Downhole pump with traveling valve and pilot

Abstract

A fluid pump apparatus for an artificial lift system has a barrel, a standing valve positioned at a lower end of the barrel so as to be movable between an open position and a closed position, a plunger reciprocatingly mounted in the barrel, a traveling valve positioned in an interior of the plunger so as to control fluid flow through the plunger, and a pilot slidably positioned in the plunger. The plunger has a first aperture at an upper portion thereof and a second aperture extending through a wall of the plunger so as to open to a channel extending through the channel. The traveling valve is slidably movable within an interior of the plunger. The plunger has a seat that is cooperative with a surface of the traveling valve. The pilot is cooperative at the surface of the traveling valve so as to move the traveling valve.

Claims

1. A fluid pump apparatus for an artificial lift system, the fluid pump apparatus comprising: a barrel having an upper end and a lower end, said barrel having an opening at said upper end and an opening at said lower end, said barrel having a first wide inner diameter section and a second wide inner diameter section and a reduced inner diameter section between said first wide inner diameter section and said second wide inner diameter section; a standing valve positioned at said lower end of said barrel, said standing valve movable between an open position and closed position; a plunger reciprocatingly mounted in said barrel, said plunger having a first aperture at an upper portion thereof and a second aperture extending through a wall of said plunger so as to open to a channel extending through said plunger, said plunger having a wide diameter section and a narrow diameter section positioned below said wide diameter section, said plunger movable within said barrel between an upper position at an upstroke of said plunger and a lower position at a downstroke of said plunger; a traveling valve positioned in an interior of said plunger so as to control fluid flow through said plunger, said traveling valve slidably movable within an interior of said plunger, said plunger having a seat cooperative with a surface of said traveling valve; and a pilot slidably positioned in said plunger, said pilot being cooperative with the surface of said traveling valve so as to move said traveling valve relative to said seat, said pilot having an end that is separable from said traveling valve during the reciprocating movement of said plunger, said pilot having a head and a stein extending downwardly from said head, said pilot having an interior passageway extending therethrough, said head of said pilot having a surface area greater than a surface area of said seat, said wide diameter section of said plunger aligned with said first wide inner diameter section of said barrel so as to define a first annulus therebetween in a position adjacent to the upper position, said narrow diameter section of said plunger aligned with said reduced inner diameter section of said barrel so as to define a second annulus therebetween in the upper position, said second annulus being in fluid communication with said first annulus in the upper position, said second aperture of said plunger communicating with at least one of said first annulus and said second annulus in the position adjacent to the upper position such that fluid urges said head of said pilot upwardly so as to displace said traveling valve.

2. The fluid pump apparatus of claim 1, wherein fluid in said barrel flows downwardly through said first aperture of said plunger around said traveling valve and through said interior passageway of said pilot and through the channel of said plunger so as to enter a lower portion of said barrel.

3. The fluid pump apparatus of claim 1, wherein said standing valve is in the open position as said plunger moves from the lower position, the wide diameter section of said plunger bearing against the reduced inner diameter section of said barrel and said bottom surface of said traveling valve is seated in said seat when said plunger moves from the lower position upwardly.

4. The fluid pump apparatus of claim 1, the wide diameter section of said plunger aligned with said first wide inner diameter section of said barrel so as to define an annulus therebetween when said plunger moves from the upper position upwardly, said second aperture of said plunger communicating with the annulus so that fluid urges against said head of said pilot so that the surface of the traveling valve is unseated from the seat of the plunger when said plunger moves downwardly from the upper position such that the fluid flows from said barrel below the plunger upwardly through said channel of said plunger and through said interior passageway of said pilot and around said traveling valve and outwardly of said first aperture of said plunger into said barrel above said plunger.

5. The fluid pump apparatus of claim 1, said pilot actuating an opening of said traveling valve before the end of the upstroke of said plunger and before a beginning of the downstroke of said plunger so as to cause a pressure equilibrium above said plunger and under said plunger.

6. The fluid pump apparatus of claim 1, said head of said pilot having said surface area greater than surface area of said seat, the fluid pump apparatus further comprising: a spring bearing against a surface of said traveling valve in an interior of said plunger, said traveling valve opening at the end of the upstroke of said plunger.

