Abstract
A fluid pump apparatus for an artificial lift system has a barrel, a standing valve positioned at a lower end of the barrel, a plunger reciprocatingly mounted within the barrel, and a traveling valve positioned in an interior of the plunger so as to control fluid flow through the plunger. The barrel has an opening at a top thereof and an opening at a lower end thereof. The standing valve is movable between an open position and a closed position. The plunger has a first aperture at an upper portion of the plunger and a second aperture extending through a wall of the plunger so as to open to a channel extending longitudinally through the plunger. The traveling valve has a head portion of the body extending downwardly from the head portion. The body is slidably movable within an interior of the plunger. The body has a fluid-passing channel therein that opens to an exterior of the body.
Claims
1. A fluid pump apparatus for an artificial lift system, the fluid pump apparatus comprising: a barrel having an interior and a 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, said barrel having an opening at a top thereof and an opening at the lower end thereof; 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 within said barrel, said plunger having a wide diameter section and a narrow diameter section positioned above said wide diameter section, said plunger having a first aperture at an upper portion of said plunger and a second aperture extending through a wall of said plunger so as to open to a channel extending longitudinally through said plunger, said plunger having a central chamber, said central chamber having a first shoulder located below said first aperture and above said second aperture; a traveling valve positioned in an interior of said plunger so as to control fluid flow through said plunger, said traveling valve having a head portion and a body extending downwardly from said head portion, said body slidably movable within an interior of said plunger, said body having a fluid-passing channel therein that opens to an exterior of said body, said shoulder defining a seating area for said traveling valve; and a spring mounted to said plunger and to said traveling valve so as to urge said traveling valve into sealing relation with said shoulder of said plunger.
2. The fluid pump apparatus of claim 1, said standing valve having a flat surface of the top thereof, said flat surface positioned within said interior of said barrel.
3. The fluid pump apparatus of claim 2, said standing valve having a stem extending outwardly from said flat surface, said stem extending through said opening at said lower end of said barrel.
4. The fluid pump apparatus of claim 1, said plunger having a rod extending upwardly from a top thereof, said rod adapted to be connected to a sucker rod of the artificial lift system.
5. The fluid pump apparatus of claim 1, said head portion of said traveling valve having a diameter suitable for seating on said shoulder of said plunger.
6. The fluid pump apparatus of claim 1, said body having a tubular member extending outwardly therefrom, said tubular member having an outer diameter less than an inner diameter of said channel of said plunger, said tubular member being slidable within said channel.
7. The fluid pump apparatus of claim 6, said tubular member having a bottom that is spaced from said channel of said barrel.
8. The fluid pump apparatus of claim 1, further comprising: an upper pipe connected to an upper end of said barrel, said upper pipe adapted to be secured to production tubing of the artificial lift system.
9. The fluid pump apparatus of claim 8, said traveling valve being movable to a position such that said reduced inner diameter section bears against said wide diameter section of said plunger so as to define a compression chamber in an area between said narrow section of said plunger and said first wide inner diameter section of said barrel, an upper end of said narrow diameter section of said plunger being in sealing relation with an inner diameter of said upper pipe.
10. The fluid pump apparatus of claim 1, said traveling valve being movable to a position such that said reduced inner diameter section bears against said wide diameter section of said plunger so as to define a compression chamber in an area between said narrow diameter section of said plunger and said first wide inner diameter section of said barrel.
11. The fluid pump apparatus of claim 10, said traveling valve being movable to a position such that said wide diameter section of said plunger is spaced from said reduced inner diameter section of said barrel so as to release compressed gas from said compression chamber toward said interior of said barrel and toward a bottom of said plunger.
12. A fluid pump apparatus for an artificial lift system, the fluid pump apparatus comprising: a barrel having an interior and a 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, said barrel having an opening at a top thereof and an opening at the lower end thereof; 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 within said barrel, said plunger having a wide diameter section and a narrow diameter section positioned above said wide diameter section, said plunger having a first aperture at an upper portion of said plunger and a second aperture extending through a wall of said plunger so as to open to a channel extending longitudinally 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 having a head portion and a body extending downwardly from said head portion, said body slidably movable within an interior of said plunger, said body having a fluid-passing channel therein that opens to an exterior of said body, said traveling valve being movable to a position in which fluid above said plunger passes through said first aperture into said channel of said plunger and passes through said fluid-passing channel of said body so as to pass into said interior of said barrel below a bottom of said plunger.
