US1963472A

US1963472A - Fluid motor

Info

Publication number: US1963472A
Application number: US448347A
Authority: US
Inventors: Penrod John
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-04-29
Filing date: 1930-04-29
Publication date: 1934-06-19
Anticipated expiration: 1951-06-19

Description

J. PEN ROD FLUID MOTOR June 19, 1934.

m P Q J. PENROD FLUID MOTOR June 19, 1934 Filed April 29,` 1930 4 Sheets-Sheet 2 n 4 l, 0/// l 4/ JOHN PE NFPOD June19, 1934. J PENROD 1,963,472

FLUID MOTOR Filed April 29, 1950 4 SheelS-Sheet 5 Ff .11" l w F1 .14. q- 9.126

130 1J? 122 Z22 i 150 J{L1/J1 120 120 L 161 T f w13! y 182 f 2H' 7 M 32 .fo/TWPE/v/fw v 5 E* J M1? vJune 19, 1934. J. PENROD FLUID MOTOR Filed April 29, 1950 4 Sheets-Sheet 4 JOHN PEA/R00 TORNEY- `Patented June 19, 1934 UNITED STATESv PATENT I oFFicE 9 Claims.

This invention relates to fluid lifts especially adapted for use in the recovery of oil from wells. The invention further embodies a novel form of fluid lift in which the arrangement of the parts thereof is such that sand present in the fluid being recovered is prevented from having destructive contact with the sleeve valves and other parts of a power unit located in the well.

A further object is to provide a fluid lift which is characterized by efciency, certainty in operation, and which is capable of long and uninterrupted use in a well.

Other objects and advantages will be apparent during the course of the following description.

In the accompanying drawings:

Figure 1 is a fragmentary side elevation illus` trating the improved fluid lift,

Figure 2 is a fragmentary vertical sectional view through the upper portion of the improved fluid lift, the view illustrating the means by which separate forces may be selectively or jointly introduced into the well to bring about the recovery of the native well fluid,

Figure 3 is a fragmentary vertical sectional view through -an intermediate portion of the pump, the view illustrating the means by which native well fluid may enter a portion of the pump, the view also illustrating a sleeve valve mechanism by which the flow of a pressure fluid at one end of a power piston is controlled,

Figure 4 is a vertical sectional view through an intermediate portion of the fluid lift, the parts being shown in the positions occupied during the completion of the down stroke of the power piston of a pressure fluid motor,

Figure 5 is a fragmentary vertical sectional view through the lower portion of the fluid lift.

Figure 6 is a horizontal sectiqnal view taken on line 6 6 of Figure 3, the viewbeing taken in the direction of the arrows, Y

Figure 7 is a -horizontal sectional view taken on line 7--7 of Figure 4, the view being taken in the direction of the arrows,

Figure 8 is a horizontal sectional view taken in the direction of the arrows,

Figure 9 is a horizontal sectional view taken on line 9-9 of Figure 4, the view being taken in the direction of the arrows,

vFigure 10 is a perspective of a dogv carrier embodied in the invention,

Figure 11 is a fragmentary vertical sectional view of that part of the fluid lift illustrated in Figure 4, the parts being shownduring an early period of the upsiroke.

on line 8-8 of Figure 4, the view being takenA Figure 12 is a horizontal sectional view taken on line 12-12 of Figure 2 the view being taken in the direction of the arrows,

Figure 13 is a detail sectional view of the power unit, the view being taken at right angles to the illustration in Figure 11,

Figure 14 is a fragmentary vertical sectional view through that portion of the fluid lift illustrated in Figure 11, the parts being shown in the positions occupied while the power piston is nearing the completion of the up stroke.

Figure 15 is a fragmentary vertical sectional view through the upper portion of a slight modification of the invention,

Fi ure 16 is a fragmentary vertical sectional 70 view hrough the intermediate portion of the modifled form of fluid lift,

Figure 17 is a fragmentary vertical sectional view through the lower portion of the modified form of fluid lift.

In openingthe detailed description of the improved fluid lift, reference might be had tothe course of the native well fluid throughthe pump and thus attention is invited to Figure 5 in which it is illustrated that a perforated or other inlet member 20 provides a means of conducting native well fluid into the lower pumping chamber 22 of a double actingplunger pump. A standing l valve 24 of conventional or other design is positioned to allow of the admission of the native 85. well fluid to the pumping chamber and to prevent the return of such fluid to the well. Outlet from the pumping chamber 22 is by way of a second standing valve 26 carried by the bushing 28 to which a working barrel 30 is connected.

