US3230782A

US3230782A - Pumping unit

Info

Publication number: US3230782A
Application number: US324713A
Authority: US
Inventors: Paul D Harryman; David T Oakes
Original assignee: Monsanto Co
Current assignee: Monsanto Co
Priority date: 1963-11-19
Filing date: 1963-11-19
Publication date: 1966-01-25
Anticipated expiration: 1983-01-25

Description

1966 P. D. HARRYMAN ET AL 3,230,782

PUMPING UNIT Filed Nov. 19, 1963 4 Sheets-Sheet 1 g I 3+ .11 i 2 Paul D. Horrymon BY David T. Oak

ATTORNEY Jan. 25, 1966 P. D. HARRYMAN ET AL 3,230,782

PUMPING UNIT FIG.2

INVENTOR. Paul D. Hurryman BY Dovld T. Oukes ATTORNEY Jan. 25, 1966 P. n. HARRYMAN ET AL 3,230,782

PUMPING UNIT 4 Sheets-Sheet 3 Filed Nov. 19, 1963 'Sumson Post 42 FIG. 3

*Somson Post FIG. 40

INVENTORS Paul D. Harrymun David T. Ookes ,o -rromqgy Jan. 25, 1966 P, n. HARRYMAN ET AL 3,230,782

PUMPING UNIT Filed Nov. 19, 1965 4 Sheets-Sheet 4.

FIG. 5a

66 "TITS." 66

FlG.5b

INVENTORS Paul D. Hurrymon BY David T. Oukes ATTORNEY United States Patent corporation of Delaware Filed Nov. 19, 1963, Ser. No. 324,713 Claims. (Cl. 74-41) The present invention relates to the pumping of liquids to the earths surface from subterranean liquid b'earing formations. More particularly the present invention relates to a pumping unit for pumping liquids to the earths surface from subterranean liquid-bearing formations.

Various types of artificial lifts are used to bring liquids to the surface of the earth when the pressure of the liquid-bearing reservoir is insufficient to produce the liquids by natural means. The most common type of artificial lift is one comprising a downhole rod pump reciprocably driven through a sucker rod string by a pumping jack located at the earths surface. Most often the pumping jack consists of a walking beam pivotally afiixed to a Samson Post and connected at one end to the sucker rod string and at the other end to a prime mover which supplies the energy for producing the reciprocating motion of the sucker rod string. Generally, the prime mover consists of an internal combustion engine or electric motor. The cost of this prime mover as well as its operation and maintenance is, in many instances, a significant factor in the economics of producing liquids from subterranean liquid bearing reservoirs. For this reason it is desirable to find methods of operating pumping units and also new and improved pumping units which may be operated with less expensive prime movers and at less operating and maintenance expense.

It is an object of the present invention to provide a pumping unit of new and novel design. Another object of the present invention is to provide a new and novel pumping unit for bringing liquids to the earths surface [from subterranean liquid-bearing reservoirs. Yet another objeot of the present invention is to provide a new and novel pumping unit for pumping liquids from subterranean formations with a more efiicient utilization of the energy used to drive the pumping means. Additional objects will become apparent from the following description of the invention herein disclosed.

The pumping unit which fulfills these and other objects comprises a vertically disposed supporting member having pivotally attached thereto a substantially horizontally disposed walking beam having at one end a means for attaching a sucker rod string and at the opposite end a slidably connected movable counterbalance weight, a substantially vertically disposed lever slidably engaged in a substantially vertical direction at its upper end with said movable counterbalance weight and rotaitably attached at its lower end to a revolving axis through which power is applied and rotatably attached at a mid point of said lever (to said walking beam such that as said lower end of said lever is caused to traverse the circle described by said revolving axis, said lever revolves on said mid point of attachment to said walking beam thereby imparting vertical movement to the walking beam and imparting to the opposite upper end of said lever a curved movement, the horizontal component of said movement being opposite in direction to that of the lower end, causing said movable counterbalance weight to move in a direction parallel to the surface of said walking beam in a direction oppositev to the direction of the horizontal component of the movement of the lower end of said lever.

The present invention provides two very distinct advantages -when comparedwith conventional pumping 3,239,782 Patented Jan. 25, 1966 units employing fixed counterbalance weights. The peak torque is significantly reduced by the present pumping unit "as is the work required in a particular situation. When the novel pumping unit of the present invention is compared with one having a fixed counterbalance weight of substantially the same weight, the peak torque on the gears of the pumping unit will be 5 to 8 percent lower with the present invention. The work required to complete one stroke of a pumping unit such as taught and claimed herein is found to be 6 to 9 percent less than for a similar unit counterbalanced with a conventional fixed beam counterbalance of substantially the same weight.

