US2276783A - Fluid operated motor for deep well pumping equipment - Google Patents

Description

March 17, 1942. G. KENNEDY ET A L 2,276,783

FLUID OPERATED MOTOR FOR DEEP WELL PUMPING EQUIPMENT 2 Sheets-Sheet '1 Filed Nov. 7, 1938 ISnuentors:

March 17, 1942.

G'. KENNEDY ETAL Filed Nov. 7, 1938 2 Sheets-Sheet 2 II I l /v////V///////////////// lllllllllll 3 4 M 0 -10, f a% 1, c 5

5 4 0 7 /47 T W 9 /2 0 0 7 9 8 8 7 9 0 9 3 x 32 4 2 3 2 W Patented Mar. 17, 1942 FLUID OPERATED MOTOR FOR DEEP WELL PUMPING EQUIPMENT.

Glen Kennedy and C. 0. Cole, Whittier, Calif. Application November 7, 1938, Serial No. 239,258 Q 6 Claims.

This invention relates in general to fluid motors and in particular to a fluid motor adapted to be positioned in a well bore for operating a deep well pump which may be associated with it. The pump preferably being of the double acting type.

While this motor may be applied to pumps used for many purposes, it is particularly adaptedto the operation of deep oil well pumps. When utilized for this purpose, the motor, having the pump associated with it, is suspended from the lower end of a string of production tubing extending downwardly in the well bore. A string of pressure tubing, preferably disposed inside the production tubing, conducts a motive fluid from a surface pressure pump to the motor. The production tubing serving to conduct to the surface the discharge of the pump and the exhaust fluid from the motor.

It is an object of this invention to provide a fluid operated motor of a highly simplified design which consequently may be easily and economically manufactured and is comparatively free from mechanical breakdown in operation.

It is a further object of this invention to produce a fluid motor having but two moving parts, a piston and a control valve, which is positive in operation and which cannot get on dead center.

It is still another object of this invention to provide a fluid motor in which the two moving parts, a piston and a control valve, are both disposed in the piston chamber whereby the wearing surface is materially reduced under that of motors of a similar character which require separate chambers to receive the valves.

The essence of this invention which renders the foregoing and other objects possible of accomplishment resides in the concepts and in the methods of closing off the supply of fluid from the supply port to the piston chamber while the valve is being shifted by the fluid under pressure; of discharging fluid from the valve space; of starting the piston in the reverse direction as the valve completes its movement relative to the piston; in carrying the valve by the piston, and in the cooperative relationships which exist between the various elements of the mechanism and their respective fluid passages as follows:

1. Between fluid passages provided by the chamber wall and fluid passages provided'by the piston.

2. Between fluid passages provided by the chamber wall and, respectively, the valveand valve fluid passages.

'3. Between the piston fluid passages and, respectively, the valve and valve fluid passages.

Other objects and advantages of this invention will be made apparent in the description which follows and in the accompanying drawings.

In these drawings:

Fig. 1 is a diagrammatic view showing the motor of this invention attached to a pump.

Fig. 2 is a vertical sectional View of the motor of this invention, showing the valve in #1 control position. v

Fig. 3 is similar to Fig. 2, except that the valve is shown in its other or #2 control position.

Fig. 4 is a horizontal sectional view taken on the line CCC of Figs. 2 and 3.

Referring to Fig. 1, a method of connecting the motor of this invention to a pump is shown. A string of pressure tubing communicating with a source of operative fluid under pressure is threadably attached to the outside shell 58 of the motor. Shell 38 providing a passage to the motor supply port as will be explained later. Motor piston chamber threadably engages. one end of head I, the opposite end of head 1 being threadably received by one end of connecting sleeve 46. Head 41 serves as shown to threadably connect sleeve 46 and pump &8 and to threadably receive the lower end of a string of production tubing 53.

Motor piston rod 10 and pump rod 52 are connected by rod connector 50. Rod connector 50 provides opening 32 in communication with motor exhaust, as will be explained later, and with the discharge from the pump. Pump rod 52 is provided with a passage adapted to receive pump tive fluid and methods of installation and operation in the well bore of fluid operated motor' pumps are matter which have been described in the patent literature and are well understood by oil field workers. They will, therefore, not be made subjects for discussion here.

Referring to Fig. 2, a preferred construction of the motor is shown in detail. A cylindrical piston chamber 5 is closed at one end with a head 6 and is provided at the other end with a head I .which provides a gland 8 and a stuffing box 9 the valve being retained in place on the piston by heads I3a and I3b, head |3,a being threadably attached to the piston, as shown. It will be observed that heads I4 and I 5 provided by the valve and piston heads I3 and I4 are in slidable and substantially fluid-tight contact with the inside chamber wall.