7. The fluid pump apparatus of claim 1, said plunger having a rod affixed or formed at an upper end thereof, said rod adapted to move said plunger reciprocatingly upwardly and downwardly in said barrel.

8. The fluid pump apparatus of claim 1, said head of said pilot having a pair passageways extending therethrough and opening at or adjacent to a top of said pilot, said pair of passageways communicating with said interior passageway of said pilot.

9. The fluid pump apparatus of claim 1, said traveling Valve being open at the end of the upstroke of said plunger such that a pressure above said plunger and a pressure below said plunger are at equilibrium.

10. A fluid pump apparatus for an artificial lift system, the fluid pump apparatus comprising: a barrel having an upper end and a lower end, said barrel having an opening at said upper end and an opening at said lower end, said barrel having a first wide inner diameter section and a second wide inner diameter section and a reduced inner diameter section between said first wide inner diameter section and said second wide inner diameter section; a standing valve positioned at said lower end of said barrel, said standing valve movable between an open position and closed position; a plunger reciprocatingly mounted in said barrel, said plunger having a first aperture at an upper portion thereof and a second aperture extending through a wall of said plunger so as to open to a channel extending through said plunger, said plunger having a wide diameter section and a narrow diameter section positioned below said wide diameter section, said plunger movable within said barrel between an upper position at an upstroke of said plunger and a lower position at a downstroke of said plunger; a traveling valve positioned in an interior of said plunger so as to control fluid flow through said plunger, said traveling valve slidably movable within an interior of said plunger, said plunger having a seat cooperative with a surface of said traveling valve; and a pilot slidably positioned in said plunger, said pilot being cooperative with the surface of said traveling valve so as to move said traveling valve relative to said seat, said pilot having an end that is separable from said traveling valve during the reciprocating movement of said plunger, said pilot having a head and a stem extending downwardly from said head, said pilot having an interior passageway extending therethrough, said head of said pilot having a surface area greater than a surface area of said seat, said plunger having another wide diameter section and another narrow diameter section positioned below the narrow diameter section of said plunger, the wide diameter section of said plunger defining an annulus with said first wide inner diameter section of said barrel when said plunger is at an uppermost position, said another narrow diameter section of said plunger defining a second annulus with said first wide inner diameter section and said reduced inner diameter section of said barrel when said plunger is in the uppermost position, said first annulus being in fluid communication with said second annulus so as to flow fluid from above said plunger to below said plunger.

11. The fluid pump apparatus of claim 10, said plunger having a radially outwardly extending portion below said another narrow diameter, said plunger movable between the upper position in which the radially outwardly extending portion bears against the reduced inner diameter section of said barrel and the lower position in which the radially outwardly extending portion and the another narrow diameter section define an annulus with the second wide inner diameter of said barrel.

12. A pumping system for pumping a fluid from a well, the pumping system comprising: a reciprocating mechanism located at a surface location; a cable connected to the reciprocating mechanism, said cable adapted to extend outwardly through the well; and a fluid pump apparatus adapted to be positioned in the well, the fluid pump apparatus comprising: a barrel having an upper end and a lower end, said barrel having an opening at said upper end and an opening at said lower end; a standing valve positioned at said lower end of said barrel, said standing valve movable between an open position and a closed position; a plunger reciprocatingly mounted in said barrel, said plunger having a first aperture at an upper portion thereof and a second aperture extending through a wall of said plunger so as to open to a channel extending through said plunger; a traveling valve positioned in an interior of said plunger so as to control fluid flow through said plunger, said traveling valve slidably movable within an interior of said plunger, said plunger having a seat cooperative with a surface of said traveling valve; and a pilot slidably positioned in said plunger, said pilot being cooperative with said surface of said traveling valve so as to move said traveling valve relative to said seat, said pilot having an end that is separable from said traveling valve during the reciprocating movement of said plunger, the cable being affixed to said plunger so as to move the plunger reciprocatingly upwardly and downwardly within said barrel, said barrel having a first wide inner diameter section and a second wide inner diameter section and a reduced inner diameter section between said first wide inner diameter section and said second wide inner diameter section, said plunger having a wide diameter section and a narrow diameter section positioned below said wide diameter section, said pilot having a head and a stem extending downwardly from said head, the wide diameter section of said plunger aligned with said first wide inner diameter section of said barrel so as to define an annulus therebetween when said plunger moves from the upper position upwardly, said second aperture of said plunger communicating with the annulus so that fluid urges against said head of said pilot so that the surface of the traveling valve is unseated from the seat of the plunger when said plunger moves downwardly from the upper position such that the fluid flows from said barrel below the plunger upwardly through said channel of said plunger and through said interior passageway of said pilot and around said traveling valve and outwardly of said first aperture of said plunger into said barrel above said plunger.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) FIG. 1 is a diagrammatic illustration of a conventional rod pumping system of the prior art.

