RU2709754C1 - Bottom-hole sucker-rod pump - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to machine building, particularly, to vertical plunger pumps with self-acting valves, especially for pumping highly viscous liquids containing mechanical impurities and gas, and can be used in oil industry. Downhole sucker-rod pump comprises a cylinder with steps of larger and smaller diameter, a suction valve comprising upper and lower seats, a shut-off member made in the form of a bushing with an upper collar mating the upper seat, a plunger with steps of greater and smaller diameter mating with the cylinder with a pressure valve, as well as a pipe rigidly connected to the small diameter plunger and telescopically connected to the bushing. Lower seat is located in pump bottom with through axial hole. In bottom part of plunger above seat there are at least three through radial holes with equal angular pitch from each other with possibility of connection with axial bores of bottom. Bushing is installed with the possibility of limited axial movement along the plunger and the branch pipe to form an alternating-volume chamber between the plunger and the branch pipe. At least one through radial hole is made in the lower part of the branch pipe with possibility of its partial overlapping by the bushing.

EFFECT: proposed is vertical plunger pump with self-acting valves.

3 cl, 6 dwg

Description

The invention relates to mechanical engineering, in particular to vertical plunger pumps with self-acting valves, especially for pumping highly viscous liquids containing mechanical impurities and gas, in particular to sucker rod pumps, and can be used in the oil industry.

A well-known sucker-rod pump (Catalog "Well sucker-rod pumps for oil production" ZINTIKhimneftemash, M. 1988, p. 22), comprising a working cylinder, inside which a hollow plunger with a discharge valve is connected with a minimum clearance, connected to the column of sucker rods, in the lower part cylinder installed suction valve.

The disadvantages of the known sucker rod pump are unacceptable volumetric losses due to insufficient throughput, the delay in opening and closing of the suction valve, as well as the likelihood of loss of stability and sagging bottom of the rod string.

A well-known sucker-rod pump containing a cylinder, a stepped plunger with a discharge valve, a suction valve with a shut-off element made in the form of a sleeve, the lower part of the plunger with the possibility of limited axial movement and the formation of a variable volume chamber (see RF Patent No. 2669058, MKP F04B 47 / 00, 2018) which is taken as a prototype.

The disadvantages of the known device are the delay in closing the suction valve due to its closure only from its weight, as well as the possibility of loss of stability and sagging bottom of the rod string.

The technical task of the invention is to reduce volumetric losses by reducing the delay in opening and closing the suction valve and the likelihood of sagging rod string when the plunger moves down.

The solution to the technical problem is achieved by the fact that in the borehole sucker rod pump containing a cylinder, a suction valve including upper and lower seats, a shut-off element made in the form of a sleeve with an upper collar responds to the upper saddle, the lower saddle located in the pump bottom with a through axial hole, a plunger with steps of a larger and smaller diameter with a discharge valve, the sleeve is installed with the possibility of limited axial movement along the plunger with the formation of a chamber of variable volume between the cylinder and the stupas according to the technical solution, the cylinder is made of steps of larger and smaller diameters in response to the plunger, the step of the plunger of larger diameter is equipped with a nozzle telescopically connected to the sleeve, the lower seat is connected to the plunger, in the lower part of which above the saddle are made at least three through radial holes with equal angular steps from each other with the possibility of communication with the axial holes of the bottom.

The discharge valve is located in the lower part of the pipe above the radial holes.

The pipe in the middle part is made of a larger diameter, with the formation of a shoulder in the lower part, with the possibility of its interaction with the upper end of the sleeve.

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

In FIG. 1 is a diagram of a downhole sucker rod pump;

In FIG. 2 is a section AA in FIG. 1;

In FIG. 3 is a section BB in FIG. 1;

In FIG. 4 - node suction valve in the open position;

In FIG. 5 - embodiment of a pump with a lower discharge valve;

In FIG. 6 is an embodiment of a pump with a lower discharge valve and an expanded nozzle.