13. A fluid pump apparatus for an artificial lift system, the fluid pump apparatus comprising: a barrel having an interior and a 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, said barrel having an opening at a top thereof and an opening at the lower end thereof; 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 within said barrel, said plunger having a wide diameter section and a narrow diameter section positioned above said wide diameter section, said plunger having a first aperture at an upper portion of said plunger and a second aperture extending through a wall of said plunger so as to open to a channel extending longitudinally 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 having a head portion and a body extending downwardly from said head portion, said body slidably movable within an interior of said plunger, said body having a fluid-passing channel therein that opens to an exterior of said body, said plunger being movable to a lower position so as to cause said traveling valve to be in a seated position such that a fluid above said plunger flows through a space between said narrow diameter section of said plunger and said second wide inner diameter section of said barrel.
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 downhole pump system of the present invention with the plunger in an upstroke position.
(3) FIG. 3 is a cross-sectional view of the downhole pump system of the present invention with the plunger in an uppermost upstroke position prior to beginning a downstroke.
(4) FIG. 4 is a cross-sectional view of the downhole pump system of the present invention showing the plunger in a downstroke position.
(5) FIG. 5 is a cross-sectional view of the downhole pump system of the present invention at the end of the downstroke and at the start of the upstroke.
(6) FIG. 6 is a cross-sectional view of the downhole pump system of the present invention showing the plunger in an initial upstroke position.
(7) FIG. 7 is a cross-sectional view of the downhole pump system of the present invention showing the plunger in an upper upstroke position.
(8) FIG. 8 is a cross-sectional view of the downhole pump system of the present invention showing the plunger in a further upstroke position.
(9) FIG. 9 is a cross-sectional view of the downhole pump system of the present invention in which the plunger is in a further upstroke position.
(10) FIG. 10 is a cross-sectional view of the downhole pump system of the present invention in which the plunger is at the end of the upstroke and at the start of the downstroke.
(11) FIG. 11 is a cross-sectional view of the downhole pump system of the present invention showing the plunger in a further downstroke position.
(12) FIG. 12 is a cross-sectional view of the downhole pump system of the present invention showing the plunger in a further downstroke position.
(13) FIG. 13 is a cross-sectional view of the downhole pump system of the present invention showing the plunger near the end of the downstroke.
(14) FIG. 14 is a cross-sectional view of the downhole pump system of the present invention showing the plunger at the end of the downstroke.
(15) FIG. 15 is a diagrammatic illustration showing a technique whereby the pump system of the present invention can be utilized in association with deviated production tubing.
(16) FIGS. 16A-16I show the various stages associated with the fluid pump apparatus in accordance with a first alternative embodiment of the present invention.
(17) FIGS. 17A-17I show the sequential stages associated with a second alternative embodiment of the fluid pump apparatus of the present invention.
(18) FIGS. 18 and 18A illustrate an alternative embodiment of the present invention wherein the standing valve is spring-loaded so as to maximize solids evacuation.
DETAILED DESCRIPTION OF THE INVENTION
(19) 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.
(20) 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.
(21) 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.
(22) FIG. 2 illustrates a detailed view showing the downhole pump 44. This downhole pump 44 includes a barrel 52, a standing valve 54, a plunger 56, and a traveling valve 58. Each of these elements cooperate so as to cause the downhole pump 44 to compensate for fluid pressures in the interior 60 of the barrel 52 below the plunger 56 and for pressures within the interior 62 of the upper pipe 64 (and the fluid column thereabove).
(23) The barrel 52 includes a first wide interior diameter section 66, a second wide interior diameter section 68 and a reduced interior diameter section 70. The reduced interior diameter 70 is located between the first wide interior diameter section 66 and the second wide interior diameter section 68. The barrel 52 includes an opening at the top thereof and an opening 72 at the bottom thereof. In particular, the barrel 52 has a narrowed bottom end 74 that will define the opening 72.
(24) The standing valve 54 is located at the bottom opening 72. In normal use, the standing valve 54 will be movable between an open position and a closed position. In the open position (as shown in FIG. 2), the standing valve 54 can allow fluids from the formation to flow upwardly into the interior 60 of the barrel 52. The standing valve 54 includes a flat top surface 76 and a stem 78 that extends downwardly through the opening 72. The flat top surface 76 is particularly configured such that if the bottom 80 of the plunger 56 should contact the standing valve 54, any forces will be distributed across the flat surface 76. As such, the problems associated with ball-type standing valves are reduced. In other words, if the bottom 80 of the plunger 56 would contact the ball positioned at the opening 72, the force of contact could tend to deform the ball. This would result in an uneven seating of the ball within the opening 72.