(2) FIG. 2 is a cross-sectional view of the fluid pump apparatus of the present invention with the plunger at the end of the downstroke and the start of the upstroke.

(3) FIG. 3 is a cross-sectional view of the fluid pump apparatus of the present invention with the plunger in an early upstroke position.

(4) FIG. 4 is a cross-sectional view of the fluid pump apparatus of the present invention showing the plunger in a further upstroke position.

(5) FIG. 5 is a cross-sectional of the fluid pump apparatus the present invention showing the plunger at the end of the upstroke and the start of the downstroke.

(6) FIG. 6 is a transparent perspective view showing the interior configuration of the plunger of the fluid pump apparatus of the present invention.

(7) FIG. 7 is an upper perspective view of the traveling valve as used in the fluid pump apparatus of the present invention.

(8) FIG. 8 is an upper perspective view of the pilot as used in the fluid pump apparatus of the present invention.

(9) FIG. 9 is a cross-sectional view of the fluid pump apparatus of the present invention with the plunger into an initial downstroke position.

(10) FIG. 10 is a cross-sectional view of the fluid pump apparatus with the plunger in a further downstroke position.

(11) FIG. 11 is a cross-sectional view of the fluid pump apparatus of an alternative embodiment of the present invention showing the plunger at the end of the upstroke and the start of the downstroke.

(12) FIG. 12 is a cross-sectional view of the fluid pump apparatus in accordance with an alternative embodiment of the present invention with the plunger in a further downstroke position.

(13) FIG. 13 is an illustration of the use of a wire or cable for controlling the reciprocating motion of the plunger of the fluid pump apparatus of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

(14) Referring to FIG. 1, there is shown a pumping system 10 in accordance with the prior art. The pumping system 10 is a reciprocating rod-type pumping system. In particular, the pumping system 10 includes a walking beam 12 that is supported above a base 14 by a samson post 16. The walking beam 12 is mounted for pivoting movement with respect to the top of the samson post. A pitman arm 18 is affixed to one end of the walking beam 18 and is engaged with a crank 20. A counterweight 22 is cooperative with the pitman arm 18 and with the end of the walking beam 12. A gear reducer 22 is cooperative with a motor 24. A V-belt 26 extends from a sheave associated with the motor 24 to a sheave 28 associated with the gear reducer 22. The motor 24 will cause a rotation of the sheave so that the V-belt 26 will cause the sheave 28 to rotate. This, in turn, causes a reciprocal movement of the crank 20 and the counterweight 22 so as to cause the walking beam 12 to pivot upwardly and downwardly.

(15) A horsehead 30 is mounted to an opposite end of the walking beam 12. A bridle 32 extends downwardly from the horsehead 30 and is joined to a polished rod 34. Polished rod 34 extends through stuffing box 36 and downwardly into the well 38. There is a tee 40 at the top of the well 38 which allows oil and gas to be transmitted from the interior of the production tubing 42 located within the well 38.

(16) A downhole pump 44 will be located at the end of a sucker rod 46. Sucker rod 46 extends through the interior of the production tubing 42. As a result, the reciprocating movement of the walking beam 12 will cause the sucker rod 46 to move upwardly and downwardly and will cause the downhole pump 44 to move upwardly and downwardly so as to draw fluids through the production tubing 42. It can be seen that the downhole pump 44 is located within an oil-bearing zone 48. Various perforations are formed in the casing 50 in the area of the production zone 48 so as to allow fluids to pass into the casing 50 and around the production tubing 42. Ultimately, the accumulation of fluids within the annulus between the production tubing 46 and the casing 50 will flow so as to be drawn by the downhole pump upwardly for discharge at the surface.