In carrying out the invention, a solid plunger 32 has a working fit within the barrel 30 and on its up stroke draws fluid into the chamber22 by way ofthe standing valve 24, while on the down stroke of the plunger', fluid is discharged from 95- the chamber 22 by way of the outlet valve 26.

Figure 5 further illustrates that the plunger 32 provides a means for varying the volume of a second or upper pumping chamber 34, an inlet to which is by way of an inlet conduit 36 and a 100 standing valve assembly 38. The inlet conduit is extended from the bushing 28 to what might be said to be a cylinder head 39 and has the lower portion thereof open and in communication with the producing formation. Thus, descent of the plunger 32 will result in drawing native well fluid into the chamber 34. The ascent of the plunger 32 will result in discharge of the native well fluid' from the chamber 34 by way of an outlet valve 42.

The fluid discharged from the pumping chambers 22 and 34 is received within and is conducted through a shell or housing 44 forming a fluid conduit. the upper end of which has connection With what might be said to be the cylinder 46 of a pressure fluid motor to be described. Figures 9 and 13 illustrate that the cylinder 46 is formed with a longitudinally extending transversely curved fluid passage 48 in constant communication with the conduit 44 to receive native well fluid therefrom.

The transversely curved passage 48 for native well uid extends for the full length of the cylinder 46 and, as shown in Figures 3 and 6, opens at the upper end thereof into an annular charnber 50. Figure 6 illustrates that constant communication between the transversely curved passage 48 and the annular chamber 50 is established through a plurality of ports 5l. From the chamber 50, the native well fluid travels upward through a passage 52 in the lower section 54 of what might be said to be an upper pumping unit. The upper section of the upper pumping unit is designated by the numeral 56 and is provided with a passage 58 in constant communication with the passage 52 to cooperate therewith in forming a fluid conduit for native well fluid. Outlet from the'passage 58 is by Way of a constantly open port or passage 60, the upper portion of which opens into the lower chamber 62 of what might be said to be a combination foot valve shoe and valve housing 64. During its ascent through the lower chamber 62 and the upper chamber 66 of the member 64, the native well fiuid is directed through a standing valve 68 between these chambers.

Figure 2 illustrates that a well tubing 69 of any desired diameter is provided at the lower portion thereof with a footing member 72 seated within a tubular seat 'I4 of the member 64. The footing member 72 is provided with cups of conventional or other design mounted on a fluid conduit, the latter forming a means by which constant communication is established between the upper chamber 66 and the well tubing 69 so that the native well fluid may pass upward through the member64 and the tubing 69. Of course, the well tubing 69 is provided with a surface connection '76 of any character affording a means by which the well fluid may be conducted to a suitable point.

1n continuing the description of the manner ln which the native well fluid enters the fluid lift and is conducted to the surface, attention is now invited to Figure 3, illustrating what might be said to be an upper pumping unit embodying a double acting plunger operating in a working barrel 82 secured rigidly at its lower portion to a uid conducting member 84 of the lower section 54 .and secured in a similar manner to a uid conducting member 86 carried by the upper section 56.

Of course, the upper pumping unit embodying the lower and

upper sections

54 and 56, respectively, and associated parts is located in the well at a level higher than the pumping unit disclosed ln Figure 5. The fluid conducting member 84 is shown to be formed with a pumping chamber 87 adapted for the reception of the plunger 80 and having the volume thereof varied thereby. Entrance to the pumping chamber 87 is by way of a port 90 and a standing valve 92. Discharge from the pumping chamber 87 is by way of a standing valve 94 and an outlet passage 96. The outlet passage 96 has constant communication with the passage 58 in consequence of which the fluid discharged from the pumping chamber 87 is introduced into the ascending column of native well fluid pumped by the lower pumping unit shown in Figure 5.

With further reference to the upper pumping unit shown in Figure 3 it is pointed out that the same is provided with a second inlet 98 for the native well fluid and communicationv between this inlet and the chamber of the member 86 is controlled by a standing valve 100. Outlet from the chamber of the member 86 is by way of a standing valve 102.

It is believed to be clear that reciprocation of the piston 80 will bring about admission of the native well fluid to the pump by way of the

ports

90 and 98 and the discharge of such well uid into the communicating

chambers

52 and 62 for mixture with. the native well fluid pumped from a lower level.