The piston, as shown, has formed therein a longitudinal primary passage I6, having primary, secondary, and tertiary and quaternary openings, designated as IT, I8, I9 and 20, respectively; and also a longitudinal secondary passage 2| having primary, secondary, tertiary and quaternary openings designated as 22, 23, 24 and 25 respectively; passage I6 connecting with the upper, and passage 2| connecting with the lower end of chamber 5. The piston further provides a longitudinal passage 26 connecting with a transverse passage 21 and passage 28 connecting with exhaust by opening 32, formed. in piston rod I0. Since passages 21, 26, 28 and opening 32 constitute a passage leading to exhaust, hereinafter a connection to passage 2'! will be termed as a connection to exhaust.

Valve I2 provides primary and tertiary openings 33 and 3| connecting respectively with annular channels 29 and 34 and furthermore provides a secondary passage in the form of an annular channel in connection at all times with transverse passage 21. Channel 30 being wide enough to cover passage 21 with sleeve valve I2 in either one of its extreme positions.

The piston chamber 5 has formed in its inside wall primary and secondary channels 36 and 31 and a supply port 35, channels 36 and 31 being axially equidistant from supply port 35. A shell attached to the chamber at 39 provides a channel for conducting motive fluid to the chamber supply port 35.

It will be observed that piston heads I3a and I3!) serve to limit the travel of valve I2, the distance of travel being that required to bring into proper registration the various cooperating ports and openings, as will be explained later.

It is also desired to point out that valve heads I4 and I5 in slidable contact with the inner surface of chamber 5 serve to define an annular passage 40.

With valve I2 in the position relative to the piston, as shown in Fig. 2, but with the piston slightly lower down in the chamber than shown, it will be apparent that a passage is established leading from supply port through annular passage 4|), through valve opening 33 and piston opening 24 into piston passage 2| and thence to the lower end of piston chamber 5. With shell 38 connected to a source of operative fluid under pressure fluid will flow through annular passage 42 to supply port 35 and thence through the passage as above described to the lower end of chamber 5 where it will act to force the piston in the upward direction. It should be noted that space 4| between valve head I4 and piston head |3a is connected with piston passage 2| by opening 23, consequently space 4| is filled with operative fluid under pressure whereby valve I2 is effectively held in its control position.

With the valve in the control position with respect to the piston, as above described, it will be clearly seen by referring to Fig. 2 that a passage for the exhaust of fluid from the upper end of chamber 5 is provided through piston passage I6 and opening 20 into sleeve valve passage 30 which connects to xhaust.

With piston I I and valve I2 in the positions shown in Fig. 2 it will be apparent that'valve head I5 has shut off the connection between supply port 35 and annular passage 40. Obviously, in this position no fluid can flow from supply port 35 to piston chamber 5; however, the full pressure of the operative fluid is applied against valve head I5 to move it in the upward direction.

As shown in Fig. 2, chamber annular passage 36 connects space 4| and piston opening 22 with piston in this position. Operative fluid pressure acting against valve head I5 causes the valve to move upwardly forcing fluid from space 4| through annular passage 36 and opening 22 thence through piston passage 2| into the lower end of chamber 5 closed off from exhaust at this time whereby the piston is caused to move upwardly, the upper end of chamber being open to exhaust. This movement of the piston continues until the valve has moved to the point where valve annular passage 30 connects opening 25' with exhaust passage 21 whereby a passage is set up from space 4| through annular passage 36, piston opening 22 and passage 2| to opening 25 then through valve annular passage 30, and, as already described, thence to exhaust.

It should be pointed out in a general way that in fluid motors of this character open exhaust passages must be maintained at all times as well as supply passages if the various fluid operated parts are to continue in motion and the motor is not to stall. It is therefore necessary to provide a slight overlapping of openings 20 and 25.

It will be seen that valve I2 in the course of its movement from control position #1 as shown in Fig. 2 to control position #2, as shown in Fig. 3 first closes opening 20 thus closing the passage established for the exhaust of fluid from the upper end of chamber 5 and just before opening 20 is completely closed valve passage 36 slightly laps opening 25 for reasons already stated. At this point openings 23 and 33 are closed, opening 3| is slightly lapping opening I9 and not until valve I2 has substantially completed its movement is opening I8 which is made narrow for this purpose connected to supply port 35. Opening I8 is a starting port and provides in part a passage for the flow of fluid to start the piston in the reverse direction as will be explained later. It thus becomes apparent that the piston moves the valve into operative relation with supply port 35 and passage 36, that at this point the supply of operative fluid is closed off from the piston chamber by valve head I5 and therefore the valve is maintained in operative relation with supply port 35 and passage 36 until it has completed its movement. Obviously it is impossible for the piston or valve to get on a dead center. It will be noted that the movement of the piston due to valve movement in either direction is very slight, due to the fact that fluid is forced against the piston head during only of the total movement of the valve, during the last of valve movement a passage to exhaust is provided, furthermore, the effective area of a valve head is much less than the working area of a piston head and the total movement of the valve relative to the piston is small.