(17) FIG. 2 shows the fluid pump apparatus 60 in accordance with teachings of the present invention. The fluid pump apparatus 60 includes a barrel 62, a standing valve 64, a plunger 66, a traveling valve 68 and a pilot 70. The barrel 62 has an upper end 72 and a lower end 74. The barrel has an opening 76 at the upper end 72 and an opening 78 at the lower end 74. The standing valve is positioned at the lower end 74 of the barrel 62. The standing valve 64 will be movable between an open position and a closed position (as shown in FIG. 2). The plunger 66 is reciprocatingly mounted in the barrel 62. The plunger 66 has a first aperture 80 at an upper portion thereof and a second aperture 82 extending through a wall of the plunger 66 so as to open to a channel 84 extending longitudinally through the plunger 66. The traveling valve 68 is positioned in the interior of the plunger 66 so as to control fluid flow through the plunger 66. The traveling valve 68 is slidably movable within the interior of the plunger 66. The plunger 66 has a seat 86 cooperative with a surface of the traveling valve 68. The pilot 70 is slidably positioned in the plunger 66. The pilot 70 will be cooperative with the surface of the traveling valve 68 so as to move the traveling valve 68 relative to the seat 86. As will be described hereinafter, the pilot 70 has an end that is separable from the traveling valve 68 during the reciprocating movement of the plunger 66.

(18) In FIG. 2, can be seen that the barrel 62 has a first wide inner diameter section 88, a second wide inner diameter section 90, and a reduced inner diameter section 92 located between the first wide inner diameter section 88 and the second wide inner diameter section 90.

(19) The plunger 66 has a wide diameter section 94 and a narrow diameter section 96 located below the wide diameter section 94. The plunger 66 also as another wide diameter section 98 and another narrow diameter section 100. The another narrow diameter section 100 is located below the another wide diameter section 98.

(20) The pilot 70 has a head 102 and a stem 104 extending downwardly from the head 102. The pilot 70 has an interior passageway 106 that extends through the stem 104. The barrel 62 has an above plunger volume 108 and an under plunger volume 110.

(21) In FIG. 2, it can be seen that the traveling valve 68 has a curved bottom surface 112 that is illustrated as received within the seat 86 of the plunger 66. A spring 114 is affixed to the plunger 66 and bears against an upper end of the traveling valve 68 so as to urge the traveling valve 68 toward its seated position. A rod 116 extends upwardly from the top of the plunger 66. Rod 116 allows the plunger 66 to be connected to a connecting rod or a connecting cable (as will be described hereinafter).

(22) FIG. 2 shows the plunger 66 within the barrel 62 at the end of the downstroke and the start of the upstroke. It can be seen that the volume of fluid in the under plunger volume 110 is relatively minimal while the amount of fluid in the above plunger volume 108 is great. The standing valve 64 is illustrated as in its closed position. The standing valve 64 has a flat top surface 120. As such, any contact between the bottom end of the plunger 66 and the flat top surface 120 of the standing valve 64 will not create any damage or destruction of the standing valve 68. The pilot 70 is illustrated as seated on a shoulder. There is an annulus 122 that is formed between the second wide inner diameter section 90 of the barrel 62 and the another narrow diameter section 100 of the plunger 66. There is an annulus 124 formed between the another wide diameter section 98 of the plunger 66 and the inner wall of the second wide diameter section 90 of the barrel 62. The annulus 122 and the annulus 124 facilitate flushing and sand removal from movement the lower plunger area. The upper portion of the plunger 66 is closed but since the first wide diameter section 94 of the plunger 66 bears against the inner wall of the reduced inner diameter section 92 of the barrel 62. As such, the somewhat sealing relationship between the plunger 66 and the barrel 62 will separate the above plunger volume 108 from the under plunger volume 110. At this end/start stroke phase, the traveling valve 68 is closed because of the dynamic effect while the direction of the stroke changes and remains closed because of the load of the fluid column.