Attention might now be directed to Figure 2 illustrating that the member 64 is provided with an inlet port communication between which and the chamber 66 is controlled by a standing valve 106.

The port 105 will be found to provide a means by which the native well fluid may enter the tubing 69 either under its own pressure or under the pressure of a lifting fluid furnished to the casing 108 through the medium of a feed line 110. The lifting fluid furnished to the casing 108 may be in the nature of compressed air, gas or the like and will exert sufficient pressure on the column of casing liquid to cause such liquid to enter the chamber 66 and the tubing 69 for movement to the surface.

The

plungers

32 and 80 of the lower and upper pumping units, respectively, have connection with a pressure fluid motor detailed in Figures 3, 4, 7,8, 9, 11, 13 and 14.

The pressure fluid motor embodies a double acting piston mounted for reciprocation within the cylinder 46 and having connection at the upper end thereof with a piston rod 122 and at the lower end thereof with a similar rod 124. The

piston rod 122 has an outer section 126 of a rei duced diameter rigidly connected to the plunger 80, while the lower piston rod 124 has a similarly reduced outer section 128 rigidly connected to the plunger 32.

As shown in detail in Figure l1, the cylinder 46 is provided with upper and

lower chambers

130 and 132, respectively, adapted for alternate communication with a transversely curved fluid passage 131. As illustrated in Figures 6 and 13, the passage l31 extends between the inner and outer walls of the cylinder 46.

Fluid under pressure may be furnished to the passage 131 by Way of a transversely curved passage 134 extending longitudinally through the pump housing 54-56, the upper end of the passage 134 being in constant communication with the outer tubing 70. Figure 2 illustrates that fluid under pressure may be furnished to the outer tubing by way of a feed member 136.

Communication is established between the pressure uid passage 131 and the chamber 130 by one or more ports 138 in the side Wall of the cylinder. Figure 3 illustrates the port or ports 138 to be uncovered by a sleeve valve 140 operating within the cylinder and adapted to be moved upwardto cover the inlet port or ports 138 and thereby cut o the admission of pressure uid to the upper chamber 130.

Admission of the pressure fluid to the chamber 132 from the longitudinally extending passage 131 is by way of one or more ports 142 in the lower portion of the chamber. These ports are controlled by a longitudinally movable sleeve valve 144 operating within the chamber 132.

The exhaustl from the upper chamber 130 is by way of oppositely located ports 150v opening into the oppositely located exhaust passage 152 in opposite sides of the cylinder 46. It is believed to be apparent that when the sleeve valve 140 is in the uppermost position as suggested in Figures 11 and 14, the admission of pressure uid by way of the port 138 is cut off and the exhaust of fluid by way of the ports 150 allowed.

The exhaust of pressure uid from the lowerv chamber 132 is by way of oppositely located ports 160 which, of course, open into the oppositely located longitudinally extending transversely curved exhaust passage 152 in the cylinder 46.

The upper and

lower sleeve valves

140 and 144, respectively, are shown in Figures 11 and'14 to be connected for operation in unison through the medium of oppositely located tie rods 164, the terminal portions of which are joined to the sleeve valves by fastening

devices

165 and 166, respectively. Spacing plates 167 and 168 are located on the

fastening devices

165 and 166, respectively, and operate loosely in slots 170 in the cylinder 46.

During the movement of the sleeve valve 140 to fluid inlet position, the sleeve 144 will be moved simultaneously to the opposite position and vice versa.

'I'he piston 120 is shown in Figure 4 to be nearing the completion of the down stroke with the lower piston rod 124 in engagement with a plurality of dogs 180 pivoted between the ends thereof to a dog carrier 182. 'I'he upper or inner portions of the dogs 180 are shown to be urged inward by coil springs 185. to position the dogs for engagement by the lower portion of the rod 124.

The dog carrier 182 is moved downward with respect to the associated sleeve 144 against the pressure of an expansion spring 186, the lower end of the spring being engaged with the lower end of the chamber 132; while the upper end of the spring is engaged with the dog carrier.

Figure 4 further illustrates that a rod encircling sleeve 190 is extended upward from the lower end of the chamber 132 and has the upper portion thereof bevelled and in the path of travel of the shouldered intermediate portions of the dogs 180 so that when the dogs are brought down into engagement with the sleeve 190,'the same are moved loutward into recesses 191 'in the sleeve valve 144. When the dogs 180 are thus swung outward into the grooves 191 the same are, of course, released from the lower end of the member 124 so that the spring 186 is freed to assert itself and thereby move the sleeve valve 144 from the lower position shown in Figure 4 to the uppe position. f

Figure 11 ilustrates the position occupied by the piston 120 and associated parts during the early phase of the up stroke of the piston. By reference to this figure, it will be seen that the dogs 180 have been swung out into engagement with the upper wall of the grooves 191 and that the spring 186 has moved the dog carrier 182 and bothsleeve valves upward.

