RU2698992C1 - Well pump suction valve - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to machine building, particularly, to valve devices of pumps for transfer of highly viscous liquids containing mechanical impurities and gas, and can be used in oil industry. Suction valve comprises housing with central axial bore, shutoff element made up of bushing. Axial hole is made two-staged to form upper and lower collar. Sleeve has outer top collar mating with central hole. In the lower part of the body the valve is equipped with a saddle in the form of a bolt including a head and a rod, and the lower part of the central hole is matched with possibility of formation of the guaranteed gap between the lower collar and the head. In upper case collar and seat head there are thrust-sealing surfaces, in collar and in lower part of sleeve there are sealing bands with possibility of simultaneous interaction with thrust-sealing surfaces of collar and seat.

EFFECT: reduced labour intensity of manufacturing and increased reliability of operation.

3 cl, 4 dwg

Description

The invention relates to the field of engineering, in particular to valve devices, especially for pumps for pumping highly viscous liquids containing mechanical impurities and gas, including downhole sucker rod pumps, and can be used in the oil industry.

Known valve assembly of a sucker-rod pump (Catalog "Well sucker-rod pumps for oil production" ZINTIKhimneftemash, M., 1988, p. 22), containing a saddle, a shut-off element made in the form of a ball, a stop limiter for lifting the shut-off element.

The disadvantages of the known valve are insufficient throughput, service life and delayed closure. Low throughput is caused by a decrease in the saddle passage of the ball body. The valve closing delay, especially when pumping high-viscosity fluid, is associated with narrowing of the channels of the seat and a significant decrease in the rate of lowering of the locking member on the seat due to its weight in a viscous medium. A significant force on the thrust-sealing surface from the pressure drop in the valve is caused by the fact that it is determined by the diameter of the ball touching the seat.

Known suction valve of a borehole submersible pump containing a cylinder with radial holes, a sleeve installed inside the cylinder with the possibility of overlapping radial holes (see Pat. RF No. 2487271, INC F04B 53/10, F04B 47/00, 2013).

The disadvantages of the known device are the insufficient capacity of the suction valve due to the movement of fluid along the annular channel with turns, as well as the possibility of accumulation of mechanical impurities in the lower part of the pump cylinder. In addition, the locking member has an insufficient resource due to the occurrence of cyclically repeated bending stresses.

A suction valve of a borehole sucker-rod pump is known, comprising a housing with a central axial and at least one radial through holes, a shut-off element made in the form of a sleeve, in the upper part of which an external shoulder is made, in the shoulder and in the lower part, the sleeve is equipped with upper and lower sealing belts in the case, above and below the side openings, in response to the sealing belts, made persistent sealing surfaces (see application No. 2017128265/06 (048770) dated 08/08/2017, IPC F04B 47/00, decision to grant a patent from June 5, 2018), which they’ll take a prototype.

The disadvantages of the known device are the significant complexity of manufacturing and lack of reliability due to the considerable complexity of ensuring the simultaneous landing of the sealing belts of the sleeve on the thrust-sealing surface of the housing. In addition, when one of the seal faces or bands is worn, the valve must be replaced.

The aim of the proposed technical solution is to reduce the complexity of manufacturing and increase reliability.

This goal is achieved by the fact that in the suction valve of the borehole pump containing a housing with a central axial hole, the shut-off element made in the form of a sleeve, the axial hole is made two-stage with the formation of the upper and lower collars with the execution of persistent sealing surfaces, the sleeve is made with the outer the upper collar responds to the central hole, while in the collar and in the lower part of the sleeve sealing belts are made with the possibility of simultaneous interaction with thrust-sealing over In the case between the shoulders, at least one radial through hole is made, according to the technical solution, the valve is equipped with a seat in the form of a bolt, including a head and a rod, and executed in response to the lower part of the central hole with the possibility of creating a guaranteed gap between the lower shoulder and the head, in which the thrust-sealing surface is made, in the lower part of the rod and the holes are made reciprocally to each other threads with the possibility of axial movement limited by the sleeve and the lower shoulder of the housing saddles.

The length of the bolt shaft is greater than the depth of the lower part of the hole below the lower shoulder with the possibility of its threaded part coming out of the central hole into which the nut with a lock nut is fitted.

Thrust-sealing surfaces and sealing bands are made with the possibility of interaction of mating pairs with the formation of annular slots expanding towards the valve inlet and their communication with radial holes.

The design of the proposed device is illustrated in the drawing.

In FIG. 1 shows a general view of a suction valve;

In FIG. 2 is a section AA in FIG. one;

In FIG. 3 - node B in FIG. one;

In FIG. 4 - downhole sucker rod pump with the proposed valve.

