US2698586A - Self-cleaning oil well production device - Google Patents

Description

A. F. STANLEY ETAL 2,698,586 SELF-CLEANING OIL wELL PRODUCTION DEVICE 2 sheets-sheet 1 I N VE N TOR 5 /Mo/vzo HSW/VLEX Jahr/yf, uf/Loom ATTORNEY Jan. 4, 1955 Filed July 25, 1951 Jan- 4, 1955 A. F. STANLEY ETAL 2,698,586

SELF-CLEANING on. WELL PRODUCTION DEVICE Filed July 25, 1951 2 Sheets-Sheet 2 ATTORNEY United States Patent Ofee 2,698,586 Patented Jan. 4, 1955 SELF-CLEANING OIL WELL PRODUCTION DEVICE Alonzo F. Stanley, Blanchard, and John A. Bullock, Madill, Okla.

Application July 25, 1951, Serial No. 238,436

14 Claims. (Cl. 10S-204) This invention relates to oil well production equipment and has particular reference to mechanism positioned below the working barrel of a string of oil well tubing which serves to guide the tubing as it is lowered into the well casing and to maintain the pump inlet and the pump elements free of foreign substances without the necessity of removing the working barrel and tubing from the well.

It has heretofore been suggested in the art to provide a plunger mechanism attached to a working barrel which could be actuated by lowering the tube string to the bottom of the well to unseat the ball valve within the cage of the standing valve, thereby permitting the oil within the barrel to escape and the ow thus created to wash away deposits of sand or the like. However, the prior art mechanisms have not been found effective in use since the backflow of oil from the barrel in the absence of positively acting cleaning mechanism does not serve to remove deposits of paraffin, asphaltum, sand, or other foreign substances congealed or otherwise solidied and encrusted upon the pump inlet, packers and seats of standing valves, or upon the valve cups of insert pumps. Such deposits or encrustation cause the pump mechanism to `become inoperative by restricting or closing the inlet passage, by interfering with the valve action and by causing -abrading and emosion of the pump surfaces, and have heretofore necessitated the pulling of the string of tubing from the well and removal of the pump mechanism for cleaning the parts thereof.

Further, during the lowering of a string of tubing into paraffin or asphaltum base oil wells, the lower end thereof frequently slides against the side wall of the casing and the pump inlet, standing valve elements or valve cups become clogged or fouled by entrance of deposits of solidified parain, asphaltum or other foreign material which have accumulated on the ledges or within recesses of the well casing. When this occurs, the pump is rendered inoperative even before the well production has started and the tubing must be removed in order to clean the inlet and working parts of the barrel.

Additionally, diiiiculties are frequently encountered in lowering tubing strings into oil wells which result from the lower end of the tubing engaging recesses or ledges caused by joints or cuts located in the wall of the well casing. Such obstructions which are also encountered in whipped stocked wells and crooked holes, are oftentimes formed by shing tools, casing perforators, falling drill bits or other tools conventionally inserted and operated in well casings. When the end of the tubing being inserted in the well encounters an obstruction of this nature, the resultant shock frequently jars the string loose from the lowering elevators by stripping of the retaining collar, thus permitting the string of tubing to drop to the bottom of the well. Recovery of the tubing string by the use of fishing tools requires additional time and labor and results in a loss of production time.

It is, therefore, an object of this invention to provide an improved oil well production device extending below the inlet end of a working barrel attached to a string of tubing which serves as a guide during the lowering of the tubing within the casing, and which serves to clear er1- crustations of foreign matter from the pump inlet by positive action and to break up and dislodge deposits and encrustations within the working barrel yby moving the standing valve or insert pump and by dislodging the check ball valve from its seat upon being actuated by contact with the well bottom and the subsequent lifting of the tubing from the bottom. w

Another object of this invention is to provide an improved oil well production device attached to the lower end of a tubing string which serves to guide the string while it is being lowered into the well, and to cause the end of the tubing to be dislodged from obstructions such as recesses and ledges existing in the wall of the well casing.

Another object of this invention is to provide an improved oil well production device positioned at the lower end of the tubing string which is provided with a spring biased plunger in which energy is stored due to the compression of Ithe spring which occurs when the plunger encounters an obstruction in the casing wall during the lowering operation, and which results in the plunger rebounding fr-om the obstacle in the wall surface to guide the tubing string away from such obstructions so that the tubing does not become hung within the well casing.