During the change in the position oi the lower sleeve valve 144 and consequently the position ofthe upper sleeve valve 140, the piston 120 is in the act of changing its direction of travel and consequently during the upward movement of the sleeve 144 the dogs 180 will ride along the side of the piston rod 124.

Referring now to Figure 14, it will be seen that as the piston 120 continues its upward movement, the upper piston rod 122 is brought into driving engagement with the dogs 200 carried by a dog carrier 202 corresponding in construction to the lower dog carrier 182. Of course, the position' of the dog'carrier 202 is opposite that of the lower dog carrier 182 to present the dogs 200 to the end of the piston rod 122. As the piston 120 continues its upward movement, the same will move the dog carrier 202 upward to compress an expansion spring 206 conned between the upper end of the dog carrier 202 and the upper end of the chamber 130.

When the dog carrier '202 reaches the limit of its upward movement under the influence of the ascending piston 120, the shouldered portions 208 of the dogs 200 will be brought into engagement with the bevelled end of the sleeve 210 depending from the upper end of the chamber 130 with the result that the dogs 200 are swung out into the groove 211 of the upper sleeve valves 140.

When the dogs 200 are thus swung into the groove 211 of the upper sleeve valve 140, the piston rod 122 will, of course, lose driving engagement with the dogs 200 so that the spring 206 will be free to expand and thereby move the sleeve valve 140 downward to cut off the exhaust of fluid by way of the ports 150 and to allow of the admission of pressure fluid 130 by way of the ports 138.

The lower dog carrier 182 is limited in its upward movement under the inuence of the associated spring 186 by a stop sleeve 214 rigidly secured to the sleeve 190. In this manner, the sleeve valve 144 and consequently the upper sleeve valve 140 are limited in' upward movement to position these valves to properly control the admission and discharge of fluid to and from the associated chambers.

On the other hand, the downward movement of the dog carrier 202 under the inuence of the expansion spring 206 is limited by a stop sleeve secured rigidly to the intermediate portion of the tubular member 210 so that, in turn, the descent of the upper sleeve 140 and consequently the lower sleeve 144 is limited.

So far as I am aware the environment of the dog carriers, the dogs carried thereby and the springs by which the dog carriers are moved endvwise, is new and marks an important phase of the linvention. That is to say, the matter of diameters of those parts that are located within A the well is of the greatest importance and I be- A lieve that'I am the first to mount a dog carrier along with the dogs and the associated motive springs within the sleeve valve of a fluid pressure motor, which, in turn, is located in the bottom of a well or at a producing level.

In the operation of the pressure fluid motor, the pressure fluid is alternately furnished to the

chambers

130 and 132 and, of course, the pressure fluid is alternately discharged from these chambers.v

When the parts of the pressure fluid motor art.

Vin the positions shown in Figures 3'and 4, the

upper sleeve 140 allows of the admission of pressure fluid by way of the ports 138 and cuts off the discharge ports 150 so that the pressure fluid thus admitted to the upper chamber will bring about the descent of the piston 120. During the descent of the piston 120, the exhaust ports 160 from the lower chamber 132 are open 'to allow of the discharge ofthe previously employed pressure fluid into the oppositely located exhaust passages .152. .Duringthis time, the ports 142 for the supply of pressure fluid to the lower chamber .132 arev closed by the-sleeve valve 144. During the approach of the piston 120 to an. extreme position, it 4will engage one of the dog carriers and compress the .associated coil spring and when such movement of thepiston in fone direction is completed, .the previously compressed spring is freed to reverse the 'position of the valve. Such reversal in the-positionof the.

sleeve valves .takes place without simultaneous compression of the operating spring associated with the other carrier and in .this manner thev sleeve valves and the operating means therefor are rendered more certain in operation.

More specifically, the alternate compression of the

springs

186 and 206 takes place during an active portion of the stroke of the piston 120. The compression of one spring takes place at a time when the- 'other spring is relatively inactive.

By the foregoing arrangement of sleeve valves and operating means therefor the movement of the sleeve valves together is in the direction opposite the immediately preceding direction of travel of the piston 120.

