US2266356A

US2266356A - Automatically governed pump

Info

Publication number: US2266356A
Application number: US208593A
Authority: US
Inventors: Clarence J Coberly
Original assignee: ROKO CORP
Current assignee: ROKO Corp
Priority date: 1938-05-18
Filing date: 1938-05-18
Publication date: 1941-12-16
Anticipated expiration: 1958-12-16

Description

Dec. 16, 19 c. J. COBERLY 2,266,356

AUTOMATICALLY GOVERNED PUMP,

Filed May 18, 1938- 2 sheets sheet 1' jam-9.

' iig a'Q /Nl/NTOR CLARENCE 1 Cogs/my ATTORNEYS.

Dec. 16, 1941.

c. J. COB ERLY AUTOMATICALLY GOVERNED PUMP Filed May 1s, 195 2 Sheets-Sheet 2 Patented Dec. 16, 1941 7 P to Rake Corporation, Reno, New, a' corporation of Nevada w s we:

This invention relates to the pumping art, and

more particularly to -iluid operated "pumping equipment.

The invention is of particular utility in the-oil industry and, consequently, is described in connection with such use, although it is to be understood that I do not intend to be limited thereby, since the invention is susceptible of other diverse;

uses. Q

This invention is 1 an improvement over the devices disclosed in my copendingpat'ent's, Nolf 2,119,736, issued June 7, 1938, iorGdverne'd fluid operated pump, and No. 2,119,737, issued June 7.

1938, for System of operating 'fluid operated 1 pumps; I v

Fluid operated pumps ior'use in deep wells ordinarily include a fluid motor with a pump unit operatively connected thereto adapted to pump oil, or other well fluid, from the well up through a '20 production tubing leading to the top of thew'ell.

For actuating the fluid motor, operating fluid such as oil is pumped underrelativelyliigh pressure from the top of the well downwardly through a a supply tubing which connects to thefluid motor," As long as the device is pumping oil from the well'j formation, it-will operate at a normal speed, biit it frequently occursthat-ga'si forms in or enters the pump so that, instead of a liquid being pumped, the pumping mechanism' is operating against a compressible gas, the' result being that a material portion of the pumping load is'removed and the pumping mechanism the'niraces or operates at'high speed until from the pumping unit. V

Such fluid operated pumps are ordinarily operated at relatively great depths in oil wells, and,

accordingly, a large volume of operating fluid under high pressure is confined in the supply tubing between the pumping mechanism and the operating pump on the surface 01- the ground which supplies the operating fluid. .Due to'the' compressibilityoi this large volume or operating I fluid, a large amount 01 energy is sto re'd'jin it backup intqxh? 'k Parts fluid under these conditions 0t operation. It for any reason thelpumping load on thefluid operated the gas is removed pump decreases, due to the presence of gas the well fluid, failure of the pump valve to seat prop-- erly, or due to any other cause, the'ope'rating fluid in the supply tubing expands as a result' ofthe: release of the energy of compression stored there in, causing the pump to run at'excessive speeds until the load is-again raised by removing'the'gas tion. The pump may'thus'race ior'a portion of a stroke or for a number of Quccessi've' strokes, and in any event the pump operate at. excessive speed'until'all of energyoi' compression stored'in the operating sum-1s released, or' until the pump ingload is again applied to the pump."

When. a i era ed u Xssive speed, it maybe very harmi'ul'to. certain parts 01' the pumping equipment is particularly true when the pump .cylinder is'pnly,partially piston wilimove'jat'ei tremely high speed during n the flrst part oi itsfstroke' while it' is compressing the" gas therein andwill' thenstrikethe liquid therein while moving at high jyelooity." hi s?in- 'trod'uces a hydraulic :shocl; gload which results in excessive stresses" on 1 e parts of the pu'mp'land may'cause considerable damage in; the, form of excessive wear or breakage, of the rampandence has-also'been found which indicates that a 7 pressure 'wave' may be setupjin the column of operating fluidin thesupply tubing which causes cavitation in the columnldirectly above the pumping mechanism. 'Ijogether with this-comdition 0t cavitation'in the operating fluid, there 'may"also 'be' an excess pressure in the column of discharge fluid in the production tubing, and in any event 11' there is a difference in direction reverse to that 1 of ,normal operation, discharge fluid from the production tubing may.