Another object is to provide an improved oil well production device for use with pumping mechanism which provides a n-ovel multiple purpose inlet for the pump chamber through which oil from the well enters the working barrel.

Another object is to provide an improved oil well production device formed with an elongated tube or conduit which depends from the working barrel in communication with the pumping chamber and which comprises a plurality of elongated inlet slots or openings positioned at spaced intervals about the wall of the tube.

Another object of the invention is to provide an improved oil well production device comprising a slotted inlet tube, one end of which is adapted to be connected with the inlet chamber of a pumping mechanism and the other end of which is provided with bearing means for slidably supporting a plunger shaft, a portion of which reciprocates interiorly of and in telescoping relation with respect to the inlet tube.

Another object of the invention is to provide an improved oil well production device comprising a slotted inlet tube, a reciprocating plunger shaft cooperating therewith, and spring means for normally maintaining the plunger shaft in extended position.

Another object of the invention is to provide an improved oil well production device comprising a slotted inlet tube and a reciprocating plunger shaft cooperating therewith having a portion provided with a plunger shoulder and a terminal end section of reduced diameter positioned interiorly of said tube when the plunger is in eX- tended position, and a portion located eXteriorly of the tube which contacts obstructions in the well casing or the bottom of the drill hole to cause relative movement between said inlet tube and said casing.

A further object of the invention is to provide Aan improved oil well production device comprising -a slotted inlet tube and a concentrically positioned reciprocating plunger shaft having a plurality of cleaning and guiding pins supported by said shaft which project within the slots of said tube and travel substantially the length thereof during movement of the plunger shaft for the purpose of loosening and removing deposits and encrustations of solidified foreign material which if left in place in the slots would restrict the inlet and interfere with the operation of the pumping mechanism. A still further object of the invention is to provide an lmproved oil well production device having means for coupling to the inlet of a pumping mechanism comprising a slotted inlet tube and a spring biased plunger shaft provided with a shoulder and a terminal end section of reduced diameter which engage respectively and move the standing Valve and check ball valve of the working barrel upon movement of the plunger against the bias of the spring.

The invention also resides in certain novel structural features which facilitate the carrying out of the foregoing objects and which contribute both to the simplicity of the self cleaning oil well production tool, its convenience in use and to the ruggedness of its construction as well as to the dependability of its operation.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings, in which:

Fig. l is a side elevational view showing the self cleaning oil well production device positioned within an oil well casing and depending from the working barrel of pumping mechanism;

Fig. 2 is an enlarged side elevational view partly in cross section showing the standing valve of a working barrel and the improved self cleaning oil well production device coupled thereto;

Fig. 3 is an enlarged cross sectional view partly in elevation showing the guide and cleaning pins within the pump inlet slots and supported by the reeiprocable plunger shaft;

Fig. 4 is a cross sectional view taken on line 4--4 of Fig. 3;

F Fig. 5 is a cross sectional view taken on line 5 5 of Fig. 6 is a perspective view of a portion of the plunger shaft shoulder and terminal end section of reduced dianteter;

Fig. 7 is an enlarged cross sectional view partly in elevation showing the ball check valve raised from its seat by the end of the plunger shaft which has a reduced cross section when the plunger shaft is in partially retracted position; and

Fig. 8 is an enlarged cross sectional view partly in elevation showing the ball valve and the standing valve assembly raised from their respective seats by the plunger elements when the plunger' is in fully retracted position.

While the invention is susceptible of various modifications and alternative constructions, we have shown in the drawings and will herein describe in detail the preferred embodiment. lt is to be understood, however, that we do not intend to limit the invention to such disclosure for we aim to cover all moditcations and alternative constructions falling within the spirit and scope of the invention as defined in the appended claims. ln the description of the invention, a standing valve has been set forth as illustrative of the forms of mechanism a seated within the lower end of the tubing string with which the invention may be employed. By the use of the term standing valve applicants mean to include other forms of mechanism, such as insert pumps and the like, which are utilized in oil well working barrels or tubing collars for equivalent purposes.

Referring to Figure l, reference numeral 19 indicates the drill hole of an oil well in which casing 12 has been inserted. The Working barrel indicated by reference numeral 14 of the pumping mechanism is secured to the lower end of the string of tubing through which oil is pumped from the well. The self cleaning oil well production device 16 of our invention is shown depending from the inlet 18 of the working barrel 14. The assembled tubing, pumping mechanism and production device are lowered in the casing 12 to the bottom of the well by methods known in the art.