In order to more [fully explain and to illustrate the present invention and its several embodiments, reference is made to the accompanying diagrammatic drawings of different views and embodiments of the present invention.

FIGURE 1 is an elevational view of a surface pumping apparatus and FIGURE 2 is an elevational view of the surface pumping apparatus of FIGURE 1 as viewed from the end.

FIGURES 3, 4, and 5 are drawings of other embodiments of the present invention.

Referring first to FIGURE 1, walking bear 10 is pivotally attached to a vertical support memlber 11, hereinafter referred to as a Samson Post, so as to pivot on center bearing 12. At the front end of walking beam 10 is shown horsehead 13 connected thereto. To the horse'head 13 is attached a rod string 14 which extends into wellhead 15 and downhole to the reciprocating subsurface pump (not shown). At the other end of Walking beam 10, a counterbalancing weight 16 is slidably attached thereto. This oounterbalancing weight is attached to walking beam 10 in a manner to facilitate longitudinal movement along the surface of the walking beam. The actual method of slidably attachmg the counterbalance weight to the walking beam is well within the ability of those skilled in the art. A particularly useful method of attachment is illustrated in FIGURE 2 hereinafter described. A substantially vertically disposed lever 17, hereinafter referred to as a pitman arm, is rotatably attached to walking beam 10 so as to rotate on tail bearing 18. At its upper end, pitman arm 17 slidably engages counterbalance weight 16 by means of a connecting bar 19 attached perpendicularly to the pitman arrn. Oounterbalance weight 16 contains a vertical slot 20 laterally disposed for receiving connecting bar 19. The lower end of pitman arm 17 is rotatably connected to lever arm 21, hereinafter referred to as a crank, by means of pitman bearing 22. Crank 21 is then connected to a power source 24 by means of a crankshaft 23. In the operation of the present inventi'on the power source 24, which may be a gasoline ongine, electric motor or the like, supplies rotational energy to crankshaft 23, which rotates crank 21 on an axis described by crankshaft 23. The rotation of crank 21 rotates pitman arm 17 on pitman bearing 22 while revolving the axis described by the center of pitman bearing 22 in a circle around an axis represented by crankshaft 23. The circular movement of the base of pitman arm 17 around the axis of crankshaft 23 produces a reciprocating vertical movement in pitman arm 17 which is imparted to walking bear 10 through tail bearing 18. This reciprocating motion pivotally rotates Walking beam 10 on centerbear-ing 12 thereby producing a reciprocal vertical movement in rod string 14, thereby activating the reciprocating pump down in the well hole. As the base of pitman arm 17 revolves around the axis of crankshaft 23, the upper end of pitman arm 17 and conneoting bar 19 attached thereto move in a curved path, the horizontal component of which movement is in a direction opposite to that of the pitman arm base. As

connecting bar 19 moves it engages the sides of slot 20 causing counterbalance weight 16 'to move along the Longitudinal surface of Walking beam in the dir ction of the horizontal component of the movement of connecting bar 19. Thus, as the base of pitman arm 17 revolves around crankshaft 23, so as to produce a downward vertical movement, or downstroke of pitman arm 17 and the rear of Walking beam 10 and to produce an upward vertical movement in rod string 14, the Weight of counterbalance 16 is caused to shift further to the rear of walking beam 10 thereby decreasing the power needed to drive crankshaft 23 through the downstroke. Conversely, as the base of pitman arm 17 revolves past the downsu'oke movement and into the upstroke movement of pitman arm 17, the counterbalance weight 16 is caused to shift forward thereby reducing the power needed to drive crankshaft 23 through the upstroke. Therefore, as previously stated, the present invention significantly reduces the size of thepower source needed as well as the cost of operating and maintaining the power source.