(23) FIG. 3 shows the fluid pump apparatus 60 with the plunger 66 in an initial upstroke position. As the plunger 66 reciprocates upwardly relative to the barrel 62, the under plunger volume 110 will increase as a result of the opening of the standing valve 64. As such, fluid will flow from the opening 78 at the lower end of 74 of the barrel 62 and around the standing valve 64 so as to enter the under plunger volume 110. The standing valve 64 will remain open until the further upstroke position of the plunger 66 (as shown in FIG. 4). The above plunger volume 108 is separated from the under plunger volume 110 by virtue of the seating of the traveling valve 68 on the seat 86. Additionally, the above plunger volume 108 is separated from the under plunger volume 110 by virtue of the close relationship of the wide diameter section 94 of the plunger 66 and the inner wall of the reduced inner diameter section 92 of the barrel 62. The second aperture 82 of the plunger 66 will be blocked from receiving fluid therein. They will also be blocked from receiving fluid therein by virtue of the close relationship of the wide diameter section 94 of the plunger 66 and the reduced inner diameter section 92 of the barrel 62. The traveling valve 68 is closed because the above plunger pressure will be greater than the under plunger pressure. In other words, the fluid within the above plunger volume 108 will enter the interior of the plunger 66 through the first aperture 80 of the plunger 66 and also bear against the traveling valve 68. As such, so as to draw fluid into the under plunger volume 110, the passageways, apertures, and openings in the plunger 66 are effectively sealed by the configuration of components.

(24) FIG. 4 shows the fluid pump apparatus 60 of the present invention with the plunger 66 in a further upstroke position and adjacent to the end of the upstroke. In this configuration, the plunger 66 has entered into the above plunger volume 108. As such, an annulus 140 is defined between the wide diameter section 94 of the plunger 66 and the first wide inner diameter section 88 of the barrel 62. A second annulus 142 will be formed between the reduced diameter section 96 of the plunger 66 and a portion of the first wide inner diameter section 88 of the barrel 62 and a portion of the reduced inner diameter section 92. The annulus 140 will communicate with the annulus 142 so that fluid can flow into the aperture 82 of the barrel 66. This will flow upwardly through the interior of the plunger 66 to bear against the head 102 of the pilot 70. This will cause an upward movement of the pilot 70 such that a protrusion 144 at the top of the head 102 of the pilot 70 will bear against the surface of the traveling valve 68 so as to dislodge the traveling valve 68 from its seat 86. This opens the interior of the plunger 66 so that fluid from the above plunger volume 108 can flow through aperture 80 around the exterior of the traveling valve 68, through the seat 86, into the passageway 148 of the pilot 70, and then into the interior passageway 104 of the pilot 70, and then into the longitudinal channel 84 of the plunger 66. Ultimately, fluid will flow into the under plunger volume 110. In this configuration, the standing valve 64 is closed. The chamber 150 between an inner wall of the plunger 66 and the pilot 70 is pressure balanced with the above plunger pressure.

(25) Importantly, the diameter of the head 102 of the pilot 70 has a greater surface area than the area of the seat 86. As such, the pilot 70 will lift the traveling valve 68 so as to operate with dynamic uncovering of the aperture 82 and the seat 86 for sand removal. This facilitates the flushing of the inner wall of the aperture 82 and the outer wall of the plunger 86. Also, and importantly, this configuration assures that the present invention utilizes inertia and the relationship of cross-sectional areas in order to create the flow through the plunger.

(26) In the present invention, the head 102 of the pilot 70 can have a greater surface area in the area of the seat 86. As such, inertia is not involved in this stage. Alternatively, when the head 102 of the pilot 70 has the surface area equal to that of the area of the seat 86, this will mean that inertia is required for the opening of the traveling valve 86. The spring 11 bears against an upper surface of the traveling valve 68 in the interior of the plunger 66. This maintains the traveling valve 68 until the inertia provided by the directional change from upstroke to downstroke creates the necessary force to open the traveling valve 86. As such, the area of the head 102 of the pilot 70 can have different sizes in relation to the area of the seat 86 in accordance with the present invention. The goal of the present invention is to use the inertia from the acceleration of the pilot 102 and the traveling valve 68 provided at the directional change from upstroke to downstroke to create the additional force required to open the traveling valve 68.

(27) The advantage of the use of such inertia guarantees the opening at the very end of the upstroke so as to allow one to maximize the effective stroke. As such, unlike prior art systems which have to compress or squeeze the fluid through the pump, the present invention actually relies on tension in order to pull the fluid through the pump. As such, in such a configuration, any gases (up to 100% gas) will flow through the pump apparatus 60 without problems. There is no possibility of fluid pound or gas lock occurring with this configuration of the present invention since the present invention relies upon tension rather than compression of the fluids.