As shown in Figure l1, the valve rods 164, the

sleeve valves

140 and 144 are in contact for the full length thereof with the associated motor cylinder and the friction incident to such contact is suflicient to hold the sleeve valves in the elevated position for the intervals that these valves are otherwise free to respond to the force of gravity.

With reference to Figures 3 and 6, it will be seen that the oppositely located exhaust passages 152 constantly communicate with the annular passage 50 with which the passage 48 for the native well fluid also communicates. Thus, the native well fluid and the exhaust of the pressure fluid motor mingle upon entering the chamber 50 and are conducted to the surface together or as a common column.

Attention is now invited to Figure 3 in which it is illustrated that the sleeve 210 is formed with a continuation 225 passing through the chamber 50 and an extension 227 thereof and having a much reduced wall thickness so that the pressure of the flu'd being pumped, combined with the `pressure of the exhaust from the pressure fluid motor, will tend to compress the continuation 225 into fluid tight contact with the adjacent portion of the piston rod 126. In this manner, the pressure fluid in the chamber 130 is prevented from passing up through the sleeve 210- 225 and entering the pumping chamber. The upper portion of the continuation 225 is diametrically enlarged and is secured in the upper portion of the extension 227 by a ring nut 230 operating on a suitable packing to establish a fluid tight seal between the pumping chamber 87 and the chamber 50-227.

Attention is now invited to Figures 4 and 5 in lwhich it is illustrated that the uncontrolled escape of pressure fluid yfrom the lower chamber 132 is prevented. With special reference to Figure 4 it will be seen that a tubular body 235 is extended into the lower portion of the cylinder 46 and is provided with a plurality of cups 236 having fluid tight contact with the wall of the surrounding tubular section secured in the lower portion of the cylinder 46.

The lower portion of the tubular body 235 is formed at a point spaced between the ends there- .has the upper portion thereof secured within the shoulder238 by. an annular series of fastening devices 241, the' lower portions of which are threaded into the separate sections of a clamping ring 242.

It will be seen that the clamping ring 242 and the fastening devices 241 will form an ellicient meansof securing the upper portion of the packing element240 in the annular groove of the shoulder 238,.,to the end that a fluid tight seal is established between the packing element 240 and the body 235.

The lower portion of the packing element 240 is annularly grooved and is received within an annular groove formed in the diametrically enlarged upper portion 248 of what mightbe said to be a sleeve nut 249, the lower portion .f which is threaded into the valve housing 39. Fastening devices 251 and a sectional clamping ringl 253 provide a means by which the annularly grooved lower portion of the packing element 240 is clamped within the enlargement 248 and at the same time is held against spreading.

Figure 5 illustrates that the packing element 240 which is of elongated formation is extended through the fluid conducting shell 44 and is entirely surrounded by and is consequently exposed to the full pressure of the native well fluid elevated by the lower pumping unit with the result that the 'packing element 240 is held in fluid tight contact with the adjacent portion of the rod 126 regardless of wear on either of these parts. Thus, the uncontrolled escape of pressure fluid from the lower chamber 132 into the housing 44, or the lower pumping unit is prevented.

Should it be desired to withdraw the pump, to the surface, the inner tubing 69 is first removed, and by reference to Figure 2 it will be seen that the combination foot valve shoe and valve housing 64 is formed with a port 270 adapted to establish c'ommunication between the tubing 69 and the casing 108 when the foot valve '72 is unseated so that the tubing fluid may be dumped into the casing. In this manner, the withdrawal of the tubing '70 will not be hampered by the presence of the fluid formerly in the inner tubing 69.

To install the form of fluid lift shown in Figures 1 to 14 inclusive, the pressure fluid motor and associated pumping units are lowered into the well on the lower end of the outer tubing '70. When the pressure fluid motor and associated pumping units have been properly located in the well, the inner tubing 69 is set with the footing member '72 thereof positioned within the seating member '74.

In describing the operation of the fluid lift shown in Figures 14 to 14 inclusive, reference might be had to a typical well of possibly 5000 feet deep and in which the natural or rock pressure is suillcient to build up a column of fluid 3500 feet in the hole. In this case, the well will not flow of its own accord and the gas initially in the oil is dissipated thereby increasing the weight of the column of fluid and rendering it less responsive to the natural forces of the well.

