CA2116614A1 - Hydraulic jack pump - Google Patents
Hydraulic jack pumpInfo
- Publication number
- CA2116614A1 CA2116614A1 CA002116614A CA2116614A CA2116614A1 CA 2116614 A1 CA2116614 A1 CA 2116614A1 CA 002116614 A CA002116614 A CA 002116614A CA 2116614 A CA2116614 A CA 2116614A CA 2116614 A1 CA2116614 A1 CA 2116614A1
- Authority
- CA
- Canada
- Prior art keywords
- hydraulic
- well
- electric
- valve
- horseheads
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B47/00—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps
- F04B47/12—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps having free plunger lifting the fluid to the surface
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/12—Methods or apparatus for controlling the flow of the obtained fluid to or in wells
- E21B43/121—Lifting well fluids
- E21B43/126—Adaptations of down-hole pump systems powered by drives outside the borehole, e.g. by a rotary or oscillating drive
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B47/00—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps
- F04B47/02—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps the driving mechanisms being situated at ground level
- F04B47/04—Pumps or pumping installations specially adapted for raising fluids from great depths, e.g. well pumps the driving mechanisms being situated at ground level the driving means incorporating fluid means
Abstract
An oil pumping jack of improved efficiency and safety, with an electric-hydraulic manifold that provides soft shift spool in normal operation.
Hydraulic compensation in the form of sacrifice of fluid output is provided if the work load increases, so that the system slows down visibly, signalling the operator and avoiding downhole damage. Further efficiency is achieved through avoidance of horizontal forces on the well-head linkage by fashioning the horseheads to have the face farthest from the center of rotation of the fulcrum beam be a convex portion of a circle circumference whose radius is the distance to the center of rotation. Safety features include a safe and total shutdown by interruption of the electrical control circuit, a positive hydraulic lock holding the pump jack in its stopped position without pressure on the hydraulic seals or fittings, and a longer circumference on the balance horsehead to facilitate tapping the well-head bottom without manual adjustments.
Hydraulic compensation in the form of sacrifice of fluid output is provided if the work load increases, so that the system slows down visibly, signalling the operator and avoiding downhole damage. Further efficiency is achieved through avoidance of horizontal forces on the well-head linkage by fashioning the horseheads to have the face farthest from the center of rotation of the fulcrum beam be a convex portion of a circle circumference whose radius is the distance to the center of rotation. Safety features include a safe and total shutdown by interruption of the electrical control circuit, a positive hydraulic lock holding the pump jack in its stopped position without pressure on the hydraulic seals or fittings, and a longer circumference on the balance horsehead to facilitate tapping the well-head bottom without manual adjustments.
Description
INTRODUCTION AND DESCRIPTION OF THE PRIOR ART
Large areas of central North America are spotted with pumpjacks recovering underground petroleum fluids for domestic and commercial use; the present invention provides an important reduction in the amount of energy required to drive the pump jack, as well as certain other advantages. Most centrally it applies an improved hydraulic control system to manage the balanced movement of the horseheads, although aspects of the weighting and geometric placement of the heads and fulcrum beam are also addressed.
The existing prior art and commercially operating machines are of many types, spanning many decades, and no attempt to exhaustively itemi~e the less efficient pump jacks will be made. For this analysis they may be said to t`all into two broad categories: those using direct mechanical linkages, and those hydraulically driven. The present invention is of the second type. Advantages including reduced mechanical wear, and hence maintenance costs, are realized by the use of hydraulics, such as specified in U.S. patent #3,369,490 (Hawk, 1968), and C~n~ n patents ~906,477 (Maasshoff, 1972);
#921,768 (Maasshoff, 1973); #994,21 1 ((~oldfein, 1976): #1.164.270 (Creamer, 1984);
and #1,193,345 (Creamer, 198~).
The layout of the hydraulics and the geometry of Ihe horseheads and fulcrum determines how efficient the pump jack is; and the cited jacks have appreciable losses from their hydraulic systems and balancing geometry. Some use a mechanical control of the hydraulic system; some have progressed to an electrical: but in all Ihe hydraulic cylinder ports are blocked in the neutral position, and pressure soars until it reaches a pre-set by-pass setting, which is very inefficient and hard on the pump, cylinder, and hydraulic fittings. As well, if the work load increases, the hydraulic system continues to drive, or drives until a safety cut-off pressure is reached and a sudden total shut-down is initiated. This can result in long-term inefficient--and eventually damaging--action, if 21~6614 there is an unnoticed downhole problem.
The present invention dramatically reduces the friction and heat losses and wear on the hydraulic parts by providing a variable output pllmp with electrical over hydraulic over hydraulic valve control of the cylinder driving the pump jack. This allows a soft shift spool in normal operation (all ports are open in the shit`ting and neutr.ll positions) greatly increasing efficiency. This is further enhanced by manually adjustable needle valves which feather the action of the cylinder by controlling the speed of the hydraulically actuated valve, hence avoiding hydraulic fluid hammering and instantaneous direction changes which cause energy losses.
Also incorporated are hydraulic compensators that will sacrifice the amount of fluid output if the work load increases. This is very important in that it gives early indication of downhole complications by actually slowing down the speed of the jack, which can be visually noticed by a well operator. This compensation also reduces the strain on the pump jack and downhole equipment in load-increase situations, saving the downhole equipment from damage. To the inventor's knowledge no other pump jack is capable of this feature.
Another advantage of the present invention is that tapping bottom in the well can be done easily by adjusting proximity switches instead of difficult manual removal of bolts on a clamp above a stuffing box, as is currently done. As well, normal speed of the jack motion is easily changed by varying the output of the pump, instead of the mechanical changing of pulley and belt sizes. Both of these features mean major advantages in time, convenience~ safety, and maintenance.
