US3592567A - Subsurface pump - Google Patents

Abstract

A subsurface pump for a producing oil well, and the like, wherein a passageway is provided for directing a lubricant into the annulus between the working barrel and pump plunger for facilitating the reciprocation of the plunger.

Description

United States Patent 1 1 3,592,567

[72] inventor Clillord C. Talbert [56] References Cited 907 McKinley Street, Seminole, Okla. Nl STATES PATENTS v 74686 1.421,004 6/1922 l-llbbard 417/432 [21] g' 21 1 l,530,624 3/1925 Smith 417/432x P e d 1971 2,405,697 8/1946 Houston etal... 417/432 [4 1 meme 2,544,094 3/1951 Knowles 417/260 Primary Examiner- Leonard H. Gerin s41 SUBSURFACE PUMP Attorney--William S.Dorman 10 Claims, 3 Drawing Figs.

[52] U.S.Cl. 417/432, 92/160, 417/260, 417/448, 4 l 7/554 [51 Int. Cl ..F04b 21/00,

F04b 47/00, F04b 39/ l ABSTRACT: A subsurface pump for a producing oil well, and [50] Field of Search 417/432, the like, wherein a passageway is provided for directing av 260, 448, 554, 430, 431; lubricant into the annulus between the working barrel and 92/158- 160 pump plunger for facilitating the reciprocation of the plunger.

PATENTED JUL 1 31971 INVENTOR.

FIG IB CLIFFORD C. TOLBERT ATTORNEY FIG. IA

6 6 4 O Q 3 4&4 4

SUBSURFACE PUMP This invention relates to improvements in subsurface pumps for producing oil wells and the like and more particularly but not by way of the limitation to a subsurface pump wherein lubrication between the pump plunger and working barrel is provided.

In producing oil wells it is common practice to provide a pump at the bottom of the well bore or at least down the well in the producing formation. The pump is normally actuated by reciprocation of the pump plunger by sucker rods which extend through the well bore from a reciprocating device at the surface of the ground and into connection with the pump. The reciprocating device at the surface is usually a horsehead-type pump and alternately raises and lowers the string of sucker rods in the well bore. Some wells, particularly in California, are producing extremely viscous fluids and it is very difficult to reciprocate the pump plunger during the pumping operation for elevating these viscous fluids to the surface. A gas or lightweight fluid is frequently forced downwardly in the well bore and into the fluid being elevated by the pump. The lightweight fluid mingles with the heavy fluid for somewhat reducing the viscosity of the heavy fluid to facilitate the pumping operation and elevation of the fluid to the surface of the well. Even under these conditions, however, the pump operation is difficult and the pump may require frequent repair or replacement which is very costly and time consuming.

The present invention contemplates a subsurface or bottom hole pump particularly designed and constructed or facilitating pumping of heavy or viscous fluids. A lubricant is directed into the annulus between the working barrel and pump plunger for facilitating operation of the pump itself thus facilitating the pumping of heavy viscous fluids and prolonging the useful life of the pump. A portion of the gas or lightweight fluid which is injected into the well for mingling with the viscous fluid is diverted through passageway means provided in the pump plunger and directed into annulus between the plunger and working barrel. The fluid is injected into the annulus at spaces or points located between the plunger packer rings whereby leakage of the lubricant from annulus is subsequently precluded during the pumping and lubricating operation. The lubrication of the plunger greatly facilitates the reciprocation thereof for increasing the pumping efficiency and prolonging the useful working life of the pump.

It is an important object of this invention to provide a subsurface pump for producing oil wells which is particularly designed and constructed for facilitating the pumping of viscous or heavy fluids.

Another object of this invention is to provide a novel subsurface pump for producing oil wells and the like wherein a lubricant is directed to the area between the working barrel and pump plunger for facilitating reciprocation of the plunger.

A further object of this invention is to provide a novel subsurface pump for producing oil wells wherein maintenance is reduced to a minimum and the useful life thereof is greatly prolonged.

It is another object of this invention to provide a novel subsurface pump for producing oil wells which is simple and efficient in operation and economical and durable in construction.

Other and further objects and advantageous features of the present invention will hereinafter more fully appear in connection with a detailed description of the drawings in which:

FIG. 1 is a sectional elevational view of the upper portion of a subsurface pump embodying the invention and disposed within a well tubing.

FIG. 1A is a view similar to FIG. 1 depicting the central portion of the pump.