The downhole sucker rod pump comprises a composite cylinder 1 (see Fig. 1), including an upper cylinder 2 of a small and lower cylinder 3 of a larger diameter, interconnected, for example, by an adapter 4, a plunger 5, consisting of an upper plunger 6 of a small diameter and a lower plunger 7 large diameters, connected, for example, by a sub 8, reciprocally made respectively by cylinders of small 2 and large 3 diameters.

In the lower part of the plunger 7 of large diameter, at least three through radial holes 9 are made (Fig. 2), located at equal angular distances between them. The holes 9 can be made in the form of a rectangle in plan.

The lower plunger 7 in the lower part, above the radial holes 9, is equipped with an upper seat 10, made, for example, in the form of a shoulder. The plunger 7 in the lower part is provided with a bottom 11, including a lower seat 12, made, for example, in the form of a disk with through axial holes 13 (Fig. 3), an emphasis 14, made, for example, in the form of a disk with a central threaded hole (in FIG. not indicated) and connected to the plunger 7 by means of a threaded connection (not shown in FIG.), mounted below the seat 12 with a guaranteed axial clearance (not shown in FIG.). Bottom in the seat 12 is made, for example, a central blind threaded hole (not shown in Fig.). The stop 14 is installed with the possibility of interaction with the seat 12 by means of an adjusting bolt 15 with a lock nut 16.

Through holes 13 of the seat 12 are made with the possibility of communication with the radial holes 9 of the plunger 7. At the stop 14, in response to the holes 13 of the seat 12 and with the possibility of communication with them, through axial holes 17 are made.

In the plunger 7 above the seat 12 is installed a shut-off member 18 of the suction valve, made in the form of a sleeve with a shoulder 19 in the upper part. In this case, the collar 19 and the side surface of the sleeve 18 are made in response to the inner surface (not shown in Fig.) Of the plunger 7 and the collar 10.

In the shoulder 19 and in the lower part of the sleeve 18 there are made persistent sealing surfaces 20 and 21, reciprocally made by the saddles 10 and 12 with the possibility of simultaneous interaction with them. Thrust-sealing surfaces 20 and 21 can be made spherical (Fig. 4), and the response surfaces of the seats 10 and 12 are conical, with the possibility of touching the mating pairs along the line. Moreover, in order to ensure sufficient force on the contact surfaces, the surface 20 and the seat 10 are touched by the maximum diameter of the thrust-sealing surface 20, and the surface 21 and the seat 12 are touched by the minimum diameter of the thrust-sealing surface 21.

In the adjusting bolt 15, for example, there is a central hole (not shown in FIG.) In which a bolt 22 (FIG. 4) with a threaded end is installed. At the bottom of the seat 12, a central blind threaded hole is made (not shown in FIG.), Corresponding to the thread of the bolt 22. At the same time, the adjusting bolt 15 is installed with the possibility of interaction with the lower end of the seat 12, and connecting the stop 14 with the seat 12 by means of a bolt 22.

The end face of the bolt 15 and the Central part of the lower end surface of the seat 12 are made, for example, spherical, in response to each other.

In the lower part of the plunger 6 of small diameter there is a discharge valve including a seat 23, a locking member 24, made, for example, in the form of a ball, and a travel stop 25 of the ball 24.

The lower seat 12 of the suction valve and the seat 23 of the discharge valve are installed with the formation of the working cavity 26 between them.

For example, in the shoulder 10 of the plunger 7, at least one through longitudinal groove 27 is made with the possibility of communicating the holes 9 with the working cavity 26.

The plunger 5 is installed in the cylinder 1 with the formation of the upper chamber 28 of variable volume formed between the side surfaces of the cylinder 3, the plunger 6, the adapter 4 and the sub 8.