Finally, two important and unique safety features are incorporated. One is to have a positive hydraulic lock that will hold the cylinder in its stopped position indefinitely until hydraulic pressure is applied to release it. This avoids the problems of prior safety locks that rely on the all-ports-blocked hydraulic valve to hold the walking 21~6614 beam; as the spool wears, this creates an unsate condition ~Secondly, the present invention can only be stopped by cutting the electrical sllr ply to the control valve; in other words. a safe and total shutdown. instead of a shut(lown which leaves pressurized hydraulics or active electrical systems (or both), as past systems have done.
An object of the present invention is to provide t`or an oil-well pump jack driven by an electric-hydraulic drive system;
the pump jack comprising: a fulcrum beam; on a saddle bearing; the beam having on one end ~ well-head horsehead with the l`ace tarthe~t from the bearing being a convex portion ol` a circle circumference whose radius is the distance to the center of the bearing, and on the other a balance horsehead with a corresponding face similarly measured from the center of the bearing but extending further downwards in order to facilitate tapping bottom of the well; well rod linkage connecting the well-head horsehead with a well-head downhole load; balance rod linkage connecting the balance hor~ehead with an equalizer; A-leg braces supporting the saddle bearing; and a welded steel base on a concrete base pad on a gravel pad, supporting the A-leg braces:
the electric-hydraulic drive system comprising: a piston driving the tulcrum beam; a hydraulic cylinder providing hydraulic fhlid driving the piston; two input/output ports from the cylinder; a dual counterbalance valve connected to the two ports; a hydraulic manifold controlling the supply of hydraulic tluid to the cylinder: the manifold comprising:
two controlled hydraulic fluid output lines, one communicating with each input/output port through the counterbalance valve; two pressurized hydraulic fluid input lines, both communicating with a hydraulic fluid reservoir and isolated from the hydraulic fluid output lines; a hydraulically piloted hydraulic valve for each fluid output line: a solenoid-controlled hydraulic pilot valve for each piloted valve; a solenoid controlling each pilot valve; electric control of the 211GSl~
-solenoids; and additional manual control of each pilot valve:
a positive lock on the hydraulic cylinder: ad jus~ahle switching me.lns to change the direction of tlow of the hydraulic fluid in the manifold at a chosen extent of the horsehead movement cycle; a pressure relief valve; a back pressure check valve; an electrically-monitored pressure gauge; a variable-displacement hydraulic pump; an hydraulic reservoir; an electric motor; a control circuit controlling the electric motor; and a power circuit to supply electric power to the electric motor;
wherein the equalizer is provided of such weighl as to counterbalance the downhole load evenly without exerting horizontal forces on the well rod linkage: wherein this even counterbalancing is arrived at by calculating the moments of gravitational force of the fulcrum, horseheads, well rod linkage, and downhole load, and by specifying the radii of the horseheads; wherein engagement of the electric motor engages the pump and drives the cylinder and hence fulcrum beam and well-head and halancing horseheads;
wherein the electric-hydraulic over hydraulic valves provide soft shift spool in normal operation, enhanced by manual adjustment; wherein the electric-hydraulic over hydraulic control, in being two separate hydraulic fluid circuits, provides hydraulic compensation in the form of sacrifice of fluid output if the work load increases such as by increased downhole load, so that the system slows down visibly, signalling the operator and avoiding downhole damage; wherein stopping the horseheads can be done only by cutting electrical supply to the electric motor, thereby depressurizing the system and effecting a safe and total shutdown; and wherein the positive hydraulic lock safely holds the cylinder in its stopped position indefinitely until hydraulic pre~sure is applied to release it.
DETAILED DESCRIPTION OF THE INVENTION
For this description, refer to the t`ollowhlg diagrams, wherein like nulllerals refer to like parts:
21166I~
Figure 1, an embodimenl of the inven~iom ~ide elevatioll;
Figure 2, detail of Figure 1, hydraulic system: block diagram: and Figure 2A, detail of Figure 2; manifold; block diagram.
In the example of the invented apparatus shown in Figure I, pump jack indicated generally as 10 is of a type common in the petroleum-pumping industry, and consists of a fulcrum beam 12 with horseheads on either end, a well-head horsehead 14 and a balance horsehead 16. The precise shape and placement of the horseheads 14 and 16 are specific to this invention, and will be discussed in more detail below.
The elements just described are supported on a saddle bearing 18, in turn supported by A-leg braces 2(), welded steel base 22. concrete hase pa(l 24. and finally gravel pad 26.
Hanging t`rom horsehead 14 is well rod linkage indicated generally as 30.
Hanging from balance horsehead 16 are corresponding equalizer linkage 40 and from it equalizer weight 42. Safety fence 4~ surrounds equalizer 42.
Also indicated on Figure I are electric-hydraulic drive system components such as piston 44 connected to fulcrum beam 12 at the ad justable pivot 1 ~; hydraulic cylinder 46; hydraulic manifold indicated generally as 48; dual counterbalance valve, comprising a positive lock, indicated generally as 50; proximity switches 52, upper, and 54, lower; pressure gauge 56; hydraulic pump 58; electric motor 6(); hydraulic reservoir 62; and fluid lines generally indicated as 90 (shown in partial length only~.
Additional components are indicated on Figure 2 and 2A: a block di.lgl~ ol`
~he electric-hydraulic drive system is ~enerally indicated a~ 7() on Figure 2. On Figure 2 can be seen additionally the placement of pressure relief valve 72, manual snubber valve 57, and back pressure check valve 74 on line generally indicated as 9(), and dual counterbalance valve 80 on isolated second fluid line generally indicated as 92. Figure 2A is an enlarget1lent of the block diagral1l of the hydraulic m,lllit`ol(l 4X~ showillg 2I1661~
solenoid-controlled valves 76 and 78 and associated manual needle valves 76a and 78a respectively on line 90.