(28) Ultimately, in FIG. 4, the under plunger volume 110 will be filled by the transfer of fluid from the of the above plunger volume 108, regardless of the quantity of gas in the under plunger volume 110.

(29) Referring to FIG. 5, there is shown the fluid pump apparatus 60 of the present invention with the plunger 66 in the uppermost position in a location above that shown in FIG. 4. In particular, the plunger 66 is at the end of the upstroke and the start of the downstroke. As a result of the momentum of the upward movement of the plunger 66, there is an over-stroke distance a. As a result of this over-stroke distance, a flushing action of the walls of the barrel 62 in the under plunger volume 110 can be accomplished. In particular, an annulus 160 will be formed between the first wide inner diameter section 88 of the barrel 62 and the wide diameter section 94, the narrow diameter section 96 and the another wide diameter section 98 of the plunger 66. Another annulus 162 will be formed between the another narrow diameter section 100 of the plunger 66 and the reduced inner diameter section 92 of the barrel 62. The annulus 160 will communicate with the annulus 162 so that a flow of fluid will move downwardly through the annulus 160, enter the annulus 162 and flow into the under plunger volume 110. Since this occurs during the over-stroke a, this flushing action occurs for a very brief period of time and with great force. As such, this will tend to flush any sand, particles or debris from the inner walls of the barrel 92 in the under plunger volume 110. This flushing stroke will occur throughout the distance a during the downward stroke of the plunger 66 within the barrel 62.

(30) In the configuration shown in FIG. 5, the above plunger volume 108 and the under plunger volume 110 are balanced with the fluid pressure column. The spring 114 will act to move the traveling valve 68 downwardly. However, the protrusion 144 on the pilot 70 will still keep the traveling valve 68 slightly open. The pilot will maintain the opening of the traveling valve 68 by autoregulation until the end of the upstroke of the plunger 66. The standing valve 64 will remain closed during this action.

(31) As stated hereinbefore, with reference to FIG. 5, the traveling valve 68 is open at the end of the upstroke. As such, the pressure of the above plunger volume 108 and the pressure of the under plunger volume 110 are the same (i. e. in equilibrium). This ensures that the load corresponding to the weight of the fluid column is no longer supported by the rod string. As a result, the release of the rod elongation is certain during each downstroke. This prevents any risk that the plunger 66 will hit the standing valve 64 at the end of the downstroke. As such, the present invention avoids these potentially damaging circumstances that can occur with conventional pumps.

(32) FIG. 6 shows, in particular, the interior configuration of the plunger 66. The plunger 66 has a pair of apertures 80 and 170 located at the top 172 of the plunger 66. Rod 116 is affixed to the top 172 of the plunger 66 so as to facilitate manipulation. Apertures 80 and 170 extend at slight angles with respect to each other so as to direct fluid flow either upwardly therethrough or downwardly therefrom. The traveling valve 68 is located within the interior 174 of the barrel 66. Wings 176 slightly bear against the inner wall of the interior 174 so as to properly guide the traveling valve 68. Spring 114 bears of the end surface of the traveling valve 68 so as to generally urge the traveling valve 68 downwardly. The cavities formed between the various wings 176 of the traveling valve 68 allow fluid to flow thereacross. As such, the wings 176 will not present any obstacle to fluid flow. There is a seat 86 formed within the interior 174 of the barrel 66. The bottom 178 of the traveling valve 68 is configured so as to have a surface that properly will seat within the seat 86.

(33) The pilot 70 has a head 102 and a protrusion 144 extending upwardly from the head 102. The protrusion 144 is in the nature of a small rod having a diameter less than the diameter of the opening of the seat 86. As such, the protrusion 144, when moved upwardly, will overcome the force of the spring 114 (and the hydraulic force behind the traveling valve 68 from the fluid column load) to unseat the surface of the traveling valve 68 from the seat 86. A chamber 180 formed on the interior of the plunger 66 accommodates the head 102 of the pilot 70. This allows the head 102 will have a diameter less than the diameter of the chamber 180 so as to allow fluid flow therearound. A shoulder 182 is formed within the interior of the plunger 66 so as to allow the bottom of the head 102 to seat thereagainst. Wings 184 are formed on the pilot 70 so as to allow fluid flow therearound. The stem 104 extends downwardly from the head 102. The chamber 150 is defined between the exterior of the stem 104 and the interior of the plunger 66.