As previously suggested, when the column of well fluid thus becomes devitalized it is a problem of the first magnitude to set the same in motion and the invention forming the subject of this umn of devitalized well fluid is to introduce compressed air or gas into the casing 108 by way of the lead line 110 so that the force of such pressure fluid will be transmitted through the column of casing fluid and the level of native well fluid in the inner tubing caused to rise substantially above the level of the casing liquid.

'Ihe next step in a typical case would be to furnish a relatively non-compressible fluid to the' pressure fluid motor disclosed in Figures 11 and 14. such supply being accomplished by Way of the outertubing 70. The relatively non-compressible fluid thus supplied to the pressure fluid motor disclosed in Figures 11 and 14 will result in the reciprocation of the piston 120 and consequently in the' reciprocation of the lower and

upper pumping pistons

32 and 80.

At this point it might be noted that the pressure from an outside source placed on the casing fluid will cooperate actively with the pressure fluid motor shown in Figures 11 to 14 since such pressure will be effective in filling the

pumping chambers

22, 34, 86, and 87 at the proper times and in urging the

plungers

32 and 80 in the direction in which the same are being moved by the power piston 120.

The pumping action of the

pistons

32 and 80, combined with the fact that the exhaust from the pressure fluid motor is into the column of native well fluid being recovered will set upA in the inner tubing a pressure superior to that prevailing within the casing and even though the pressure prevailing within the casing iswof an inferior order of magnitude it will nevertheless be effective in aiding in the recovery of the native well fluid.

'Ihe foregoing is true for several reasons; first, because the pressure prevailing Within the casing will have the Aeffect of filling` the

various pumping chambers

22, 34, 86 and 87 under pressure and more or less solidly. That is to say, such gas as may be in the fluid being pumped is compressed by the pressure prevailing within the casing and will act alternately on the ends of each of the plungers to cooperate with the power piston 120 in bringing about the operation of the pumping units. For example, in Figure 3, the piston 80 is shown to be on thedown stroke with the outlet valve 102 from the chamber 86 closed and the inlet valve 100 open. The pressure prevailing Within the casing is allowed to assert itself through the port 98 and the pumping chamber 86 against the descending plunger 80 so that such casing pressure acts as an auxiliary power means cooperating with the pressure fluid lmotor in bringing about the desired reciprocation on the part of the pumping plungers.

' In further adverting to the manner in which the inferior pressure prevailing within the casing is allowed to cooperate with the pressure fluid motor in bringing about the reciprocation of the

plungers

32 and 80, continued reference to Figure 3 will show that on the down stroke of the plunger the outlet valve 102 from the pumping chamber 86 is held in a closed position by the superior pressure prevailing Within the inner tubing and thus the superior pressure prevailing within the tubing is prevented from opposing the inferior pressure in the casing,

The inferior pressure prevailing within the casing also acts through the

other pumping chambers

87, 22 and 34 in assisting the pressure fluid motor in the operation of the several pump.

ing units. In this connection, attention might be invited to Figure 5 in which it is shown that the piston 32 is on the down stroke and native well fluid is entering the chamber 34 by way of the port or passage 36. The pressure existing within the casing by reason of thek supply Yof compressed air or gas from an outside sourceA into the casing will assert itself against the upper end of the piston 32 and urge downward.

Thus, the pressure existing within thefcasing the piston v acts in concert with the pressure fluid motor"4 in in urging the pisf may enter the various pumping chambers 'to a.

value superior to the pressure -existing within the inner tubing 69 so that the several pumping units are positively prevented from becoming gas bound.

The supply of a relatively non-compressible fluid to the pressure fluid motor shown lin Figures 11 to 14 is continued until the well has been relieved of the column of devitalized native ywell fluid. After such relief has been accomplished air or gas under pressure make take the place of-a relativ-ely non-compressible fluid as an yoperating medium for the pressure fluid motore. The change 'from a relatively non-compressible fluid to air or gas as an operating medium forv the pressure fluid motor will result in the ac-` celerated action of the several pumping units and sinc'e the exhaust from the pressure fluid` motor is into the columnof fluid being elevated,r

the light air or gas forming the exhaust will mingle with and .thus further vitalize the fluidy being elevated.

In summarizing the mode of operation as thus far described, it will be seen that to set the column of devitalized and thus heavy well fluid in motion a non-compressible fluid is employed while after the place of the devitalized fluid hasbeen taken by lively well fluid,. a compressible source of power with less friction and weight may be employed to provide for the accelerated travel of the fluid being recovered.

