US1957320A - Method of and apparatus for pumping wells - Google Patents

Description

May 1, 134. c. J. COBERLY Er AL METHOD OF AND APPARATUS FOR PUMPING WELLS Filed Dec. 19, 1932 i 3 Sheets-Sheet l H4 AAS.

' y 1934- c. .1. COBERLY ET AL 1,957,320

METHOD OF AND APPARATUS FOR PUMPING WELLS Filed Dec. 19. 1932 3 Sheets-Sheet 2 Fga Cmesrvcs 605524,. Faea M Haze/s,-

y 1, 1934s C.'J. COBERLY ET AL 1,957,320

METHOD OF AND APPARATUS FOR PUMPING WELLS Filed Dec. 19, 1952 's Sheets-Sheet s vm n 427 I l 1 I I I I L ii 1% ,4 I! L Patented'May 1934 f .951.320 METHOD OF AND- mmrrus lion. rmmna warms "am... i. Coberiy and Ford w. Harris, m Angeles, Calif., assignors to Kobe, Ina, Huntington Park, Calif., a corporation of California Application December 19, 1932, Serial No. 647,925

7 Claims.

The invention is particularly applicable to wells which are pumped by fluid pressure pumps, al.- though applicable. under certain conditons to other pumping systems. It is particularly applicable to the pumping of deep oil wells by means of fluid pressure pumps.

The standard method of pumping an oil well at the present time is by means of a pump placed at or near the bottom of the well, this pump being 10 actuated through pump rods which are connected to this pump and which extend up inside the tubing of the well, being actuated, by suitable pumping'mechanism placed in the derrick above the surface of the ground. Such pumps while l5 quite satisfactory for wells of moderate depth, have proved quite unsatisfactory in very deep wells, 1. e., wells having a depth of 5,000 feet or more. In these deep wells the stretching of the pump rods and the tubing is excessive, thus cutting down the efiective stroke of the pump, and in.

these deep wells thefactor of safety in the pump rods is necessarily small due to the weight of the rods and the column of fluid which it is necessary to sustain thereon.

To overcome these difficulties various inventors have devised fluid-operated pumps in which oil under pressure is used as a motive power for a fluid motor placed just above and connected to the pump proper which is situatednear the bot- 'tom of the well. Such fluid-operated pumps may 40 in thederrlck above the surface of the ground,

a this actuating pump being driven by .a suitable source of power and being used to supply 011 under pressure to an oil supply pipe leading to the fluid motor in the well.

It is diflicult to determine exactly how much oil a well will produce, and although the productive capacity of the well does not ordinarily suddenly change, there is usually a slow decrease in productive capacity due to the exhaustion of they oil sands around the well. Since the fluid motor is linked to the actuating pump at the surface of the ground by means of-a column of oil, the capacity of the apparatus to pump oil from the well is governed by the speed of the actuating pump. The speed of the actuating pump can,

of course, be regulated by a suitable speed regulator applied to the driving means-therefor, but since these pumps operate for long periods without an attendant, frequent changes in the speed of the actuating pump may be necessary if the well is to be kept pumped down (that is, with its fluid at its lowest depth at which the pump in the well with operate), and the'operation of the pump in the well at low efliciencies is to. be avoided, since if the pump is operated at a higher capacity than the well will produce, it will eventually exhaust the oil in the well and start to pump gas. Itis highly desirable that the well be kept pumped down.ii the well is to produce a maximum amount of 011, since by keeping the fluid levelof the oil in the well very low, there is no which the pump will operate at a high efliciency.

. Further objects and advantages will be made evident hereinafter.

Referring to the drawings, which are for illusv trative purposes only: I

Fig. 1 shows in diagrammatic form the appa-' ratus required when our invention is applied to a fluid-operated pump applied to an oil well.

Fig. 2 is a diagram of the electrical connections 'by which the pump is controlled.

, Fig. 3 is a diagram showing an alternate method of connection.

Fig. 4'is a diagram showing another alternate method of connection.

Fig. 5 is a general assembly of the apparatus shown in Fig. 4. a

In the form of the invention illustrated, an oil well is shown having a bore 11 which extends down from the surface of the ground 12 any desired distance. It is practical by using our invention to eificiently and positively pump wells which are 6,000 feet deep or deeper. Our invention can, of course, be applied to shallow wells and is quite eflicient when so applied, butit has a peculiar utility when applied to very deep wells in which the present methods of pumping are not satisfactory.

The bore 11 of the well may be casedwith a steel casing which may be perforated at the bottom in accordance with standard practice. This casing is not sliown since it forms no part of our present invention.