(25) The plunger 56 includes a wide diameter section 82 and a narrow diameter section 84. The narrow diameter section 84 is located above the wide diameter section 82. A first aperture 86 is formed at the top of the plunger 56. A second aperture 88 is formed through the sidewall of the plunger 56 so as to open into a volume 90 located within the interior of the plunger 56. A channel 92 has one end opening to the interior 90 of the plunger 56 and opposite end opening at the bottom 80 of the plunger 56. The channel 92 extends longitudinally through the plunger 56. A rod 96 is connected to the top of the plunger 56 and extends upwardly. This rod 96 can be connected to the sucker rod 46 of the pumping system. The plunger 56 also includes a shoulder 98 at a bottom of the interior 90 and generally above the wide diameter section 82. The seating area for the traveling valve 58 (as seen in FIG. 4) at the bottom chamber 90 (as shown in FIG. 6).
(26) The traveling valve 58 includes a head 100 having a diameter suitable for seating on the shoulder 120 (as shown in FIG. 4). This head 100 has an inverted V-shape configuration so as to provide a funnel-like effect for fluid flowing thereby. A body 102 is connected to the head 100 of the traveling valve 58. The body 102 is adapted for slidable movement within the interior 90 of the plunger 56. The body has a fluid-passing channel 104 so as to open at the exterior of the body 102. The body 102 also includes a tubular member 106 extending downwardly therefrom. The tubular member 106 has an outer diameter that is less than an inner diameter of the channel 92 of the plunger 56. As will be described hereinafter, a spring can be mounted to the head 100 of the traveling valve 58 so as to urge the head 100 downwardly toward the shoulder 120 of the plunger 56.
(27) In FIG. 2, it can be seen that the plunger 56 is in an upper position. Importantly, this upper position will define a compression chamber 110. The compression chamber 110 is formed between the first wide inner diameter section 66 of the barrel 52 and the outer surfaces of the plunger 56. In particular, it can be seen that the wide diameter section 82 of the plunger 56 will be in close relationship to the narrow inner diameter section 70 of the barrel 52. In generally, this is in a sealed relationship. The compression chamber 110 is also defined between the narrow diameter section 84 of plunger 56 and the wide diameter section 82 of plunger 56. The narrow diameter portion 84 of the plunger 56 extends upwardly so as to have an upper end generally in sealing relationship with an inner wall of the upper pipe 64. In this position, fluids located within the compression chamber 102 are suitably compressed.
(28) Importantly, the compressed fluid within the compression chamber 110 can flow only through the second aperture 88. This force urges the body 102 of the traveling valve 58 upwardly so as to unseat the head 58 from the interior of the plunger 56. As a result, fluids located within the interior 62 of the upper pipe 64 can flow through the first aperture 86 (as indicated by the arrows), around the head 100 of the traveling valve 58, through the channel 104 of the traveling valve 58 and downwardly through the tubular member 106. These fluids will then flow downwardly through the channel 92 in the plunger 56 so as to enter the interior 90 of the barrel 52. The compressed fluid from the compression chamber 110 will also flow through the second aperture 88 and downwardly through the space between the tubular member 106 of the traveling valve 58 and within the channel 92 of the plunger 56. The flow of the fluid serves to equalize pressure between the top and bottom of the plunger 56. The compressed fluid passing therethrough can serve to remove debris, such as sand, scale, calcium carbonate, iron sulfide, and other materials from the working surfaces associated with the barrel 56. As such, the present invention effectively provides a flushing action so as to remove the sand, while, at the same time, equalizing pressures within the barrel 52. Also, the friction movement in the fluid participates in this flashing action. The contribution of the compressed volume and the friction movement will depend on the composition of the fluid (i.e. the gas quantity).
(29) FIG. 3 illustrates the plunger 56 in an upper position. In this upper position, the compression chamber 110 is opened so as to allow the compressed fluids to flow outwardly (as indicated by arrow 120) from the compression chamber through the spaces between the wide diameter section 82 of the plunger 56 and the first wide inner diameter section 66 of the barrel 52. As such, during the further upstroke of the plunger 56, these fluids can further be used so as to flush sand from the outer surfaces of the barrel 56 and from the inner wall of the barrel 52. As can further be seen, the compressed fluids will continue to flow until the wide diameter section 82 of the plunger 56 passe out of the bore 70 of the barrel, as shown by arrow 120. Once the plunger passes outwardly of the bore 70, the traveling valve 58 moves in a downward direction. Once again, this serves to equalize pressure and also provide a force which causes sand to be evacuated from the interior of the plunger 56 and from the interior of the barrel 52. Since the standing valve 76 is in an closed position, the gas, fluid and sand can be passed outwardly of the barrel 52. As a result, sand is effectively removed from the pump 44 of the present invention.