The suction valve of a downhole sucker-rod pump contains a housing 1 (Figs. 1 and 2) with a through-hole in the center (not shown in Fig.), In which a locking element 2 is made in response, and the locking element 2 is made in the form of a sleeve with an external collar 3 in its upper parts. The Central hole of the housing 1 is made two-stage with the formation of the upper 4 and lower 5 shoulder. In response, the lower part of the central hole in the housing 1 is equipped with a saddle 6 made in the form of a bolt including a head 7 and a rod 8.

On the upper shoulder 4 of the casing 1 and the head 7 of the saddle 6, there are made persistent-sealing surfaces 9 and 10, and in the shoulder 3 and the lower part of the sleeve 2, respectively, in response to the indicated persistent-sealing surfaces 9 and 10, sealing belts 11 and 12 are made.

In the housing 1, between the head 7 of the saddle 6 and the thrust-sealing surface 9 of the housing, at least one radial through hole 13 is made.

In the sleeve 2, below the shoulder 3, at least two symmetrically arranged longitudinal, open from the bottom, groove 14 are made with the formation of longitudinal slotted channels 15 with the possibility of their communication with holes 13.

In order to increase the pressing force of the sleeve 2 to the thrust-sealing belts 11 and 12, the mating surfaces are made with the possibility of interaction of the surface 9 with the belt 11 along their largest diameter, and the interaction of the surface 10 with the belt 12 - along their smallest diameter. This is achieved by the fact that the thrust-sealing surfaces 9, 10 and the sealing belts 11, 12 are made with the possibility of interaction of the mating pairs with the formation of annular slots 16 and 17 expanding towards the valve inlet (Fig. 3) and communicating with the radial holes 13.

The housing 1 in the upper part may be provided, for example, with an adapter 18 provided with a stop 19 of the sleeve 2.

The saddle 6 is installed with the formation of a guaranteed gap (not shown in Fig.) Between the shoulder 5 and the lower end of the head 7 of the saddle 6.

In the lower part of the housing 1 and the rod 8 of the bolt (saddle) 6, threads are made in response to each other (not shown in Fig.) With the possibility of axial movement of the saddle 6.

The saddle 6 is installed in the housing 1 with the possibility of the part of the thread of the rod 8 coming out, onto which, for example, a nut 20 with a lock nut 21 is screwed.

The saddle 6 using the threaded part of the rod 8 is installed with the possibility of simultaneous interaction of the sealing belts 11 and 12 with the thrust-sealing surfaces 9 and 10 of the housing 1 and the saddle 6 in the lower position. The sleeve 2 is also installed with the possibility of interaction with the upper end with a stop 19.

The inner cavity 22 of the sleeve 2 and the adapter 18 communicates with the working cavity of the pump (not shown in FIG.), Which, when the sleeve 2 is lifted above the seat 6, communicates with the reservoir medium (not shown in FIG.) Through lateral through holes 13.

In order to ensure high accuracy of installation of the sleeve, the thread of the rod 8 and the housing 1 can be performed in small steps.

The downhole submersible pump can be equipped with the indicated suction valve (Fig. 4), including a housing 1, a shut-off element 2, a seat 6. An adapter 18 can be connected to the pump cylinder 23, inside which a plunger 24 is installed, by means of a coupling (not shown). with a discharge valve 25. The plunger 24 in the upper part is connected to the column of rods 26. The sleeve 2 and the discharge valve 25 are installed with the possibility of the formation of a working cavity 27, which alternately communicates with the reservoir medium (not shown in Fig.) through the side openings 13 and the supercharger Leaking line 28.

Assembly and adjustment of the valve is as follows. A saddle 6 is screwed into the housing 1 with the location of the thrust-sealing surface 10 below the holes 13 until the head 7 interacts with the shoulder 5. Next, the sleeve 2 is installed with the possibility of tight interaction of the sealing girdle 11 of the sleeve 2 with the thrust-sealing surface 9 of the housing 1. A sub 18 is installed.

Holding the sleeve 2 in a stationary state by means of a threaded connection, the rod 6 is lifted up to fit snugly on the sealing strip of the sleeve 2 with the thrust-sealing surface 12 of the seat 6.

Valve tightness is checked by pouring liquid on top of the sub, incl. under pressure.

The suction valve operates as follows.

Let the sleeve 2 (Fig. 1-3) is in the lower position, ensuring the interaction of the sealing belts 11 and 12 of the sleeve with the thrust-sealing surfaces 9 and 10.