Suspended in the well is tubing 13. This tubing may be either of the rotary or reciprocating type.

In the apparatus shown, the oil is passed through the fluid motor 16 to actuate same, and

after the pressure of the oil has'been reduced by the operation of the motor 16, it passes through openings 19 into a space 20 between the pressure pipe 15 and the interior of the'tubing 13.

The pump 18 shown in the drawings draws oil through an opening 21 which communicates with the space 22 in the well outside the tubing 13 and delivers this oil through openings 23 into the space 20. A standing valve 48 may be provided in the opening 21 for holding the oil in the space 20 when the apparatus is not operating. Oil from the space 20 flows through the delivery pipe 14 to tankage or through an auxiliary tank 25 from which it is conducted througha pipe 26 to suitable storage. T

The motor 16 operates the pump 18 at a deflnite rate which is determined by the rate at which oil is delivered to the motor 16through the pres: sure pipe 15. Oil .is delivered to the pressure pipe 15 through a pipe 2'7 which is connected to the pressure side of an actuating pump 28. This actuating 'pump may be of any desired form,

many pumps being now available which may be used for this service. The pump shown is therefore diagrammatic and consists of a pump cylinder 30 having a plunger 31 which is connected through a connecting rod 32 with a cross-head 33. The cross-head 33 is reciprocated through a connecting rod 34 driven by a crank 35 carried on a shaft 36. The shaft 36 is, driven by any suitable means such as a pulley 37, a belt 38, and a pulley 39 from a shaft 40 of an electric motor 41. A pressure valve 45and an exhaust valve 46-are provided, the pressure valve 45 preventing oil from passing fromthe pipe 2'7 into the interior of the cylinder 30, and the exhaust valve 46 being so placed as to prevent oilfrom passing backwardly from the cylinder 30 into a' suction pipe 4'7 which draws oil from the tank 25.

As the piston 28 moves upwardly, it draws oil through the suction pipe 4'7 past the valve 46, tilling the cylinder, the valve 45 beingin its closed position. 0n the down stroke of the piston 31, the valve 46 seats, and oil from the cylinder passes the valve 45 into the pipe 2'7. The actuating pump therefore periodically delivers oil under pressure to the pipe. 27. In actual practice the actuating pump 28 will be provided with several cylinders so that substantially continuous delivery of oil to the pipe 2'7 is provided for.

All of the above apparatus is old in the art and no claim is madethereto except in combination with certain methods of and apparatus for controlling its operation. In practice the various parts are made of sufficient size so that'by their combined operation oil may be pumped from the well at a' considerably faster rate than the well will naturally produce oil. In other words, if the apparatus were allowed to run continuously, it would pump the fluid in the .well'down to a point where only gas would be drawn in through the opening 21. For example, in a'well which will produce a maximum of 100 barrels a day, the capacity of the apparatus previously described operating continuously should be in excess of 100 barrels a day and might be as high as 200 barrels per day.

It is highly desirable that the oil in the well be maintained at as low an average level as possible so that there will be no back pressure on the oil sands surrounding the well due to av column of oil standing in the well. This condition can be assured by usingcur invention in which one form apparatus is shown diagrammatically, and stand ard apparatus is available on the market which will perform the functions thereof. This standard apparatus may have a different form from that shown. The contactor 61 is shown in the form of a solenoid having a core 71, this core being pulled upwardly as the solenoid '70 is actuated. The core '71 lifts a member '72, which bridges main contacts '73 when the core '71 is in its lower position. A member 74 is also attached to the core 71 which connects setting contacts '75 when the core '71 is pulled up. A member '76 attached to the core '71 connects locking contacts '77 when the core is pulled up. .The contactor 61 is preferably of the instantaneous type, that is, it is not provided with any means for retarding itsoperation. The instantaneous underload relay 62 consists of a solenoid which pulls a core 81 upwardly when the solenoid is energized, the core 81 being attached to a member 82 which closes underload contacts 83 when the core is down. A stop 84 is provided for limiting the upward movement of the member 82, and the relay 62 is so constructed that the position of the stop 84 may be regulated, or the weight of the moving parts may be regulated so that the core 81 will drop whenever the current in the solenoid 80 falls below a predetermined value. This value may be approximately eighty per cent or less of the current taken by the motor when pumping at full capacity.