(30) In FIG. 5, it can be seen that the head 100 of the standing valve 58 being seated upon the shoulder 120 within the interior 90 of the traveling valve 58. The seating of the head 100 (as shown in FIG. 6) upon the shoulder 120 serves to prevent further fluid flow from the interior 62 above the barrel 56 through the apertures 86. So as to equalize pressure, the fluid in the interior 62 can flow around the exterior of the plunger 56 and downwardly into the interior 60 below the plunger 56. In this configuration, the standing valve 54 is closed. Additionally, as can be seen, there is no compression chamber since the outer surfaces of the plunger 56 are in spaced relationship to the second wide inner diameter section 68 of the barrel 52.
(31) Following this downstroke position, the piston 56 can be moved upwardly so as to once again create the compression chamber and to carry out the movement of fluids in the manner described herein before in association with FIGS. 2 and 3.
(32) FIG. 5 is a detailed view of the pump 44 of the present invention. As stated hereinbefore, the pump 44 includes a barrel 52, a plunger 56, a standing valve 54 and a traveling valve 58. In FIG. 5, it can be seen that there is a spring 130 that is provided so as to urge the traveling valve 58 into a seated position adjacent to the shoulder 120 of the plunger 56. Spring 130 serves to prevent any rattling of the valve 58 during its movement. In FIG. 5, the head 100 of the standing valve 58 includes a rod-like portion 132 which extends upwardly therefrom and which is received by the spring 130.
(33) In particular, FIG. 5 illustrates the pump 44 in which the plunger 56 is at the end of the downstroke and the start of the upstroke. In this configuration, the standing valve 54 is closed and the traveling valve 58 is lightly open. In this configuration, the plunger 56 is uncovered. The above plunger area 134 and the below plunger area 136 are connected so as to communicate with each other through the channel 92, through the channel 104 and through the apertures 86.
(34) FIG. 6 shows the plunger 56 at the beginning of the upstroke. In FIG. 6, the standing valve 54 is opened so as to allow fluids to be drawn into the below the plunger area 136. The standing valve 54 will remain open until the plunger 56 is at the position illustrated in FIG. 7. The standing valve 54 should be open as large as possible so as to facilitate solids evacuation. In the position shown in FIG. 6, the plunger 56 is covered. The below piston area 136 and the above piston area 134 are separated since the traveling valve 58 is closed and since the wide diameter section 82 of the plunger 56 will bear against the narrow inner diameter section 70 of the barrel 52. In this configuration, the above plunger area 134 will have a greater pressures than the below plunger area 136. As a result, the rod 96 will be moved under tension. As a result, fluids are drawn from the annulus into the barrel 92 and, in particular, into the below plunger area 136.
(35) FIG. 7 shows an upward upstroke position of the plunger 56. There is an accumulation of fluid within the below plunger area 136. In this position, the compression chamber 110 is formed in the manner described herein previously. The continued upward movement of the plunger 56 will further serve to compress the volume of fluid within the compression chamber 110. In this position, the traveling valve 58 is moved upwardly by the pressures within the compression chamber 110. As such, the channel 104 is properly opened. These forces will urge against the resistance of the spring 130. The traveling valve 58 is thereby opened and uncovered. The above plunger area 134 is connected to the below plunger area 136 in the manner described hereinbefore. In particular, these are connected through the channel 92, through the channel 104 and through the aperture 86. In this position, pressures are equalized. In particular, the pressure fluid column in the above plunger area 134 is transmitted to the below plunger area 136. The traveling valve 76 is illustrated as closed.
(36) FIG. 8 illustrates the plunger 56 in a further upstroke position. It can be seen that the flow through the traveling valve 58 helps to evacuate solids from the interior of the plunger, in the manner described herein previously. The above plunger area 134 and the below plunger area 136 remain connected. The above plunger area 134 and the below plunger area 136 are balanced with the pressure fluid column. In this configuration, the fluid within the compression chamber 110 is further compressed so as to flow through the interior of the plunger 56 in the manner described herein previously. In this configuration, the standing valve 76 remains closed.