Referring now to Fig. 3 it will be noted that valve I2 is in control position #2, that is, it is in its extreme upward position and passages have been established for the exhaust of fluid from the lower end of chamber 5 and for the supply of fluid to the upper end of chamber 5 to effect the downward movement of piston I.

In the position of piston I I and valve I2 shown in Fig. 3 it is apparent that a passage for the supply. of fluid has been established from supply port 35, through opening l8 and thence through piston passage I to the upper end of chamber 5. As piston I l moves a slight distance in the downward direction Valve. head l5 will connect supply port 35 with annular passage 40; the passage for the supply of fluid to the upper end of piston chamber 5 will then be from supply port'35, through annular passage 40, through openings 3| and l9 and thence along piston passage l6. It will be noted that supply port 35 is sufficiently wide to permit valve head I5 to pass it without being closed and that fluid pressure is maintained in space 44 through opening l8, thus holding valve I2 in position.

As shown in Fig. 3 a passage for conducting fluid from the lower end of chamber 5 to exhaust is set up as follows: through piston passage 2| to opening thence through valve passage 3!) to exhaust.

With valve [2 in the position relative to piston l l as above described and shown in Fig. 3, the piston will travel downwardly until the fluid filled space 44 is connected to piston passage opening I! by passage 31 and valve head 43 closes 01f supply port 35 from the established passage leading to the upper end of chamber 5, the situation being entirely analogous to that shown in Fig. 2 and already described.

Fluid pressure acting against valve head l4 moves valve 12 downwardly. During the'flrst /2 of the valve movement fluid from space 44 is forced through passage 31, and opening l1 along piston passage l6 and thence into the upper end of piston chamber 5 whereby the piston is moved downwardly a slight distance, at this time the upper end of piston chamber being closed off from exhaust and the lower end open thereto. As Valve l2 completes its movement, valve passage connects opening 20 to exhaust, whereby a passage from space 44 to exhaust is provided through opening I 8 and along passage Hi to opening 20.

With the piston in its extreme downward position and with valve i2 having completed its movement valve 12 is now in a position with respect to the piston, as shown in Fig. 2 and with a passage to exhaust setup as previously described. However, valve head [4 has supply port closed off from annular passage 40. Opening 23 being connected to supply port 35 fluid flows through opening 23 and passage 2| to the lower end of chamber 5 causing the piston to start moving in the upward direction. As valve head l4 passes supply port 35 a supply passage is set up as first described and the piston continues to move in the upward direction to the position shown in Fig. 2. Thus the cycle is completed. Obviously, with a continuous supply of operative fluid the piston will continue to reciprocate.

It will be apparent that valve l2 in shifting from control position #2 to control position #1 moves in a manner analogous to the shift from position #1 to position #2. In the course of the first part of valve movement from position #2 to position #1 openings 25, I9 and I8 are closed. As the valve continues its movement, opening 20 is connected to exhaust by passage 30, there being, as previously explained, a slight overlapping of openings 23 and 25, passage 30 being sulficiently wide to effect this; opening 24 registers with opening 33 and just before valve movement is completed opening 23 is connected to supply port 35. As explained with regard to opening l8, opening 23 is made narrow to insure that before it is connected to supply port 35 valve movement will be substantially completed.

. Since openings I8 and 23 act as starting ports, there is therefore no possibility 'of the piston starting in the reverse direction from either one of its extreme positions before valve movement is completed.

It should be noted that although for the sake of clarity a somewhat'lengthy and detailed description of valve action has been given valve movement is actually relatively rapid. The rapidity of action, of course, being dependent on the rate at which motive fluid is supplied to the motor.

Thus it will beseen that a motor, operative by oil as the motive fluid, has been produced, the valve action of which is rendered positive at-all times by the foregoing described arrangement of passages and ports. Byfirst connecting the space ahead of the valve to a piston chamber end closed off from exhaust and subsequently, in consequence of valve movement, providing a connection to exhaust provision is made for the complete exhaust of fluid trapped ahead of the valve and the maintenance of live fluid pressure against the other end of valve throughout its entire course of travel without possibility of a connection between supply and exhaust occurring at any time. Obviously in a motor operated by an incompres- 'sib1e fluid such as oil any fluid trapped ahead of the valve would block its action.

We claim:

1. In a fluid operated motor: a motor body providing a chamber; a piston slidable in said -cham'ber providing'a valve space, a valve in saidspace, a port opening through one end of said piston, another port opening through the opposite end of said piston, one of said ports coopcrating with a suitable passage provided by the chamber at ne extreme limit of piston travel'and the other of said ports cooperatingwith another chamber passage at the opposite extreme limit of piston travel to set up a passage in each case for the discharge of fluid from said valve space into that end of said chamber closed off from exhaust at that time.