The lower plunger 7 of larger diameter is equipped with a pipe 29, rigidly connected to the sub 8 and telescopically connected to the sleeve 18 with the formation of the lower annular chamber 30 of variable volume. In the lower part of the pipe 29 and in the adapter 8, at least one through radial holes 31 and 32 are made with the possibility of communication of the working cavity 26 with the upper chamber 28 of variable volume by means of radial holes 31, 32 and the lower annular chamber 30.

The radial hole 31 of the pipe 29 is made with the possibility of partial overlapping of the side surface of the sleeve 18 in its extreme upper position.

In the upper part of the pipe 29, at least one additional through radial hole 33 can be made.

The locking body 18 may be provided with a stop 34, made, for example, in the form of a split ring, having the ability to interact with the lower end (not shown in Fig.) Of the pipe 29 with the possibility of limited axial movement.

The upper plunger 6 is connected, for example, to the drive, by means of a column of rods (not shown in FIG.).

The discharge valve is installed with the possibility of communication of the working cavity 26 with the discharge line 35.

The saddle 23 (Fig. 5) of the discharge valve can be installed in the lower part of the pipe 29 above the radial hole 31 made in the lower part of the pipe with the possibility of its partial overlap by the sleeve 18 at its upper position.

The pipe 29 (Fig. 6) in the middle part can be made of a larger diameter, i.e. the outer diameter of the pipe 29 in the middle part is larger than the internal diameter of the sleeve 18. At the same time, a collar 36 can be made in the lower part of the pipe 29 at the transition point with the possibility of its interaction with the upper end of the sleeve 18. The distance between the end of the sleeve 18 and the lower end of the collar 36 determined by the stroke of the sleeve 18.

Assembly of the pump is as follows.

At the beginning, the plunger with valves is assembled. Simultaneous landing of the thrust-sealing surfaces 20 and 21 of the seats 10 and 12 is provided by adjusting the position of the saddle 12 with the bolt 15. First, the shoulder is seated on the saddle 10, and then the saddle 12 is lifted up to touch with the thrust-sealing surface 21 with the stationary sleeve 18.

The device operates as follows.

Let the plunger 1 is in the initial lifting position of the plunger 5 (Fig. 1). When the discharge valve is open, the shut-off element 24 is raised above the seat 23, the suction valve is closed. The sleeve 18 is in its lowest position with the possibility of interaction of the seats 10 and 12 with the contact sealing surfaces of the shoulder 19 and the lower end of the sleeve 18. The pressure in the working cavity 26 is equal to the pressure in the discharge line 35. The pressure in the lower annular chamber 30 of variable volume pressure is slightly higher pressure in the cavity 26 due to the movement of fluid from the upper chamber 28 of variable volume into the working cavity 26.

When the lower plunger 7 of large diameter moves up, the volume of the chamber 28 decreases. As a result, the volume of fluid displaced from the chamber 28 through the openings 32, 31, the chamber 30, the working cavity 26 and the discharge valve flows into the pressure line. In addition, liquid is supplied to the pressure line from the movement of the plunger 6 of small diameter.

When approaching the plunger 5 to the upper position, its speed decreases. This leads to the lowering of the ball 24 on the seat 23.

In the extreme upper position of the plunger 5, its speed is zero, and the locking member 24 is lowered to the seat 23.

With the reverse stroke of the plunger 5 down, the volume of the chamber 28 increases, reducing the pressure in it. Under the action of the created pressure drop, liquid from the lower annular chamber 30 flows into the chamber 28, reducing the pressure in it. When the pressure in the chamber 30 becomes less than in the pump intake, i.e., in the openings 13 and 17, the sleeve 18 begins to move upward, breaking away from the seats 10 and 12. When moving upward, the sleeve 18 begins to overlap the radial holes 31, increasing the pressure drop between the working cavity 26 and the camera 30.

In the further movement of the lower plunger 7 downward, the sleeve 18 rises completely upward until the stop 34 interacts with the lower end of the pipe 29. In this case, fluid from the reservoir medium (not shown in Fig.) Through the axial holes 17 and 13 of the stop 14 and saddle 12, radial holes 9 of the plunger 7 enters the working cavity 26.