(37) FIG. 9 shows a further upward position of the plunger 56 during the upstroke. As can be seen, the bottom 80 of the plunger 56 has separated from the narrow inner diameter section 70 of the barrel 52. As such, the compressed fluid can flow through the space between the plunger 56 and the inner wall of the barrel 70 so as to clean the inner surfaces of the barrel 52 and to discharge sand therefrom. The above plunger area 134 and the below plunger area 136, along with the compression chamber 110, are balanced by the pressure fluid column. The spring 130 associated with the traveling valve 58 causes the traveling valve 58 and move to the closing time of the traveling valve 58 is controlled by the plunger channel 92 covering at the bottom.
(38) FIG. 10 illustrates the plunger 56 in its uppermost positioned at the end of the upstroke and the start of the downstroke. This uppermost position can be controlled by a position indicator associated with the pump 44 of the present invention. The traveling valve 58 is illustrated as slightly open because the traveling valve's closing time is under control through the balancing between the spring force of the spring 130 and the drop pressure created by the pressure resulting until the start of the downstroke. The standing valve 76 is shown in a closed position. In particular, the compression chamber 110 is completely open since the outer wall of the plunger 56 is located within the first wide inner diameter section 66 of the barrel 52.
(39) FIG. 11 shows the start of the downstroke of the plunger 56. As can be seen in FIG. 11, the traveling valve 58 is in the open position. The standing valve 76 remains closed. The fluid can flow through the traveling valve 58, through the channel 104, and through the interior of the plunger 56.
(40) FIG. 12 shows a further downstroke position of the plunger 56 within the barrel 52. As can be seen, the wide diameter section 82 of the plunger 56 is approaching the narrow inner diameter section 70 of the barrel 52. The standing valve 76 remains closed. The traveling valve 58 is open so as to equalize for fluid pressures in the above plunger area 134 and the below plunger area 136.
(41) FIG. 13 shows the plunger 56 near the bottom of the downstroke. In this position, the traveling valve 58 remains open. The standing valve 76 remains closed. The fluid will flow through the traveling valve 58 in the manner described hereinafter from the below plunger area 136 toward the above plunger area 134. As a result, the pump 44 is able to accumulate fluid in the above plunger area 134. The plunger 56 remains covered but close to the opening area.
(42) FIG. 14 shows the plunger 56 in the at the end of the downstroke. The plunger 56 is uncovered in this position. The below plunger area 136 and the above plunger area 134 are connected through the interior structures of the plunger 56. Fluid will flow from the below plunger area 136 to the above plunger area 134 through the plunger until the end of the downstroke. This helps to evacuate solids from the plunger 56 along with the barrel 52. The traveling valve 58 is slightly open because the closing time of the traveling valve is under the control of the spring force of spring 130 and the pressure drop created by the covering of the plunger hole.
(43) FIG. 15 is an illustration of a mechanism for controlling the movement of the plunger 56 within the barrel 52. In particular, the rod 200 is connected within a housing 220 located at the top of the plunger 56. In particular, the housing 220 serves to retain a pivot mechanism 222 therein. Stops 224 and 226 serve to restrict the amount of pivotal movement of the rod 200 relative to the piston 56. This configuration facilitates the ability to utilize the pump of the present invention in associated with deviated production tubing. As a result of the construction of FIG. 15, the rod 20 can create proper movement of the piston 56 within the barrel 52 regardless of the angle of orientation of the production tubing. The pivot mechanism is free floating so as to absorb any misalignment.
(44) FIGS. 16A-16I show sequentially the operation of the fluid pump apparatus 300 in accordance with a first alternative embodiment of the present invention. This first alternative embodiment is an alternative to the previous embodiment so as to will have only two sealing areas during the upstroke between the above plunger area and the under plunger area instead of three sealing areas. There is also a top guidance cylinder of the traveling valve.
(45) The fluid pump apparatus 300, shown in FIG. 16A, is illustrated at the start of the upstroke of the plunger. In this position, the standing valve 302 is closed. The traveling valve 304 is slightly open. The wide diameter section of the plunger 306 of the plunger 308 is uncovered by the inner wall of the barrel 310. The above plunger area 312 and the under plunger area 314 are connected through the uncovered area between the plunger 308 and the inner wall of the barrel 310. The plunger over-stroke compensates for the approximation of the barrel/rod string position.