The self cleaning oil production device 16 is formed with a tubular member 2li which slidably supports a plunger shaft generally indicated by reference numeral 22. Tubular member 20 may be formed with any cross sectional conguration, such for example, as a rectangular or square shape. Preferably the member is circular in cross section as shown in the drawings. The upper end of tubular member 20 is provided with coupling means in the form of a threaded section which interfits the threads on coupling member 24 of working barrel 14 which supports seats 26 upon which standing valve 23 is seated during operation of the pumping mechanism.

The standing valve 23 is of conventional construction and is provided with a cheek ball valve 27 which is seated upon the cage assembly 28 and resilient packer rings 29 which frictionally engage the interior wall of the working barrel 14.

When the tubular member 2t) and the working barrel 14 are coupled in the manner shown in Figures l and 2, the tubular member depends from the working barrel and serves as an extension of the pump inlet. A plurality of elongated slots 3) are provided. in the wall of tubular member 2t) which extend longitudinally thereof and are positioned at spaced intervals about the circumference of the wall. The use of four slots positioned at 90 intervals about the wall circumference have been found preferable, although a greater or less number arranged in other angular displacement can be used without det tion adjacent the seat of the standing valve cage.

parting from the spirit of this invention. The elongated slots extend completely through the wall of the tube and serve as inlet orifices for oil drawn into the pumping mechanism. The end of tubular member 28 opposite coupling member 24 is threaded to coact with the threaded section of a bearing guide 32 which serves as an end cap for the tube 20. The bearing guide is formed with an opening in the end thereof and the wall of the opening serves as a bearing and guide surface 34 for plunger shaft 22 as will be hereinafter more fully described. The bearing and guide surface 34 is positioned concentrically about the axis of tubular member 20. The external diameters of coupling member 24, tubular member 28, and bearing guide 32 are preferably of substantially the same dimension in order to eliminate discontinuity of the exterior wall surfaces. By the structure thus far described it will be apparent that a clear and unimpcdded passage is provided for the flow of oil from the bore hole through elongated slots 30 in tubular member 20 into the interior of the tubular member and then to the inlet 18 of working barrel 14. The combined area of the openings in the elongated slots 30 is considerably greater than the area of the inlet opening in the working barrel in order that pressure drop will be reduce/,l to a minimum during the ow of oil through the slotted inlet openings to the pumping mechanism in the working barrel.

The plunger shaft 22 is slidably supported by the tubular member 20 for reciprocating movement and is positioned with a lower end 36 of the plunger shaft extending outwardly of the tubular member. As best shown in Figs. 2 and 3, plunger shaft 22 passes through bearing guide 32 and surface 34 serves as a guide for the shaft during reciprocating movement thereof. An anchor collar 38 is preferably positioned at the lower terminal end of the plunger shaft, and this collar rnay be internally threaded to serve as a coupling element for the connection thereto of a mud anchor or other implement (not shown) to the lower end of the string of tubing and pump assembly. it will be understood that preselected lengths of anchor tubing may be attached to and depend from the collar 38 in order that the working barrel may be positioned adjacent to the producing level of the oil sand. As best shown in Figures 2 and 3, the upper portion 40 of the plunger shaft is threaded at 42 in order that a pin supporting collar 44 may be adjustably positioned thereon as is hereinafter more fully described. The terminal end section 46 of upper portion 40 is provided with a reduced cross section which permits it to pass through the seat openings of the standing valve 23. Additionally, a shoulder 48 is provided on plunger shaft 22 a spaced distance from end 50 of the reduced portion 46.

Preferably terminal end section 46 and shoulder 4S are mounted on plunger shaft 22 by forming an internally threaded bore 52 in the end of upper section 4@ into which an element comprising terminal end section 46 and shoulder 48 are secured by the coacting threads on stud member 54. The shoulder 48 is formed with a smaller diameter than the opening through seat 25 of the standing valve cage, and is provided with a plurality of castellations 56 having inclined bottom surfaces in order that the flow of oil from the interior of the working barrel will not be impeded when shoulder 48 is moved to a posiln view of the fact that the end of terminal section and shoulder 48 upon upward movement of plunger shaft 22 contact and lift check ball valve and the standing valve cage assembly 28 respectively, these elements are formed of hardened metal in order to withstand the pressures to which they are subjected during use.

