US3168052A

US3168052A - Plunger and valve assembly

Info

Publication number: US3168052A
Application number: US255890A
Authority: US
Inventors: Clyde L Pate
Original assignee: Individual
Current assignee: Individual
Priority date: 1963-02-04
Filing date: 1963-02-04
Publication date: 1965-02-02
Anticipated expiration: 1982-02-02

Description

Feb. 2, 1965 c. L.. PATE 3,168,052

PLUNGER AND VALVE ASSEMBLY Filed Feb. 4, 1965 VENTOR. C: m:- a P4 r!- United States Patent Ofilice 3,168,052 Patented Feb. 2, 1965 3,168,052 PLUNGER AND VALVE ASSEMBLY Clyde L. Pate, Oklahoma City, Okla. Filed Feb. 4, 1963, Ser. No. 255,890 6 Claims. (Cl. 103225) This invention relates generally to improvements in subsurface oil well pumps of the reciprocating type and more particularly, but not by way of limitation, to a novel plunger and valve assembly for such pumps.

As it is well known in the oil industry, the majority of oil wells being produced by artificial lifting means are pumped by use of sucker rod type reciprocating pumps. Such pumps comprise, generally speaking, a working barrel having a standing valve assembly in the lower end thereof and a tubular plunger reciprocally disposed in the working barrel. The working barrel is provided with a standing valve in its lower end and the plunger is provided with an upwardly opening traveling valve so that on each upward movement of the plunger, well fluid, which may include gas and salt water as well as oil, is drawn into the barrel through the standing valve. On the subsequent downstroke of the plunger this well fluid is compressed (during the initial part of the downstroke) until its pressure is greater than the hydrostatic pressure of the column of fluid extending from the plunger to the surface of the earth, after which the traveling valve in the plunger opens, permitting the fluid trapped below the plunger to flow through the plunger valve into the fluid column thereabove during the remainder of the downstroke. Of course, on each upward stroke of the plunger, the traveling valve closes and the entire oil column is lifted to discharge a portion of the oil into a feed line at the surface.

At the present time, each traveling valve is constructed of a plurality of elements which usually include a valve body, a ball, a valve seat, a ball guide, and a stop in the body to limit the upward movement of the ball. These elements may be assembled within a tubular plunger in various portions of the elements to be threaded for threaded connections. Since the well fluid as it accumulates within the well bore may contain salt water, among other things, the well fluid pumped by a subsurface well pump of the reciprocating type may be both a corrosive and an abrasive fluid. The destructive nature of the well fluid galls and destroys the threaded portions of the tubular plunger in normal use so that when it is necessary to replace a traveling valve because of normal wear the operation is not only diflicult, but also time consuming and expensive. Since many times it is necessary for a subsurface well pump to be repaired in the field, the ease and simplicity of such repair is especially desirable.

The present invention contemplates a novel plunger and valve construction wherein the plunger itself forms the valve body for the traveling valve or valves. The ball stop and guide are formed as a unitary valve cage which is press fitted in the lower end of an upper barrel of a separable plunger in such a manner that threaded portions of the elements are not required. The valve seat is formed as a separate element and press fitted into the upper portion of a cooperating lower barrel of the separable plunger, thereby avoiding the provision of a threaded portion of the seat. The separate parts of the traveling valve may be heat treated in any desired manner, and the effective length of the traveling valve assembly reduced. Furthermore, present plunger construction greatly facilitates the use of double traveling valves. The present invention also contemplates a novel valve assembly which may be used as a standing valve in the lower end of the pump working barrel.

An object of the invention is to provide an improved subsurface oil well pump having a novel plunger and valve assembly.

Another object of the present invention is to provide a plunger and valve construction which substantially decreases the number of threaded connections required for assembly thereof.

It is another object of the present invention to provide an improved plunger and valve assembly which is economical in construction.

And another object of the present invention is to provide a plunger and valve assembly which has a long service life.

It is a further object of this invention to provide a novel plunger and valve assembly which is efficient in operation.

It is a still further object of this invention to provide a plunger and valve assembly which facilitates an assembly and disassembly thereof.

Other objects and advantages of this invention will be evident from the following detailed description, when read in conjunction with the accompanying drawings which illustrate my invention:

In the drawings:

FIG. 1 is a vertical sectional view of a portion of a subsurface oil well pump of the reciprocating type having a plunger and valve assembly therein constructed in accordance with this invention.

FIG. 2 is a transverse sectional view as taken along the lines 2-2 of FIG. 1.

FIG. 3 is a transverse sectional view as taken along lines 3-3 of FIG. 1.