(46) As with the previous embodiment, it can be seen that there is a rod 316 that extends upwardly from the plunger 308. An aperture 318 extends so as to open to the interior of the barrel 310 in the above plunger area 312. A spring 320 is mounted in the central chamber 322 so as to bear against the interior of the plunger 308 and also to bear against the traveling valve 304. Another aperture 324 opens through the wall of the plunger 308 so as to communicate with the channel 326 that extends longitudinally within the plunger 308. Another channel 328 communicates between the central chamber 322 and the chamber 330. In FIG. 16A, it can be seen that the wide end of the traveling valve 304 is slightly opened with respect to the longitudinal channel 332 that extends from the bottom of the plunger 308 toward the chamber 330.
(47) FIG. 16B shows that the initialization of a first stage of the upstroke of the plunger 308 within the interior of the barrel 310. In this position, the standing valve 302 is opened. It will remain open until the end of the initial stage of the first upstroke position. The standing valve is open as wide as possible so as to facilitate solids evacuation. The wide diameter section 340 of the plunger 308 is shown as covered by the reduced diameter section 342 and the inner wall of the barrel 310. The above plunger area 312 and the under plunger area 314 are isolated from each other and closed with respect to each other. The traveling valve 304 is illustrated as sealed closed and seated over the channel 332. The traveling valve 304 will be closed because the above plunger pressure is greater than the under plunger pressure. The under plunger area 314 can then begin filling with fluids.
(48) FIG. 16C shows the end of the first stage of the upstroke. In FIG. 16C, it can be seen that the narrow diameter section 350 of the plunger 308 will be engaged with the inner wall of the upper pipe 352. The inner wall of the pipe 352 has a diameter less than the narrowest inner diameter of the barrel 310. The fluid within the compression chamber 354 is suitably compressed in the area between the outer shoulder 356 of the plunger 308 and the end of the upper pipe 352. The traveling valve 304 will unseat from its position over the channel 352. The above plunger area 312 and the under plunger area 314 will be connected through the opening caused by the movement of the traveling valve 304. In other words, fluid will flow from chamber 330 through the channel 352 and into the under plunger area 314. The pressure fluid column in the above plunger area 312 is transmitted to the under plunger area 314. The standing valve 302 is suitably closed.
(49) FIG. 16D shows the end of an upper stage of the upstroke of the plunger 308. It can be seen that the traveling valve 304 is moved upwardly away from the channel 352. The traveling valve 314 moves so as to uncover the aperture 324 and to unblock the opening to the chamber 322. The flow through these areas will help to evacuate solids from the respective chambers 322 and 330. In particular, the fluid flow through from the chamber 322 through the aperture 328 facilitates this solids evacuation. The above plunger area 312 is still fluidically connected to the under plunger area 314. The above plunger area 312 and the under plunger area 314 are balanced with the pressure fluid column. This means that the under plunger area 314 is filled regardless of the initial gas quantity in the above plunger area 312. The standing valve 302 remains closed.
(50) FIG. 16E shows the end of a third stage of the upstroke of the plunger 308. The chambers 322 and 330 remain connected through the aperture 328. Additionally, the chambers 322 and 330 communicate fluidically through the apertures 318 to the above plunger area 312. The above plunger area 312 and the under plunger area 314 along with the chambers are balanced with the pressure fluid column. The spring 320 urges to close the traveling valve 304 and to close the aperture 324. The closing time for the traveling valve 304 is going to close the channel 352. The standing valve 302 remains closed.
(51) FIG. 16F shows the end of the upstroke of the plunger 308 and the start of the downstroke of the plunger 308. The overstroke will compensate for the approximation of the barrel/rod string position. It can be seen that the traveling valve 304 is slightly opened because the closing time for the traveling valve 304 is under control through the balancing between the spring force of spring 320 and the drop of pressure created into the plunger channel until the downstroke begins.
(52) FIG. 16G illustrates a first stage of the downstroke of the plunger 308. In this first stage of the downstroke, the traveling valve 304 remains opened because fluid flow therethrough. The standing valve 302 remains closed. The fluid will flow through the traveling valve 304 by the flow of fluids from the under plunger area 314 upwardly through the chamber 330, through aperture 328 into chamber 322 and outwardly through the apertures 318 to the above plunger area 312.
(53) FIG. 16H shows the end of the downstroke of the piston 308. At the end of the downstroke, the traveling valve 304 is still opened due to the flowing of fluids. The standing valve 302 remains closed. The wide diameter section 340 of the plunger 308 is sealed against the reduced diameter section 342 of the barrel 310.