Refore detailillg lhe operalioll of Ihe appar.~ imrorl.lnl lo note. with reference to Figure 1, that outer surfaces 14e and 16e respeclively of horsehea(ls 14 and 16 are portions of the circumference of circles measured from bearing 18, and have different radiuses Rl and R2 respectively. These distances are same as the horizontal distances D 1 and D2, respectively, between center 100 of saddle bearing 18 and the horizontal centers of well rod linkage 30 and balance rod linkage 4(). This ensures that there is no pressure on the linkages from side loading; all the force will be delivered smoothly in the vertical direction. Horizontal forces c~use wellhe~(l p;lcking to we~r ~nd can create a hazardous blowout condition; and energy is wasted in the general running of the system if all the t`orce is not used to vertically drive well rod linkage 30. Accordingly, in order to deliver any desired specific height, indicated as 3(~x, of vertical stroke in well rod linkage 30, the outer circumference of well-head horsehead 14 measured between points 14b and 14c is fashioned equal to at least this distance 30x, plus an extra amount 30y, equal to the distance between points 14a and 14b, to facilitate tapping bottom in the well without having to make difficult adjustments to the equipment. The circumference of balance horsehead 16 is fashioned this same amount 30x, measured between points 16a and 16b, plus the same extra amount 30y, between points 16b and 16c (note that Figure I
is not a scale drawing). Weight of equalizer 42 is calculated, using well-known simple geometric techniques, from the moments of gravitational force of the (lownhole load (not shown); well rod linkage 30; balance linkage 40; horseheads 14 and 16; and fulcrum beam 12.
The apparatus operates as follows. Engagement of electric motor 60, seen on Figure I, drives pump ~, moving hydraulic fluid (not shown) from reservoir 62 into primary line 90. As can be seen best with ret`erence to hydraulic ~low block diagram, Figure 2, tlui(l is then routed Ihrough marlual v.llve 57, ~o the pre~sure sg.luge 56, an(l through hack pressllre check valve 74. past pressure releas~ v;llve 72, all(l intO hy(lralllic manifold 4X. In the enlarged detail of the Inanifold, Figllre 2A, il call be seell ~hat Illlid is then routed through electrically-controlled solenoid valves 76 and 78 and correspondillg manual needle valves 76a and 78a, and presses hydraulically on isolaled hydraulic line 92. Although this is not indicated expressly on the simplified schematic of hydraulic manifold 48 shown on Figure 2, the solenoids 76 and 78 determine the manifold direction; i.e. pressure is applied alternatingly to line 92a and line 92b. Referril1g agaill to Figure 2, the pressure can be seen to flow through dual counterbalance valve 80 and then directly into cylinder 46 to drive piston 44. Ad jll~tahle pr(~imity switches 52 and 54, as seen on Figure 1, are triggered by position indicator 53 alternatingly during the motion of fulcrum beam 12, and form electrical connection with solenoid valves 76 and 78 shown on Figure 2A, to determine the direction of fluid pressure through manifold 48. The position of switches 52 and 54 is adjustable, which will in turn change the amplitude of rotation of the horseheads 16 and 14; this adjustment can be used to control tapping bottom in the well more safely and easily than the changing of clamps and bolts required in the prior art.
An important feature of this system is the isolation of line 92 from line 90, allowing a soft shift spool so that all ports in line 92 and dual counterhalance valve 80 are open in the shifting and the neutral positions. This avoids hydraulic fluid "dead-head"
found in previous mechanical over hydraulic, or electrical over hydraulic systems, in which pressure rose until it reached a pre-set bypass setting. This was very inefficient and hard on the pumps, cylinders, and hydraulic fittings. Also note that manual needle valves 76a and 78a in the present invention allow further adjustment to avoid hydraulic fluid hammering and inefficient installtalleous direction changes, which in previous systellls caused rod stretch and hammering on mechanical parts such as the cylinder.
A further advalltage of tllis hydraulic over hydr.llllic sy~lelll in reliatioll lo previous systems is hydraulic compensation, in whicll the .nlnount -f tluid output is saclificed if the work load h~creases. Thus i~ cylhl(ler 44 hl Figllre 2 resi~cts more strongly than usual due to a downhole problem (not shown), increased pressure in isolated fluid line 92 will mechanically affect the action of manifold 4X, allowin~ for a drop in the amount of fluid and automatic slowdown of the movement of fulcrum beam 12 of Figure t. This is very advantageous, both as a signalling mechanism to an operator, and to avoid damage to downhole parts.
The eleclrical system l`or the illustrated example is ~Iraightforwilrd and will not be diagrammed. lf radius Rl from Figure I is 4 feet I I inches and all otherdimensions are proportional, then an appropriate power supply for this particular size of pump jack 10 is a 3 horsepower, enclosed, fan cooled motor. Main power supply could be a 3-phase, 480 volt alternating current, or adapted to suit any available voltage such as 240 volt single-phase. The power circuit has a main disconnecting means, a magnetic starter, and overload protection.
The correspondhlg control circuit (not diagrammed) is a 1 2()V A.C~. from a 4-1 stepdown transformer. The control starts at the transformer and goes to an on-off switch located in a control panel. From there it travels to a hand switch installed near the pump.
After this it goes to a pressure switch on the wellhead to monitor wellhead pressure: this switch will interrupt the control circuit if a preset pressure is reached. If all these are electrically satisfied then the electric pump, such as pump 60 on Figure 1, starts and drives the hydraulic system as detailed above. Proximity switches, shown as 52 and ~4 on Figure 1, are linked by a simple relay (not diagrammed) to solenoids 76 and 78, seen in Figure 2A in manifold 48. Note that an important safety feature of this set-up is that the pump jack 10 can only have its motion stopped by cutting electrical supply to the entire control circuit, for a safe and total shut-down. In other words, the dangerous 21~
` -configuratioll used by previous systems in which a fulcr~ be~m i~ mech-lllically locked while a pressulized hydraulic system i~ still eleclric.llly dl-ivel~ nvoide(l.