FIG. 1B is a view similar to FIGS. 1 and IA depicting the lower portion on the pump.

Referring to the drawings thedetail reference numeral 2 generally indicates a pump comprising a plunger 4 reciprocally disposed within a workingbarrel 6. The workingbarrel 6 is preferably set within thewell tubing 8 by a suitable packer (not shown) or the like as is well known and in such a manner that thepump 2 is disposed in the proximity of or within a producing formation (not shown) of the well bore (not shown). The pump plunger 4 may be connected with the suitable hollow sucker rods (not shown) in any well-known manner and as depicted herein acoupling member 10 is provided in the upper end of the plunger 4 for suitable connection with the lowermost sucker rod. Thus reciprocation of the sucker rods is transmitted to the plunger 4 for reciprocation thereof within the workingbarrel 6 to provide the pumping action for thepump 2 as is well known.

The plunger 4 comprises anupper bushing 12 having acentral bore 14 extended longitudinally thcrethrough. Thebore 14 is threaded at the upper end thereof as shown at 16 for receiving thecoupling member 10 therein. Thebore 14 is reduced in 18 to provide a restricted fluid passageway through the bushing l2. A first threadedportion 20 is provided on the outer periphery of thebushing 12 for receiving one end of a tubular member or sleeve 22 thereon. Anannular shoulder 24 is provided at the upper end of the threadedportion 20 for receiving the end of the sleeve 22 thereagainst. The outer periphery of thebushing 12 is provided with a second threadedportion 26 spaced below the threaded portion 22 and of a smaller diameter than the thread 22. One end 0 an inner sleeve ortube 28 is threadably engaged with the threadedportion 26 and extends longitudinally within and concentric with the sleeve 22. The outer diameter of thesleeve 28 is smaller than the inner diameter of the sleeve 22 to provide anannulus 30 therebetween. A plurality of circumferentially spaced angularly extendingbores 32 extend from thebore 14 to the outer periphery of thebushing 12 between thethread portions 20 and 26 to provide communication between thebore 14 and theannulus 30.

Thebushing 12 is provided with a reducedneck portion 34 at the lower end thereof and which is externally threaded as shown at 36 for receiving a backpressure valve assembly 38 thereon. Theback pressure valve 38 comprises anouter sleeve 40 having the inner periphery thereof threaded at 42 for engagement with the threadedneck portion 36. An inwardly directedcircular flange 44 is provided on the inner periphery of the sleeve below the threadedportion 42 for supporting anannular valve seat 46. A plurality of circumferentially spaced angularly disposed bores 48am provided in the sidewall of thesleeve 40 and spaced below theflange 44 to provide communication between the interior and exterior of thesleeve 40. Aball member 50 is yieldably retained in engagement with thevalve seat 46 by areciprocal piston member 52 which is slidably disposed within thesleeve 40.

The piston orplunger 52 is provided with a suitable sealing member such as an O-ring 5a, or the like, around the outer periphery thereof for sealing between the plunger and the inner periphery of thesleeve 40 to preclude leakage of fluid therebetween. In addition, theplunger 52 is provided with a downwardly extending reducedstem portion 56 providing anannular shoulder 58 around the outer periphery of theplunger 52 spaced below thesealing ring 54. Thestem 56 extends slidably into acentral bore 59 of ascrew 60 which is threadedly secured through aretainer cap member 62. Thecap 62 is threadedly secured to the lower end of thesleeve 40, and asuitable jam nut 64 is preferably interposed between thecap 62 and the head of thescrew 60. A plurality ofsuitable spring washers 66 are interposed between the upper end of thescrew 60 and theshoulder 58 of theplunger 52 for constantly urging theplunger 52 in an upward direction as viewed in the drawings to maintain theball 50 in a normal seating position against thevalve seat member 46. The outer diameter of thesleeve 40 is smaller than the inner diameter of thesleeve 28 to provide anannular space 68 therebetween for flow of fluid therebetween for a purpose as will be hereinafter set forth.