The relatively non-compress'ble fluid is ernployed initially to provide the great pressure necessary to set the relatively heavy column of Well fluid in motion, while compressed air or gas maybe found to be sufficient to provide for continued operation of the fluid lift, especially when aided by the natural force of the well.

At any time, such, for example, as after a shut down, or when the natural force of the vvvell has diminished, a non-compressible lifting medium under pressure may again be employed to operate the pressure fluid motor.

If, after the Well has been relieved of the column of devitalized fluid and the natural forces of the well are found to be sufllcient when combined with the exhaust from the pressure fluid motor to raise the products of the well to the surface, the pressure supplied to the casing from an outside source may vbe cut off or materially diminished.

When the well has been enlivened, the port 105 may become the major inlet for the fluid to the tubing 69, in which event compressed air or gas may be furnished to the casing to aid the natural forces of the well in inducing the flow of fluid into the tubing 69 by way of the port 105.

When the well has thus been livened up and the natural or rock pressure allowed to assert itself, the -pressure within the casing will become superior to the column of native well fluid ascending through the inner tubing 69. This will be especially true after the change from relatively non-compressible fluid to compressed air or gas as the actuating medium for the pressure uld motor.

In many wells, it is necessary to maintain a back pressure on the producing stratum to restrict or avoid the incursion of water. The herein disclosed invention provides a simple means by which a back pressure most adaptable to prevailing conditions may be provided. It will be seen that the pressure supplied to the casing not only places a back pressure on the producing stratum but at the same time actively cooperates with the pressure fluid motor in bringing about the reciprocation of the

plungers

32 and 80, this latter feature of the invention having been fully described and several concrete examples given.

In the form of invention illustrated in Figures 15, 16, and 17, the pressure fluid motor and associated pump is suspended from a tubing 300, the lower portion of which is provided with a footing element 304 adapted to seat within the shoe 306 secured to the upper portion of the cylinder 30'7 of a pressure fluid motor corresponding generally to the pressure fluid motor illustrated in Figures 11 and 14.

As shown in Figure 16, the pressure fluid motor in the modified form of invention embodies a piston 350 corresponding to the piston 120. The lower pumping unit designated generally by the numeral 355 corresponds to the lower pumping unit illustrated in Figure 5, while the equivalent of the upper pumping unit suggested in Figure 3 is omitted. Thus, the upper dog actuating rod 360 is provided with a short tapered stem or terminal portion 362 adapted to pass between the dogs 364.

As illustrated in Figure 15, the shoe 306 is in the nature of inner and outer concentric spaced tubular members, the outer tubular member having connection with a tubular support 308 for a packing element 310. More specifically, the upper portion of the support 308 is reduced or olfset inward to form a neck 31'1, the upper portion of which is formed with an annular flange 312 L-shaped in cross section to form a recess for the reception of the lower portion of the packing element 310.

The lower portion of the packing element 310 is shown to be secured within the flanged upper portion of the support 308 through the medium of fastening devices 314. More particularly, the lower portion of the packing element 310 is annularly grooved to define an attaching ring or portion 316 through which the fastening devices 314 are extended.

A plurality of arms 318 are anchored at the lower ends thereof to the lower portion of the sealing element 310 through the medium of the fastening devices 314 and are secured at the upper ends thereof to an annulus 320 mounted on the upper end of the sealing element.

The sealing element or packer 310 has the upper portion of its bore flared for the reception of the flared head 330 of a mandrel 332. The mandrel is slidable through the sealing element 310 and has the flared head thereof provided with a plurality of spaced internal lugs 334 adapted to be engaged by a coupling 336 or some other part of the tubing 300 to urge the mandrel into expansive contact with the sealing element 310.

When itis desired to unseat the pump illustrated in Figures 14, 15 and 16, the tubing is drawn upward to relieve the lugs 334 from the pressure of the coupling 336 and to subsequently bring the radial lugs 340 of the foot valve 304 upward into pressure engagement with the lower end of the mandrel 332 whereupon the mandrel is raised into the upper portion of the sealing element 310.

The upward movement of the mandrel 332 will bring the head thereof into pressure engagement with the annulus 320 with the result that the arms 318 are straightened and are caused to draw the packing element 310 in from pressure engagement with the wall of the surrounding casing.

Continued upward movement of the lugs 340 will result in the engagement of such lugs with the inwardly offset upper portion 342 of the support 308 so that further upward movement of the tubing will result inelevation of the pump. When the tubing is thus elevated and the foot valve 304 moved upward above the level of the port 345, the tubing fluid may flow back into the casing or the well by way of this port.