FIG. 4 is a top end view partly in section.

FIG. 5 is a bottom end view.

Referring to the drawings in detail, and particularly FIG. 1, reference character 10 generally designates a sucker rod type pump (only a portion of which is shown) which includes a tubular working barrel or pump barrel 12 having a standing valve assembly (not shown) disposed in the lower end thereof. An elongated separable plunger 14 is slidingly disposed in the working barrel 12 and has a bore 16 extending longitudinally therethrough. The plunger 14 comprises a first or upper barrel 18 and a second or lower barrel 20. The upper barrel or tubular housing 18 is provided with a counterbore 22 extending upwardly from the lower end of the barrel 18 to terminate in a downwardly facing circumferential shoulder 24. The second barrel or tubular housing 20 is provided in its upper portion with a downwardly extending counterbore 26 which terminates in an upwardly facing circumferential shoulder 28.

The first and

second barrels

18 and 20 are secured together by a threaded connection 30 which is treated by a suitable protective coating to preclude destruction thereof by an abrasive and corrosive well fluid. A set screw 32 extends transversely through the lower end of the upper barrel 18 into engagement with the upper end of the lower barrel 20 to further secure the threaded connection 30 in a locked position. The upper end of the first barrel 18 is closed by an integral end piece 34 which is provided with a plurality of longitudinally extending apertures 36 that permit the pumped well fluid to flow therethrough. The end piece 34 is further provided with a central longitudinally extending threaded bore 38 which receives the threaded lower end of a sucker rod string 40 that provides for reciprocation of the plunger assembly 14 within the working barrel 12.

A novel traveling valve assembly 41 carried by plunger 14 comprises at least one valve cage 42, one ball 54, and one valve seat 56. The valve cage 42 comprises a triangularly shaped end piece 46 having a leg 48 downwardly depending from each apex thereof. The end piece 46 and legs 48 cooperate with the inner periphery of the barrel 18 to define a plurality of longitudinally extending passages 47. The legs 48 are relieved at their lower ends 52 to provide a counterbore 49 which terminates in a downwardly facing shoulder 50. The relieved ends 52 act as a guide for a ball 54 as it is moved upwardly within the counterbore 22 during an upward flow of fluid when the plunger 14 is moved downwardly within the working barrel 12. The upward movement of the ball 54 is limited by the shoulder 50 which acts as a ball stop. The longitudinal distance to which the legs 48 are relieved determines the upward movement of the ball 54 within the cage 42 and, if so desired, the legs 48 may be so relieved as to allow the end piece 46 to act as a ball stop.

An annular valve seat 56, having a central axially extending bore 58 and an arcuate annular face 60 for receiving the ball 54, is press fitted into the counterbore 26 so that its lower end abuts the circumferential shoulder 28. The valve seat 56 cooperates with the counterbore 26 and the shoulder 28 to provide a metal-to-metal seal therebetween. It is to be understood that the valve cage 42, the ball 54 and the Valve seat 56 may be suitably heat treated prior to assembly within the plunger 14. Since the cage 42 is press fitted into the upper barrel 18 and the valve seat 56 is press fitted into the lower barrel 20, the use of threaded portions in the assembly of the plunger 14 is substantially reduced thereby precluding the measure of damage to a plunger which may be attributed to the well fluid attacking the threaded portions thereof.

The inner surface of the lower end of the lower barrel 20 is provided with a threaded portion 62 and an upwardly extending counterbore 63 so that the separable plunger 14 may be threadably secured to another traveling valve assembly to provide a plurality of traveling valves within the assembly 10. It is to be understood that a complementary traveling valve assembly (not shown) for the plunger 14 would have a pin end or threads on the outer periphery of its upper end for a connection with the threaded portion 62. It is preferable to provide a plurality of traveling valve assemblies so that the sucker rod pump will continue to operate even though one traveling valve may become inoperative due to normal wear. The lower end of the barrel is also provided with a transverse slot 64 so that a suitable tool (not shown) may be positioned therein for tightening the threaded connection 30.

The upper barrel 18 is provided with a plurality of circumferential grooves 66 in which are disposed a plurality of suitable resilient piston rings 68 for sealing the plunger 14 within the working barrel 12. The lower barrel 20 is also provided with a plurality of grooves 66 for receiving a similar number of resilient piston rings 68. In the embodiment shown, the piston rings 68 are suitable O-rings.