Acollar member 70 is threadedly secured to the lower end of theinner sleeve 28 and is provided with an outwardly directedannular shoulder 72 on the outer periphery thereof for receiving the lower end of thesleeve 28 thereagainst. The diameter of the outer periphery of theshoulder 72 is substantially equal to the outer diameter of theinner sleeve 28 as clearly shown in FIG. 1, and is open to theannular passageway 30. An annular groove 74 is provided around the outer periphery of thecollar 70 and is also in open communication wit theannular fluid passageway 30. The outer diameter of thecollar 70 is enlarged at 76 and is of a diameter substantially equal to the inner diameter of the outer sleeve 22 for insertion within the lower end thereof. An outwardly extendingcircumferential shoulder 78 is provided on the enlarged portion 76 or receiving the lower end of the sleeve 22 thereagainst and a plurality of longitudinally spaced sealingmembers 80 are interposed between the enlarged portion 76 and the sleeve 22 for precluding leakage of fluid therebetween. In addition, a plurality of circumferentially spacedports 82 are provided in the sidewall of thecollar 70 and spaced below theshoulder 78 to provide communication between the interior of thecollar 70 and the workingbarrel 6 for a purpose as will be hereinafter set forth. A plurality of circumferentially spacedpassageways 83 are provided in the sidewalls of thecollar 70 and extend longitudinally therethrough from the shoulder 76 downwardly as clearly shown in FIG. 1.

Aplunger tip member 84 is threadedly secured to the lower end of thecollar 70 and is provided with acentral bore 86 ofa size complementary to the inner diameter of thecollar 70. A plurality of circumferentially spacedpassageways 88 are provided in the walls of theplunger tip 84 in substantial alignment with thebores 83 and extend .longitudinally through theplunger tip 84 to provide a fluid passageway therethrough. The lower end of theplunger tip member 84 is reduced at 90 for insertion within the upper end of anouter pump sleeve 92 and a plurality of sealingmembers 194 are interposed between theplunger tip 84 and thesleeve 92 as shown in FIG. 1A. In addition, the inner periphery of theplunger tip 84 is threaded at 94 for receiving the upper end of aninner pump sleeve 96 therein.

The inner diameter of theouter sleeve 92 is larger than the outer diameter of theinner sleeve 96 to provide anannular space 98 therebetween. Theannulus 98 is in open communication with the lower end of thepassageways 88 as shown in FIG. 1A and for a purpose as will be hereinafter set forth. The outer diameter of theouter sleeve 92 is slightly less than the inner diameter of the workingbarrel 6 to provide a relativelysmall annulus 100 therebetween; as is well known. A plurality ofsuitable packer members 102 are provided around the outer periphery of theouter pump sleeve 92 and in the proximity of the upper end thereof to provide a sealing engagement with the inner periphery of the workingbarrel 6. In addition, a plurality ofsimilar packing members 104 are provided around the outer periphery of thesleeve 92 in the proximity of the lower end thereof for similarly providing a seal between thesleeve 92 and thebarrel 6. Of course, substantially any desired number of additional packings, such as shown at 106, may be interposed between the packings, thepackings 102 and 104 as desired for sealing between thesleeve 92 andbarrel 6. A plurality ofcircumferentially ports 108 are provided in thesleeve 92 between thepackings 102 and 106 for communication of fluid between theannulus 98 and theannulus 100. Similar ports 110 are provided in thesleeve 92 between thepackings 106 and 104 to establish communication between theannular spaces 98 and 100.

The lower end of the inner tube orsleeve 96 is threadedly secured at 112 to the upper end of a coupling member 114, and the lower end of theouter sleeve 92 is threadedly secured at 116 to the upper end of the coupling 114. It will thus be apparent that the coupling 114 closes the lower end of theannulus 98. The lower end of the coupling 114 is threadedly secured to the upper end ofa suitable travelingvalve 118. The travelingvalve 118 may be of any suitable type and as disclosed in FIG. 1B comprises a cage member 120 having one end threadedly secured to the coupling member 114. Avalve seat member 122 is disposed within the cage member and is retained against an inwardly directedannular shoulder 124 provided on the inner periphery of the cage 120 by aretainer sleeve 126. Aball member 128 is disposed within the cage 120 above thevalve seat 122 and is retained in a normally closed position thereagainst by gravity. An apertured web orspider member 130 is provided in the cage 120 above theball 128 for limiting the upward movement of theball 128 during opening of thevalve 118 while permitting a flow of fluid through the travelingvalve 118. The lower end of theretainer sleeve 126 is open as shown at 132 to provide an access port for thevalve 118 for entry of fluid thereto, as is well known.