(34) FIG. 7 shows, in particular, the configuration of the traveling valve 68. Traveling valve 68 has a first set of wings 200 at an upper end thereof and a second set of wings 202 at a lower end thereof. The first set of wings 200 is spaced away from the second set of wings. Each of the first set of wings 200 and the second set of wings 202 defines a cavity 204 between adjacent wings so as to allow fluid flow thereacross. Fluid can also flow across the central portion 206. A cavity 208 is formed at the top of the traveling valve 68 so as to accommodate the end of the spring 114. The bottom end 210 of the traveling valve 68 is rounded so as to conform to the shape of the seat 86.

(35) FIG. 8 shows the pilot 70. Pilot 70 includes a pair of apertures 220 and 222 located at the upper end of the head 102. As such, this will allow fluid flow therethrough and into the interior passageway of the stem 104. Wings 184 define channels across which water can flow. The protrusion 144 is located at the top of the head 102 and between the passages 220 and 222. The protrusion 144 has a flat upper surface 224 which serves to contact the bottom surface of the traveling valve 68 in the manner described herein previously.

(36) FIG. 9 shows the fluid pump apparatus 60 of the present invention at a first stage of a downstroke of the plunger 66 in the barrel 62. In this configuration, the traveling valve 68 is open. The pilot 70 is in a fully balanced configuration with respect to the above plunger volume 108. This is because the pressure of the fluid that is in the annulus 240 between the first wide inner diameter section 88 of the barrel 62 and the wide diameter section 94 will act through aperture 82 upon the head 102 of the pilot 70 at the same time that pressure bears on the traveling valve 68 through the apertures 80 and 170 at the top of the plunger 66. Although the pilot 70 is fully balanced, it will tend to go downwardly as a result of gravity. Generally, the pilot 70 will be maintained against the traveling valve 68 depending upon the upward force provided by the flow through apertures 222 and 224 if a longer flushing time is required. Proper dimensioning of the apertures can also achieve a longer or shorter flushing time. The standing valve 64 remains closed. Fluid will flow through the traveling valve 68 by transfer from the under plunger area 110 through the longitudinal channel 84, through the interior passageway 104, through the apertures 222 and 224, through the opening between the surface of the traveling valve 68 and the seat 86, around the traveling valve 68, and outwardly of the apertures 80 and 170 and into the above plunger volume 108. The flow from the under plunger to the upper plunger and the flow through the pilot 70 can maintain the opening of the traveling valve 68 depending upon the particular dimensional choices and configurations for the apertures 222 and 224.

(37) FIG. 10 shows the fluid pump apparatus 60 of the present invention after a further downward movement of the plunger 66 within the barrel 62. It can be seen that the traveling valve 68 is still open due to the flow of fluid from under plunger to above plunger. The standing valve 64 remains closed.

(38) Referring to FIGS. 11 and 12, there is shown an alternative embodiment of the fluid pump apparatus 260 of the present invention. The illustrations of FIGS. 11 and 12 correspond to the FIGS. 5 and 10 of the previous embodiment of the present invention. FIGS. 11 and 12 show this alternative embodiment of the fluid pump apparatus 260 as having a closed slot 362 located at the narrow diameter portion 300 of the plunger 266. Importantly, the bottom of the plunger 266 includes radially outwardly extending portion 302 that bears closely to the reduced inner diameter section 292 of the barrel 262. This closed slot 362 is defined between the another wide diameter section 298 of the plunger 266, the another narrow diameter section 300 of plunger 266 and the radially outwardly extended portion 302. This alternative embodiment of the fluid pump apparatus 260 serves to reduce internal leakage. Any accumulation of debris, particles or sand within this closed slot 362 will move during the downward movement of the stroke of the plunger 266 and will be flushed at the end of the downstroke (as shown in FIG. 12).