discharge fluid frequently contains working parts in addition to the undesirable a stresses which it may introduce. 4 Ordinarily inoperating a fluidioperated pump, considerable careis taken to obtain clean operating fluidby the use or flltering equipment and otherwise, and the purpose thereof is defeated it water,;sand, or other undesirable" foreign materials are allowed to H To'prevent such-affluidloperated pump from racing at excessivespeeds under the conditions discussed, a governor mechanism may be provided in the supply tubing conveying operating fluid to the pump immediately thereabove which will control therate oi flow or operating fluid to the fluid'motor and. prevent it. from exceeding a saielimit ,of speed. My above noted Patents No.

2,119,736 "and No.2,1 1 9,737 show such governors v 1 providing means for controlling the rate of flow from the pump or otherwise rectifying the condi;

oi operatinsfluid, which governors may be ad- Justed before they are run into the well, and also pressurein the be caused to back'up through the'fluidfmotor show means of adjusting the flow control thereof after the governors have been run into the well by movement of the operating fluid supply tubing. It is very inconvenient to remove such governors from the well for the purpose of adjustment of the flow control setting mechanism thereof, and it is frequently inconvenientor impossible to adjust a governor in a well satisfactorily by moving the supply tubing to attempt to meet well flow conditions which may constantly vary.

It is therefore a primary object of my invention to provide a fluid operated pumping device for deep wells having incorporated therewith means for preventing the above discussed undesirable conditions.

It is a further object of my invention to provide a fluid operated pumping device for deep" wells in combination with a flow governing device for controlling the flow of operating fluid to the pumping device in response to changes in the rate of flow of operating fluid thereto.

Another object of the invention is to provide a flow governing device which will automatically adJust its flow capacity in response to changes in the rate at which operating fluid is supplied thereto.

Still another object of the invention is to provide a fluid operated pumping device for deep wells having incorporated therewith a fluid flow governor set in the well including means for changing the normal flow capacity of the governor from the surface of the ground without withdrawing the same from the well or moving any' of the tubing in the well.

A further object of the invention is to provide a fluid flow governor for controlling a flow of fluid therethrough, the fluid flow capacity thereof being variable in response to a very gradual change in the rate of flow therethrough. To accomplish this, I prefer to provide a governor requiring a certain definite time interval to adjust itself to the increased or decreased rate of fluid flow therethrough.

A still further object of my invention is to provide a fluid flow governor having a main valve for controlling the flow of fluid through the governor, a metering oriflce in series with the main valve through which the fluid flows to impress a pressure differential on a piston member which controls the operation of the main valve, and an adjustable control means for controlling the operation of the piston member.

A further object of my invention is to provide a flow governor adapted to maintain the rate of flow of fluid therethrough below a predetermined maximum irrespective of momentary changm in the rate of flow, but responsive to a continued change in the rate of flow to readjust the maximum normal flow capacity thereof.

A further object of my invention is to provide flow governor adapted to permit a sudden predetermined increase in the rate of flow above the then established or prevailing rate of flow in response to momentary changes in load, but which automatically requires further increase in the rate of flow ,to be gradual and in re-' sponse to an increased rate of flow maintained over a sustained period.

Another object of the invention is to provide a fluid flow valve having opposed ports so that any unbalance normally produced by low pressure areas produced by high rates of flow of fluid therethrough will be substantially equal and op osite so as to neutralize the effect thereof.

Still another object of the invention is to provide a fluid flow valve having ports cooperating with a valve stem, in which fluid pressures on the valve stem are equalized to prevent fluid leakage along the stem tending to clog or jam the valve stem by the introduction of sand or other foreign materials.

Other objects and advantages will appear in the following specification and in the drawings,

in which:

Fig. 1 is a diagrammatic view, partly in section, of my invention installed in a well.

Fig. 2 is a vertical sectional view of my invention showing the control valve in fully opened position and the main valve in partially closed position.

Fig. 3 is an enlarged sectional view taken on the line 33 of Fig. 2.

Fig. 4 is an enlarged sectional view taken on the line 4-4 of Fig. 2.

Fig. 5 is an enlarged sectional view taken on the line 5-5 of Fig. 2.

Fig. 6 is an enlarged sectional View taken on the line 6-6 of Fig. 2.