A final important safety control of the apparatus is a posilive hydraulic lock, incorporated in dual counterbalance valve 5() in Figure 1, which holds piston 44 of cylinder 46 in a stopped position without relying on hydraulic fluid pressure, which has been used by previous systems and risks a free-falling fulcrum beam in the event of a hose, valve or fitting leak or break.
The foregoing is by exalllple only, and ll~e scope ol tl~e h~venlion shoul-l be limited only by the appended claims.
Large areas of central North America are spotted with pumpjacks recovering underground petroleum fluids for domestic and commercial use; the present invention provides an important reduction in the amount of energy required to drive the pump jack, as well as certain other advantages. Most centrally it applies an improved hydraulic control system to manage the balanced movement of the horseheads, although aspects of the weighting and geometric placement of the heads and fulcrum beam are also addressed.
The existing prior art and commercially operating machines are of many types, spanning many decades, and no attempt to exhaustively itemi~e the less efficient pump jacks will be made. For this analysis they may be said to t`all into two broad categories: those using direct mechanical linkages, and those hydraulically driven. The present invention is of the second type. Advantages including reduced mechanical wear, and hence maintenance costs, are realized by the use of hydraulics, such as specified in U.S. patent #3,369,490 (Hawk, 1968), and C~n~ n patents ~906,477 (Maasshoff, 1972);
#921,768 (Maasshoff, 1973); #994,21 1 ((~oldfein, 1976): #1.164.270 (Creamer, 1984);
and #1,193,345 (Creamer, 198~).
The layout of the hydraulics and the geometry of Ihe horseheads and fulcrum determines how efficient the pump jack is; and the cited jacks have appreciable losses from their hydraulic systems and balancing geometry. Some use a mechanical control of the hydraulic system; some have progressed to an electrical: but in all Ihe hydraulic cylinder ports are blocked in the neutral position, and pressure soars until it reaches a pre-set by-pass setting, which is very inefficient and hard on the pump, cylinder, and hydraulic fittings. As well, if the work load increases, the hydraulic system continues to drive, or drives until a safety cut-off pressure is reached and a sudden total shut-down is initiated. This can result in long-term inefficient--and eventually damaging--action, if 21~6614 there is an unnoticed downhole problem.
The present invention dramatically reduces the friction and heat losses and wear on the hydraulic parts by providing a variable output pllmp with electrical over hydraulic over hydraulic valve control of the cylinder driving the pump jack. This allows a soft shift spool in normal operation (all ports are open in the shit`ting and neutr.ll positions) greatly increasing efficiency. This is further enhanced by manually adjustable needle valves which feather the action of the cylinder by controlling the speed of the hydraulically actuated valve, hence avoiding hydraulic fluid hammering and instantaneous direction changes which cause energy losses.
Also incorporated are hydraulic compensators that will sacrifice the amount of fluid output if the work load increases. This is very important in that it gives early indication of downhole complications by actually slowing down the speed of the jack, which can be visually noticed by a well operator. This compensation also reduces the strain on the pump jack and downhole equipment in load-increase situations, saving the downhole equipment from damage. To the inventor's knowledge no other pump jack is capable of this feature.
Another advantage of the present invention is that tapping bottom in the well can be done easily by adjusting proximity switches instead of difficult manual removal of bolts on a clamp above a stuffing box, as is currently done. As well, normal speed of the jack motion is easily changed by varying the output of the pump, instead of the mechanical changing of pulley and belt sizes. Both of these features mean major advantages in time, convenience~ safety, and maintenance.
Finally, two important and unique safety features are incorporated. One is to have a positive hydraulic lock that will hold the cylinder in its stopped position indefinitely until hydraulic pressure is applied to release it. This avoids the problems of prior safety locks that rely on the all-ports-blocked hydraulic valve to hold the walking 21~6614 beam; as the spool wears, this creates an unsate condition ~Secondly, the present invention can only be stopped by cutting the electrical sllr ply to the control valve; in other words. a safe and total shutdown. instead of a shut(lown which leaves pressurized hydraulics or active electrical systems (or both), as past systems have done.