Pin supporting collar 44 is adjustably positioned and secured to the threaded section of upper portion 4t) of the plunger shaft by the use of lock ring 69 which is positioned below the pin supporting collar and lock ring 62 which is positioned immediately above the supporting collar. Lock rings and 62 are internally threaded to coact with the external threads 42 on the upper portion 40 of the plunger shaft. By the use of this construction the position of the pin supporting collar may be adjusted axially of the upper portion 40 of the plunger shaft by tightening the locking rings 60 and 62 against the side surfaces of the pin supporting collar.

The collar 44 has mounted thereon a plurality of guiding and cleaning pins 64 which extend therefrom substantially perpendicular with respect to the axis of the plunger shaft. As best shown in Figures 2, 3, and 4, each of the pins 64 mounted in collar 44 extend within and project through the elongated slots 30 and are adapted to travel the length thereof during the reciprocating movement of plunger 22. The guiding and cleaning pins 64 are preferably cylindrical in shape and have a diameter greater than the widths of the slots with the end of each pin which is positioned Within a slot formed with flattened opposite side surfaces indicated by reference numeral 65. The flattened side surfaces of each pin are spaced a distance apart slightly less than the width of slots 30 so that the pins may slide therein without bending and at the same time serve as cleaning elements for deposits of foreign material encrusted upon the walls of and within the slots 30. The shoulder provided at the interior end of the attened side surfaces 65 is located within tubular member 20 adjacent to the edges of the slots and aids in the guiding and cleaning action of the pins. During the travel of pins 64 within elongated slots 30, all deposits of foreign material solidified and encrusted within the slots are encountered by the pins which serve as positive cleaning means to break up and dislodge the material from the slots, which have heretofore been described as constituting the inlet of the pumping mechanism.

As best shown in Figure 4, the pin supporting collar 44 and the locking rings 60 and 62 are provided with external castellations 66 which serve as channel-ways for the oil flowing from one side of the collar to the other during the movement of the plunger shaft, and the cousequent travel of pins 64 in the respective slots 30.

Recesses are formed at spaced positions about the circumference of the pin supporting collar 44. The recesses are positioned in angular relation to each other and correspond in number and to the spaced relation of elongated slots 30 formed in the wall of tubular member 20. A guide and cleaning pin 64 is positioned within each of the recesses provided in pin supporting collar'44 and extends outwardly therefrom a suflicient distance so that the opposite flattened side surfaces thereof pass through the slots with which the recesses are aligned as has heretofore been explained. The pins 64 are secured in the recesses of pin supporting collar 44 by the use of set screws 74 which are tightened in position prior to securing the collar by lock ring 62.

A castellated nut 68 which is provided with internal threads that coact with the threads of upper portion 4t) is adjustably positioned on plunger shaft 22 within the tubular member 20 and serves as an abutment to limit the outward movement of the plunger shaft. With the nut 68 adjusted as indicated in Figure 2, the edge of eastellated nut 68 engages the internal end surface 70 of bearing guide 32 when the plunger shaft reaches the extreme of its outward movement thereby terminating the movement of the plunger shaft. After being adjustably positioned on the upper portion 40 of the plunger shaft, the castellated nut 68 is secured in position by tightening thereagainst lock nut 72 which is also provided with corresponding castellations.

Spring means are provided for urging the plunger shaft 22 outwardly of the tubular member 2t). As shown in Figures l, 2 and 3, a compression spring 76 is concentrically positioned about the lower end 36 of plunger shaft 22 and is positioned intermediate the exterior terminal end surface of bearing guide 32 and an abutment formed by enlargement 38 which is positioned adjacent to the lower end of the plunger shaft. When the plunger shaft is fully extended in an outward direction by the compression spring 76 as indicated in Figures l and 2, the edge of castellated nut 68 engages internal end surface 70 of bearing guide 32. When the plunger shaft is in this extended position, the pin supporting collar 44 is located on the plunger shaft to position pins 64 in the lowermost portion of elongated slots 30.