Operation The pump 10 operates in the usual manner, in that well fluid is drawn into the bore 16 of the barrel 20 on the upstroke of the pump and fluid is forced through the traveling valves 14 on the downstroke of the pump. The fluid forced through the valve lifts the ball 54 off the face 60 in order that the upwardly moving well fluid can flow therearound and through the apertures 47 in the end piece 46 of the valve cage 42.

With respect to economy, it will be observed that the cage 42, the ball 54, and the valve seat 56 may be machined separately which, because of their simple construction, may be easily done. Since there are no threaded portions required on these elements, the cost of the machine operation is materially reduced.

From the foregoing it will be apparent that the present invention contemplates a novel pump plunger construction wherein the use of threaded connections is substantially decreased since threaded connections in a traveling valve are subject to attack from the destructive nature of the well fluid. The present valve assembly provides a structure which will have a substantial service life. It will also be apparent that the present valve assembly may be assembled in a plunger or standing valve construction in a simple manner by normal operating personnel, with little likelihood that the parts of the valve assembly will be incorrectly arranged and the valve rendered inoperative. It will befurther apparent that the present valve assembly is simple in construction, is economically manufactured, and may be easily assembled and disassembled in the field.

Changes may be made in the combination and arrangement of parts or elements as heretofore set forth in the specifications and shown in the drawings, it being understood that changes may be made in the precise embodiment shown without departing from the spirit and scope of the invention as defined in the following claims.

I claim:

1. A plunger and valve assembly adapted to be reciprocated by a sucker rod string within the working barrel of a subsurface oil well pump, comprising:

a first tubular barrel having an upper end forming an outlet and adapted to be secured to the lower end of a reciprocating sucker rod string, said barrel having a counterbore therein extending from the lower end thereof partially therethrough and having a female thread formed in the lower end portion of said counterbore;

a second tubular barrel having a lower end forming an inlet, said second barrel having a counterbore therein extending from the upper end thereof partially therethrough and having a male thread thereon threadedly engaged with the female threads in said first tubular barrel;

a valve cage pressed into the counterbore of said first barrel, said cage being provided with a plurality of axially extending apertures for permitting the passage of fluid therethrough;

an annular valve seat pressed into the counterbore of said second barrel, said seat having an axial bore therethrough whereby fluid passing through said seat will be directed relatively away from said threads; and,

a valve ball loosely disposed in said valve cage for a flow of fluid upwardly around said ball and through said valve cage and being of a size to mate with said seat to prevent a flow of fluid downwardly through the plunger and valve assembly.

2. A plunger and valve assembly as defined in claim 1 being further characterized by at least one of said barrels being provided on its outer periphery with sealing means which cooperate with the working barrel for establishing an eflicient fluid seal therebetween.

3. A plunger and valve assembly adapted to be reciprocated by a sucker rod string within the working barrel of a subsurface oil well pump, comprising:

a first tubular housing having an upper end forming an outlet and adapted to be secured to the lower end of a reciprocating sucker rod string, said housing having a counterbore therein extending from the lower end thereof partially therethrough to form a downwardly extending circumferential shoulder and having a female thread formed in the lower end .portion of said counterbore;

a second tubular housing having a lower end forming an inlet, said second housing having a counterbore therein extending from the upper end thereof partially therethrough to form a downwardly extending circumferential shoulder and having a male thread thereon threadedly engaged with the female thread in said first tubular barrel;

an annular valve seat pressed into the counterbore of said second housing to abut said shoulder, said seat having an axial bore therethrough whereby fluid passing through said seat will be directed relatively away from said threads;

a ball adapted to be received by said valve seat and to cooperate therewith for precluding a flow of fluid through said housings when the plunger is moved upwardly within the working barrel;

an apertured valve cage pressed into the counterbore of said first housing said cage limiting the upward travel of the ball when the plunger is moved downwardly within the working barrel on the downstroke of the plunger.

4. A plunger and valve assembly as defined in claim 3 further characterized in each tubular housing carrying on its outer periphery a plurality of sealing rings which cooperate with the working barrel to provide an efficicnt fluid seal therebetween.

5. A plunger adapted to be reciprocated by a sucker rod string within the working barrel of a subsurface oil well pump, comprising:

a first tubular housing having an upper end forming an outlet and adapted to be secured to the lower end of a reciprocating sucker rod string, said housing having a counterbore therein extending from the lower end thereof partially therethrough to form a downwardly extending circumferen ial shoulder and having a female thread formed in the lower end portion of said counterbore;

a second tubular housing having a lower end forming an inlet, said second housing having a counterbore therein extending from the upper end thereof partially therethrough to form a downwardly extending circumferential shoulder and having a male thread thereon threadedly engaged with the female threads in said first tubular barrel;

a valve ball loosely disposed in said counterbore;

a valve cage having an upper apertured end and a plurality of legs downwardly depending therefrom, said cage being press fitted into the counterbore so that its upper end abuts the upper circumferential shoulder and its legs form a guide and stop for said ball during an upward flow of fluid around said ball when the plunger is moved downwardly within the working barrel;

a valve seat press fitted into the counterbore so that it abuts the lower circumferential shoulder and forms metal-to-metal seal around its outer periphery, said seat cooperating with the ball to preclude a flow of fluid through the housing upon an upward movement of the plunger within the working barrel, said seat having an axial bore therethrough whereby fluid passing through said seat will be directed relatively away from said threads.

6. A plunger and valve assembly adapted to be reciprocated by a sucker rod string within the working barrel of a subsurface oil well pump, comprising:

a first barrel having an axially extending bore which is provided with a counterbore in its lower portion so as to form a downwardly facing circumferential shoulder and having a female thread formed in the lower end portion of said counterbore, said first barrel being secured at its upper portion to the lower end of a reciprocating sucker rod string;

a second barrel having an axially extending bore which is provided with a counterbore in the upper portion thereof so as to form an upwardly facing circumferential shoulder and having a male thread thereon threadedly engaged with the female thread in said first barrel;

a ball loosely disposed in said counterbores;

an apertured cage press fitted into the counterbore of the first barrel to abut said shoulder and adapted for the passage of fluid therethrough and for limiting the travel of a ball within the counterbore;

a valve seat press fitted into the counterbore of the second barrel to abut said shoulder and adapted to cooperate with the ball for closing the bore against the passage therethrough of fluid, said seat having an axial bore therethrough whereby fluid passing through said seat will be directed relatively away from said threads;

a plurality of piston rings provided on the outer circumference of said first and second barrels and adapted to sealingly engage the inner periphery of the working barrel;

a transverse groove provided in the lower portion of the second barrel for receiving a tool for the tightening of the threaded connection.

References Cited in the file of this patent UNITED STATES PATENTS 1,580,402 Brett Apr. 13, 1926 1,588,705 Cope et al June 15, 1926 1,620,347 Hawkins et al Mar. 8, 1927 2,026,058 Perry Dec. 31, 1935

Claims

1. A PLUNGER AND VALVE ASSEMBLY ADAPTED TO BE RECIPROCATED BY A SUCKER ROD STRING WITHIN THE WORKING BARREL OF A SUBSURFACE OIL WELL PUMP, COMPRISING: A FIRST TUBULAR BARREL HAVING AN UPPER END FORMING AN OUTLET AND ADAPTED TO BE SECURED TO THE LOWER END OF A RECIPROCATING SUCKER ROD STRING, SAID BARREL HAVING A COUNTERBORE THEREIN EXTENDING FROM THE LOWER END THEREOF PARTIALLY THERETHROUGH AND HAVING A FEMALE THREAD FORMED IN THE LOWER END PORTION OF SAID COUNTERBORE; A SECOND TUBULAR BARREL HAVING A LOWER END FORMING AN INLET, SAID SECOND BARREL HAVING A COUNTERBORE THEREIN EXTENDING FROM THE UPPER END THEREOF PARTIALLY THERETHROUGH AND HAVING A MALE THREAD THEREON THREADEDLY ENGAGED WITH THE FEMALE THREADS IN SAID FIRST TUBULAR BARREL; A VALVE CASE PRESSED INTO THE COUNTERBORE OF SAID FIRST BARREL, SAID CAGE BEING PROVIDED WITH A PLURALITY OF AXIALLY EXTENDING APERTURES FOR PERMITTING THE PASSAGE OF FLUID THERETHROUGH; AN ANNULAR VALVE SEAT PRESSED INTO THE COUNTERBORE OF SAID SECOND BARREL, SAID SEAT HAVING AN AXIAL BORE THERETHROUGH WHEREBY FLUID PASSING THROUGH SAID SEAT WILL BE DIRECTED RELATIVELY AWAY FROM SAID THREADS; AND, A VALVE BALL LOOSELY DISPOSED IN SAID VALVE CAGE FOR A FLOW OF FLUID UPWARDLY AROUND SAID BALL AND THROUGH SAID VALVE CAGE AND BEING OF A SIZE TO MATE WITH SAID SEAT TO PREVENT A FLOW OF FLUID DOWNWARDLY THROUGH THE PLUNGER AND VALVE ASSEMBLY.