Referring now to FIGURE 2, in which the same reference characters are used to identify the corresponding elements in FIGURE 1, walking beam 10 is shown pivotally attached to Samson Post 11 by means of center bearings 12. Counterbalance 16 is slidably attached to walking beam 10 by means of slot 25 in the under surface of counterbalance weight 16 and raised guide or' track 26. Raised guide 26 is shown on the upper surface of walking beam 10 with receiving slot 25 being shown within counterbalance weight 16. The position of raised guide 26 and slot 25 can, if desired, be reversed with raised guide 26 being on the under surface of counterbalance weight 16 and receiving slot 25 being on the upper surface of walking beam 10. The sliding contact of the adjacent surfaces of counterbalance weight 16 and walking beam 10 may be facilitated by the use of lubricants, roller hearings or other friction reducing means well within the ability of those skilled in the art. Two pitman arms-17 are shown in FIGURE 2 attached to the sides of walking beam 10 by means of tail bearings 18; The upper ends of pitman arms 17 are connected by connecting bar 19 which is positioned in laterally disposed vertical slot 20 in counterbalance weight 16.- The lower ends of pitman arms 17 are connected by meansof pitman bearings 22 to cranks 21 which are connected to a common crankshaft 23 which is driven by a power source 24. FIGURE 3 is another embodiment of this invention and shows an elevational view of a portion of the walking beam to which the counterbalance Weight is attached. In this embodiment the pitman arm is curved or bent at its upper end such that the axis of connecting bar 45 does not intersect the major axis of pitman arm 42. In FIG- URE 3, counterbalance weight 41 is slidably attached to walking beam 10 to which is rotatably attached pitman arm 42, at tail bearing 43. The upper end of pitman arm 42 is shown bent toward the point of attachment of walking beam 10 to the Samson Post. It is within: the scope of the present invention thatthe pitman arm may be curved at its upper end either toward or away from the point of attachment of walking beam 10 to the Samson Post according to the circumstances of the particular application of the present invention. Pitman arm 42 is shown to be slidably engaged with counterbalance weight 41 by means of connecting bar 45 and vertical slot 44.@

FIGURES 4A and 4B illustrate another embodiment of the present invention. FIGURE 4A shows an elevational view of a portion of the walking beam to which the counterbalance is attached and FIGURE 4B shows an end elevational view of the portion of the walking beam shown in FIGURE 4A. In this embodiment, vertically disposed grooves in the sides of the counterbalance weight are used rather than the laterally arranged vertical slot shown in FIGURES 1 and 3. In FIGURES 4A and 4B, counterbalance weight 51 is shown slidably attached to walking beam 50 which is rotatably affixed by means of tail bearings 53 to pitman arm 52. At the upper end of pitman arm 52 a short bar 55 extends perpendicular to the pitman arm into groove 54 where it engages counterbalance weight 51. To facilitate movement of short bar 55 in groove 54 a sliding shoe may be rotatably attached to the end of short bar 55 to slide in groove 54.

FIGURES 5A and 5B show another embodiment of the present invention. In the invention as depicted by this figure, the counterbalance weight is both above and below the walking beam with the walking beam passing through the counterbalance Weight. FIGURE 5A is an elevational view of a portion of the walking beam to which the counterbalance is attached and- FIGURE 5B is an end elevational view of the portion of the walking beam shown in' FIGURE 5A. To walking beam 10 is slidably attached counterbalance weight comprising upper weight 61 and lower weight 62. Pitmanarm 64 is rotatably attached to Walking beam by tail bearing 65. At its upper end pitman arm 64 has attached thereto connecting bar 66 which slidably engages the laterally disposed vertical slot 63 in the upper portion of counterbalance weight 62.

In addition to the embodiments shown by the accompanying drawings, it will be immediately apparent to those skilled in the art that many other embodiments exist. Such variations, so long as they provide for a movable counterbalance weight slidably attached to the walking beam which is caused by the pitman arm to move toward the Samson Post on the upstroke of the pitman arm and away from the Samson Post on the downstroke of the pitman arm arewithin the spirit and scope of the present invention What is claimed is:

1.- In thepumping of liquid from subterranean liquidbearing formations with pumping units comprising a subsurface reciprocating rod string pump, a sucker rod string for reciprocating said rod string pump, a walking beam pivotally attached to a vertical support and attached at one end to said sucker rod string and at the other end to a pitman for supplying pivotal motion to said walking beam,- said pitman being attached to a power means, the improvement which comprises a movable counterbalance weight slidably attached to said Walking beam on the end of said walking. beam to which said pitman is attached, said pitman being slidably connected at one end thereof to said movable counterbalance weight,- rotatably connected intermediate its ends to said walking beam and rotatably connected at its other end to a rotatable crank armon said power means.

2. In the pumping of liquid from subterranean liquidbearing formations with pumping units comprising a subsurface reciprocating rod string pump, a sucker rod string for reciprocating said rod string pump, a walking beam pivotally attached to a vertical support and attached at one end to said sucker rod string and at the other end to a pitman for supplying pivotal motion to said walking beam, said pitman being attached to a power means, the improvement which comprises a movable counterbalance weight slidably attached'to said Walking beam on the end of said walking beam to which said pitman is attached, said pitman being slidably connected at one end thereof to said-movable counterbalance weight at a point directly above the point of attachment of said pitman to said walking beam when said pitman is in a vertical position, said pitman being rotatably connected intermediate its ends to said Walking. beam and rotatably connected at its other end to a rotatable crank arm on said power means.