Fig. 7 is an enlarged sectional view taken on the line 1-1 of Fig. 2.

Fig. 8 is a vertical sectional view of my invention showing the control valve in partly closed position and the main valve in fully opened position.

Fig. 9 is a vertical sectional view of my invention showing ,the control valve and main valve in fully opened positions.

Referring to Fig. 1 of the drawings, I show a well having a well casing 20 perforated at its lower end as is common in the art to permit well fluid to flow thereinto from the well formation, and having a casing head 2| provided at its upper end from which it is suspended. Also suspended from the casing head 2| is a production tubing 22 having secured at its lower end an inlet check valve member 23 provided with an inlet opening 24 communicating with a conical pump seat 25 adapted to receive in seating relation the lower tapered end of a fluid operated pump 28, a ball valve member 21 being provided to seat in the inlet opening 24 to permit well fluid to flow through the inlet check valve member into the fluid operated pump but preventing a reverse flow thereof. The fluid operated pump 28 may be of any suitable type well known in the art, but I prefer to use a fluidoperated pump such as shown and described in my above Patent- No. 2,119,736, to which reference is hereby made for the details of construction thereof.

Connected to the upper end of the fluid operatedpump 26 is an inlet pipe 28 to which is connected the flow governor 30 of my invention. Connected to the upper end of the flow governor 30 is a string of supply tubing 3| which extends through the casing head 2| to a surface pumping mechanism 32 of any suitable type adapted to pump an operating fluid, such as clean oil, under high pressure downwardly through the supply tubing 3!, the flow governor 30, and the inlet pipe 28 to the fluid operated pump 26 to actuate the same. Also connected to the casing head 2|, and communicating with the production tubing 22, is a discharge pipe 33 adapted to convey fluid discharging therethrough to a point of discharge or use (not shown). a

The flow governor 30, as shown in Figs. 2, 8, and 9, has an outer tubular shell 35 which is connected at its lower end through a lower collar 35 to the inlet pipe 28, and is connected at its 2,2 36,356 I upper end through an upper collar 31 the lower by the plug element 48 acts as a Stop end of the supply tubing 3|.

In general, the flow governor 38 is'com'prised of a valve actuating means 38 for actuating a main valve means '38, and a control valve means 48 for controlling the operation of the valve actuating means 38. The valve actuating means 38 is comprised of a valve piston 4| havinga cen-.-

tral chamber 42 therein, an upper bore 43, and

downwardly extending passages 44 in the lower. face of the valve piston, there being an annular space 45 between the bore '46 of the outer tubu-- lar shell 35 and 'the outer surface of [a tubular extension 41 formed on the lower face, of the.

valve piston 4|. The passages 44 are made as large as possible without weakening the' structure. extension 41' is a plug element 48 which closes the lower end thereof. The valve piston 4| is adapted to reciprocate in the bore 46 of the outer tubular shell 35 and is provided with suitable piston rings 48 for forming a substantially fluid-tight fit 'therebetween.

The main valve means 38 is comprised of a tubular valvebody 58 spaced-from the. outer tubular shell 35 to provide an annular space therearound and having a head portion 52 which makes a fluid-tightfit with the walls of the bore 45 of the outer tubular member 35. The lower end of the tubular valve body 58 is closed by a plug member 53 threaded therein which seats on an upper shoulder 54 formed by the upper end of the lower collar 36, and has radial openings 55a communicating between the annular space 5| and the inlet pipe 28 through thelower collar 36. The head portion 52 is provided with an upper valve passage 55 and a lowervalve passage 56 which are provided with annularrecesses 51 and 58) respectively. The plug member 53 is internally bored at 58 .to receive the lower end of a main valve spring 68, the upper end of which engages an annular plate member 6| provided with a counterbore 62 which receives a lower head portion 63 of a main'valve piston 64 which extends upwardly through the head portion 52 of the tubular valve body 58 and into a, suitable opening formed in the Threaded into the lower end-of the tubularv plug element 48 of the valve actuating means 38. Annular recesses 65 and 66 are formed on the main valve piston 64, being separated by a valve head 61.