An object of the present invention is to provide t`or an oil-well pump jack driven by an electric-hydraulic drive system;
the pump jack comprising: a fulcrum beam; on a saddle bearing; the beam having on one end ~ well-head horsehead with the l`ace tarthe~t from the bearing being a convex portion ol` a circle circumference whose radius is the distance to the center of the bearing, and on the other a balance horsehead with a corresponding face similarly measured from the center of the bearing but extending further downwards in order to facilitate tapping bottom of the well; well rod linkage connecting the well-head horsehead with a well-head downhole load; balance rod linkage connecting the balance hor~ehead with an equalizer; A-leg braces supporting the saddle bearing; and a welded steel base on a concrete base pad on a gravel pad, supporting the A-leg braces:
the electric-hydraulic drive system comprising: a piston driving the tulcrum beam; a hydraulic cylinder providing hydraulic fhlid driving the piston; two input/output ports from the cylinder; a dual counterbalance valve connected to the two ports; a hydraulic manifold controlling the supply of hydraulic tluid to the cylinder: the manifold comprising:
two controlled hydraulic fluid output lines, one communicating with each input/output port through the counterbalance valve; two pressurized hydraulic fluid input lines, both communicating with a hydraulic fluid reservoir and isolated from the hydraulic fluid output lines; a hydraulically piloted hydraulic valve for each fluid output line: a solenoid-controlled hydraulic pilot valve for each piloted valve; a solenoid controlling each pilot valve; electric control of the 211GSl~
-solenoids; and additional manual control of each pilot valve:
a positive lock on the hydraulic cylinder: ad jus~ahle switching me.lns to change the direction of tlow of the hydraulic fluid in the manifold at a chosen extent of the horsehead movement cycle; a pressure relief valve; a back pressure check valve; an electrically-monitored pressure gauge; a variable-displacement hydraulic pump; an hydraulic reservoir; an electric motor; a control circuit controlling the electric motor; and a power circuit to supply electric power to the electric motor;
wherein the equalizer is provided of such weighl as to counterbalance the downhole load evenly without exerting horizontal forces on the well rod linkage: wherein this even counterbalancing is arrived at by calculating the moments of gravitational force of the fulcrum, horseheads, well rod linkage, and downhole load, and by specifying the radii of the horseheads; wherein engagement of the electric motor engages the pump and drives the cylinder and hence fulcrum beam and well-head and halancing horseheads;
wherein the electric-hydraulic over hydraulic valves provide soft shift spool in normal operation, enhanced by manual adjustment; wherein the electric-hydraulic over hydraulic control, in being two separate hydraulic fluid circuits, provides hydraulic compensation in the form of sacrifice of fluid output if the work load increases such as by increased downhole load, so that the system slows down visibly, signalling the operator and avoiding downhole damage; wherein stopping the horseheads can be done only by cutting electrical supply to the electric motor, thereby depressurizing the system and effecting a safe and total shutdown; and wherein the positive hydraulic lock safely holds the cylinder in its stopped position indefinitely until hydraulic pre~sure is applied to release it.
DETAILED DESCRIPTION OF THE INVENTION
For this description, refer to the t`ollowhlg diagrams, wherein like nulllerals refer to like parts:
21166I~
Figure 1, an embodimenl of the inven~iom ~ide elevatioll;
Figure 2, detail of Figure 1, hydraulic system: block diagram: and Figure 2A, detail of Figure 2; manifold; block diagram.
In the example of the invented apparatus shown in Figure I, pump jack indicated generally as 10 is of a type common in the petroleum-pumping industry, and consists of a fulcrum beam 12 with horseheads on either end, a well-head horsehead 14 and a balance horsehead 16. The precise shape and placement of the horseheads 14 and 16 are specific to this invention, and will be discussed in more detail below.
The elements just described are supported on a saddle bearing 18, in turn supported by A-leg braces 2(), welded steel base 22. concrete hase pa(l 24. and finally gravel pad 26.
Hanging t`rom horsehead 14 is well rod linkage indicated generally as 30.
Hanging from balance horsehead 16 are corresponding equalizer linkage 40 and from it equalizer weight 42. Safety fence 4~ surrounds equalizer 42.
Also indicated on Figure I are electric-hydraulic drive system components such as piston 44 connected to fulcrum beam 12 at the ad justable pivot 1 ~; hydraulic cylinder 46; hydraulic manifold indicated generally as 48; dual counterbalance valve, comprising a positive lock, indicated generally as 50; proximity switches 52, upper, and 54, lower; pressure gauge 56; hydraulic pump 58; electric motor 6(); hydraulic reservoir 62; and fluid lines generally indicated as 90 (shown in partial length only~.
Additional components are indicated on Figure 2 and 2A: a block di.lgl~ ol`
~he electric-hydraulic drive system is ~enerally indicated a~ 7() on Figure 2. On Figure 2 can be seen additionally the placement of pressure relief valve 72, manual snubber valve 57, and back pressure check valve 74 on line generally indicated as 9(), and dual counterbalance valve 80 on isolated second fluid line generally indicated as 92. Figure 2A is an enlarget1lent of the block diagral1l of the hydraulic m,lllit`ol(l 4X~ showillg 2I1661~
solenoid-controlled valves 76 and 78 and associated manual needle valves 76a and 78a respectively on line 90.
Refore detailillg lhe operalioll of Ihe appar.~ imrorl.lnl lo note. with reference to Figure 1, that outer surfaces 14e and 16e respeclively of horsehea(ls 14 and 16 are portions of the circumference of circles measured from bearing 18, and have different radiuses Rl and R2 respectively. These distances are same as the horizontal distances D 1 and D2, respectively, between center 100 of saddle bearing 18 and the horizontal centers of well rod linkage 30 and balance rod linkage 4(). This ensures that there is no pressure on the linkages from side loading; all the force will be delivered smoothly in the vertical direction. Horizontal forces c~use wellhe~(l p;lcking to we~r ~nd can create a hazardous blowout condition; and energy is wasted in the general running of the system if all the t`orce is not used to vertically drive well rod linkage 30. Accordingly, in order to deliver any desired specific height, indicated as 3(~x, of vertical stroke in well rod linkage 30, the outer circumference of well-head horsehead 14 measured between points 14b and 14c is fashioned equal to at least this distance 30x, plus an extra amount 30y, equal to the distance between points 14a and 14b, to facilitate tapping bottom in the well without having to make difficult adjustments to the equipment. The circumference of balance horsehead 16 is fashioned this same amount 30x, measured between points 16a and 16b, plus the same extra amount 30y, between points 16b and 16c (note that Figure I
is not a scale drawing). Weight of equalizer 42 is calculated, using well-known simple geometric techniques, from the moments of gravitational force of the (lownhole load (not shown); well rod linkage 30; balance linkage 40; horseheads 14 and 16; and fulcrum beam 12.