3. In the pumping of liquidfrom subterranean liquidbearing formations with pumping units comprising a subsurface reciprocating. rod string pump, a sucker rod string for reciprocating. said rod string pump, a walking beam pivotally attached to a vertical support and attached at one end to said sucker rod string and at the other end to a pitman for supplying pivotal motion to said walking beam, said pitman being attached to a power means, the improvement which comprises a movable counterbalance weight slidably attached to said walking beam on the end of said Walking beam to which said pitman is attached, said pitman being slidably connected by means of a substantially horizontal connecting bar at one end thereof to said movable counterbalance weight, said pitman being rotatably connected intermediate its ends to said walking beam and rotatably connected at its other end to a rotatable crank arm on said power means, said pitman being bent at its upper end such that the horizontal axis of said connecting bar does not intersect the longitudinal axis of that portion of the pitman connecting said crank arm to said walking beam.

4. In the pumping of liquid from subterranean liquidbearing formations with pumping units comprising a subsurface reciprocating rod string pump, a sucker rod string for reciprocating said rod string pump, a walking beam pivotally attached to a vertical support and attached at one end to said sucker rod string and at the other end to a pitman for supplying pivotal motion to said walking beam, said pitman being attached to a power means, the improvement which comprises a movable counterbalance weight slidably attached to said walking beam on the end of said walking beam to which said pitman is attached, said pitman being slidably engaged at one of its ends with said movable counterbalance Weight by means of a connecting bar positioned such as to be perpendicular to said pitman, Which connecting bar engages said counterbalance weight in a laterally disposed vertical slot in said counterbalance weight, said pitman being rotatably 6 connected intermediate its ends to said Walking beam and rotatably connected at its other end to a rotatable crank arm on said power means.

5. In the pumping of liquid from subterranean liquidbearing formations with pumping units comprising a subsurface reciprocating rod string pump, a sucker rod string for reciprocating said rod string pump, a walking beam pivotally attached to a vertical support and attached at one end to said sucker rod string and at the other end to a pitman for supplying pivotal motion to said walking beam, said pitman being attached to a power means, the improvement which comprises a movable counterbalance weight slidably attached to said Walking beam on the end of said walking beam to which said pitman is attached, said pitman being slidably engaged at one of its ends with said movable counterbalance weight by means of a bar perpendicularly attached to said pitman and slidably engaged with a vertically disposed groove in said counterbalance weight, said pitman being rotatably connected intermediate its ends to said walking beam and rotatably connected at its other end to a rotatable crank arm on said power means.

References Cited by the Examiner UNITED STATES PATENTS 1,293,609 2/1919 Dayton 744l 1,795,922 3/1931 Baker 7441 1,891,552 12/1932 McCroSky 74-41 2,198,348 4/1940 Porter 74-41 BROUGHTON G. DURHAM, Primary Examiner.

Claims

1. IN THE PUMPING OF LIQUID FROM SUBTERRANEAN LIQUIDBEARING FORMATIONS WITH PUMPING UNITS COMPRISING A SUBSURFACE RECIPROCATING ROD STRING PUMP, A SUCKER ROD STRING FOR RECIPROCATING SAID ROD STRING PUMP, A WALKING BEAM PIVOTALLY ATTACHED TO A VERTICAL SUPPORT AND ATTACHED AT ONE END TO SAID SUCKER ROD STRING AND AT THE OTHER END TO A PITMAN FOR SUPPLYING PIVOTAL MOTION TO SAID WALKING BEAM, SAID PITMAN BEING ATTACHED TO A POWER MEANS, THE IMPROVEMENT WHICH COMPRISES A MOVABLE COUNTERBALANCE WEIGHT SLIDABLY ATTACHED TO SAID WALKING BEAM ON THE END OF SAID WALKING BEAM TO WHICH SAID PITMAN IS ATTACHED, SAID PITMAN BEING SLIDABLY CONNECTED AT ONE END THEREOF TO SAID MOVABLE COUNTERBALANCE WEIGHT, ROTATABLY CONNECTED INTERMEDIATE ITS ENDS TO SAID WALKING BEAM AND ROTATABLY CONNECTED AT ITS OTHER END TO A ROTATABLE CRANK ARM ON SAID POWER MEANS.