The time reclosing relay consists of'a solenoid 85 which pulls upwardly on a core 86 and which carries a member 87 which closes reclosing contacts 88 when the core is down. A dash-pot 89 or other adjustable retarding mechanism is provided for preventing the core 86 from moving upwardly for a definite time after the solenoid 85 is energized. This time may be assumed to be ten minutes, although it may be a longer or shorter period, if desired. In other words, the circuit through the contacts 88 is opened about ten minutes after the solenoid 85 is energized.-

The time limit relay 64 consists of a solenoid 90 which pulls upwardly on a core 91 when the solenoid is energized, causing a member 92 to close time relay contacts 93. A dash-pot 94 is also attached to the core, this dash-pot providing a time element which may be about ten seconds. In other words, the circuit through the contacts 93'is closed by the member 92 about ten seconds after the solenoid 90 is energized. A starting switch 95 is provided which may be closed or opened manually to start or stop the pump.

7 drops, closing a circuit through the contacts 83." The relay 64 having previously operated the circuit is also closed through the contacts 93.- This Current is supplied from asuitable source of supply through wires 100 and 101. .7 H

The wire 100 isconnected to one terminal of the armature 50 and the field 51 of the motor. and is also connected to'a control wire 102 leading to one terminal of the solenoid '70 and to one of the setting contacts '75. The-other terminals. of the armature 50 and held 51 are connected through a wire 103 with one side of the solenoid of the instantaneous underload relay 62, the other side of this solenoid 80 being connected through a wire 104 with one of-the contacts '73. The other side of the solenoid '70 is connected through a wire 105 with one of the locking contacts '77 and with one of the contacts 93. .The other contact 93 is connected through a wire 106 with one of the contacts 83, the other contact 83 being connected to a wire 107 which connects with one of the contacts '77 andone of the contacts 88. The other side ofthe solenoid 90 is connected to the wire 104. The wire101 is connected to the starter 95, the other'side of which is connected.

to one of the contacts '73, to one side or the solenoid and 0 one of the contacts 88. The other side of the solenoid 85 is connected to one oi the contacts '75. i

The method of operation is as follows:

Prior to starting operations, all the parts are in the position shown in Fig. 2, and no current flows in any circuit shown therein. The operator starts operations by closing the starter 95 which energizes the motor through the contacts '73 and the solenoid 80 of the instantaneous overload re-- lay. This starts the motor which operates the actuating pump 28 and pumps oil under pressure through thepipe 2'7to the fluid motor 16. Ordinarily, \the starting current of the motor is considerably more than its normal full load current, and this heavy starting current causes the solenoid 80 of the instantaneous relay 62 to pull the core 81 upwardly, thus opening the circuit through the underload contacts 83.

t For the purpose of preventing premature operation of the other control parts prior to the time the motor builds up its full load we use the time limit relay 64. It will be noted that the circuit through the contacts 93 is normally opened and is not closed until ten seconds after the solenoid is energized. This time element of ten seconds is arbitrarily chosen for purposes of description, and under certain conditions of operation it may be advisable to make it longer or shorter. The solenoid 90 is energized whenever the motor 41 is energized, since the solenoid 90 is in parallelwith the motor.

The time limit chosen for the relay 64 must be such that the motor 41 can build up its full load before circuit is closed through the contacts 93. As long as this circuit is open the position of the member 82 of the relay 62 is oi no importance, since the contacts '93 and the contacts 83 are in series. As soon as the motor has built up its full load current the solenoid 80 will have opened thecircuit through the. contacts 83 and will be held in its upper position as long as the motor 41 draws its full load current.

The motor now operates the actuating pump until thelwell pumps down", that is, until the level of fluid in the well falls below the'intake opening 21 or the pump 18. As soon as this occurs, the pump 18 ceases to take oil and the current on thrmotor falls due to a decrease in the load thereon. j

The current in the solenoid 80 (which is in series with the motor 41) falls and the core 81 circuit is fed through the wire 101 and. the contacts 83 and 93 to the solenoid '70 of the contactor' 61 and completed through the wire 102 to the wire 100.

This causes the core '71 to bepulled upwardly,

breaking the main circuit at the contacts '73 through the solenoid 80 and the motor 41' and opening the circuit through the solenoid 90. The

motor then stops and pumping ceases.