The apparatus operates as follows. Engagement of electric motor 60, seen on Figure I, drives pump ~, moving hydraulic fluid (not shown) from reservoir 62 into primary line 90. As can be seen best with ret`erence to hydraulic ~low block diagram, Figure 2, tlui(l is then routed Ihrough marlual v.llve 57, ~o the pre~sure sg.luge 56, an(l through hack pressllre check valve 74. past pressure releas~ v;llve 72, all(l intO hy(lralllic manifold 4X. In the enlarged detail of the Inanifold, Figllre 2A, il call be seell ~hat Illlid is then routed through electrically-controlled solenoid valves 76 and 78 and correspondillg manual needle valves 76a and 78a, and presses hydraulically on isolaled hydraulic line 92. Although this is not indicated expressly on the simplified schematic of hydraulic manifold 48 shown on Figure 2, the solenoids 76 and 78 determine the manifold direction; i.e. pressure is applied alternatingly to line 92a and line 92b. Referril1g agaill to Figure 2, the pressure can be seen to flow through dual counterbalance valve 80 and then directly into cylinder 46 to drive piston 44. Ad jll~tahle pr(~imity switches 52 and 54, as seen on Figure 1, are triggered by position indicator 53 alternatingly during the motion of fulcrum beam 12, and form electrical connection with solenoid valves 76 and 78 shown on Figure 2A, to determine the direction of fluid pressure through manifold 48. The position of switches 52 and 54 is adjustable, which will in turn change the amplitude of rotation of the horseheads 16 and 14; this adjustment can be used to control tapping bottom in the well more safely and easily than the changing of clamps and bolts required in the prior art.
An important feature of this system is the isolation of line 92 from line 90, allowing a soft shift spool so that all ports in line 92 and dual counterhalance valve 80 are open in the shifting and the neutral positions. This avoids hydraulic fluid "dead-head"
found in previous mechanical over hydraulic, or electrical over hydraulic systems, in which pressure rose until it reached a pre-set bypass setting. This was very inefficient and hard on the pumps, cylinders, and hydraulic fittings. Also note that manual needle valves 76a and 78a in the present invention allow further adjustment to avoid hydraulic fluid hammering and inefficient installtalleous direction changes, which in previous systellls caused rod stretch and hammering on mechanical parts such as the cylinder.
A further advalltage of tllis hydraulic over hydr.llllic sy~lelll in reliatioll lo previous systems is hydraulic compensation, in whicll the .nlnount -f tluid output is saclificed if the work load h~creases. Thus i~ cylhl(ler 44 hl Figllre 2 resi~cts more strongly than usual due to a downhole problem (not shown), increased pressure in isolated fluid line 92 will mechanically affect the action of manifold 4X, allowin~ for a drop in the amount of fluid and automatic slowdown of the movement of fulcrum beam 12 of Figure t. This is very advantageous, both as a signalling mechanism to an operator, and to avoid damage to downhole parts.
The eleclrical system l`or the illustrated example is ~Iraightforwilrd and will not be diagrammed. lf radius Rl from Figure I is 4 feet I I inches and all otherdimensions are proportional, then an appropriate power supply for this particular size of pump jack 10 is a 3 horsepower, enclosed, fan cooled motor. Main power supply could be a 3-phase, 480 volt alternating current, or adapted to suit any available voltage such as 240 volt single-phase. The power circuit has a main disconnecting means, a magnetic starter, and overload protection.
The correspondhlg control circuit (not diagrammed) is a 1 2()V A.C~. from a 4-1 stepdown transformer. The control starts at the transformer and goes to an on-off switch located in a control panel. From there it travels to a hand switch installed near the pump.
After this it goes to a pressure switch on the wellhead to monitor wellhead pressure: this switch will interrupt the control circuit if a preset pressure is reached. If all these are electrically satisfied then the electric pump, such as pump 60 on Figure 1, starts and drives the hydraulic system as detailed above. Proximity switches, shown as 52 and ~4 on Figure 1, are linked by a simple relay (not diagrammed) to solenoids 76 and 78, seen in Figure 2A in manifold 48. Note that an important safety feature of this set-up is that the pump jack 10 can only have its motion stopped by cutting electrical supply to the entire control circuit, for a safe and total shut-down. In other words, the dangerous 21~
` -configuratioll used by previous systems in which a fulcr~ be~m i~ mech-lllically locked while a pressulized hydraulic system i~ still eleclric.llly dl-ivel~ nvoide(l.
A final important safety control of the apparatus is a posilive hydraulic lock, incorporated in dual counterbalance valve 5() in Figure 1, which holds piston 44 of cylinder 46 in a stopped position without relying on hydraulic fluid pressure, which has been used by previous systems and risks a free-falling fulcrum beam in the event of a hose, valve or fitting leak or break.
The foregoing is by exalllple only, and ll~e scope ol tl~e h~venlion shoul-l be limited only by the appended claims.
Claims (14)
1. An oil pumping jack driven by an electric-hydraulic drive system comprising at least an electric-hydraulic manifold controlling two separate hydraulic fluid circuits by means of a hydraulic over hydraulic valve that provides soft shift spool in normal operation.
2. An apparatus as in Claim 1, in which hydraulic compensation in the form of sacrifice of fluid output is provided if the work load increases, so that the system slows down visibly, signalling the operator and avoiding downhole damage.
3. An apparatus as in Claim 1, wherein moments of gravitational force of portions of the pump jack, including at least: fulcrum beam; horseheads; well rod linkage;
and downhole load, are used to calculate the weight of an equalizer that counterbalances the downhole load evenly so that there are no horizontal forces on the well rod linkage during normal operation.
and downhole load, are used to calculate the weight of an equalizer that counterbalances the downhole load evenly so that there are no horizontal forces on the well rod linkage during normal operation.
4. An apparatus as in Claim 3, wherein said absence of horizontal forces is further ensured by fashioning each of the horseheads to have their face farthest from the center of rotation of the fulcrum beam be a portion of a convex circumference whose radius is the distance to the center of rotation of the fulcrum beam.
5. An apparatus as in Claim 1, wherein stopping the movement of the pump jack can be done only by interrupting an overall electric control circuit, thereby depressurizing the system and effecting a safe and total shutdown.