(54) FIG. 16I shows the conclusion of the downstroke of the plunger 308. In this final position, the wide diameter section 340 of the of the plunger 308 is uncovered from the inner walls of the barrel 310. The above plunger area 312 is connected to the under plunger area 314 through the opening 316 created between the outer walls of the plunger 308 and the inner wall of the barrel 310. Fluid will flow from the upper plunger area 312 from the under plunger area 314 to the above plunger area 312 through this opening 360 until the end of the downstroke. This helps to evacuate solids from the plunger 308 and the barrel 310. The traveling valve 304 will remain slightly opened because the traveling valve's closing time is under control through the balancing between the spring 320 and the drop force created by the covering of the channel in the plunger of the channel 326 of the plunger 308.
(55) FIGS. 17A-17I show the various stages during the operation of a second alternative embodiment of the fluid pump apparatus 400 of the present invention. This second alternative embodiment allows only two sealing areas during the upstroke between the above plunger area 402 and the under plunger area 404. A different configuration of the traveling valve 406 is particularly shown.
(56) FIG. 17A shows the start of the upstroke of the fluid pump apparatus 400 of the present invention. As can be seen in FIG. 17A, the standing valve 408 is closed. The traveling valve 406 is slightly open with respect to the channel 410 in the plunger 412. The wide diameter section 414 of the plunger 402 is uncovered. The above plunger area 402 is connected to the under plunger area 404 through a flow path 416 formed between the outer wall of the plunger 402 and the inner wall of the barrel 418. The overstroke position of the plunger 412 compensates for the approximation of the barrel/rod string position.
(57) FIG. 17B illustrates an initial stage of the upstroke of the fluid pump apparatus 400 of the present invention. In this initial stage, the standing valve 408 is opened until the end of this initial stage of the upstroke. The standing valve 408 will be open as wide as possible so as to facilitate solids evacuation. The flow path 416 will be closed because of the sealing relationship between the wide diameter section 414 of the plunger 412 and the reduced diameter section 416 of the barrel 418. In this position, the above plunger area 402 is isolated from the under plunger area 404. The traveling valve 406 will be closed because the above plunger pressure will be greater than the under plunger pressure. In this initial stage of the upstroke, the under plunger area 404 will begin filling with fluid.
(58) FIG. 17C shows the end of the first stage of the upstroke. In this configuration, the narrow diameter section 430 of the plunger 412 is engaged with the inner wall of the upper pipe 432. As stated hereinbefore, the inner diameter of the upper pipe 432 is less than the smallest diameter of the inner wall of the barrel 418. The compression chamber 434 is compressed so that the volume will push the sleeve 430 toward the top. The traveling valve 406 will unseat from covering the channel 410. The above plunger area 402 will be connected to the under plunger area 404 through the opening created by the traveling valve 406. As such, the pressure fluid column in the above plunger area 402 is transmitted to the under plunger area 404. The standing valve 408 remains closed.
(59) FIG. 17D illustrates the end of a second stage of the upstroke of the plunger 412. In this configuration, the traveling valve 406 moves upwardly and away from the channel 410 so as to cause an opening 440 between the interior of the sleeve 430 and the outer surface of the plunger 412. This flow will evacuate solids from the area between the inner wall of the sleeve 430 and the outer wall of the plunger 412. The above plunger area 402 is still connected to the under plunger area 404. The pressure and the above plunger area 402 and the under plunger area 404 are balanced with the pressure fluid column. This means that the under plunger area is filled regardless of the initial gas quantity in the under plunger area 404. The standing valve 408 remains closed.
(60) FIG. 17E shows the end of a third stage of the upstroke of the plunger 412 in the fluid pumping apparatus 400. In this configuration, the compression chamber 434 is connected to the above plunger area 402 through the space 450 formed between the first wide inner diameter section 452 of the barrel 418 and the wide outer diameter section 454 of the plunger 412. This space 450 serves to create an opening which helps to evacuate solids from the plunger 412 and the compression chamber 434. The above plunger area 402 and the under plunger area 404, along with the compression chamber 434, are balanced with the pressure fluid column. The traveling valve 406 being closed by the action of the spring 456. The closing time for the traveling valve 406 is controlled by the compression chamber 434 and until the covering of the sleeve 430 at the bottom thereof.