' Due to the member '76 closing a circuit through 4 in its open position until its solenoid circuit is opened at the contacts 88. i

As the core '71 moves into its upperposition it closes a circuit through the setting contact '75,

this circuit including the solenoid 85 of the reclosing relay 63. This relay operatesto open the circuit through the contacts 88 when a definite time has elapsed after the solenoid 85 is energized. We may assume this time to be ten minutes, although this time may be longer or shorter, depending upon conditions. Whatever the time may be, it remains definite and constant unless the relay 63 is readjusted by the operator. when this definite time interval has elapsed, the circuit through-the contacts 88 and the solenoid '70 is opened at the contacts 88 and current being'cut ofl from the solenoid '70, the core '71 drops. i

This restores the apparatus to the condition shown irnFig. 2, except that the core 86 of the relay 63 is in its upper position. The relay 63 is so constructed that the core 86 drops immediately after the circuit is cut oil through the solenoid 85. I

The closing of the main circuit through the contacts '73 causes the motor to start, and the time limit relay 64 to be energized, and the cycle to be repeated. p I

In Fig. 3 we show an alternate method of control. In this figure weshow a motor 201' fed with a three-phase alternating current from the wires 202 through a three-pole main contactor 203 having an operating coil 204. The contactor shown is of the gravity release type; that is, the moving element drops intothe position shown in Fig. 3 whenever the circuit of the coil 204 is opened. A time limit relay 205 is provided? this relay having a coil 206 and being adapted to close a circuit between stationary contacts 207 a definite time after the coil 206 is energized. This time may, for example, be ten minutes. The relay 205 is preferably of the quick return type; that is, it drops freely to the lowerposition, shown is opened, although requiring ten minutes to rise from its inactive position shown in Fig. 3 to its closed position in which the contacts 207 are connected together by the movable element 208.

The relay shown is, of course, entirely diagrammatic and in practice we use a relay of a motordriven type which, however, accomplishes the same result. I

We also provide a change-over relay 210 having a coil 211 and two pairs of stationary c0ntacts 212 and 213. The relay 210 is also of the gravity release type, the moving parts dropping intothe position shown in Fig. 3 whenever current is cut off from the coil 211. 'The relay 210 may be provided with two movable bridging 212, the bridging member 215 being held against v the contacts 213.

When the coil 211 is energized and the relay is moved to closed position, the collar 218 strikes against the bridging member 215, lifting it away from the contacts 213. Before the circuit is broken at the contacts 213 the spring 216 will have forced the bridging member 214 into contact with the contacts 212 so that during thetransition from open'to closed position the circuit between the contacts 212 and the circuit between the contacts 213 are both closed for, a short interval.

The purpose of this arrangement is to prevent either circuit being broken until after the other is established, this purpose being, of course, capable of accomplishment by various devices which might be substituted for the relay 210.

We also provide a pressure switch'220 which in the form shown-consists of a block 221 having a cylindrical opening therein, the lower end of this opening being connected through a pipe 222 with the pipe 27 of Fig. 1. A piston223 slides freely in the opening, being held in the position shown in Fig. 3 by a compressionspring 224 which presses against a stationary abutment 225. A piston rod 226 carries abridging member 228 which is insulated from the rod 226 and which in its lower position as shown in Fig. 3 closes a circuit between stationary contacts 227. ,The purpose or the pressure switch is to open the circuit between the contacts 227 whenever the pressure on the bottom of the piston 223 rises above a certain value fixed by the spring 224, and it will be obvious that any 01 many well-known types of pressure switches could be substituted therefor.

We also provide a manually operable switch 230 having a movable arm 231 which is shown in its oil? position indicated at 233. One end of this arm may be'moved into its -automatic position in contact with a contact 232, as shown in dotted lines, Fig. 3, or into its hand position in contact and the other terminal is connected through a a contact 212.

wire 302 with. the contact 234, through a wire 303 with a contact, 207, and through a wire 304 with The other contact 212 is connected through a wire 309 withthe contact 232 and the other contact 2071s connected through a wire 315 with the contact 232. The arm 231 is permanently connected through a wire 305 with the wire 202-'2.

One terminal of the coil 206 is connected through a wire 306- with the contact 232, and the other terminal of the coil 206 is connected through a wire 307 with a contact 213, the other contact 213 being connected through a wire 308 with the wire 202-1.

One terminal of the coil 211 is connected through a wire 310 withthe wire 202-1, and through a wire 311 with a contact 227. The other terminal of the coil 211 is connected through a wire 312 with one terminal of the resistance 240, and through a wire 313 with a. contact 227. The other terminal of the resistance 240 is connected through a 'wire 314 with the contact 232.

t will be obvious from the above description and Fig. 3 that the coil 204 of the main contactor 203 maybe energized either'by moving the arm 231 of the manually operable switch 230 to the contact 232, or by a. closure of the circuit between the contacts 207 of the time relay 205, or by a closure of the circuit between the contacts 212 205 is energized, however, when the movable arm 231 is on the contact 232 and the circuit is completed between the contacts 213, as shown ini inthe oiT position and-all of the apparatus is in the position it assumes prior to starting operations. When it is desired to start. the-pump in operation, the moving arm 231 is moved into contact with the contact 234 and the coil 204 of the main contactor 203 is energized, closing the main contactor circuit and starting the motor. This motor will then run until the arm 231 is moved 011 the contact 234. a v