Having thus described the invention, what is claimed is:

1. In a pressure fluid motor, a cylinder having a chamber, provided with intake and exhaust ports, a sleeve valve controlling said ports, a piston in the cylinder, a member movably associated with the valve and having a dog for driving engagement with the sleeve valve, and piston actuated means to move the dog into driving engagement with said sleeve valve, said member and the dog thereof being positioned within said sleeve valve. 1

2. In a pressure fluid motor, a cylinder having a chamber, provided with intake and exhaust ports, a sleeve valve movable lengthwise of said cylinder and controlling said ports, a member located within said sleeve Valve and having a pivoted dog for driving engagement with said sleeve valve, and a spring at one end of said member and acting through said member and the dog thereof to move said sleeve valve from one extreme position to another.

3. In a pressure -fluid motor, a cylinder having a chamber, provided with intake and exhaust ports, a sleeve valve movable lengthwise of saidf cylinder and controlling said ports, a member located Within said sleeve Valve and having a dog for driving engagement with said sleeve valve, a spring at one end of said member and acting through said member and the dog thereof to move said sleeve valve from one extreme position to another, and a piston in said cylinder and having means acting through said dog and said member to charge said spring.

4. In a pressure fluid motor, a cylinder, a piston in the cylinder and dividing the same into separate chambers, each of said chambers being formed with separate intake and exhaust ports, sleeve valves for said chambers and having means controlling the intake and exhaust ports, means connecting the valves for movement in unison, members Within said sleeve valves and having dogs for operative connection with said sleeve valves, separate springs alined with said members and acting through said members and the dogs thereof to move the sleeve valves together from one position to another, said piston being provided with means acting through said dogs and said members to alternately charge said separate springs.

5.' In a pressure fluid motor, a cylinder, a piston in the cylinder and dividing the same into separate chambers, each of said chambers being formed with separate intake and exhaust ports, sleeve valves for said chambers and having means controlling the intake and exhaust ports, means connecting the valves forv movementvin unison,

ysubstantially cylindrical members Within said sleeve valves and having dogs for operative con- I in the cylinder and dividing the same into separate chambers, each of said chambers being formed with separate intake and exhaust ports, sleeve valves for said chambers and having means controlling'the intake and exhaust ports, means connecting the valves for movement in unison, substantially cylindrical members having dogs for operative connection with said sleeve valves said members and the dogs thereof being surrounded by said sleeve Valves, springmeans acting `through said members and the dogs thereof to move the sleeve valves `together from onel position to another, said pistonbeing provided' with means acting through said dogs and said members to alternately charge said spring, releasing devices value, and stop elements limtingfendwise movement of said members.

'7. In a pressure uid motor, a cylinder provided with ports, a sleeve valve movable lengthwise within said cylinder and controlling said ports, a dog carrier located within said sleeve valvel and having a pivotally mounted dog, said sleeve being provided with an internal groove having one end formed with a shoulder for engagement by said dog, a spring at one end of said dog carrier and acting through the dog carrier and the sleeve thereof to move said sleeve valve from one extreme position to another, and a piston in said cylinder and having means acting through said dog and said dog carrier to move the dog carrier endwise Within the sleeve valve to charge said spring.

8. In a pressure fluid motor, a cylinder having a chamber provided with ports, a sleeve 'valve' movable lengthwise within said cylinder and controlling said ports, a dog carrier located within said sleeve valve and having a pivotally mounted dog, said sleeve being provided with an internal groove having one end formed with a shoulder for engagement by said dog, va spring at one end of said dog carrier and acting through the dog carrier and the sleeve thereof to move said sleeve valve from one extreme position to another, and a piston in said 'sleeve and having a rod provided with a shoulder to engage said dog to .move said dog carrier endwise Within the sleeve valve to charge said spring, and a stop sleeve receiving said rod and having a shoulder in the path of travel ofsaid dog to actuate the dog.

9. In a pressure uid motor, a cylinder provided with ports, a sleeve valve movable lengthwise within said cylinder and controlling said ports, a dog carrier located within said sleeve valve and having a pivotally mounted dog, said sleeve being provided with an internal shoulder for engagement by said dog, a spring at one end of said dog carrier and acting through the dog carrier and the sleeve thereof to move said sleeve valve from one extreme position to another, and a piston in said cylinder and having means acting through said dog and the dog carrier to move the dog carrier endwise Within the sleeve valve to charge said spring.

JOHN PENROD.

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