During pumping operations of a well, the string of tubing with the working barrel and the self cleaning device depending therefrom is positioned as shown in Figure l with the lower end of the plunger shaft located a short distance above the bottom hole 72. When it is desired to clean the inlet to the pumping mechanism, the tubing string is lowered by operation of the elevator mechanism (not shown) until the lower end of anchor collar 38 or anchor tubing depending therefrom contacts the bottom hole 72. Further lowering of the tubing string causes the plunger shaft to be retracted or moved inwardly of tubular member 20 against the pressure of spring 36 and pins 64 travel upwardly in elongated slots 30 to clean therefrom deposits of foreign material. Upon additional inward movement of the plunger shaft, the end 50 of the reduced cross section 46 is moved through inlet 18 of the standing valve 23 in working barrel 14. As the movement of end 5t) continues, it impinges upon check ball valve 27 and lifts the ball from its seat, as is best shown in Figure 7 of the drawings. During this additional movement of plunger shaft 22 the pins 64 have moved upwardly in elongated slots 3) and have served to dislodge and remove foreign matter encrusted within the slots by a positive cleaning action. Additionally, the pins 64 serve to guide the upper portion 40 of the plunger shaft as the shaft moves inwardly of the tubular member 20. The continued travel of plunger shaft 22 serves to move shoulder 48 through the upper end of tubular member 2t) until it contacts the lower portion 78 of the standing valve cage assembly 23. Additional movement of the plunger shaft serves to lift the standing valve cage assembly from its seat 26, thus breaking up and dislodging the accumulation of solidified foreign material encrusted on the valve cage assembly. Figure 8 discloses the position of the standing valve assembly 28 and check ball valve 27 when the plunger shaft 22 is in a fully retracted position, at which position the pins 64 are located in the upper end of the elongated slots.

Upon the lifting of the tubing string by the elevating mechanism at the top of the well, the tubular member 2t) of our self cleaning oil well production device is raised, and the plunger shaft 22 is forced outwardly of the tubular member by virtue of the pressure exerted by compression spring '76. During movement of the plunger shaft in an outward direction under the influence of the pressure of spring 76, shoulder 43 and end 50 carried by the upper portion of the plunger shaft are moved out of contact with the check ball valve 27 and standing valve cage assembly 28 so that these elements may resume their normal position in the working barrel 14. During the outward movement of plunger shaft 22 the pins 64 serve to guide the plunger shaft, and in addition the return movement of the pins through slots 30 positively serve to break up, dislodge and scrape oif all accumulations of foreign material which may have remained in place during the initial inward travel of the pins. The operation of raising and lowering the tube string may be repeated if necessary to insure the breaking up and removing of solidied substances upon the valve parts and within the inlet passages.

lt will be apparent that when the plunger shaft is retracted into the tubular member 2t) and the ball check valve and standing valve cage assembly are broken free of encrustations and dislodged as shown in Figure S, they may be withdrawn in a conventional manner by the sucker rod without pulling the tubing. The oil within the working barrel and tubing is thus free to flow outwardly of the barrel inlet to wash away deposits of sand, paraffin, asphaltum, or other foreign material which have been broken up and dislodged by the unseating of the ball check valve and the cage assembly and by the movement of the pins through the slots. Additionally, if the working barrel is worn, replacement may be made after pulling the drained tuoing which eliminates the diflculties encountered in handling wet tubing. Further, well treating materials such as acidifying agents inserted in the tube string and working barrel may freely ow outwardly through the valve mechanism and inlet of the working barrel to the bottom portion of the well so that in addition to serving as means for cleaning the pump mechanism the device of this invention serves as means for introducing well treating agents into the bottom of the well.

During the lowering of the tube string into the well casing, the lower end of the plunger shaft will engage any obstructions such as cuts, ledges, and the like projecting from the wall of the casing and tend to be retracted inwardly of the tubular member against the pressure of the spring. The energy stored in the spring will cause the plunger end to be deccted away from the obstructions so that the string of tubing may be lowered past the obstructions without difficulty. In the case of whipped stocked or curved wells, the plunger serves in a similar manner as guiding means for the tube string.

We claim:

1. In a well pumping` mechanism comprising a pump casing having an inlet opening, the combination comprising, a tube depending from the inlet opening of said pump casing provided with a plurality of elongated slots positioned in spaced relationship in the wall thereof, a plunger shaft slidably supported for reciprocating movement axially of said tube having one end thereof extending outwardly and through the end of said tube, a plurality of pins carried by said shaft, at least one of which is positioned within each of said slots and is free to move the substantial length thereof during reciprocating movement of said plunger shaft, and a compression spring to urge said plunger shaft outward of said tube whereby pressure applied to the outwardly extending end of said plunger' shaft will cause said plunger to move against the bias of the spring and said pins to travel the length of the slots to remove therefrom deposits of solidified and encrusted foreign matter and release of such pressure will cause said pins to move with the plunger in the opposite direction under action of said spring.