The starting of the motor causes the pump 28 to build up a pressure in the pipe 27, which pressure is communicated to'the piston 223, .this pressure being sufl'icient to move the piston 223 upwardly against the pressure of the spring 224 and to open the circuit at the contacts 222'. If after the pump is started it is desired to put it in condition'to operate automatically, the arm 231 is moved to the automatic position in con- .tact' with the contact 232. The coil 206 is thereby energized and the time relay 205 starts to move. upward slowly. It will be remembered that it takes ten minutes for this relay to complete its operation.

At the time the arm 231 is moved to the automatic position, current flows through the wire 314, resistance 240, the coil 211, and the wire 310 so that the coil 211 is energized, it being understood that the circuit between the contacts 227 is then open due to the pump being in operation and oil pressure being exerted on the piston 223.

The moving of the arm 231 from the contact 234 opens the circuit to the coil 204, and the main contactor 203 opens the circuit to the motor, which would eventually stop if the main contactor 203 were not immediately closed. Owing to the fact that there is considerable inertia in'the oil moving in the pipe27, although the current is interrupted from the motor, the pressure on the piston 223 does not immediately fall and before this-pressure can, fall sufficiently to close the circuit between the contacts 227, the changeover relay, which is of the quick acting type,

operates, first closing the circuit between the contacts 212,- and then opening the circuit between the contacts 213. As soon as the circuit between the contacts 212 is closed, the main contactor 203 Zis immediately thrown in so that current is again supplied to the motor and the apparatus continues to operate. It will be noted that by the operation of the change-over relay 210, the circuit through the coil 206 has been opened at the contacts 213 and the time relay 205 quickly returns to its initial positionas shown in Fig. 3. v

The pump then operates until such a-time as the well is pumped down; in other words. until there is no oil to be lifted irom the well, at which time the oil pressure in the pipe 2'? falls due to the fact that it has no work to do except to overcome the frictional head. The spring 224 is of such strength that Just before the well is entirely pumped down, the spring 224 iorces the piston 223 downwardly and closes the circuit between the contacts 227. This short-circuits the coil 211 and the change-over relay 210 drops, thus disconnecting the circuit through the coil 204 of the main contactor at the contacts 212. The main contactor 203 then opens and the pump stops.. At the same time the change-over relay 210 closes the circuit to the coil 206 of the time 1 relay'and the time limit relay starts to operate.

After a definite time interval, which, for illustration, we have selected as ten minutes, during which the pump. is not operating, the time relay completes its operation and closes the circuit between the contacts 207. This energizes the coil 204 and the main centactor 203 closes, thus again starting the motor. Since oil has collected in the well during the time the apparatus is shut down, the pump immediately builds up suiiicient pressure to open the circuit between the contacts 227, which again energizes the coil 211 of the changeover relay 210. The relay 210 then closes the circuit to the coil 204 by completing the circuit between the contacts 212 and opens the circuit through the coil 206 by opening the circuit between the contacts 213. The closing of the circuit through the coil 204 insures the main con-= tactor 203 remaining closed after the time limit relay. 205-drops due to the circuit through the coil 206 having been opened at the contacts 213.

The apparatus then repeats the cycle. The pump continues to operate for a sufiicient period to pump down the well,'at which time the main contactor opens and the motor shuts down. After an interval of say ten minutes the pump is again started.

In Fig. 4 we show another method of control. In this ,figure we show the pump 28, the pressure pipe 2'? leading from the pump down to the well to supply a motive fluid to the motor 16, the easing 13, and the pipe 14 bringing fluid from the casing head. We then provide a closed tank 401, the

pipe 14 being connected in gas-tight relationship in the top thereof. We-also provide a pipe 402 passing in gas-tight relationship through the top of the tank401 and leading from the bottom a Wm d chiick any reverse flow from th Pipe 403 to the pipe 405, a I if Connected into the tank 401 near the top thereof is a pipe 410 which is connected to a constricted orifice 411, the other end of which is connected into a pipe 414. The pipe 414 is in turn com nected to a pressure regulating valve 412. A pipe 413 leads from the regulating valve tostorage.

. We may use as the pressure regulating valve 412 any of the well-known valves of this type which have the characteristic of remaining closed until the pressure in the pipe 414 is in excess of the pressure in the pipe 413. This difference in pressure is commonly known as the operating pressure of the valve. The valve 412 is set so that it requires an operating pressureslightly in excess of the available pressure in the pipe 405.