2. ma fluid operated motor the combination of "abody -providing a chamber and passages;

a piston providing a valve space; a fluid operated valve slidably assembled in said space; said piston providing primary and secondary longitudin'al passages opening through and extending back from opposite ends of said piston, said passages each providing: a primary opening adapted to cooperate with one of said chamber passages to conduct fluid from said valve space to end of said chamber closed off from exhaust during first part of valve shift, a secondary opening, valve controlled and arranged to open as said valve reaches an extreme limit oftravel, tertiary and quaternary openings arranged to cooperate with passage means provided by said valve to control the supply and exhaust of fluid to and from said chamber.

3. In a fluid operated motor the combination of: a motor body providing a chamber and passages; a piston comprising two heads anda connecting body portion of reduced diameter thereby providing a valve space; a sleeve-like valve providing supply ports and an exhaust passage slidably assembled on said body portion between said two heads; said piston providing primary and secondary longitudinal passages opening through and extending back from opposite ends of said piston, said passages each having lateral openings as follows: a primary opening through a piston head opposite to that end of the piston from which its respective passage extends, said opening being adapted to cooperate with a chamber passage to conduct fluid from said valve space, a secondary opening through said piston body, valve controlled and arranged to open as said valve reaches an extreme limit of travel, a tertiary opening through said piston body adapted to cooperate with one of two supply ports provided by said valve and a quaternary opening controlled by an exhaust passage formed in said valve in communication wit-h exhaust at all times, said piston providing a passage leading to exhaust having a lateral opening through said piston body covered by said valve exhaust passage at all times.

4. In a fluid operated motor: a motor body providing a chamber and passages in the wall thereof and intermediate said passages a supply port; apiston in said chamber providing a valve space and a longitudinal pasage opening through the first end of said piston and laterally through said piston adjacent its second end, another similar passage opening through said piston second end and laterally through said piston adjacent its first end; a fluid operated valve slidable in said valve space and providing means to control the supply of fluid from said supply port; one or the other of said chamber passages being adapted as said piston approaches one or the other of its extreme limits of travel to connect one end of said valve space with the piston passage lateral opening in communication with the end of said chamber closed off from exhaust at that time at substantially the same time that said fluid supply port registers with the other end of said valve space and control means provided by said valve close off the communication between said supply port and said chamber whereby the shifting of said valve is permitted and effected.

5. In a fluid operated motor the combination of: a motor body providing a chamber and in its side fluid passage means adjacent each end and intermediate thereof a supply port; a piston comprising two heads and a connecting .body portion of reduced diameter thereby providing a valve space; a sleeve-like valve providing supply ports and exhaust passage slidably assembled on said body portion between said two heads; said piston providing primary and secondary longitudinal passages opening through and extending back from opposite ends of said piston,

.exhaust;

said passages each having lateral openings as follows: a primary opening through a piston head opposite to that end of the piston from which its respective passage extends, said opening being adapted to cooperate with a chamber passage to conduct fluid from said valve space at extreme limits of piston travel, a secondary opening through said piston body, valve controlled and arranged to open as said valve reaches an extreme limit of travel, a tertiary opening through said piston body adapted to cooperate with a valve fluid supply port and a quaternary opening controlled by said valve exhaust passage; said piston providing a passage leading to exhaust having a lateral opening through said piston body covered bysaid valve exhaust passage at all times; said valve constructed with a flange adjacent each end thereof and adapted to cooperate with said chamber fluid supply port to close off the supply of fluid to said piston chamber ends during the time fluid is supplied to a valve space end to effect valve movement.

6. In a fluid operated motor the combination of: a motor body providing a chamber, a supply port and two passage means; a piston slidably mounted in said chamber, and providing a valve space; a valve in said space; said piston providing an exhaust passage and fluid passage :means in alternate valve controlled communication with said exhaust passage for conveying fluid to and from opposite ends of said chamber to actuate said piston comprising a longitudinal passage opening through and extending from the end of the first piston head to and opening laterally through the second piston head and another longitudinal passage opening through and. extending from the end of the second piston head to and opening laterally through the first piston head; as said piston approaches an extreme limit of travel, one of said body passages is adapted to provide a connection between the lateral opening in communication with that end of chamber closed ofi from exhaust at that time and one end of said valve space whereby initially,

a passage is established for the discharge of fluid from said valve space end into said chamber end and subsequently in consequence of valve travel a passage is provided leading to the complete shifting of said valve thereby being permitted and connection between supply and exhaust prevented.

GLEN KENNEDY.

C. C. COLE.

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