The tubular valve body 58 is provided witha central bore 68 in the upper end of which is, a

valve seat member 58 which is pressed into the.

head portion 52 and which makes a fluid-tight fit with the central bore 68. The valve seat member 68 has an axial bore 18 in which the main valve piston 64 makes a close sliding fit, the upper end of the bore 18 communicating through a radial opening 1| with the annular recess 51, being separated by an annular shoulder 12 from a valve chamber 13 formed therein which communicates through a radial dischargeopening 14 and a radial opening 15 formed in the tubular valve body 58 with the annular space 5|. The lower end of the valve chamber 13 is partially closed by an annular lower shoulder 16. The main valve piston '64 fits into a recess in the plug element 48 so as to hold it centered, and bears against the bottom of the recess so that the piston moves in-response to movement of the valve actuating means 38.

The control valve means 48 includes a control to limit downward movement of the control piston .88 in thercontrol cylinder 8|. A helical control groove 83 is'for'med on the outer surface 83 are im portant, as will lbe described hereins aiter The control piston 88' isprovided with a cylindrical chamber 84 in its lower end, and a downwardlyprojecting tubular stem 85 isthreaded into the control piston, the tubular stem having an axial passage 86 communicating between,

the chamber 84 and a check valve chamber 81 formed in the control piston. As willbe noted, the tubular stem'85projects belowthe lower end of the control piston-88 and is adapted to engage the plug element 48 to act as a stop meansto limit downward movement of the. control piston 88. A control'spring 88 is provided in the cylindrical chamber 84 in the s ace'between the tubular stem 85 and the contol piston. 88 and'engages the plug element 48 and the control piston 88, the spring being under compression so' as to exert an upward force on the control piston tending to] maintain it in its uppermost position.

Carried in the, check valve chamber- 8.1 is a ball valve element 88 adapted to seat-in the upper end of the axial passage 86. to\ prevent a downward flow. of fluid therethrough but permitting an upward flow of fluid therethrough. The check valve chamber 81 communicates through a radial orifice. 88 formed in the control piston 88 with the controlgroove 83, and the point of connection thereto is an important feature of the invention, as will be described hereinafter.

Formed on or connected to the upper end of the'control piston 88 is acylindrical control "element 8| which has a conical bore 82, the'control element being providdXwith upwardly opening V,-notches 83, preferably four in number, around the periphery thereof. The controi' element 8| extends'through the upperbore 43 of the valve piston 4|, and when it isin its lowermost position, as shown in Fig. 2, the area of the V- notches 83 is at a maximum. When the control element 8| is in its uppermost position, the base portion 84 thereof will completely close the upper bore 43 to prevent any'fluid from passing therethrough.

In operation, the elements are installed in the well casing 28 as shown in Fig. 1, and operating fluid under relatively high pressure is conveyed by the surface pumping mechanism 32 through the supply tubing 3|, the flow governor 38, and the inlet pipe 28 to the fluid operated pump 26 to operate the same to pump well fluid from the well casing 28 through the inlet check valve member- 23,.the fluid operated pump 25, and the production tubing 22 to the top oi'the well from which it is discharged through the discharge pipe 33.to a suitable point of use or storage (not shown). 5 I

In passing through the flow governor 38, the operating fluid flows from the supply tubing 3| through the upper collar 31 and into the upperv end of the bore 46 of the outer tubular shell 35 above, the valve piston 4|. It then passes through the V-notches 83 of the controlelement 8|, through the central chamber 42, and dis'charges through the passages 44 into the annular space 45. It then passes downwardly through the annular spaceg45 and through the upper and

lower valve passages

55 and 56 and the annular from the annular shoulder I2 the same distance;

that the lower shoulder 96 is spaced from the annular lower shoulder 16, regardless of the position of the main valve piston 64, and the spacings them of permit equal flows of operating fluidfrom the' upper and

lower valve passages

55 and 58, respecf tively, 'into' the valvechamber 18 from opposite directions, and any unbalance ofthe valve piston 64 produced-by low pressure areas at high. rates of flow of operating fluid will be equal and opposite and therefore will neutralize each other.