In this method of connection we use the apparatus shown in Fig. 3 except that we substitute for the pressure switch 220 a diaphragm switch 420, substituting for the'contacts 227 contacts 421, these contacts being connected to the wires i 311 and 313 of the diagram shown in Fig. 3.

We may use as a diaphragm switch 420 any 0! several well-known forms, that shown consisting of a diaphragm 422 carried in a casing 423, the space inside the casing to the left of the diaphragm 422 being connected to the pipe 410 by a small pipe 424, and the space inside the casing 423 to the right of the diaphragm 422 being connected to the pipe 414 by a small pipe 425. A compression spring 426, the tension of which may be adjusted by a hand-wheel 427, is provided, this spring tending to force the diaphragm to the left as shown in Fig. 4. An operating rod 428 carries a bridging member 429 which closes the circuit between the contacts 421 at all times unless there is an excess of pressure in the pipe 424 over the pressure in. the pipe 425. Whenever this, excess pressure reaches a certain value, which is determined by adjusting the. tension of the spring 426, the diaphragm 422 is moved to the right and the bridging member 429 is pulled away from the contacts 421, thus opening the circuit therebetween.

The method of operation of the apparatus,

when the method'oi. control shown in Fig. 4 is If it is desired to operate the pump continuously; the arm 231 is thrown into, the hand position in which it makes contact with the contact 234, thusenergizing the coil 204 of the'main contactor 203, and starting the pump in operation. The pump creates a suction on the pipe 47 and oil under pressure from the pipe 405 will flow freely through the check valve '404 and the pipe 403. The pump then delivers-oil to the well 1 until such time as all of the piping, including the casing 13, is filled with oil and return oil starts 'to be delivered through the pipe 14 to the tank 401.- As soon as oil starts to fill the tank 401 pressure starts to build up therein and as soon as the pressure in the tank 401 is in excess oi the -140 pressure in the pipe 405, the check valve 406 closes and no more oil is delivered to' the system,

the pump 28 taking 'oil through the P1118 402 from the bottom ofv the tank and recirculating it.

Since the pump 16 in the bottom of the well is 145 to open the 'regulating valve 4 so that oil'may 1 9 be delivered through the pipes 410, 411, 414, and 413 to storage. Whenever the pressure built up in the constricted pipe 411 exceeds the pressure of the spring 426, this pressure moves the diaphragm 422 and opens the circuit between the contacts 421. These contacts are connected to the coil 211 in exactly the same manner as the contacts 22'? shown in Fig. 3 and as long as the bridging member 429 is in contact with the contacts 421, the coil 211 is short-circuited and inoperative. As soon as the bridging member 429 is pulled away from the contacts 421, the coil 211 is in a condition to be energized. In other words, the pump operates with the member 231 in the hand position until oil starts to be delivered to storage through the pipe 413. If now the arm 231 is moved to the contact 232 or automatic position, the coil 206 of the time relay is,

of course, energized, but since this relay moves very slowly, the contacts 207 are not immediately closed. The coil 211 of the change-over relay 210 is, however, energized and circuit is immediately made to the coil 204 of the main contactor through the contacts 212. If the arm 231 is moved slowly the main contactor may drop out during the transition period of the movable arm 231 from the contact 234 to the contact232, but as soon as it.reaches the contact 232 the main contactor is immediately thrown'in and the pumping continues.

It will be understood that due to the inertia of the oil, the diaphragm switch 420 will not have time to act during this transition period. The pump therefore continues to operate and the moving oil in the constriction 411 holds the diaphragm switch 420 in its open position.

As soon as the well pumps down or the flow of oil in the constriction 411 ceases for any rea-' son, there will be no difference in pressure in the pipes 424 and 425 and the spring 426 pushes the bridging member 429 into the position shown in Fig. 4, thus closing the circuit between the contacts 421. This short-circuits the coil 211 of the change-over relay 210 and the bridging members 214 and 215 drop into the position shown in Fig. 3, thus opening the circuit of thecoil 204 of the main contactor 203 at the contacts 212 and closing the circuit of the coil 206 of the time relay 205 at the contacts 213. The motor stops due to the main contactor opening and the time relay starts to operate.

During the time the time relay is operating, which we have assumed to be ten minutes, the pump will be shut down and no oil will flow. At the expiration of this ten minute period the bridging member 208 of the time relay will close the circuit between the contacts 207, thus energizing the coil 204 of the main contactor 203 and closing the main circuit and starting the motor. Due to the factthat the pump has been shut down for ten minutes, it may require some time for the flow of oil to be reestablished through the constriction 411. Whatever this time may be,'the apparatus will'continue to operate without any change in the position of any part thereof until sufficient pressure is .established between the pipes 424 and 425 due, to the constriction 411 to operate the diaphragm switch.