The effort to lift the sleeve 18 up is determined by the unbalanced cross-sectional area of the sleeve 18, which is proportional to the difference between the squares of the maximum and minimum diameters of the contact surfaces 20 and 21, respectively, as well as the difference in the pressure of the liquid in front of the pump and in the chamber 30.

When lowering the plunger 5 downward, a force from the differential pressure on the small diameter plunger 6 acts on top of it.

When approaching the plunger 5 to its lowest position, it stops. The movement of fluid through the openings 17, 13, 9 is stopped. The pressures in the working cavity 26, chambers 30, 28 and in the formation medium are equalized. Under the influence of weight, the sleeve 18 is lowered on the saddles 10 and 12.

At the beginning of the movement of the plunger 5, then the lower plunger 7, upward, the pressure of the chambers 28 and 30 increases. This leads to an increase in contact pressure in the mating pairs of shoulders 19 - saddle 10 and sleeve 18 - saddle 12.

Next, the cycle repeats.

When you install a discharge valve (Fig. 5) in the lower part of the pipe 29 reduces the harmful volume of the cylinder. This helps to reduce the delay in valve opening.

The regulation of the opening force of the suction valve is also achieved by changing the area and the amount of overlap by the sleeve 18 of the radial holes 31.

When performing the pipe 29 (Fig. 6) of a larger diameter in its middle part, the harmful volume of the cylinder decreases. This also allows you to increase the capacity of the discharge valve by increasing the passage of the seat 23. In addition, the stepped execution of the pipe 29 allows you to perform the function of the stop sleeve 18 collar 36 of the pipe 18.

Thus, the execution of the suction valve in the form of a sleeve 18 having the possibility of a limited emphasis of movement along the plunger 7 and overlapping the seat of the suction valve significantly increases the throughput of the suction valve. The location of the sleeve 18 in the lower part of the plunger 7 between the plunger 7 and the pipe 29, with the formation of a variable volume chamber 30 in its upper part, allows you to open the suction valve at the very beginning of the suction cycle and keep the sleeve 18 in the upper position for the entire suction cycle.

When making radial holes 9 of rectangular cross-section, the throughput of the suction valve reaches a significant value even with a slight rise in the sleeve 18.

Thus, the execution of the suction valve in the form of a sleeve with the possibility of limited axial movement along the plunger and cover the lower part of the nozzle can significantly increase the throughput of the suction valve while reducing the delay in opening and closing. In addition, the proposed design of the pump allows you to place the discharge valve in the lower part of the plunger, close to the suction valve, which significantly reduces the harmful volume of the cylinder. Moving the plunger down under the action of a liquid column above the small plunger eliminates the possibility of sagging rod string.

Claims (3)

1. A well pump with a cylinder, a suction valve, including upper and lower seats, a shut-off element made in the form of a sleeve with an upper shoulder responding to the upper seat, the lower seat is placed in the pump head with a through axial bore, a plunger with steps of large and smaller diameter with a discharge valve, the sleeve is installed with the possibility of limited axial movement along the plunger with the formation of a chamber of variable volume between the cylinder and the stage of the plunger of large diameter, characterized in o the cylinder is made with steps of larger and smaller diameter in response to the plunger, the step of the plunger of larger diameter is equipped with a nozzle telescopically connected to the sleeve, the lower seat is connected to the plunger, in the lower part of which above the saddle are made at least three through radial holes with equal angular spacing from each other with the possibility of communication with axial holes of the bottom. 2. The pump according to claim 1, characterized in that the discharge valve is located in the lower part of the pipe above the radial holes. 3. The pump according to claim 2, characterized in that the pipe in the middle part is made of a larger diameter with the formation of a shoulder in the lower part with the possibility of its interaction with the upper end of the sleeve.

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