Thus, mymain valve means 39 will'be fully balanced at an urate of flow,- an attainment not'pos- Figs. 8 and 9. If, however, the pressure differential on the valve piston'4l increases above the force exerted by the main valve spring 69, the valve, piston 4| will move downwardly until the pressure differential thereon is balanced by the upward force of the main. valve'spring 69, carrying with it the main valve piston 64, thus closing or partially closing the main valve means 39, as shown in Fig. 2, to throttle theflow of operating fluid therethrough. The throttling action of the main Valve ineans 39 is substantially proportional tothe amount the pressure differential on the valve piston exceeds the predetermined value for-which the main valve spring 69 is designed, so that the throttling action of the main valvemeans '39 'will increase as the excess pressure 'diflerential on the valve piston 4| increases 'sible with my prior types of flowvalves. Furthermorefit will be noted that sinc'e'the fluid pressures on the main valve piston 64 balance each other, there" will be no leakage of operating fluidv along the piston tending to'force desirable foreign .materialsfsudh as sand, into the sliding fit thereof. These featuresare an and will odecreaseas' the" excess pressure difierential thereon decreases. Undesired changes in pressure'diflerential on the valve piston 4| are ordinarily caused by changesin the rate of flow of operating fluid through the metering orifice means-91, which usually result from a change in load conditions on the fluid operated pump 26.

Since the surface pumping mechansm 32 is of the positive displacement type, the change in f rate "of flow of operating fluid may be due to the important part of the invention and greatly add to the reliability ofth'e mainvalve means '39 under operating conditions.

The operating fluid then passes from the valve jso expansion of the operating fluid when the load on the fluid operated pump 26 is reduced.

Operation of the control valve means 49 is as follows. 'The control valve means 49 presents *a constant area to'the upstream pressure of the chamber. 13 through the radial discharge opening 1 l4 andthe radial opening 15 into the annular space. 6|; through which it passes downwardlyand through the, radial openings 56a of the-plugmember 53 .into the lower collar-36, from which it passes through the inlet pipe 28 to thefluid operated pump 28.5.. a l

The flow governor39 isadapted to control the rateof flow of the, high pressure operating fluid flowing throughthe supply tubing 3| and inlet pipe 28 to the fluid operated .pump 26; The mainoperating fluid in the upper collar 31 and central' chamber 42 of the valve piston 4|, and the control spring 88 exerts a substantially constant upward force on the control piston 89 tendingto hold the control piston 89 in its uppenor closed position. Operating fluid flows through the V-notches 93 and the central chamber' 42 and exerts a downward force on the projected area of the control element 9| of the control piston 89 tending to balance the upward valve means 39. is adapted to control the rate of- I;

flow of operating fluid therethrough inresponseto movement of the valve actuating m'eans"38,

the main valve means SS-permittinga high rateof flow of operating fluid therethrough with a low pressure drop when it is in opened position, as shown in Figs. 8 and 9, in which the valve actuating means 38 is'in its uppermost position,

and greatly increasing the pressure drop for the same rate of flow when the valve actuating means 38 is in a lower position, as shown in Fig. 2. The V-notches 93 of the controlvalve means 49 form a metering orifice means 91 which .is in series through the passages 44 of thevalve'actuating means 38 with the main valve means 39.

Operating fluid flowing under high pressure 1" through the metering orifice means 91, the cen"- tral chamber, and the passages 44 creates a pressure differential between the upper and lower faces of the valve piston 4| which tends to de press the. valve piston 4|, and consequently the main valve piston 64 against the opposmg' ac== tion of the main valvespring 69. The main valve-- spring 89 is normally adjusted before-the flow governor 39-is installed in the-well-to provide aforce of the control spring 88, the control piston 89movingdownwardly to a position in which the V-notch'es 93 .which 'form the metering orifice means 9T-provide suflicient area of opening so that the-drop in fluid pressure across the metering orifice means'91 multiplied by the projected area of the control element 9| of the control piston 89 exactly balances the upward force exerted by the control spring 88. There will, therefore, be a constant drop in fluid pressure through the metering-orifice means 91 and, therefore, a constant fluid pressure diflrential between the upper and lower faces of the valve piston 4|. If .the flow of operating fluid is reduced to zero, the