In operation, the workingbarrel 6 is set in thetubing 8 in the proximity of the producing formation in any well-known manner. The usual standing valve (not shown) is provided in thewell tubing 8 below the workingbarrel 6 and in communication with the fluid to be produced from the well bore, as is well known. The pump plunger 4 is reciprocated within the working barrel by the hollow sucker rods (not shown) in the usual manner. On the upstroke of the plunger 4, a suction is created in thetubing 8 above the standing valve for opening the standing valve and pulling a quantity of the well fluid into the interior of thetubing 8. On the downstroke of the plunger 4, the pressure of the fluid in thetubing 8 opens the travelingvalve 118 whereby the well fluid is introduced into the interior of thesleeve 96. Of course, continued reciprocation of the plunger 4 causes the fluid within thesleeve 96 to rise therein for filling the sleeve and for discharge through theports 82. The fluid is discharged from theports 82 into the workingbarrel 6 above the packing 102, and suitable ports (not shown) are provided in the workingbarrel 6 for directing the fluid into the interior of thewell tubing 8 above thepump 2, as is well known in this type of pumping apparatus.

When thepump 2 is being utilized for pumping of extremely viscous fluids, a suitable lightweight fluid may be injected into the fluid within thetubing 96 by forcing the lightweight fluid downwardly through the hollow sucker rods (not shown) and to theback pressure valve 38. This is normally accomplished by means ofa pump at the surface of the ground which is actuated when the delivery of the lightweight fluid is desired. Theback pressure valve 38 is retained in the normally closed position thereof by the force of thespring washers 66 and the fluid pressure within the plunger 4 acting on thepiston 52. When the pressure of the lightweight fluid acting downwardly on theball 50 exceeds the upward pressure on thepiston 52 thepiston 52 is moved downwardly for opening thevalve 38 and permitting the lightweight fluid to move downwardly through thepassageways 48 for introduction into the fluid contained with the plunger 4.

Prior to the opening of the valve 38 a quantity of the lightweight fluid is temporarily trapped within theupper bussing 12. A portion of this fluid is directed through thepassageways 32 and into theannulus 30. The fluid moves downwardly through theannulus 30 and into the groove 74 which directs the fluid into the alignedpassageways 83 and 88. The fluid moves through thepassageways 83 and 88 and into theannulus 98. As the fluid moves downwardly in theannulus 98, a portion thereof is diverted through thepassageways 108 and 110 into theannulus 100. Theannulus 100 is between the reciprocating plunger 4 and thestationary working barrel 6 and between theuppermost packings 102 andlowermost packings 104, and functions for lubricating the plunger 4 during the reciprocation thereof. The lubrication of the plunger 4 during reciprocation thereof greatly facilitates the operation ofthepump 2, particularly during the pumping of heavy or extremely viscous fluids.

Whereas the particular embodiment depicted herein discloses a stationary working barrel and a reciprocal internal plunger, it is to be noted that the internal plunger may be stationary while the outer barrel is reciprocated, as is well known in bottom hole or subsurface pumps of this type. Of course, a lubricating fluid may be directed to the annular space between the stationary plunger and reciprocal barrel in a similar manner as hereinbefore set forth to provide for lubrication of the relative movement between the working elements of the pump.

From the foregoing it will be apparent that the present invention provides a novel subsurface pump for producing oil wells wherein a lubricant is directed into the annulus between the reciprocating plunger and the stationary working barrel. The overall operation of the pump is greatly enhanced by the lubrication of the plunger, thus facilitating the producing of heavy fluids and prolonging the useful life of the pump itself. The novel pump is simple and efficient in operation and economical and durable in construction.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.

What I claim is: g

1. A subsurface well pump comprising a first elongated stationary tubular member, a second elongated tubular member concentrically arranged with respect to the stationary tubular member and reciprocal with respect thereto, packing means interposed between the stationary and reciprocal tubular members, an annulus provided between the stationary and reciprocal tubular members and interposed between the packing means, traveling valve means carried by the reciprocal tubular member for admitting well fluid into the pump, discharge port means provided in the stationary and reciprocal tubular members for discharging the well fluid therefrom, and means for directing a lubricating fluid into the annulus between the stationary and reciprocal tubular members for lubrication thereof during operation of the pump.

2. A subsurface well pump as set forth in claim 1 wherein the means for directing a lubricating fluid into the annulus comprises a bushing for receiving the lubricating fluid therein, longitudinally extending passageway means provided in one of the tubular members, outlet ports provided in said bushing for directing a portion of said lubricating fluid to the longitudinal passageway means, and discharge port means provided in the said one of the tubular members providing communication between the longitudinal passageway means and the annulus for directing the lubricating fluid into the annulus.

3. A subsurface well pump as set forth in claim 1 wherein back pressure valve means is carried by one of said tubular members whereby a relatively lightweight fluid may be admitted into the pump for mingling with the well fluid therein.

4. A subsurface well pump as set forth in claim 3 wherein the back pressure valve means comprises an outer housing having a fluid inlet therein, a valve seat secured within the housing in communication with the fluid inlet, a ball member cooperating with the valve seat for providing alternate open and closed positions for the back pressure valve, piston means reciprocally disposed within the housing for supporting the ball member, spring means engageable with the piston means for constantly urging the piston in a direction to provide a normal closed position for the ball member against the valve seat, outlet ports provided in the housing and in communication with the valve seat in the open position of the, back pressure valve, said piston movable against the force of the spring means upon sufficient pressure differential acting thereon for opening of the valve whereby the lightweight fluid is discharged from the discharged ports and into the well fluid within the pump.

5. A subsurface well pump comprising a stationary working barrel, plunger means reciprocally disposed within the barrel, packing means interposed between the working barrel and reciprocal plunger means, an annulus provided between the working barrel and interposed between the packing means, traveling valve means carried by the plunger means for admitting well fluid into the interior of the plunger means, discharge port means provided in the plunger means and working barrel for discharging the well fluid from the pump,

andmeans rovided in the lunger means for directing a lubricating uid into the annu us between the working barrel and plunger means for facilitating the reciprocation of the plunger means.

6. A subsurface well pump as set forth in claim 5 wherein the last mentioned means comprises a chamber for receiving the lubricating fluid therein, longitudinal passageway means extending through the reciprocal plunger, passageway means providing communication between the chamber and the longitudinal passageway for directing a portion of the lubricating fluid into the longitudinal passageway means, and radial bore means provided in the reciprocal plunger and extending into communication between the longitudinal passageway means the annulus for directing said lubricating fluid into the annulus.

7. A subsurface well pump as set forth in claim 5 and including back pressure valve means carried by the plunger means for admitting a portion of said lubricating fluid into the well fluid in the interior of the plunger means.

8. A subsurface well pump as set forth in claim 7 wherein said back pressure valve means comprises a housing secured within the plunger means, valve seat means secured within the housing and in open communication with the source of lubricating fluid, ball means cooperating with the valve seat to provide alternate open and closed positions for the back pressure valve means, piston member yieldably supported within the housing and engageable with said ball means for urging the ball means into engagement with the valve seat means to provide a normal closed position for the back pressure valve means, said piston responsive to pressure differential acting thereon for moving in a direction away from the valve seat means whereby the ball means is disengaged therefrom to provide said open position for said valve, and passageway means provided in the housing and in communication with the interior and exterior thereof for directing fluid to the exterior of the back pressure valve means in the open position thereof.

9. A subsurface well pump as set forth in claim 5 wherein the reciprocal plunger comprises outer sleeve means of an outer diameter slightly less than the inner diameter of the working barrel to provide said annulus therebetween, inner sleeve means concentrically arranged with said outer sleeve means, the outer diameter of said inner sleeve means being slightly less than the inner diameter of the outer sleeve means to provide an annular space therebetween for forming said longitudinal passageway through the plunger means, bushing means supporting said inner and outer sleeve means within said working barrel, a chamber provided within said bushing for receiving the lubricating fluid therein, and bore means provided in said bushing for directing a portion of the lubricating fluid from the interior thereof to the longitudinal passageway, and port means provided in said outer sleeve for directing said lubricating fluid from the longitudinal passageway to the annulus between the plunger and working barrel.

10. A subsurface well pump as set forth in claim 9 and including back pressure valve means carried by the plunger means and disposed below the fluid receiving chamber in the bushing, said back pressure valve responsive to pressure differentials acting thereon to provide alternate closed and open positions for intermittently admitting the lubricating fluid into the well fluid within the plunger means.

Claims (10)

1. A subsurface well pump comprising a first elongated stationary tubular member, a second elongated tubular member concentrically arranged with respect to the stationary tubular member and reciprocal with respect thereto, packing means interposed between the stationary and reciprocal tubular members, an annulus provided between the stationary and reciprocal tubular members and interposed between the packing means, traveling valve means carried by the reciprocal tubular member for admitting well fluid into the pump, discharge port means provided in the stationary and reciprocal tubular members for discharging the well fluid therefrom, and means for directing a lubricating fluid into the annulus between the stationary and reciprocal tubular members for lubrication thereof during operation of the pump.

2. A subsurface well pump as set forth in claim 1 wherein the means for directing a lubricating fluid into the annulus comprises a bushing for receiving the lubricating fluid therein, longitudinally extending passageway means provided in one of the tubular members, outlet ports provided in said bushing for directing a portion of said lubricating fluid to the longitudinal passageway means, and discharge port means provided in the said one of the tubular members providing communication between the longitudinal passageway means and the annulus for dIrecting the lubricating fluid into the annulus.

3. A subsurface well pump as set forth in claim 1 wherein back pressure valve means is carried by one of said tubular members whereby a relatively lightweight fluid may be admitted into the pump for mingling with the well fluid therein.

4. A subsurface well pump as set forth in claim 3 wherein the back pressure valve means comprises an outer housing having a fluid inlet therein, a valve seat secured within the housing in communication with the fluid inlet, a ball member cooperating with the valve seat for providing alternate open and closed positions for the back pressure valve, piston means reciprocally disposed within the housing for supporting the ball member, spring means engageable with the piston means for constantly urging the piston in a direction to provide a normal closed position for the ball member against the valve seat, outlet ports provided in the housing and in communication with the valve seat in the open position of the back pressure valve, said piston movable against the force of the spring means upon sufficient pressure differential acting thereon for opening of the valve whereby the lightweight fluid is discharged from the discharged ports and into the well fluid within the pump.

5. A subsurface well pump comprising a stationary working barrel, plunger means reciprocally disposed within the barrel, packing means interposed between the working barrel and reciprocal plunger means, an annulus provided between the working barrel and interposed between the packing means, traveling valve means carried by the plunger means for admitting well fluid into the interior of the plunger means, discharge port means provided in the plunger means and working barrel for discharging the well fluid from the pump, and means provided in the plunger means for directing a lubricating fluid into the annulus between the working barrel and plunger means for facilitating the reciprocation of the plunger means.

6. A subsurface well pump as set forth in claim 5 wherein the last mentioned means comprises a chamber for receiving the lubricating fluid therein, longitudinal passageway means extending through the reciprocal plunger, passageway means providing communication between the chamber and the longitudinal passageway for directing a portion of the lubricating fluid into the longitudinal passageway means, and radial bore means provided in the reciprocal plunger and extending into communication between the longitudinal passageway means the annulus for directing said lubricating fluid into the annulus.

7. A subsurface well pump as set forth in claim 5 and including back pressure valve means carried by the plunger means for admitting a portion of said lubricating fluid into the well fluid in the interior of the plunger means.

8. A subsurface well pump as set forth in claim 7 wherein said back pressure valve means comprises a housing secured within the plunger means, valve seat means secured within the housing and in open communication with the source of lubricating fluid, ball means cooperating with the valve seat to provide alternate open and closed positions for the back pressure valve means, piston member yieldably supported within the housing and engageable with said ball means for urging the ball means into engagement with the valve seat means to provide a normal closed position for the back pressure valve means, said piston responsive to pressure differential acting thereon for moving in a direction away from the valve seat means whereby the ball means is disengaged therefrom to provide said open position for said valve, and passageway means provided in the housing and in communication with the interior and exterior thereof for directing fluid to the exterior of the back pressure valve means in the open position thereof.

9. A subsurface well pump as set forth in claim 5 wherein the reciprocal plunger comprises outer sleeve means of an outer diameter slightly less than the inner diameter of the working barrel tO provide said annulus therebetween, inner sleeve means concentrically arranged with said outer sleeve means, the outer diameter of said inner sleeve means being slightly less than the inner diameter of the outer sleeve means to provide an annular space therebetween for forming said longitudinal passageway through the plunger means, bushing means supporting said inner and outer sleeve means within said working barrel, a chamber provided within said bushing for receiving the lubricating fluid therein, and bore means provided in said bushing for directing a portion of the lubricating fluid from the interior thereof to the longitudinal passageway, and port means provided in said outer sleeve for directing said lubricating fluid from the longitudinal passageway to the annulus between the plunger and working barrel.

10. A subsurface well pump as set forth in claim 9 and including back pressure valve means carried by the plunger means and disposed below the fluid receiving chamber in the bushing, said back pressure valve responsive to pressure differentials acting thereon to provide alternate closed and open positions for intermittently admitting the lubricating fluid into the well fluid within the plunger means.

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