shock and impact on the bottomhole formation zone.

The vibrator consists of a case with windows, with a movable clutch located in it with a landing seat under the locking organ ball. The movable sleeve is connected via fingers to the sleeve, which in turn is equipped with a locking sleeve. The sleeve rests on a compression spring.

Disadvantages:

- the device is made for conditions of use in a narrow frequency range, a change in this frequency in this design is not provided;

- the joint movement of the sleeve with the coupling leads to uncertainty in the process of generating a hydraulic shock (hydrodynamic impulses), since the flushing windows in the body of the body are blocked by the body of the coupling when it is moved;

- the need to dump the ball from the surface with its landing on the landing seat in the sleeve requires additional work time.

The device cannot be used in the mode of pumping formation fluid from a well with superimposed hydrodynamic flow and pressure pulses on the flow, i.e. the scope of this device is limited.

Known downhole pulsator [2], consisting of a housing, in the axial channel of which a pipe is concentrically placed with windows forming an annular gap between its inner and outer walls. The upper end of the pipe is muffled, and the lower is connected to a coupling equipped with a spring shock absorber mounted under the saddle in its axial channel.

A spring-loaded ball valve is installed on the seat.

Disadvantages:

- the force of the springs with which the ball valve is pressed against the seat is constant, and if necessary, it is not possible to change the setting for the operating conditions of a particular well. This must be done especially when several wells are operating on one field reservoir.

The device can be used to generate hydrodynamic pulses only when equipped with an elevator pipe string and supply formation fluid from the reservoir, but cannot be used to generate hydrodynamic pulses when pumping hydraulic fluid into the reservoir, for example, to increase injectivity or to clean the bottomhole zone, t .e. there is a limitation on the scope.

A device for influencing the bottomhole zone of a well [3], taken by the authors as a prototype.

The device consists of a hollow body with a hollow pipe located in its axial channel with the formation of an annular cavity between them. The hollow pipe is connected to the perforated partition, which in turn is fixed in the hollow body. The hollow pipe has a conical axial channel with a seat under the ball valve, which is pressed by a spring through the sleeve. The axial channel of the hollow pipe is constantly hydraulically connected to the well cavity. The annular gap between the hollow body and the hollow pipe is also hydraulically connected through holes in the perforated baffle to the well cavity and is closed from above by a spring-loaded piston.

The force of pressing the ball valve to the seat is regulated by changing the spring fluid, which allows you to adjust the frequency of the pulsation of the working fluid.

The disadvantages of the design include:

- the use of a device for producing reservoir fluid with superimposing on the flow of hydrodynamic pulses of a certain frequency and amplitude, with an increase in the required limits in the flow rate pulse of the reservoir fluid, is difficult, because the formation conditions of a particular well, its design features, in particular depth, influence this process pipe diameter of the elevator column, gas factor, water cut coefficient, etc. When working several wells on one field reservoir, it is also necessary to take into account the pressure in it, the presence of pulsations and the amplitude of the pressure fluctuations. The imposition of self-oscillations in the reservoir and the addition of the generated pulses of the device itself to the flow of the formation fluid pumped from the wellbore from the well and their addition to the generated pulses of the device itself can lead to a change in the pulses for the worse in the pipe string, which will reduce the efficiency of the device. Those. expand the scope is not possible. The device can be used only in the case of the supply of working fluid into the reservoir, when the factors of the reservoir do not affect the generation of hydrodynamic pulses.

The need to adjust the pressure force of the piston by the spring from the end surface of the sleeve does not play any role in the generation of pulses by the device, since the latter by the differential pressure in the axial channel of the pipe tubing string is compressed from above and is in a closed state. In addition, there is no clear signal at which it would be regulated, the flow rate of the formation fluid in the axial channel of the pipe tubing string was changed by the calculated value.

An analysis of the inventive step showed the following:

- known design of a hydraulic vibrator (see US Pat. RF No. 2297598, MKl. E21B 28/00; 43/25, publ. 01/27/2003) to create a water hammer, in which a tension spring is used as a working body, the turns of which wound up to the density of contact of the turns. When creating a pressure drop inside the cavity created by the spring, the coil of the spring diverges and opens a helical spiral channel for the passage of the working fluid. The pressure in the spring cavity is equalized, and the turns abruptly close with the occurrence of water hammer. The cycle repeats.

A known method of preventing paraffin deposits during oil production from a well (see US Pat. RF No. 2083804, Ml. 6 ЕВВ 37/00, publ. 07/10/97), in which for its implementation a flow of formation fluid is passed with a change in its speed, why use a fitting device. Pressure drop from 0.015 MPa to 0.035 MPa. Those. it is necessary to adjust to the technological mode of supply - superimposing on the flow rate of one stream supplied continuously, the second stream supplied in a pulse with a calculated pressure drop.

In the patent and scientific and technical literature, we did not find a device in which a spring has variable hydraulic resistance, the turns of which extend the technological gap with an increase in the pressure drop across the shut-off element and flow rate.