Ordinarily the period required to reestablish the flow of oil through the constriction 411 will be short. The pump will, however, operate until this flow of oil is reestablished and if necessary during this period it will pump oil from the pipe 405. Assoon as oil starts to flow through the constriction 411 at a sufllcient rate to operate the diaphragm switch 420, the circuit between the contacts 421 isopened, thus operating the change-over switch 210 and opening the circuit to the coil 206 of the time relay 205 and simultaneously closing the'circuit through the coil 204 of the main contactor. The main contactor is, of course, closedat the time this occurs, the purpose of closing the circuit to the contacts 212 being to insure the main contactor remaining closed as the time relay drops to its open position.

The pump will now continue to operate with the change-over switch closed until such a time as oil ceases to flow through the constriction 411 in sulficient amount to hold the diaphragm switch open. If the well pumps down or for any other reason the flow in the constriction 411 ceases, the diaphragm switch will close and the circuit to the coil 211 of the change-over switch 210 will beinterrupted and this switch will drop. This will open the circuit to the coil 204 of the main contactor 203, thus shutting down the motor, and will start the time relay in operation so that the motor will be started again in ten minutes.

It will be noted that the above-described method of control has several advantages. the first place, the pump will operate, taking oil from the pipe 405 if necessary, until such a time as an adequate flow of oil is established in the constriction 411. The pump will further continue to operate as long as this flow in the constriction 411 continues at a rate sufilcient to hold the diaphragm switch open. As soon as the flow ceases the pump is shut down and remains shut down for a period of say ten minutes. At the end of this time the pump again starts and then pumps for a sufiicient period to reestablish the flow regardless of conditions.

A very convenient arrangement of the apparatus is that shown in Fig. 5 in which a pressure regulating switch 420 is used as above described and in which the pressure regulating valve 412 is dispensed with and the pipe 414 is carried up and delivers oil into the top of a tank 500, the pipe 405 in this case being connected to the bottom of this tank and an overflow pipe 501 being provided for taking excess oil from the top of the tank 500. The tank 500 should be of sufiicient size to fill the piping of the entire system in the event the pump is shut down for any reason and the piping is allowed to drain.

It may take a few minutes or a much longer time for the cycle of operation to be completed. As soon as the fluid in the well is pumped down the motor stops and remains stopped for a deflnite time (assumed for illustrative purposes to be ten minutes). During the time the pump is inactive (that is, for ten minutes) fluid enters the well from thesurrounding sands. At the end of said period of ten minutes the pump is again started and operates for whatever period is necessary to again pump the well down. When this condition .is reached the pump is again shut down for ten minutes.

It will be seen that the pumping cycle is divided into two periods; that is, a definite and constant time period assumed to be ten minutes, and an indefinite time period which depends on how much-fluid runs into the well during the entire 1 i-so 1,957,320.. Y; cycle as long as fluid flows into the well at the rate of one hundred barrels per day. 1

As the fluid is exhausted in the sands surrounddecrease. The pumping intervals will then become shorter. For example, when the rate of fiow falls 'to twenty barrels per day the wellwill pump two and one-half minutes and remain shut down. for ten minutes. Or, in the event the rate of flow of oil into the well increases for any reason, 'the pumping intervals will automatically become longer. For example, with a pump having a capacity of two hundred barrels a day and adjusted for a ten minute idle period, if the oil flows into the well at the rate of one hundred fifty barrels per day, the pump will operate thirty minutes and remain shut down for ten minutes.

It will be seen that the pumping period will vary to suit the capacity of the well without the necessity for any change or adjustment in the apparatus, the shut-down period remaining constant.

Among the advantages the following:

(a) The same apparatus may be used in all wells having a productive capacity less than the capacity of. the apparatus. In other words, an apparatus having a capacity of two hundred barrels per day will pump all.wells having a lesser capacity.

(b) The apparatus when operating will run atits fullrated capacity and at high efliciency.

.(c) The apparatus will keep the well pumped down so that. at no time willthere be in the well more oil than will run in during the deflnite period for which the relay 63 is set.

(d) A constant speed motor 41 maybe used to operate the actuating pump and no resistance'-- or'other speed regulator is needed in connection therewith.