2. ln a well pumping mechanism comprising a pump casing having an inlet opening, a tubing seat collar, a valve cage removably positioned on said seat and a check valve seated in said cage, the combination comprising, a tube depending from the inlet opening of said pump casing provided with a plurality of elongated slots positioned in spaced relationship in the wall thereof, a plunger shaft slidably supported for reciprocating movement axially of said tube having one end thereof extending outwardly through the end of said tube, the other end of said plunger shaft provided with a section of reduced diameter and a shoulder positioned a spaced distance from the terminal end of said shaft, a plurality of pins carried by said shaft, at least one of which is positioned within each of said slots and is free to move the substantial length thereof during reciprocating movement of said plunger shaft, and a compression spring to urge said plunger shaft outward of said tube whereby pressure applied to the outward end of said plunger' shaft will cause said plunger to be retracted against the bias of the spring to cause said pins to travel the substantial length of said slots to dislodge accumulations of foreign material and to cause said terminal end to contact and lift said check valve from its seat and to cause said shoulder to contact and lift said valve cage from its seat on the tubing collar.

3. An extension for a well pumping mechanism provided with an inlet end comprising in combination, a tube provided with a plurality of elongated slots positioned in spaced relationship in the wall thereof, coupling means for securing the upper end of said tube to the inlet end of said pumping mechanism so that said elongated slots serve as inlet orifices for said mechanism, a plunger shaft slidably supported for reciprocating movement within said tube having one end thereof extending through the lower end of said tube, a plurality of pins carried by said plunger shaft at least one of which is positioned within each of said elongated slots and being free to move the substantial length thereof during reciprocating movement of said plunger shaft, and spring means to urge said plunger shaft to an extended position.

4. An extension for a working barrel of well pumping mechanism provided with an inlet end comprising in combination. a cylindrical tube provided with a plurality of elongated inlet slots in the wall thereof and having means at the upper end thereof for coupling to the inlet end of said working barrel, a plunger shaft supported by said tube for reciprocating movement provided with a portion interior of said tube and an exterior portion which extends outwardly of the lower end of said tube, a plurality of pins supported on said interior portion for reciprocating movement during movement of said plunger shaft, at least one of said pins slidably positioned within each of said slots and a compression spring positioned intermediate the lower end of said tube and said exterior portion of said plunger to urge the plunger shaft to an extended position.

5. An extension for the working barrel of well pumping mechanism provided with an inlet end comprising in combination, a tube provided with a plurality of elongated inlet slots positioned in spaced relationship in the wall thereof, coupling means at the upper end of the tube for connecting said tube to the inlet end of said working barrel and an axially positioned guide bearing located adjacent to the lower end of said tube, a plunger shaft extending through said guide bearing and being freely slidable therein, a plurality of pins supported within said shell by said plunger shaft, one of said pins projecting within each of said elongated inlet slots and movable the substantial length thereof during movement of said plunger shaft, and spring means to bias said plunger shaft into extended position to maintain said pins in the lower portions of the respective slots.

6. An extension for a working barrel of well pumping mechanism provided with an inlet end comprising in combination, a cylindrical tube provided with a plurality of elongated inlet slots positioned in spaced relationship in the wall thereof, said tube provided adjacent to the upper end thereof with coupling means for connecting the tube to the inlet end of said working barrel and an axially positioned guide bearing located adjacent to the lower end of said tube, a plunger shaft extending through said guide bearing and being freely slidable therein, provided with a spring engaging means on the portion of said shaft exterior of said tube, a pin slidably positioned within each of said elongated slots carried by said plunger shaft, and a compression spring positioned between said tube and said spring engaging means to urge said plunger in an extended position.

7. An extension for a working barrel or well pumping mechanism provided with an inlet end comprising in combination, a cylindrical tube provided with a plurality of elongated inlet slots in the wall thereof and having means at the upper end thereof for coupling to the inlet end of said working barrel, a plunger shaft slidably supported by said tube for reciprocating mover-nent provided with a portion interior of said tube and an exterior portion which extends outwardly of the lower end of said tube, interengageableabutment means positioned on said interior portion of said plunger shaft and on said tube to limit the movement of said shaft outwardly of said tube, a plurality of pins supported on said interior portion of said shaft for movement therewith during reciprocation of said shaft, at least one of said pins slidably positioned within each of said slots and a compression spring positioned intermediate the lower end of said tube and the outward end of said shaft to urge the abutment means into engagement.