(39) Relative to FIG. 11, the fluid pump apparatus 260 is shown with the plunger 266 in the uppermost position. In particular, the plunger 266 is at the end of the upstroke and the start of the downstroke. As a result of the momentum of the upward movement of the plunger 266, there is an over stroke distance a. Unlike the previous embodiment, there will be no flushing action on the walls of the barrel 266 in the under plunger volume 310. The radially outwardly extended portion 302 serves to prevent this flushing action. In FIG. 11, an annulus 360 is formed between the first wide inner diameter section 288 of the barrel 262 and the wide diameter section 294, the narrow diameter section 296 and the another wide diameter section 298 of the plunger 266. The slot 362 is formed between the another narrow diameter section 300 of the plunger 266 and the reduced inner diameter section 292 of the barrel 262. The annulus 360 will communicate with the annulus 362 so that a flow of fluid will move downwardly through the annulus 360 and enter the annulus 362. Further movement of the flow of fluid is prevented by the radially outwardly extended portion 302 of the plunger 266.

(40) In the configuration shown in FIG. 11, the above plunger volume and the under plunger volume 310 are balanced with the fluid pressure column. If used, the spring 314 can act to move the traveling valve 268 downwardly. The protrusion 314 on the pilot 270 will still keep the traveling valve 268 slightly open. The pilot 270 will maintain the opening of the traveling valve 268 by autoregulation until the end of the upstroke of the plunger 266. The standing valve 264 will remain closed during this action.

(41) FIG. 12 shows the fluid pump apparatus 260 in accordance with this alternative embodiment of the present invention after a further downward movement of the plunger 266 within the barrel 262. It can be seen that the traveling valve 268 is still open due to the flow of fluid from the under plunger volume to the above plunger volume. The standing valve 264 remained closed.

(42) Importantly, it can be seen that the slot 362 is moved downwardly so as to create an annulus 380 between the outward end of the radially outwardly extended portion 302 of the plunger 266 and the inner wall of the second wide inner diameter 288 of the barrel 262. As a result, any particles or debris that are accumulated within the slot 362 are released and flushed downwardly through the annulus 380 and into the under plunger volume 310. As can be seen in FIG. 12, this non-opening slot 362 serves to reduce internal leakage between the plunger 266 in the barrel 262.

(43) FIG. 13 shows the application of the fluid pump apparatus 60 of the present invention in a well 300. It can be seen that well 300 is a deviated well having a straight section 302 and a curved or deviated section 304. There is a connector 306 that connects a reciprocating mechanism 308 to the plunger 310 of the pumping apparatus 60. The reciprocating mechanism 308 can be a beam pump, a rocking-horse pump, a spool, or a linear hydraulic mechanism. In other words, the rod 312 can be moved upwardly and downwardly for a desired distance so as to properly reciprocate the plunger 310 of the fluid pump apparatus 60.

(44) Importantly, since the present invention draws the fluid upwardly in the well 300 by tension, as opposed to compression, there is no need for rigid structures to connect the reciprocating mechanism 308 with the plunger 310. The plunger 310 can simply settle downwardly by gravity rather than being forced downwardly. The only action that is necessary is a tension so as to pull the plunger 310 upwardly. This can be achieved with a simple cable, chain, wire, wire rope, webbing, or other type of flexible structure. As a result, very minimal wear occurs with the wall 312 of the pipe within the well 300. In the past, when rigid rods are required (as with compression-type pumps), these rigid rods could wear on the surfaces of the pipe and create damage. This damage would require repair and/or replacement. In order to counter this problem, guides have been placed along such rods so as to protect the surfaces of the pipe from the wearing action caused by the reciprocating movement of such rods. The use of a wire, or other type of flexible connector, will create minimal damage to the surfaces of the pipe since the pressure is not very great. Typically, a flexible line will conform to the interior surfaces of the pipe rather than create friction and strong forces thereagainst. Additionally, the use of a cable or other type of flexible line significantly reduces the cost associated with oil production. Also, unlike prior art systems, very little intervention is required in order to operate the system. Even though the present invention is used in very gassy environments, there is no possibility of a gas lock or a fluid pound.

(45) The foregoing disclosure and description of the invention is illustrative and explanatory thereof. Various changes in the details of the illustrated construction can be made within the scope of the appended claims without departing from the true spirit of the invention. The present invention should only be limited by the following claims and their legal equivalents.