6. An apparatus as in Claim 1, wherein a positive hydraulic lock safely holds the pump jack in its stopped position.
7. An apparatus as in Claim 1, wherein tapping bottom in the well is controlled by adjustment of proximity switches controlling depth of stroke of the jack.
8. An apparatus in Claim 1, in which speed of the jack is controlled by adjusting the output of a variable output pump.
9. An oil-well pump jack driven by an electric-hydraulic drive system;
the pump jack comprising at least:
a fulcrum beam; a saddle bearing; a well-head horsehead; a balance horsehead; well rod linkage; balance rod linkage; equalizer; and support means;
the electric-hydraulic drive system comprising at least:
a hydraulic cylinder;
a dual counterbalance valve:
a hydraulic manifold comprising at least:
electrical control over two separate hydraulic fluid circuits, including a hydraulic over hydraulic valve; and additional manual control of said valve;
a positive lock on the hydraulic cylinder; and adjustable switching means to change the direction of flow of the hydraulic fluid in the manifold at a chosen extent of the horsehead movement cycle;
wherein the electric-hydraulic over hydraulic valves provide soft shift spool in normal operation, optionally enhanced by the manual control.
the pump jack comprising at least:
a fulcrum beam; a saddle bearing; a well-head horsehead; a balance horsehead; well rod linkage; balance rod linkage; equalizer; and support means;
the electric-hydraulic drive system comprising at least:
a hydraulic cylinder;
a dual counterbalance valve:
a hydraulic manifold comprising at least:
electrical control over two separate hydraulic fluid circuits, including a hydraulic over hydraulic valve; and additional manual control of said valve;
a positive lock on the hydraulic cylinder; and adjustable switching means to change the direction of flow of the hydraulic fluid in the manifold at a chosen extent of the horsehead movement cycle;
wherein the electric-hydraulic over hydraulic valves provide soft shift spool in normal operation, optionally enhanced by the manual control.
10. An apparatus as in Claim 9, in which the electric-hydraulic over hydraulic control provides hydraulic compensation in the form of sacrifice of fluid output if the work load increases such as by increased downhole load, so that the pump jack slows down visibly, signalling the operator and avoiding downhole damage.
11. An apparatus as in Claim 9, wherein the equalizer is provided of such weight as to counterbalance the downhole load evenly without exerting horizontal forces on the well rod linkage, and this even counterbalancing is arrived at by calculating the moments of gravitational force of the fulcrum, horseheads, well rod linkage, anddownhole load; and further arrived at by specifying the horseheads to have their face farthest from the center of rotation of the fulcrum beam be a convex portion of a circle circumference whose radius is the distance to the center rotation.
12. An apparatus as in Claim 9, in which the electric-hydraulic system further comprises an electric control system driven by an electric motor, including an electric control of the adjustable switching means.
13. An apparatus as in Claim 12, in which electric control of the adjustable switching means comprises proximity switches, and said proximity switches can beadjusted to control amplitude of rotation of the horseheads and hence to tap bottom in the well.
14. An apparatus as in Claim 12 in which the control system comprises additionally a shut-off that simultaneously interrupts said control system and depressurizes the hydraulic system, thereby effecting a safe and total shutdown.15. An apparatus as in Claim 11, comprising additionally a positive hydraulic lock that safely holds the cylinder, and hence the fulcrum beam, in its stopped position indefinitely until hydraulic pressure is applied to release it.
16. An oil-well pump jack driven by an electric-hydraulic drive system;
the pump jack comprising:
a fulcrum beam; on a saddle bearing; the beam having on one end a well-head horsehead with the face farthest from the bearing being a convex portion of a circle circumference whose radius is the distance to the center of the bearing, and on the other a balance horsehead with a corresponding face similarly measured from the center of the hearing but extending further downwards in order to facilitate tapping bottom of the well;
well rod linkage connecting the well-head horsehead with a well-head downhole load;
balance rod linkage connecting the balance horsehead with an equalizer;
A-leg braces supporting the saddle bearing; and a welded steel base on a concrete base pad on a gravel pad, supporting the A-leg braces;
the electric-hydraulic drive system comprising:
a piston driving the fulcrum beam;
a hydraulic cylinder providing hydraulic fluid driving the piston;
two input/output ports from the cylinder;
a dual counterbalance valve connected to the two ports;
a hydraulic manifold controlling the supply of hydraulic fluid to the cylinder; the manifold comprising:
two controlled hydraulic fluid output lines, one communicating with each input/output port through the counterbalance valve;
two pressurized hydraulic fluid input lines, both communicating with a hydraulic fluid reservoir and isolated from the hydraulic fluid output lines;
a hydraulically piloted hydraulic valve for each fluid output line;
a solenoid-controlled hydraulic pilot valve for each piloted valve;
a solenoid controlling each pilot valve;
electric control of the solenoids; and additional manual control of each pilot valve;
a positive lock on the hydraulic cylinder;
adjustable switching means to change the direction of flow of the hydraulic fluid in the manifold at a chosen extent of the horsehead movement cycle;
a pressure relief valve;
a back pressure check valve;
an electrically-monitored pressure gauge;
a variable-displacement hydraulic pump;
a hydraulic reservoir;
an electric motor;
a control circuit driven by the electric motor; and a power circuit to supply electric power to the electric motor;
wherein the equalizer is provided of such weight as to counterbalance the downhole load evenly without exerting horizontal forces on the well rod linkage;
wherein this even counterbalancing is arrived at by calculating the moments of gravitational force of the fulcrum, horseheads, well rod linkage, and downhole load, and by specifying the radii of the horseheads;
wherein engagement of the electric motor engages the pump and drives the cylinder and hence fulcrum beam and well-head and balancing horseheads;
wherein the electric-hydraulic over hydraulic valves provide soft shift spool in normal operation, enhanced by manual adjustment;
wherein the electric-hydraulic over hydraulic control, in being two separate hydraulic fluid circuits, provides hydraulic compensation in the form of sacrifice of fluid output if the work load increases such as by increased downhole load, so that the system slows down visibly, signalling the operator and avoiding downhole damage;
wherein stopping the horseheads can be done only by cutting electrical supply from the electric motor, thereby depressurizing the system and effecting a safe and total shutdown; and wherein the positive hydraulic lock safely holds the cylinder in its stopped position indefinitely until hydraulic pressure is applied to release it.
