US3139039A

US3139039A - Oil well pump

Info

Publication number: US3139039A
Application number: US204557A
Authority: US
Inventors: Elmer C Adams
Original assignee: Individual
Current assignee: Individual
Priority date: 1962-06-22
Filing date: 1962-06-22
Publication date: 1964-06-30
Anticipated expiration: 1981-06-30

Description

June 30, 1964 c, ADAMS 3,139,039

OIL WELL PUMP Filed June 22, 1962 M T14 55:1 INVENTOR.

ELMEQ C. ADA/W5 United States Patent 3,139,039 OIL WELL PUMP Elmer C. Adams, Box 274, Jones, ()hia. Filed June 22, 1962, Ser. No. 264,557 9 Claims. (Cl. 1ii3179) This invention relates to improvements in reciprocating pumps of the type utilized in the lower portion of an oil Well for removing oil from the oil bearing strata to the surface of the earth. More particularly, but not by way of limitation, the invention relates to improvements in the traveling valves used in reciprocating-type oil well pumps. In present petroleum production technology. the majority of producing wells employ so-called sucker rod pumps to lift the oil from the oil bearing formation to the surface of the earth. This type of pump is a reciprocating pump which is operated by a power unit located at the surface through the use of a string of rods, termed sucker rods, which extend from the surface downward through the well bore to the piston of the pump. In general, such pumps are provided with a stationary check valve at the lower end thereof, termed a standing valve, and a second check valve which is mounted in the piston of the pump and moves therewith, which is termed the traveling valve.

One of the types of malfunctioning which occasionally occurs in sucker rod pumps is a gas lock of the traveling valve which prevents it from opening and closing properly during reciprocation of the pump. Such gas locking of the traveling valve results from the accumulation of pockets of gas above or below the valve which exert a pressure either upwardly or downwardly through the fluid column between such gas pockets and the valve to effect the closure or opening of the valve at times when the opposite valve action should occur in order for the pump to function properly. In other words, the force exerted by the compressed pocket of gas within the production tubing of the well is of sufiicient magnitude to overcome the force which normally acts to open or close the traveling valve during reciprocation of the pump. stances, the only forces which are expected to result in the normal closure of the traveling valve are the force of gravity acting downwardly upon the valve and the frictional resistance of the fluid through which the valve and its piston are moving. Upon the downward stroke of the pump piston, only the fluid resistance to the movement of the piston downwardly in the production tubing normally causes the traveling valve to unseat and move upwardly to its open position. In either of these situations, the exertion of a greater opposing force as a result of gas accumulations in the column of production fluid can prevent the valve from opening and seating in the desired manner.

Although several constructions have previously been proposed for preventing gas locking of the traveling valve, these constructions are relatively expensive and, in some cases, do not operate in a sufiiciently trouble-free manner over extended periods of time to encourage their widespread use.

The present invention contemplates a novel reciprocating pump for use in oil wells, which pump is constructed to prevent or minimize gas locking of the traveling valve to prevent its opening and closure at the proper intervals during reciprocation of the pump. In principle, the pump relies upon the provision of a resistance member which is attached to the valve closure member of the traveling valve and which frictionally bears against the internal walls of the production tubing to slidingly reciprocate in the production tubing, and, by virtue of such frictional contact, opposes the force exerted upon the valve closure member by pockets of gas located in the column of production fluid at such time as the latter forces tend to In some in prevent the traveling valve from opening or closing according to the intended operation of the pump. More specifically, the present invention comprises a traveling valve cage and an associated valve seat attached to the lower end of the sucker rod string of an oil well pump, an upper liner connected to the traveling valve cage and depending downwardly therefrom with the liner forming a seal between the valve seat and the internal walls of the working barrel of the pump, a lower liner disposed below the upper liner and frictionally engaging the internal walls of working barrel, and an elongated, rigid member interconnecting the lower liner with the valve closure member of the traveling valve and functioning to carry the lower liner upwardly in the working barrel as the pump piston and traveling valve move upwardly in the tubing during reciprocation of the pump. During the downward reciprocation of the pump, the upper liner moves into abutting contact with the lower liner and forces the latter element of the invention downwardly in the working barrel. The rigid member which interconnects the valve closure member with the lower liner is slightly longer than the upper liner. At. the instant of stroke turn-around at the commencement of the down stroke of the pump, the upper liner is spaced slightly apart from the lower liner and, in commencing its downward stroke, moves across such space into contact with the lower liner as the valve closure member is lifted off its seat by the rigid connecting member which interconnects its with the lower liner. The elements of the present invention are simple and inexpensive in construction, facilitating ease of maintenance by field maintenance personnel and also relatively low installation costs.

From the foregoing description, it will be apparent that it is an important object of the present invention to provide an improved sucker rod pump which is less subject to malfunctioning by virtue of gas locking of the traveling valve than those types of sucker rod pumps heretofore proposed.

A further object of the present invention is to provide an improved traveling valve for use in sucker rod pumps, which traveling valve is simple and economical in construction, yet is characterized by a long and trouble-free operating life.

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

In the drawings:

FIGURE 1 is a vertical sectional view through a pump constructed in accordance with this invention.

FIGURE 2 is a sectional view taken along line 22 of FIGURE 1.

FIGURE 3 is a sectional view taken along line 33 of FIGURE 1.

FIGURE 4 is a sectional view as taken along line 4-4 of FIGURE 1.

Referring now to the drawings in detail, and particularly to FIGURE 1, reference character 10 generally designates a pump structure embodying the present invention and including an elongated tubular working barrel 12. The pump 10 may be of any suitable type, but is preferably of the type which is inserted in the lower portion of an oil well tubing and which may be removed separately from the tubing. The working barrel 12 is of substantial length and has a suitable guide structure (not shown) in its upper end to slidingly receive the lower end portion of a string of sucker rods extending from the top of the well. The lower end of the sucker rod string is suitably connected to the upper connecting rod or pull rod 14 of the pump for operating the pump as Will be more fully hereinafter set forth.

A tubular valve cage 16 is threaded into the lower end of the Working barrel 12 and is provided with a conven tional spider 18 in the upper portion thereof to limit the upward movement of a ball type standing valve 20. Apertures 22 extend through the spider 18 in the usual manner. The lower end of the valve cage 16 is internally threaded to receive the upper end of a suitably constructed anchor or shoe 23. A seat 24 for the ball valve 20 may be secured between opposed shoulders formed in the valve cage 16 by the anchor 23. The anchor 23 is utilized to seat the pump in a complementary shaped shoe (not shown) secured on the lower end of the well tubing in a conventional manner whereby the pump 10 will be anchored in the lower end of the tubing by friction, yet the pump 10 may be pulled upwardly through the tubing when a substantial force is imposed on the sucker rod string.

The pump piston and traveling valve assembly of the present invention is designated generally by reference character 26. The piston and traveling valve assembly 26 is disposed in the working barrel 12 at some distance above the standing valve and reciprocates in the working barrel to lift oil flowing thereinto through the anchor 23, the spider 18 and the valve cage 16. The valve cagetraveling valve assembly 26 comprises a cylindrical cage member 28 which is provided with a hemispherical recess 30 at its lower end and is associated with a valve seat 32 preferably constructed of resilient material and positioned in abutting contact with the lower end of the valve cage 28. The valve seat 32 is provided with a central aperture 33 to permit passage of the oil therethrough. The hemispherical recess 30 is sufficiently large to accommodate vertical movement of a spherical valve closure member 34 as it is lifted from the valve seat 32 during reciprocation of the pump. The valve cage 28 is connected by a plurality of radially extending vanes 36 (see FIGURE 2) to a centrally positioned hub 38. The hub 38, vanes 36 and cage 28 thus define a plurality of axially extending passageways 40 through which oil is permitted to move upwardly during the downward reciprocation of the pump.

The pull rod 14 is suitably secured to the hub 38 centrally located in the valve cage 28 in the piston and standing valve assembly 26 such as by threading the lower end of the pull rod into a cooperating threaded opening in the hub as shown in FIGURE 1. Secured to the outer periphery of the cylindrical valve cage 28 is a downwardly depending liner 42. The upper end of the liner 42 is provided with an enlarged bore so that a shoulder 44 is formed on the internal periphery of the liner 42 to receive and support the valve seat 32. The outside diameter of the liner 42 is such that it frictionally and slidably engages the internal walls of the working barrel 12 and thus provides a seal between the valve seat 32 and the working barrel 12.

1 From the description of the invention as thus far described, it will be perceived that the valve cage 28, the liner 42, the valve seat 32 and the valve closure member 34 conjunctively constitute a valved piston affixed to the lower end of the pull rod 14 and functioning during the upstroke of the pull rod to lift the column of oil above the traveling valve upwardly in the working barrel 12. On the downstroke of the pump, the pull rod 14 drives the valve cage 28 and liner 42 downwardly, causing the valve closure member 34 to unseat and move upwardly in the hemispherical space 30 in the valve cage. Oil is thus permitted to flow through the annular central opening 33 in the valve seat 32 and through the passageways 40 formed by the valve cage 28, vanes 36 and hub 38.

Were only the elements of the pump as thus far described provided, the traveling valve assembly 26 would be subject to malfunctioning as a result of gas pressure exerted upon the valve closure member 34 to prevent it from moving on and off the valve seat 32 at the proper time during reciprocation of the pump. In order to relieve or prevent such gas locking of the valve closure member 34, a second or lower liner 46 is positioned below the upper liner 42 and frictionally engages the internal walls of the working barrel 12. The fit of the lower liner 46 in the working barrel 12 is of considerable importance to the proper functioning of the invention, as will be subsequently described in greater detail. It sufiices to say at this point that the lower liner 46 must be in sliding engagement with the working barrel 12 so that it is capable of being reciprocated or telescoped within the working barrel 12 by a force which is well within the capacity of the power unit of the pump located at the surface.

At its upper ends, the lower liner 46 is secured to a cylindrical member 48 which is also in frictional engagement with the internal walls of the working barrel 12 and which is provided with a central hub 50. The central hub 58 of the cylindrical member 48 is connected to the cylindrical member by a plurality of radially extending vanes 52 in substantially the same manner as the traveling valve cage 28 is connected to its hub 38. In a preferred embodiment of the invention, the cylindrical member 48 is of a metallic construction, but under some conditions of use, it may be preferable to provide a rubber or plastic construction.

The hub 50 of the cylindrical member 48 is threadedly engaged by the lower end of a rigid connecting member or rod 54 which extends upwardly through the upper liner 42 and is threadedly engaged at its upper end to the valve closure member 34. The length of the rigid connecting member 54 is slightly greater than the distance from the valve closure member 34 to the lower end of the upper liner 42 so that when the valve is seated as shown in FIGURE 1, the cylindrical member 48 and the lower liner 46 to which it is connected will be spaced slightly below the upper liner 42. The length of the rigid connecting member 54 is further selected so that the upper liner 42 may move downwardly into abutting contact with the cylindrical member 48 during downward reciprocation of the pump without the valve closure member 34 moving upwardly in the hemispherical cavity to the extent of contacting the hub 38 of the standing valve cage 28. In other words, the clearance between the upper liner 42 and the cylindrical member 48 connected to the lower liner 46 is smaller than the clearance between the valve closure member 34 and the hub 38 of the valve cage 28. This prevents the valve closure member 34 from being subjected to repeated impact with the hub 38 of the valve cage 28 during reciprocation of the pump.

Operation With the pump 10 installed in the lower end of the string of well tubing, and the pull rod 14 connected to the usual sucker rod string, the pull rod 14 and the piston and traveling valve assembly 26 connected thereto will be reciprocated upon reciprocation of the sucker rod string. During the upstroke of the pump 10, the hydrostatic head of oil above the piston and traveling valve assembly 26 will force the valve closure member 34 into engagement with the valve seat 32. In the eventuality that a substantial accumulation of gas below the piston and traveling valve assembly 26 exists within the working barrel 12, a force will be exerted upon the valve closure member 34 tending to prevent its seating upon the seat 32. The force which may be exerted upon the valve closure member 34 by such entrapped gas is, however, counteracted by a drag imposed upon the valve closure member 34 through the rigid connecting member 54 by the cylindrical member 48 and the lower liner 46. The latter elements, as has been previously explained, are in frictional engagement with the internal walls of the working barrel 12 and thus resist upward movement of the piston and traveling valve assembly 26. The extent of frictional engagement is such that the forces normally developed by accumulations of gas within the working barrel 12 may be overcome by the drag imposed upon the valve closure member 34 in the manner described. The fit of the liner 46 and cylindrical member 48 with the working barrel 12 should not, however, be any tighter than is necessary to meet this requirement so that an excessive load will not be placed upon the power unit of the pump.

As the piston and traveling valve assembly 26 continues to move upwardly in the working barrel 12, the upper liner 42 will be spaced apart from the cylindrical member 48 and lower liner 46 in the manner shown in FIGURE 1. Following stroke turnaround and commencement of the downstroke of the pump, the upper liner 42 will be forced downwardly toward the lower liner 46 until the lower end of the upper liner 42 comes into abutting contact with the upper edge of the cylindrical member 48. Concurrently with this movement, the valve closure member 34 will be lifted olf the valve seat 32 by the rigid interconnecting member 54. At the time of such movements, the lower liner 46 and cylindrical member 48 will remain substantially stationary in the working barrel 12 by virtue of their frictional contact therewith and will remain stationary until the cylindrical member 48 is contacted by the upper liner 42. Thereafter, the lower liner 46 will be forced downwardly in the working barrel 12 ahead of the upper liner 42. At this time, the valve closure member 32 is maintained in spaced relation to the valve seat 32 by the positive action by the rigid connecting member 54. Accumulations of gas in the production fluid above the piston and traveling valve assembly 26, though exerting a force acting on the valve closure member 34 in a direction tending to close this element, will not generally be sufiicient to overcome the frictional resistance to downward displacement of the liner 46 and cylindrical member 48 relative to the working barrel 12. The valve closure member 34 will therefore remain open and will not become gas locked on the seat during the downstroke of the pump. Oil is thus permitted to flow upwardly through the central aperture 33 in the valve seat 32 through the spherical cavity 39 around the valve closure member 34 and out through the passageways 40 in the valve cage 28.

From the foregoing description, it will be apparent that the present invention provides a relatively simple and inexpensive improvement in oil well pumps which greatly aids in relieving malfunctioning of the traveling valve due to gas locks which occasionally occur. The assembly of the pump is uncomplicated and is such that repairs and parts replacements may be easily eifected by field maintenance personnel. Also, the pump is characterized by a long service life and may be economically manufactured.

Changes may be made in the combination and arrangement of the parts or elements set forth in the specification and shown in the drawings, it being understood that the preferred embodiment hereinbefore described is exemplary only and that slight changes or modifications will be readily apparent to those skilled in the art. For example, it may be desirable in some instances to form the cylindrical member 48 integrally with the lower liner 46. Such changes as the latter, and other changes which are readily apparent to those skilled in the art, are considered to be circumscribed by the spirit and scope of the present invention, except as the same may be necessarily limited by the appended claims.

I claim:

1. A pump for use in an oil well, comprising a tubular working barrel;

a standing valve in the lower end of the barrel to prevent the downward flow of oil from the barrel;

a pull rod extending downwardly in said barrel;

a valve cage attached to the lower end of said pull rod for reciprocating movement therewith;

a valve seat associated with said valve cage;

an upper liner secured to said valve cage and depending downwardly therefrom in said barrel in frictional contact with the internal walls of said barrel, said upper liner forming a seal between said valve seat and said barrel;

a lower liner in said barrel between said standing valve and the lower end of said upper liner and frictionally engaging the internal Walls of said barrel;

a valve member positioned in said cage and cooperating with said seat to prevent the downward flow of oil in the barrel during the upward movement of said pull rod; and

rigid connecting means connecting said valve member to said lower liner, said connecting means being dimensioned to contact said valve member with said seat when the upper end of said lower liner is spaced from the lower end of said upper liner.

2. A pump as claimed in claim 1 wherein the frictional fit of said lower liner in said barrel is such as to overcome forces produced by compressed gases in said barrel and acting to prevent actuation of said valve upon reciprocation of the pull rod.