The technical result that can be obtained by carrying out the present invention is as follows:

- the ability to adjust the pulsation frequency by changing the stiffness of the spring and creating a variable local hydraulic resistance to the flow of the working (reservoir) fluid by a helical spiral spring when it is compressed when the hydraulic channel is fully open due to a change (decrease) in the technological gap between the spring coils;

- the possibility of using the device to generate flow pulses and pressure.

The use of variable hydraulic resistance in the form of coils of a spiral spring and the possibility of changing the slotted gap in the path of the second additional flow makes it possible to clearly excite hydraulic pulses in the axial channel of the pipe tubing string and to ensure a clear cut-off of the reservoir fluid by equalizing the pressure in the axial channel of the full body above the end valve and beneath it and landing the mechanical valve on the seat in the curly axial channel of the sleeve.

The technical result is achieved using a known device that is installed as part of an elevator pipe string, with installation at a given depth.

The device comprises a housing, in the axial channel of which a sleeve with a figured cylindrical bore with a seat and an end valve on a figured piston is installed and fixed, forming a movable connection with the sleeve. A support washer with longitudinal grooves around the perimeter rests on the end face of the sleeve, pressed from above by a helical spiral spring with an adjusting nut on the case.

The shaped piston is equipped with a thrust passed through the axial channel of the perforated baffle with a spring, which is pressed by the mechanical valve to the seat.

A technological bore is made inside the body of the figured piston, in which a replaceable fitting is installed, preloaded by the threaded cup, the upper end of the threaded cup is installed with the possibility of the formation of a movable connection with the support washer and the end interaction of the figured piston.

The technological bore in the body of the figured piston is constantly hydraulically connected to the axial channel of the housing under the sleeve by radial holes.

From the sources reflected in the analysis of the inventive step, it is known that in order to protect the pipe wall of the elevator column from paraffin deposits, it is necessary to change the flow rate of the reservoir fluid with an increase in pressure drop by the calculated value.

Those. it is necessary to have a constant flow of formation fluid, on which a stream of formation fluid is additionally superimposed when the device is operating in the pulse supply mode through an additional channel.

In the prototype, this cannot be done, since when the working fluid is supplied from above, only the axial channel in the sleeve opens, with the ball being squeezed from the seat. The bypass channel is constantly closed by a spring-loaded piston, which does not play any role in the generation of hydrodynamic pulses.

In the case of using the device in production wells, i.e. it is rotated 180 ° from the position, as shown in the drawing, the self-oscillation mode is possible only when the ball is squeezed from the saddle and the formation fluid freely passes into the tubing string with an uncontrolled flow rate and pulse frequency, which will not allow controlling the process of exposure to paraffin molecules in the stream and prevent their deposition on the walls of the pipes of the elevator column.

In addition, during production it is also difficult to obtain hydrodynamic pulses of a given amplitude and frequency when there is an influence of additional formation factors and a reservoir, which usually has several wells. This leads to a self-oscillating process in the system superimposed on the self-oscillating process generated by the device. Thus, conditions may arise when the generation of hydrodynamic pulses may be absent altogether or have characteristics insufficient to effectively influence the flow.

From the above it follows that the prototype has a limited scope

Thus, the achieved technical result is due to the unknown properties of the parts of the device under consideration, established with the possibility of interaction with each other and the formation of a hydrodynamic impulse in the axial channel of the housing due to changes in hydraulic resistance during compression of the coils of the spiral spring during the end interaction of the figured piston with the support plate with the opening of the end valve and supply with an increased flow rate of formation fluid in the axial tubing string, when the mechanical valve is returned on the saddle in the figured bore of the sleeve and the increase in the gap between the turns of the spiral coil spring.

The invention does not explicitly follow from the prior art, i.e. meets the criterion of "inventive step".

A hydraulic pulsator for influencing the flow of a pumped fluid or a working fluid by generating hydrodynamic flow and pressure pulses is shown in the drawings, where:

figure 1 presents the design of the device in section, in the initial position;

figure 2 - the design of the device at the time of pressure growth under the locking element, with its opening.

The claimed device consists of a detachable housing 1, then the housing, in the axial channel of which is installed a sleeve 2 with a protrusion 3, fixed at the junction of the parts of the detachable housing 1.

The sleeve 2 inside is made with a figured bore 4, into which a figured piston 5 is inserted with an end valve 6 resting on the seat 7. The figured piston 5 is adopted larger in diameter than the diameter of the end valve 6 at the place of its seating on the seat 7. The figured piston 5 is provided a rod 8, passed through a perforated partition 9, rigidly connected with the body of the sleeve 2. A spring 10 compresses the mechanical valve 6 to the seat 7.

A stepped bore 11 is made in the body of the figured piston 5, in which a replaceable fitting 12 is installed, which is pressed by the threaded cup 13. The stepped bore 11 is connected by radial holes 14 with the axial channel of the sleeve 2 above the seat 7.