When the pressure in the cavity 22 decreases under the action of the created pressure differential between the environment and the cavity 22, the sleeve 2 begins to rise upward, communicating the side inlets 13 with the cavity 22. Fluid from the environment, for example, from the formation, begins to flow through the openings 13, the internal channel (not shown in Fig.) bushings 2. The implementation of the holes 13 in the form of tangential open grooves significantly increases the area of their passage. This allows to minimize the stroke of the sleeve 2 to ensure sufficient passage area.

On the path of the fluid flowing through the openings 13, the channel of the sleeve 2 there are no bodies narrowing the passage.

The lifting height of the sleeve is determined by the differential pressure in the valve. With a significant pressure drop, the sleeve 2 can rise up to interact with the stop 19.

With a decrease in fluid flow through the openings 13 due to a rise in pressure in the cavity 22 and a simultaneous decrease in the pressure drop between the environment and the cavity 22, the sleeve 2 begins to fall down. In the absence of fluid movement through the holes 13, the sleeve 2 with its sealing belts 11 and 12 interacts with the thrust-sealing surfaces 9 and 10, completely sealing the cavity 22.

With increasing pressure in the cavity 22, the sleeve 2 under the action of the pressure drop on the unbalanced area, determined by the contact diameters of the belts 11 and 12 with the surfaces 9 and 10, is pressed simultaneously to the housing 1 and the seat 6. The contact diameters of the belts 11 and 12 with the surfaces are selected exclusively based on ensuring the tightness of the mating nodes. This eliminates excessive contact pressure in the sealing surfaces.

Then there is a decrease in pressure in the cavity 22, and the cycle repeats.

Consider the operation of a downhole sucker rod pump (Fig. 4), equipped with the proposed suction valve.

Let the rod string 26 with the plunger 24 move up. In this case, the sleeve 2 is raised above the saddle 6, i.e. the suction valve is open and the discharge valve 25 is closed. The fluid from the reservoir through the side holes 13, the channel of the sleeve 2 enters the working cavity 30. The fluid from the discharge line 28 through the riser (not shown) is raised to the surface.

When the plunger 24 approaches the top dead center, its speed decreases, leading to a decrease in fluid flow through the suction valve. In this case, the pressure drop across the sleeve 2 is reduced, and it drops down. In the extreme upper position of the plunger 24, the sleeve 2 with its sealing belts 11 and 12 interacts with the thrust-sealing surfaces 9 and 10, sealing the working cavity 27.

When lowering the plunger 24 downward, the pressure in the working cavity 27 increases, and the sleeve 2 is pressed against the seat and the supporting-sealing surface 9 of the housing 1. Under the action of a differential pressure, the discharge valve opens, and the liquid from the working cavity 27 flows into the discharge line 28. In the lower position of the plunger 24, the suction valve is closed, and the discharge valve 25 is slightly ajar.

With the movement of the plunger 24, the pressure in the working cavity 27 decreases, and the discharge valve 25 closes. Under the action of a differential pressure, the sleeve 2 rises above the seat 6. Next, the cycle repeats.

Thus, the implementation of the lower seat of the suction valve is adjustable in height to ensure the simultaneous landing of the shut-off element of the suction valve on two thrust-sealing surfaces, providing high tightness.

The force acting on the shut-off element of the suction valve can be selected on the basis of ensuring the required contact pressure in the mating pairs by assigning the appropriate contact diameters of the sealing girdles of the sleeve with the supporting-sealing surfaces.

Claims (3)

1. The suction valve of the borehole pump, comprising a housing with a central axial hole, a shut-off element made in the form of a sleeve, the axial hole is made two-stage with the formation of the upper and lower shoulders, with the implementation of persistent sealing surfaces, the sleeve is made with the outer upper shoulder in response to the central the hole, while in the shoulder and in the lower part of the sleeve there are sealing bands with the possibility of simultaneous interaction with thrust-sealing surfaces, in the housing between the shoulder beams at least one radial through hole is used, characterized in that the valve is provided with a seat in the form of a bolt including a head and a rod, and is formed in response to the lower part of the central hole with the possibility of creating a guaranteed gap between the lower shoulder and the head in which the thrust-sealing surface is made, in the lower part of the rod and the holes are made in response to each other threads with the possibility of axial movement of the saddle bounded by the sleeve and the lower shoulder of the housing. 2. The suction valve according to claim 1, characterized in that the length of the bolt shaft is greater than the depth of the lower part of the hole, lower than the lower shoulder with the possibility of its threaded part coming out of the central hole into which the nut with a lock nut is fitted. 3. The suction valve according to claim 1 or 2, characterized in that the thrust-sealing surfaces and sealing bands are made with the possibility of interaction of mating pairs with the formation of annular slots expanding towards the valve inlet and communicating with the radial holes.

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