3. A pump as claimed in claim 1 wherein said valve member is spherical and said cage is dimensioned to permit said valve member to clear said cage when said upper and lower liners are in abutting contact.

4. A pump as claimed in claim 1 wherein said upper and lower liners each comprise a metallic, cylindricallyshaped sleeve concentrically and slidingly engaging the inner walls of said barrel.

5. A reciprocating sucker rod type oil well pump comprising:

a pump barrel;

a string of sucker rods extending downwardly into the pump barrel;

a standing valve at the lower end of the pump barrel;

guide means including a valve seat connected to the lower end of the sucker rod string and bearing against the internal walls of said barrel for retaining the concentricity of the sucker rod string in the barrel during reciprocation of the sucker rods;

a liner frictionally engaging the internal walls of said barrel below said guide means and vertically aligned with said guide means;

valve closure means cooperating with said valve seat during upward movement of the sucker rod to prevent the downward flow of oil in said barrel; and

means rigidly interconnecting said valve closure member to said liner and retaining said liner in vertically spaced relation to said guide means when said valve closure member is closed on said seat.

6. A pump as claimed in claim 5 wherein said liner is cylindrical in configuration and is frictionally engaged with said barrel to force said valve member off said seat to the open position during downward movement of the sucker rod string and its associated guide means.

7. A pump as claimed in claim 6 wherein said valve closure member is spherical, said cylindrical liner is provided with radial, inwardly extending vanes at its upper end, and said rigid interconnecting means comprises a rod connected at one of its ends to said spherical valve member at its other end to said vanes.

8. A ptunp as claimed in claim 5 wherein said guide means comprises a valve cage associated with said valve seat; and

a cylindrical liner concentrically positioned in said barrel above said first-mentioned liner and connected at its upper end to said valve cage, said second-mentioned cylindrical liner being vertically aligned with said first-mentioned liner so that said liners are brought into abutting contact at their adjacent ends when said sucker rod string is reciprocated downwardly in said barrel.

9. A reciprocating sucker rod pump for use in oil wells comprising:

a working barrel;

a standing valve at the lower end of the working barrel;

a traveling valve positioned above the standing valve in the Working barrel and including valve seat means slidingly mounted in the working barrel, and

a movable valve closure element positioned to sealingly engage said valve seat means during reciprocation of the pump;

resistance element slidingly positioned below said traveling valve in the working barrel of the pump and frictionallyengaging the internal walls of the barrel for axial sliding movement in said barrel by a force exceeding the net'flnid forces acting in an axial'direction in the barrel on said movable valve and the valve closure element of said traveling valve and spacing said resistance element below the valve seat means of said travelingvalve when said valve closure element sealingly engages said valve seat means whereby said valve closure element is actuated in response to axial movement of the valve seat of the traveling'valve relative to said resistance element.

References Cited in the file of this patent closure member during operation of the pump; and 10 UNITED STATES PATENTS means rigidly interconnecting said resistance element 1,602,879 Browning Oct. 12,1926

Claims

1. A PUMP FOR USE IN AN OIL WELL, COMPRISING A TUBULAR WORKING BARREL; A STANDING VALVE IN THE LOWER END OF THE BARREL TO PREVENT THE DOWNWARD FLOW OF OIL FROM THE BARREL; A PULL ROD EXTENDING DOWNWARDLY IN SAID BARREL; A VALVE CAGE ATTACHED TO THE LOWER END OF SAID PULL ROD FOR RECIPROCATING MOVEMENT THEREWITH; A VALVE SEAT ASSOCIATED WITH SAID VALVE CAGE; AN UPPER LINER SECURED TO SAID VALVE CAGE AND DEPENDING DOWNWARDLY THEREFROM IN SAID BARREL IN FRICTIONAL CONTACT WITH THE INTERNAL WALLS OF SAID BARREL, SAID UPPER LINER FORMING A SEAL BETWEEN SAID VALVE SEAT AND SAID BARREL; A LOWER LINER IN SAID BARREL BETWEEN SAID STANDING VALVE AND THE LOWER END OF SAID UPPER LINER AND FRICTIONALLY ENGAGING THE INTERNAL WALLS OF SAID BARREL;