8. An extension for a string of well tubing, said well tubing having an inlet end and a valve seat therein, and movable fluid retaining means seated on said seat, comprising in combination, a tube provided with a plurality of elongated slots positioned in spaced relationship in the wall thereof, coupling means for securing the upper end of said tube to the inlet end of said well string to provide a passageway from said slots to the intake end thereof, a plunger shaft slidably supported by said tube for reciprocating movement having a portion interior of said tube provided with a shoulder and an exterior portion which extends outwardly of the lower end of sai/.t tube, a plurality of pins carried by said plunger shaft, one of which is positioned within each of said elongated slots and is free to move the substantial length thereof during reciprocating movement of said plunger shaft, and spring means to urge said plunger shaft outwardly of said tube to position said pins in the lower portion of the respective slots and said shoulder within said tube, whereby said shaft shoulder upon retraction of said plunger shaft in opposition to said spring will pass through the upper end of said tube and Contact said seated fluid retaining means to move it from seated position.

9. An extension for a working barrel of weli pumping mechanism provided with an inlet end, a seated standing valve cage and a ball check valve therein, comprising in combination, a cylindrical tube provided with a plurality of elongated inlet slots positioned in spaced relationship in the wall thereof, said cylindrical tube provided adjacent the upper end thereof with coupling means for connecting the tube to the inlet end of said working barrel and an axially positioned guide bearing located adjacent to the lower end of said tube, a plunger shaft extending through said guide bearing and being freely slidable therein, provided with a spring engaging means on the portion of said shaft extcriorly of said tube and a shoulder on the portion interiorly of said tube,

a plurality of pins carried by said plunger shaft, one of which is positioned within each of said elongated slots and is free to move the substantial length thereof during reciprocating movement of said plunger shaft, a compression spring positioned between said spring engaging means and said tube to urge said plunger shaft outwardly of said tube to position said pins in the lower portion of the respective slots and said shoulder within said tube and upon compression thereof to enable said plunger to be moved to a retracted position during which said pins travel in said slots to the upper portion thereof and said shoulder passes through the upper end of said tube to contact and move said standing valve cage from its seat.

10, An extension for a string of well tubing, said well tubing having an inlet end and a valve seat therein, and movable iluid retaining means seated on said seat, comprising in combination, a cylindrical tube provided with a plurality of elongated inlet slots positioned in spaced relationship in the wall thereof, coupling means for securing the upper end of said tube to the inlet end of said well tubing to provide a passageway from said slots to the intake side of the tubing, a plunger shaft slidably supported by said tube for reciprocating movement having a portion interior of said tube provided with a shoulder and an exterior portion which extends outwardly of the lower end of said tube, interengageable abutment means positioned on said interior portion of said plunger shaft and on said tube to limit the movement of said shaft outwardly of said tube, a plurality of pins carried by said plunger shaft, one of which is positioned within each of said elongated slots and is free to move the substantial length thereof during reciprocating movement of said plunger shaft, a compression spring positioned intermediate the lower end of said tube and the outward end of said plunger shaft to urge said plunger shaft outwardly of said tube to position said pins in the lower portion of the respective slots and said shoulder within said tube and upon compression thereof to enable said plunger to be moved to a retracted position during which said pins travel in said slots to the upper portion thereof and said shoulder passes through the upper end of said tube to contact and move said fluid retaining means from its seat.