A supporting washer 15 rests on the upper end of the sleeve 2, with longitudinal grooves 16 around the perimeter, pressed from above by a helical spiral spring 17, the rigidity of which and the size of the technological gap between the turns are regulated by a nut 18.

The supporting washer 15 is made with a Central hole 19, into which the upper end of the threaded cup 13 is movably inserted.

The axial channel of the detachable housing 1 above the support washer 15 has a constant hydraulic connection through technological gaps between the turns of the helical coil spring 17 with the axial channel of the pipe tubing.

The stroke of the figured piston 5 inside the figured bore 4 of the sleeve 2, together with the rod 8 and the threaded cup 13, is determined from the condition of the end interaction of the figured piston 5 with the support washer 15 and compression of the coils of the spiral coil spring 17 with the formation of a minimum technological gap between the coils or even to the full closing at full stroke up of the shaped piston 5.

The operation of the hydraulic pulsator.

Consider the operation of the hydraulic pulsator used in the method of protecting the pipe tubing from paraffin deposits, when it is located in the pipe tubing at a given design depth.

When the device is lowered into the well, the tubing string is filled through the channel of the replaceable fitting 12.

A well is launched and developed with access to the production technological regime.

Replaceable fitting 12 is selected from the conditions for the production of part of the volume of reservoir fluid from the calculated flow rate parameters.

The figured piston 5 with the face valve 6 is pressed against the seat 7 by the spring 10 on the rod 8. The pressure under the figured piston 5 increases, which, with a certain increase in it, leads to the separation of the mechanical valve 6 on the figured piston 5 from the seat 7. Moreover, on the figured piston 5, which has a larger bore in the figured 4 bushings 2 than the diameter of the figured piston 5, an additional axial force acts on the additional area of the latter, which leads to a sharp upward movement of the figured piston 5 inside the figured bore 4 of the sleeve 2 with access to the end face t Figure 5 with the piston support washer 15 and a helical compression coil spring 17 to form a technological minimum clearance between its turns. This leads to an increase in pressure in the axial channel of the detachable body 1 above the sleeve 2, comparable to the pressure in the axial channel of the sleeve 2 under the seat 7, which contributes to a sharp return of the shaped piston 5 with the mechanical valve 6 into the figured bore 4 of the sleeve 2 with the mechanical valve 6 fitted saddle 7. In this case, the support washer 16, by the force of the compressed helical coil spring 17, is returned to the end of the sleeve 2 with the formation of a complete technological gap between the turns of the helical coil spring 17 and the ejection of a portion of the liquid into the axial channel of the elevator column RUB further with a portion of the formation fluid supplied continuously through the channel 12. The replaceable nozzle nut 18 may be adjusted technological gap between the turns of the helical coil spring 17 until its turns clamping.

By changing the stiffness of the spring 10 on the rod 8, you can adjust the pressure drop at which the mechanical valve 6 will detach from the seat 7, by selecting the dimensions of the channel of the replaceable nozzle 12, you can set the hydraulic pulsator to a wide range of flow rates and pulsations, taking into account the flow rate and pressure in the reservoir .

When connecting a detachable body to the pipe tubing with the opposite end, a hydraulic pulsator can be used in the well when pumping process fluids into the formation, for example, for performing insulation work. The application of hydrodynamic pulses to the flow in this case will allow the insulating composition to penetrate at a greater distance from the wellbore.

The device can also be installed at the wellhead as part of a manifold or as part of a process piping during grouting operations, pumping cement in a pulsed mode into the annulus of the well, intensifying the flow of hydrocarbons by impulse treatment of the bottom-hole formation zone with stimulation fluids, which reduces hydraulic resistance when downloading and improve the quality of work performed.

Sources of information taken into account

1. A.S. No. 817219, Ml. Е21В 43/00 “Hydraulic vibrator”. Publ. 03/30/81, bull. Number 12.

2. A.S. No. 439593, Mcl. Е21В 43/00 “Downhole pulsator”. Publ. 08/15/74, Bull. Number 30.

3. A.S. No. 153971, Ml. ЕВВ 43/00 “Device for impacting the bottom-hole zone of a well”. Publ. 01/15/90, Bull. No. 2 (prototype).

Claims (1)

A hydraulic pulsator comprising a housing, a sleeve with a seat and a mechanical valve in its axial channel, a perforated baffle, characterized in that in the axial channel of the housing an additional washer is installed on the end face of the sleeve with longitudinal grooves around the perimeter from the outside, pressed from above by a spiral coil spring with with an adjusting nut, the sleeve is made with a figured cylindrical bore and equipped with a seat with a figured piston and an end valve equipped with a rod passed through an axial channel in a perforated a partition and a compressible spring, and the shaped piston contains a step-boring with a removable fitting and a threaded cup installed in it with the possibility of forming a movable connection with a support washer and end-face interaction with the figured piston, and the step-boring is constantly hydraulically connected by radial holes with the axial channel of the housing under the sleeve .

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