(61) FIG. 17F shows the end of the upstroke in the start of the downstroke of the barrel 412 of the fluid pumping apparatus 400 of the present invention. The overstroke compensates for the approximation of the barrel/rod string position. The traveling valve 406 is lightly open because the closing time of the traveling valve is under control through the balancing between the spring force and the drop pressure created by the sleeve 430 in relation to the plunger 412. The standing valve 408 remains closed.
(62) FIG. 17G shows an initial stage of the downstroke of the piston 412 in the fluid pumping apparatus 400 of the present invention. In this configuration, it can be seen that the traveling valve 406 is opened due to the flowing of fluids therethrough. The standing valve 408 remains closed. Fluid will flow through the traveling valve 406 from the under plunger area 404 for transfer through the central chamber 460 of the plunger 412 and through the apertures 462 into the above plunger area 402.
(63) FIG. 17H shows the end of the first stage of the downstroke of the plunger 412 within the fluid pumping apparatus 400 of the present invention. It can be seen that the traveling valve 406 is still opened due to the flowing of fluids therethrough. The standing valve 408 remains closed. Fluid flows through the traveling valve 406 by fluid transfer between the under plunger area 404 and the above plunger area 402. The flow path 470 between the wide diameter section 452 of the plunger 412 and the second wide inner diameter section 450 of the barrel 418 is illustrated as closed.
(64) FIG. 17I illustrates the end of the second stage of the downstroke of the fluid pumping apparatus 400 the present invention. The end of the second stage of the downstroke has the flow path 470 uncovered. The above plunger area 402 is connected to the under plunger area 404 through the flow path X. Fluid will flow from the under plunger area 404 to the above plunger area 402 through this flow path X until the end of the downstroke. This helps to evacuate solids from the plunger 412 and from the interior of the barrel 418. The traveling valve 406 is lightly open to cause the traveling valve's closing time to be under control through the balancing between the spring force of the spring 456 and the drop pressure created by the flow path 474.
(65) FIGS. 18 and 18A illustrate an alternative embodiment of the present invention wherein the standing valve is spring-loaded so as to maximize solids evacuation. FIG. 18A shows the standing valve 502 abutting a return spring 504. The spring force is shown at 506. In the alternative embodiment of the present invention, the standing valve 502 is opened by the reverse return spring 504. This is opposite to the conventional use of return springs wherein the return springs are used for closing a valve. The flat top of the standing valve 502 could have a conical shape or other profile in order to facilitate the evacuation of solids accumulated on it.
(66) In the alternative embodiment of the present invention, the closure of the standing valve 502 is delayed during the end of the upstroke phase of the fluid pump apparatus 500, as is shown in FIG. 18. At this time, the flow is delivered from the fluid column (under high pressure) through port 508, acting as a flushing of the area 510.
(67) The delay of closing of the standing valve 502 will depend on the balance between the spring force 506, the passage area thru standing valve 502, and the passage area through traveling valve (via port 508). The minimum pressure required in UP chamber 510 to close the valve 502 corresponds to the force 504 applied on section 512 of standing valve 502. So, once the flow through the traveling valve is great enough big to create the minimum pressure, the standing valve will close and will be fully closed before the end of the upstroke phase. Note that the return spring characteristics will have to be defined according depth level range of the well.
(68) The spring-loaded standing valve 502 shown in FIGS. 18 and 18A can be used as an alternative to the standing valves shown and described in each of the embodiments above.
(69) The present invention provides a downhole pump that has a fixed barrel with a reciprocating plunger moving therein by way of a rod string. A standing valve is located at the bottom of the barrel and a traveling valve is at the plunger. The barrel chamber is provided between the traveling valve and the standing valve and expands during an upstroke movement and contracts during the downstroke movement. A hydraulic actuation system is provided to open the traveling valve before the end of the upstroke in order to make communication between the barrel chamber and the fluid column. When the traveling valve is open, the weight of the column ensures the pressure balancing instantaneously regardless of the gas volume within the barrel chamber. This occurs through the use of the opening traveling valve. Gas within the barrel chamber can vent through the traveling valve in order to prevent gas locks. The immediate balancing pressure above and below the plunger allows the ability to minimize stress on the sucker rods in order to avoid the fluid pounding effect. As such, damage to the rod string is effectively prevented. As a result, the present invention reduces the need to ever pull the rod string. This avoids the very expensive, labor-intensive, and equipment-intensive procedures. It also serves to avoid lost production. The present invention effectively provides a mechanism whereby any solids present within the pump can be discharged so as to avoid a sand locking of the piston or damage to the components of the plunger and barrel.
(70) 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 present 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.