17. An apparatus as in Claim 16, in which speed of the jack is controlled by adjusting the output of the variable-displacement hydraulic pump.
16. An oil-well pump jack driven by an electric-hydraulic drive system;
the pump jack comprising:
a fulcrum beam; on a saddle bearing; the beam having on one end a well-head horsehead with the face farthest from the bearing being a convex portion of a circle circumference whose radius is the distance to the center of the bearing, and on the other a balance horsehead with a corresponding face similarly measured from the center of the hearing but extending further downwards in order to facilitate tapping bottom of the well;
well rod linkage connecting the well-head horsehead with a well-head downhole load;
balance rod linkage connecting the balance horsehead with an equalizer;
A-leg braces supporting the saddle bearing; and a welded steel base on a concrete base pad on a gravel pad, supporting the A-leg braces;
the electric-hydraulic drive system comprising:
a piston driving the fulcrum beam;
a hydraulic cylinder providing hydraulic fluid driving the piston;
two input/output ports from the cylinder;
a dual counterbalance valve connected to the two ports;
a hydraulic manifold controlling the supply of hydraulic fluid to the cylinder; the manifold comprising:
two controlled hydraulic fluid output lines, one communicating with each input/output port through the counterbalance valve;
two pressurized hydraulic fluid input lines, both communicating with a hydraulic fluid reservoir and isolated from the hydraulic fluid output lines;
a hydraulically piloted hydraulic valve for each fluid output line;
a solenoid-controlled hydraulic pilot valve for each piloted valve;
a solenoid controlling each pilot valve;
electric control of the solenoids; and additional manual control of each pilot valve;
a positive lock on the hydraulic cylinder;
adjustable switching means to change the direction of flow of the hydraulic fluid in the manifold at a chosen extent of the horsehead movement cycle;
a pressure relief valve;
a back pressure check valve;
an electrically-monitored pressure gauge;
a variable-displacement hydraulic pump;
a hydraulic reservoir;
an electric motor;
a control circuit driven by the electric motor; and a power circuit to supply electric power to the electric motor;
wherein the equalizer is provided of such weight as to counterbalance the downhole load evenly without exerting horizontal forces on the well rod linkage;
wherein this even counterbalancing is arrived at by calculating the moments of gravitational force of the fulcrum, horseheads, well rod linkage, and downhole load, and by specifying the radii of the horseheads;
wherein engagement of the electric motor engages the pump and drives the cylinder and hence fulcrum beam and well-head and balancing horseheads;
wherein the electric-hydraulic over hydraulic valves provide soft shift spool in normal operation, enhanced by manual adjustment;
wherein the electric-hydraulic over hydraulic control, in being two separate hydraulic fluid circuits, provides hydraulic compensation in the form of sacrifice of fluid output if the work load increases such as by increased downhole load, so that the system slows down visibly, signalling the operator and avoiding downhole damage;
wherein stopping the horseheads can be done only by cutting electrical supply from the electric motor, thereby depressurizing the system and effecting a safe and total shutdown; and wherein the positive hydraulic lock safely holds the cylinder in its stopped position indefinitely until hydraulic pressure is applied to release it.
17. An apparatus as in Claim 16, in which speed of the jack is controlled by adjusting the output of the variable-displacement hydraulic pump.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002116614A CA2116614A1 (en) | 1994-02-28 | 1994-02-28 | Hydraulic jack pump |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002116614A CA2116614A1 (en) | 1994-02-28 | 1994-02-28 | Hydraulic jack pump |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2116614A1 true CA2116614A1 (en) | 1995-08-29 |
Family
ID=4152988
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002116614A Abandoned CA2116614A1 (en) | 1994-02-28 | 1994-02-28 | Hydraulic jack pump |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2116614A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102352737A (en) * | 2011-09-28 | 2012-02-15 | 黄天坤 | Twin-well two-way hydraulic linkage oil pumping method and adopted oil pumping device thereof |
| US9786456B2 (en) | 2014-11-20 | 2017-10-10 | Ryan Patrick CLAGGETT | Fail-safe system for process machine |
| CN108425657A (en) * | 2018-02-08 | 2018-08-21 | 西安石油大学 | A kind of hydraulic accumulation energy type dynamic balancing energy-saving pumping unit |
| CN112177908A (en) * | 2020-09-30 | 2021-01-05 | 广州钦丰科技有限公司 | Torque-variable balancer for high-end equipment manufacturing oil pumping unit |
-
1994
- 1994-02-28 CA CA002116614A patent/CA2116614A1/en not_active Abandoned
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102352737A (en) * | 2011-09-28 | 2012-02-15 | 黄天坤 | Twin-well two-way hydraulic linkage oil pumping method and adopted oil pumping device thereof |
| US9786456B2 (en) | 2014-11-20 | 2017-10-10 | Ryan Patrick CLAGGETT | Fail-safe system for process machine |
| CN108425657A (en) * | 2018-02-08 | 2018-08-21 | 西安石油大学 | A kind of hydraulic accumulation energy type dynamic balancing energy-saving pumping unit |
| CN112177908A (en) * | 2020-09-30 | 2021-01-05 | 广州钦丰科技有限公司 | Torque-variable balancer for high-end equipment manufacturing oil pumping unit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |