US1882069A - Oil well pumping equipment and system - Google Patents

Description

2 Sheets-Sheet l E. C. EKSTROMER OIL WELL PUMPING EQUIPMENT AND SYSTEM Filed Jan. 3, 1928 oct. 11, 1932.

Uct. l1, 1932. E. c. EKsTRoMER OIL WELL PUMPING EQUIPMENT AND SYSTEM Fiied Jan. 5. 1928 2 Sheets-Sheet INVENTOR. 6. 25J/bmw iras vtamme natuur EDWARD C. EKSTROMER, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, F ONE-HALF TO JAMES F. GALLAGHEIR, OF BOSTON, MASSA- CHUSETTS, AND ONE-HALF TO THE EDWARD C. EKSTROMER CORPORATION, OF RENO, NEVADA, A CORPORATION OIE' NEVADA` Y ont.` wm PUMPING' EQUIPMENT AND ssrsrn'Ji/ry application linea January 3, 192s. serial No. 244,208.

My present invention relates to oil Well pumping apparatus and a control means therefor and more particularly to an improved arrangement of electric motors and\ E control. l

An object of my vinvention is to provide an improved form of oil well pump wherein the Aelectric motors and the pump can be low-v ered as a unit into the well.

Another object of my invention is to provide an improved arrangement of motors for oil well pumps and the like, whereby a power unit of any 'desiredcapacity can be obtained without necessitating an enlargement of the well casing.l

A further object of my invention is to pro-v vide an electrically driven reciprocating pump unit for deep well pumping which can be lowered in a casing and controlledfrom the surface without the use of reversing Y switches within the well.

Another object of my invention is to provide a driving means for an oil well pump which will permit the use of a number of individual motors. y

A further object of my invention is to provide a control system whereby a reversible electric motor Jfor driving a reciprocating pump can be reversed and the pump Stroke varied without the use of reversing limit switches. p I

Another object of my invention is to provide an improved reversible motor drive for an oil well reciprocating pump wherein a plurality of motors operating in tandem are used to operate the pump. 1

A further object of my invention is to provide a system of control for a plurality of motors acting in tandem upon the same load whereby the number of motors so operating will be controlled in response to variations in the load.

Other objects and advantageous `features, some-of which with the foregoing will be set forth at length in the following description wherein I have outlined in 'full that form of apparatus which I have selected for illustratlon in the drawings accompanying and 'forming a part of this specification. 5G At the present time oil well pumps of the reciprocating type are operated by means of a motive power unit located on the surface at the top of the well. These units comprise a prime mover, a walking beam which is oscillated by means of a pitman connected to the` prime mover and a sucker rod which Arod extends downwardly into the well where it connects to the moving parts of the pump. The use of such a sucker rod is attended with many undesirable features, some of which are: stretching, whipping7 and its weight. All of these undesirable' features become more exaggeratedas the depth of the well increases and it is therefore desirable that some means be provided whereby these diliticulties can be overcome.

In order to overcome these difficulties, I propose to construct a prime mover element for operating a reciprocating oil well pump which can be lowered into the well and which will dispense with the use of the above referred to motive power units and its cooperating sucker rod. The greatest obstacle in providing such a unit is in providing a unit small enough to be inserted into the well casing, which casing is of a relatively small diameter for such a purpose. This restriction in the size of such a unit, however, applies only to its horizontal or diametrical dimensions and since it can be made of almost any desired length, I propose to build an electro-mechanical power'unit by employing a plurality of smaller units, each of which `is small enough tol be inserted in the well.

These units are then connected mechanically together through a suitable rack which is adapted to be connected with the sucker rod of a pump which will be secured to the lowe end of the motive power unit.

A further feature of my invention isin the manner of controlling these electro-mechanical power units. It is essential that no sparking or electric arcs be present within the well because of the danger of explosions which might be caused by the gases present. In order to overcome this diliculty and make my device safe under these conditions, I provide motive power units of the induction type and control the direction of rotation or movement thereof by means of a controller or reversing switch located at the top of the well which can be located at any convenient and safe point thereabout.

For a better understanding of my invention, reference should be had to the accompanying drawings, in whichI have shown by way of illustration and not of limitation apparatus which represents the best embodi- .ment of my device now known to me. I desire to have it understood, however, that many changes and modifications can be made therein without departing from the spirit of my invention.

In these drawings- Fig. 1 is a fragmentary vertical sectional view of a motive power unit built in accordance with my invention and located as it is used in an oil well casing,

Fig. 2 is a view similar to at right angles thereto,

Fig. 3 is a partial sectional view taken along the line III-III `of Fig. 1, looking in direction vof arrows,

Figs. 4, 5, and 6 are sectional views taken respectively along lines IV-IV, V-V, and VI-VI of Fig. 1, looking in direction of arrows,

Fig. 7 is a partial sectional view looking along line VII-VII of Fig. 1, looking npward, as indicated by arrows,

Fig. 8 is a fragmentary vertical sectional view similar to that of Fig. 2 together with Fig. taken a schematic showing of the controller or,y

reversing switch, and

Figs. 9 and 10 are diagrammatic wiring lay-outs showing the electrical control circuits employed with the apparatus herein disclosed.

In Figs. 1 and 2 of the drawings I show a well bore having a casing 10 therein as is the practice in wells of this kind. Located within the casing-10 I also show a housing 11 which is substantially circular in cross section. This housing is of such a size that it will slide freely within the casing 10 so that it can be lowered into the well by `means of an oil discharge pipe 12 to which it is secured. The housing 11 is provided with end members 13 and 14 which are secured respectively to the top and bottom thereof. These end members are cored out and are provided with ports which align with suitable passageways for the oil, which I have designated by the numeral 15, through the housing member 11. 'Ihe upper member 13 is provided with a central opening into which the discharge pipe 12 is threaded and it is also provided with an opening through which an electric conduit 16y can be inserted and the lower member 14 is also provided with ports which align with the passages 15, a central opening to which the pump is secured, and a packing gland 17 through which a pump sucker rod 18 projects. When the housing 11 and the end members 13 and 14 are secured together, an enclosing housing is produced in which electrical apparatus or the like can be enclosed free from contamination by oil and the like, the passageways 15 cooperating with the end members and their respective ports to provide a passageway for the pumped oil around the enclosed portion of the housing.

Located within the housing formed as above, I provide a plurality of electric motor units 19 which are securely fastened together. In the drawing I have shown three such motor units, but I desire to have it understood that this is merely by way of illustration and that any necessary number of such units can be used and I have therefore made the housing member 11 of a sufiicient length to permit the insertion of the desired number of such motors and in the event that as located centrally of the housing 11 and at a sufficient distance from the end member 14 to permit the sucker rod 18 to be recipro cated therebelow without interfering with The motor elements are its normal stroke. each provided with a pinion 21 and arranged adjacent the pinions 21 I provide a rack 22 which is adapted to move with a reciprocating motion along a guideway 23 as the motor units 19 rotate irst in one direction and then in the other. 'Ihe rack 22 projects downwardly below the motor units and at its lower end it is provided with an offset arm 24 to which the sucker rod 18 is attached. Arranged within the space between the motor units 19 and the end member 14 I provide buffers or stops 25 and 26 which serve to limit the stroke of the rack so as to prevent it from becoming disengaged from* the pinions 21.

Y Referring to Figs. 4, 5, and 6 it .will he Seen that the housing member 11 has substantially three longitudinally extending openings, the outer ones of which constitute the oil passages 15. From these views of the drawings it will be seen that the central opening is substantially larger than the passageways 15 and that recesses are provided in' the sides thereof with which the motor units 19 engage. It will also be seen that the rack 22 and its cooperating guide 23 are also located in this compartment. It should be noted that I have provided fins 27 which project from the motor supporting partition of the housing 11 into the oil passages 15. These fins serve to conduct the heat generated by the motor units 19 to the oil bemg pumped so that the heat will be car- ,ried away thereby and thus insure a conmy invention after having determined the number of units' required, the rack will be properly placed therein and after the motor umts are assembled in a vert-ical line, as sug-` gested above, and after the desired connections are made, this assembly will be inserted in the housing, the lowermost motor unit being forced against a supporting pa-rtition 29. If the number of motor units used are not suiicient to completely fill the housing 11, spacing members 2,0 are placed end to end with the motors until the motor enclosing space is completely taken up. These spacing members20 are made of substantially the same dimensions as the motor units 19 so that, should it be found necessary to add a mot-or unit, it can be done by replacing one of these spacers with a motor. 1t should be pointed out here that other means of securing the motors within the casing might be used and that this specic arrangement is 4not important. After the members are. thus assembled the top member 13 will be secured in place. The opening through which the conduit 16 extends' will then be securely closed by means ofa suitable packing. The pump sucker rod 18 and the lower end can then be secured ,in place grid, after the unit is secured to the discharge pipe-12, the whole can then be lowered into the well, where it can be operated a-s will hereinafter appear.

The motive power units 19 in the present embodiment of my invention are shown as of the induction motor type. These motors are provided with an alternating current winding, which in the present instance has three phases.. vThe primary windings are of the. distributed type and the rotor or secondary winding is of squirrel-cage construction, the' s econdary winding preferably being one of high resistance so that a high starting torque will be produced thereby. Beca-use of the absence of sliding contacts which might cause sparking, these motors are particularly suited to my device.l In order to further eliminate the possibility of sparking because of changing electrical circuits, I propose to` provide a reversing means for these motors which can be located at the top of the well and at a sulficient distance therefrom to avoid any danger 1 from explosions due to ignition of the gases present. The arrangement of rack and the size ofthe pinions 21 are proportioned so that in producing a` stroke in the neighborhood of thirty inches, the motor units 19 turn over from ten to twenty revolutions in each direction as the current flow thereto is reversed. By referring to Figs. 8, 9, and 10 ofthe drawings it will be seen that the cable 28 terminates in three conductors which Arepresent the three conductors of a three-phase alternating current power circuit.` rll`hese conductors are connected to a suitable terminal block 30 which is provided with brushes in contact with a rotating drum 31. Opposite the terminal block 30 l show a. second similar terminal block 32 also having brushes which engage the opposite side of the drum 31. The brushes upon the terminal block 32 are cennected directly to a suitable source of power by means of a switch 33 which connects with a suitable transformer 34. rlhe drum 31 is provided with three sets of contacts 35 arranged radially therearound, the oppositely disposed contacts being arranged with interlinking connections so 'that as the drum is rotated two of the phases of the three-phase circuit will be reversed to thus produce a reversal of the energy supplied to the motor units 19. The drum 31 is mounted upon suitable journals 36 and is continuously driven by a variable speed motor 37 through a suitable speed reducing gear 38. Connected within the circuit ofthe motor 37 l provide a speed controller 39 by means of which the operator can vary the speed of the motor 37 The operator can then, by manipulation of the speed controller 39, regulate the number.

of reversals of current per unit of time and thus control the speed ofthe pump and also the stroke thereo f In these drawings I have shown only three motorunits 19 connected to the power lines, but it should be understood that any necessary number of these units 19 'can be used, the only limiting factor in this respect being in the length of the housing 11, and, since this housing can be of any length, this factor need not necessarily constitute a limitation. By referring particularly to Figs. 9 and 10 it will be seen that the segments 35 of the reversing switch are connected so that paths for current are provided between the oppositely disposed hand conductors lof the three-phase circuit and thus effect a reversal of which, as'is well known, will versal in the direction induction motor units 19.

The modification illustrated in Fig. 10 of the drawings involves the provision of additional electro-magnetic contactors 42 and 43 phase rotation produce a re.- of rotation of the ier ` thereon does not require all of the motor units.

Because of the manner of connecting the coils 44 and 45 in series with the power line of at least one'or a number of the motor units, they will insure the operation of a sullicient number of the motor units to provide the necessary amount of starting torque and lalso shorten the period of excitation of some of the motors when they are not required in driving the pump. This latter feature will be found desirable as it will reduce the combined heating effect of the motors over that which would exist if all of the motors were continuously energized, as previously suggested. In this figure of the drawings I have shown but three motor units with a contacter in the circuit of each unit,'but I desire to have it understood that a greater number of motor units may and will no doubt be used andunder these conditions, instead of providing contactors in each motor unit circuit, I may arrange the units in groups and provide a con` tactor for each group as, for instance, instead.

of a single motor as shown in the drawings, each of these moto-r representations may represent a group of two or more such units.

Vhile I` dol not limit myself to the use of an induction motor type of motive power unit, it will be seen that this type of unit Will, because of its starting characteristics, be admii-ably suited to this use, as it will produce a starting torque greatly in excess of its runing` torque and since the frequent reversals thereof will necessitate frequent starting, this characteristic of the unit is very desirable.

It should be pointed out here that these in-v dividual units .19 are designed so that they will not dangerously overheat when stalled. ln'ot-hcr words, they will operate more in the nature of atorque producing unit than a motor in the strict sense of the word. As a result 0f this feature, it will be possible to operate the rack 22 by permitting it to engage the stops 25 and 26 at the ends of its travel before a reversal of the phase" rotation of the motor fields is effected. It will, however, be found desirable to operate the rack 22 between these limits and rely upon the stops 25 and 26 only under extreme conditions or where'a maximum stroke is required. In this connection it.

should be noted that the stroke ofthe rack 22, and therefore the stroke of the sucker rod.

`18, can be varied by speeding up the operation of the reversing switchy drum 31. This will shorten the period of excitation of the motor units and cause them to lreverse more often and thus produce a shorter stroke of the rack 22, as will hereinafter appear. This feature of my invention makes it possible to shorten the stroke so that the sucker rod will be reciprocated very rapidly with a comparatively short stroke and when operated in this fashion, the device will be very eective in shaking up the well without having to make external adjustments such as are now necessary with the present types of pump driving means.

In order that a clearer understanding of my invention may be had, I shall describe a typical device which I' have designed for pumping the average well. The reciprocating pump has a normal stroke of approximately thirty inches and requires from five to seven and one-half horse-power to operate it at a. speed of from fifteen to thirty strokes per minute. The individual motor units are capable of exerting approximately one-fifth of a horse-power and have a starting torque of substantially four times their normal running torque, or lin other words, a starting .torque of approximately four-fifths of a horse-power. TheV number of such units which will be required with a pump of the above type will therefore be approximately ten units. If it is found that the pump requires more units than anticipated, these additional unit-s Ican easily be added without enlarging the housing 1l by merely substituting a motor unitfor one of the spacing blocks 20. The pitch diameter of the pinions 21 is approximately one inch. This will require substantially ten revolutions of the rotor of the motor unit to effect a complete stroke of the rack in one direction and, as a result, it

will be seen that these motors will not attain a as shown by way of illustration in Fig. 8. In

this figure of the drawings the pump is shown at the lower end of its stroke with the contactsl 35 of the reversing controller 3l completing a circuit from the transformer 34 to the motors, which circuit, it is further assumed, is just opening. As the drum 31 continues to rotate the following setof contacts 35 will engage the brushes upon the terminal blocks 30 and 32 and re-establish, the electric power circuit, the circuit in this case, however` having a direction of phase rotation opposite to that of the former circuit. This will energize the motor units 19 in the reverse direction and cause them to rotate clockwise as viewed in this ligure of the drawings and cause the rack to be moved upwardly thus the rack' t'o be moved downwardly to e'ect the reverse stroke of the pump. This operation will continue as long as the controller drum 3l is caused to rotate and if it is desired to regulate the-rate of motor reversals, this will be done by varying the speed of the controller driving motor 37 by means of the manual control means 39.

While I have shown the preferred form of my invention as now known to me, it is to be understood that various changes may be made in its construction without departing from the spirit of the invention as defined in the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patswitch between ent is l. In a control system for electro-mechanically driven reciprocating pumps of the character described, the combination of a sucker rod, a rack connected to said sucker rod, an electro-mechanical means for driving said rack, a source of polyphase alternating current power for supplying current to said electro-mechanical means, and a reversing said electro-mechanical means and said source of polyphase current for periodically reversing theV phase rotation of said Vcurrent and thereby cause said rack and sucker rod to be driven with a reciprov cating motion, characterized by the fact that the periodicity of phase reversals may bev varied to determine the stroke of the sucker rod without resort'to other circuit interrupting means.

2. In a control system for electro-mechan-- ically driven reciprocating pumps of the character described, the combination of a reciprocating pump, a sucker rod for said pump, a rack connected to said sucker rod and mounted to be driven with a reciprocating movement, anl electro-mechanical means for driving said rack, a source of polyphase alternating current electric power for supplying-currentjo said electro-mechanical means, a continuously operating phase reversing switch in said alternating current supply for periodically reversing the phase rotation of the current supplied to said electro-mechanical means, whereby areciprocating motion will be imparted to said rack, and

ymeans for varying the frequency of operation of said phase reverslng swltch to con-` trol the stroke of the sucker rod.

3. In a drive for the sucker rod of reciprocating oil well pumps, the combination of a discharge pipe adapted to be lowered into an oil well, an induction motor unit as a motive power means located at 4the bottom end of said discharge pipe, a pump havingv its outlet connected with said discharge pipe, a sucker rod for said pump adapted to be driven by said motive power means, a source of polyphase alternating current for said induction motor unit, a periodically operating reversing switch at the top of the well discharge pipe and connected between the motor unit and said source of current to periodically reverse the phase rotation of the alternating current supplied to the motor unit, whereby the direction of rotation of the motor unit will be periodically reversed, and a driving connection -.between said motor unit and the sucker rod for imparting a reciprocating movement to the pump sucker rod as the motor unit is reversed.

4. In a control system for reciprocating oil well pumps, the combination oiga dispcharge pipe adapted to be lowered into an ly reverse the phase rotation of the current supplied to said motor, a reciprocating pump having its outlet connected with said discharge pipe, a sucker rod for operating the pump, and a mechanical driving connection between said motor and said sucker rod for imparting a reciprocating motion to the pump sucker rod as the direction of rotation of said motor is periodically reversed.

5. In an alternating current motor control system for pumps of the `character described, the combination of a discharge pipe adapted to be lowered into an oil well, a polyphase alternating current electro-motive device supported upon the bottom end of said discharge pipe and adapted to be submerged in an oil well, a reciprocating pump having its outlet connected to the lower end of said discharge pipe, a sucker rod for said pump, a source of alternating current for said electro-motive device, a phase reversing switch between the electro-motivedevice and said source of alternating current located at the top end of the well discharge pipe, means for operating said phase reversing switch t'o periodically reverse the phase rotation of the current supplied to said electro-motive device, and a driving connection between said electro-motive device and said sucker rod, characterized by the fact that as the phase rotation of the current supplied to said device is periodically reversed at the top of the well a reciprocating motion will be imparted to the pump sucker rod.

6. `A drive for reciprocating oil well pumps and the like comprising an oil well discharge pipe, a pump-having, its outlet communicating with said discharge pipe, a sucker rod for operating said pump, a rack connected with said sucker rod, a plurality of reversible induction motor units geared to said rack, said rack and said motor units being enclosed in a housing mounted upon the bottom end of said discharge pipe andadapted to be lowered into a well, a current conducting cable for Aconnecting said motor units with a source of current supply, and current reversing means at the top end of said discharge pipe for controlling and reversing the vdirection of rotation of said motors to thereby impart a reciprocating movementto said rack and sucker rod and operate the pump.

7. An electro-mechanical drive for the sucker rod of a reciprocating pump comprising an oil discharge pipe adapted to be lowered into a well, a plurality of reversible motor units having pinions upon their driving ends arranged in alignment and supported at the bottom end of said discharge pipe, a pump having its outlet communicating with said oil discharge pipe, a sucker rod for said pump, a rack connected with said sucker rod extending upwardly and meshing with said pinions, and means at the top end of said discharge pipe for periodically reversing the direction of rotation of said motor units, whereby a reciprocating movement will be imparted to said sucker rod and pump as said motors areperiodically reversed.

8. In a drive for the sucker rod of reciprocating oil well pumps, the combination of a discharge pipe adapted to be lowered into an oil well, an induction motor unit as a motive power means located at the bottom end of said discharge pipe, a pump having its outlet communicating with said discharge pipe and adapted to be driven by said motive power means, a source of polyphase alternating current for said induction motor unit, a periodically operating reversing switch at the top of the well discharge pipe and connected between the motor unit and said source of current to periodically reverse the phase rotation ofthe alternating current supplied to the motor unit, whereby'the direction of rotation of the motor unit will be periodically reversed, and a driving connection between said motor unit and the pump for operating the pump as the motor unit is reversed.

9. In an alternating current motor control system for pumps of the character described, the combination of a discharge pipe adapted to be lowered into an oil well, a polyphase alternating current electromotive device supported upon the bottom end of said discharge pipe and'adapted to be submerged in an oil well, a pump connected-to pump oil into said discharge pipe, a source of alternating current for said electro-motive device, a phaseI reversing switch between the electromotive device and said source of alternating current located at the top end of the well discharge pipe, means for operating said phase reversing switch to periodically reverse the phase rotation of the current supplied to said electro-motive device, and a driving connection between said electro-motive device and said pump, characterized by the fact that as the phase rotation of the current supplied to said device is periodically reversed at the top of the well a pumping motion will be imparted to the pump.

10. An electro-mechanical drive for a reciprocating pump comprising an oil discharge pipe adapted to be lowered into a well, a plurality of reversible motor units having pinions upon their driving ends arranged in alignment and supported upon the bottom end of said discharge pipe, a reciprocating pump connected to pump oil into said discharge pipe, a rack adapted to be driven by said pinions and connected to operate said pump, and means at the top end of said discharge pipe for periodically lreversing the direction of rotation of said motor units,

whereby a reciprocating movement will bev imparted yto Athe pump as said motors are periodically reversed.

EDWARD C. EKSTROMER.

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