1l. An extension for a string of well tubing, said well tubing having an inlet end and a valve seat therein, and

movable iluid retaining means seated on said seat, com# prising in combination, a cylindrical tube provided with a plurality of elongated inlet slots positioned in spaced relationship in the wall thereof, said cylindrical tube provided adjacent to the upper end thereof with coupling means for connecting the tube to the inlet end of said string of well tubing, and an axially positioned guide bearing located adjacent to the lower end of said tube, a plunger shaft extending through said guide bearing and being freely slidable therein provided with a spring engaging means on the portion of said shaft exteriorly of said tube and a shoulder on the portion interior of said tube, interengageable abutment means positioned on said interior portion of said plunger shaft and on said tube to limit the movement of said shaft outwardly of said tube, a plurality of pins carried by said plunger shaft, one of which is positioned within each of said elongated slots and is free to move the substantial length thereof during reciprocating movement of said plunger shaft, a compression spring positioned between said spring engaging means on said shaft and the lower end of said tube to urge said plunger shaft outwardly of said tube and said abutment means in engaging relation and to position said pins in the lower portion of the respective slots and said shoulder within said tube, and upon cornpression of said spring to enable said plunger to move to a retracted position during which movement said pins travel in said slots to the upper portion thereof and said shoulder passes through the upper end of said tube to contact and move said fluid retaining means from its seat.

12. An extension for a string of well tubing, said well tubing having an inlet end and a valve seat therein, and movable uid retaining means seated on said seat comprising in combination, a tube provided with a plurality of elongated slots positioned in spaced relationship in the wall thereof, coupling means for securing the upper end of said tube to the inlet end of said string of well tubing to provide a passageway from said slots to the intake end of said well tubing, a plunger shaft slidably supported by said tube for reciprocating movement having a portion extending outwardly of the lower end of said tube and an upper terminal end of decreased diameter, a plurality of pins carried by said plunger shaft, one of which is positioned within each of said elongated slots and is free to move the substantial length thereof during reciprocating movement of said plunger shaft, and a compression spring to urge said plunger shaft outwardly of said tube to position said pins in the lower portion of the respective slots and upon compression thereof to enable said plunger shaft to be moved to a retracted position during which said pins travel in said slots to the upper portion thereof and said terminal end contacts and unseats said fluid retaining means.

13. An extension for a working barrel of well pumping mechanism provided with an inlet end having a seat therein and a movable valve member operably engageable with said seat, comprising in combination, a cylindrical tube provided with a plurality of elongated inlet slots positioned in spaced relationship in the wall thereof, said cylindrical tube provided adjacent to 'the upper end thereof with coupling means for connecting the tube to the inlet end of said working barrel, an axially positioned guide bearing located adjacent to the lower end of said tube, a plunger shaft extending through said guide bearing and being freely slidable therein provided with a spring engaging means on the portion of said shaft exteriorly of said tube and an upper terminal end having decreased diameter, abutment means positioned on said plunger shaft interiorlv of said tube in coacting relation with said guide bearing to limit the movement of said shaft outwardly of said tube, a plurality of pins carried by said plungeishaft, one of which is positioned within each of said elongated slots and is free to move the substantial length thereof during reciprocating movement of said plunger shaft, a compression spring positioned between said spring engaging means on said shaft and the lower end of said tube to urge said plunger shaft outwardly of said tube and to position said pins in the lower portion of the respective slots, and upon compression of said spring to enable said plunger to move to a retracted position during which movement said pins travel in said slots to the upper portion thereof, and said terminal end of decreased diameter makes contact and lifts said movable valve member from said seat in order to permit oil to return through pump mechanism for cleaning of same, or to drain tubing preparatory to pulling of same, thus preventing waste of oil and accumulation of overrun oil at top of well.

14. An extension for a Working barrel of well pumping mechanism provided with an inlet end and a seated standing valve comprising in combination, a tube provided with a plurality of elongated slots positioned in spaced relationship in the wall thereof, coupling means for securing the upper end of said tube to the inlet end of said working barrel to provide a passageway from said slots to the intake end of the said standing valve, a plunger shaft slidably supported by said tube for reciprocating movement, having one end thereof extending outwardly of the lower end of said tube, and the other end formed with a decreased diameter and provided with a shoulder a spaced distance from the terminal end thereof, a plurality of pins carried by said plunger shaft, one of which is positioned within each of said elongated slots and is free to move the substantial length thereof during the reciprocating movement of the plunger shaft, spring means to urge said plunger shaft outwardly of said tube to position said pins in the lower portion of the respective slots, and upon compression thereof to enable said plunger shaft to be moved to a retracted position during which said pins travel in said slots to the upper portion thereof, said terminal end lifts the ball of said standing valve from its seat and said shoulder contacts and moves said standing valve from its seat.

References Cited in the iile of this patent UNITED STATES PATENTS 654,729 Green July 3l, 1900 1,277,309 Hall Aug. 27, 1918 1,867,092 Pipher et al. July 12, 1932

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