(e) When the apparatus is once installed it will operate over a long period without varying the adjustments thereof even though the amount of fluid running into the well may vary considerably. a

While We have described in the above description three methods of insuring the desired result of intermittent pumping, it should be understood that we do not wish to limit ourselves to anyone of these three methods; In other words, our invention'broadly contemplates pumping the well for a suiflcient period to pump it down, then allowing it to stand for a definite time interval; during which the well refills itself, and then repeating the cycle. While we illustrate inFig. 1 a method in which we accomplish" this result, by

utilizing the current flowing to the motor as an actuating force for determining the timelg-i ior shut-down, we show ini ig. 3 a method of 'utiliaing the pressure in the pipe 27' for determining the time of shutdown, and we show in Fig. 4 a method of utilizing the rate of flow of the oil in the pipe 410 for determining the time oi shutdown, we recognize that there may be other methods by, which this result. may be accom-,

'plished and we do not wish to limit ourselves to any of the illustrated methods, all or which come within the scope of the following claims. What-' ever system of control-is used, the general result is the same when the apparatus is 'operating automatically. The motor operates the pump far a suflicient period to pump down the fluid in the? well. T

of this arrangement are We claim as our invention:

1. ,A method of pumping a fluid from a well,

which comprises: pumping said fluid from said certain predetermined value due to the exhaustion of fluid in said well; allowing'the fluid to flow into the well, without pumping for a deflnite time interval; resuming said pumping at the end of said time interval; and continuously repeating the cycle.

2. In a well pumping outfit adapted torepcatedly pump a well sulfliciently toreduce the fluid level ther'einto a definite low point regardless of variations in rate of flow of fluid into said well, the combination of: a.pump adapted to reduce said level when in operationlby removing fluid from said well at a rate greater than the maximum'rate of flow of fluid into said well; means for'preventing the fluid in said well from being pumped below said low point by stopping said val has elapsed after each'stopping of said pump.

3. In a well, pumping outfit adapted to repeatedly pump a well sufdciently to reduce the fluid level therein to a deflmte low point regardless of variations in rate of flow of fluid into said well.

the combination of a pump adapted to reducesaid level when in operation by removing fluid from said well at a rate greater than the maxlmum rate of flow of fluid into said well; means for preventing the fluid in said well from being pumped below said low point by stopping said pump automatically whenever said fluid is pumped down to said low point; means adapted to re-start said pump after each stoppage thereof by again supplying power thereto; and'a definite time element means for insuring that the pump shall be inactive for a period of deflnite duration by actuating said re-starting means whenever said periodhas elapsed after any stoppage,

pumped below said low/pointv by stopping said pump automatically whenever the rateof flow "of the fluid delivered from said pump-falls below a predetermined minimum; and means for insuring that the pump will eventually remove all the fluid which flows into said well by starting said pump whenever. adeiinite time interval has elapsed after each stopping or said pump.

5. In a, well pumpingoutflt adapted to repeatedly pump a" well sufficiently to reduce the fluid level therein to a definite low point regardless of variations in rate-orflow o! fluiddnto said well, the combination of: 1a pump'adapted to reduce thefluid delivered from said pump falls below apredetermined minimum; means adapted to restart said pump after each stoppage thereof by again supplying power thereto; and a definite time element means for insuring that the pump shall be inactive for a period of definite duration by actuating said re-starting means whenever said period has elapsed after anystoppage of the pump. r L

6. In a well pumping outfit adapted to repeatedly pump a well suificiently to reduce the fluid level therein to a definite low point regardless of variations in rate of flow offluid into said well,

the combination of: a pump adapted to reduce termined minimum whenever said fluid is pumped said level when in operation by removing fluid from said well at a rate greater than the maximum rate of flow of-fluid into said well; means for stopping said pumpby discontinuing the apes plication of power thereto; means for actuating said stopping means whenever the power'required to drive the-pump falls below a predetermined minimum whenever said fluid is pumped down to said low point; and means for insuring that the pump will eventually remove all the fluid which flows into said well by starting said pump whenever a definite time interval has elapsed after each stopping of said pump.

7. In a well pumping outfit adapted to repeatedly pump a well sufficiently to reduce the fluid level therein to a definite low point regardless of variations in rate of flow of fluid into said well, the combination of: a pump adapted to reduce said level when ,in operation by removing fluid stopping said pump by'discontinuing the application of power thereto; means for actuating said stopping means whenever the power re; quired to drive the pump falls below a prededown to said low point; means adapted to restart said pump after each stoppage thereof by again supplying power thereto; and a definite time element means for insuring that the pump shall be inactive for a period of definite duration by actuating said 're-starting means whenever said period has elapsed after any stoppage of the pump. 77

CLARENCE J. COBERLY. FORD W. HARRIS.

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