upward force exerted by the control spring 88 will cause the control piston 89 to move upwardly to its fully closed positionin which the V-notches 93 pass beyond the lower edges of the bore 43 and the base 94 thereof completely closes the bore 43." On the other hand, if the flow of opera'tingfluid is increased, the fluid pressure drop the control spring 98, and the control piston 89 will move downwardly to a'position in which the predetermined upward force urging the main valve piston 64 toward open position and urging the valve piston 4| upwardly. As long as the pressure differential on the valve piston 4| is less than the upward force exerted by the main valve spring 69, the main valve means 39 will remain in its fully open position. as shown in V-notches93 have a. greater area of opening so as to permitthe increased flow of operating fluid therethrough- Thus; so long. as operating fluid is flowing through'th'e -metering orifice means 91, the drop in fluid pressure thereacross will be maintained at a substantially constant predetermined'valu'e. The only change in pressure drop across the metering orifice means 81 will be due to the change in load on the control spring 88 due to the change in deflection thereof. However, the initial deflection of the control spring 88 is preferably ten to twenty times the change in deflection thereof due to the movement of thecontrol piston 88, and, therefore, the fluid pressure drop across the metering orifice means 81 will not vary more than from to If the, above noted ratio of the force of the control spring 88 to the projected area of the control piston 88 is such that the pressure ditferential applied to the valve piston 4| is slightly less than the upwardly opposing force of the main valve spring 88, the valve actuating means.

38 will remain in its upper position, as shown in Figs. 8 and 9, and the main valve means 38 will remain in its open position. It, for example,

spring 88.

to this value of 20% in excess of the rate of flow required for maintaining the control piston 88 in equilibrium against the action of the control The maximum iorce, therefore, which can be exerted by the operating fluid to open the control valve means 48 can only be 20% in excess of the force exerted by the control spring 88 when no operating fluid is passing through the metering orifice means 81 and there is no pressure drop thereacross tending to move the control piston 88 toward open position. In order that the rate of opening of the control valve means 48 under their force of 20% of the force force of the control spring 88, the radial orifice the pressure differential between the upper and lower faces of the valve piston 4| is less than the force required to move the main valve piston 64 against the upward force exerted by the main valve spring 68, then the main valve means 38 will remain in open position and the control piston 88 will vary its position in accordance with the rate of flow through the metering orifice means 81. 1

The rate of movement of the control piston 88 depends upon therate at which operating fluid will flow through the helical control groove 83 and the force which is applied to the control piston to cause it to move. If the pressure differential across the metering orifice means 81 drops below the upward force exerted by the control spring 88, the control piston 88 will start 'to move upwardly toward closed position, and operating fluid will flow downwardly through the helical groove 83 to keep the lower end of the control cylinder 8| filled with operating fluid. The strength of the control spring 88 and the cross-sectional area and hydraulic radius and length of the control groove 83 are preferably formed so that the control piston 88 will move its full distance of travel under the force of the control spring 88 in approximatelytwo minutes, although dimensions of the parts may be selected permitting a'shorter or longer period of travel as desired. The control piston 88 will thus move gradually upwardly until the open areas of the V-notches 83 are decreased to a point at which the reduced rate of flow through the metering orifice means 81 produces a pressure differential thereacross which exactly balances the upward force of the control spring 88, at which time upward movement of the control piston 88 will cease. If the rate of flow of operating fluid through the metering orifice means 81 is increased to a rate producing a pressure differential across the metering orifice means 81 twice that required to balance the upward force exerted by the control spring 88, then the control piston 88 will move downwardly at a rate requiring ap-' proximately two minutes for full travel thereof. However, if the rate of flow of operating fluid through the metering orifice means 81 produces,

a pressure differential thereacross which exceeds the downward force required to balance the upward force exerted by the control spring 88 by more than 20%, then this excess pressure differential, which is also applied to the faces of the valve piston 4|, will cause the valve piston 4| to move downwardly, carrying with it the main valve piston 64 toward closed position, which thus restricts the flow of operating fiuld therethrough 88 communicates with the control groove 88 at a point 20% of the length of the control groove be- I ward closed position, operating fluid flows from I the central chamber 42 downwardly through the control groove 88, closing the ball valve element 88, and thus is forced to flow through the entire length of the control groove 83 to reach the lower end of the control cylinder 8| to permit upward movement of the control piston 88. It will thus be understood that the lower end of the control cylinder 8| below the control piston 88 operates as a dash-pot to provide a gradual timed movement oi' the control piston 88 in both directions, the axial passage 86, the ball valve element 88, and the radial orifice 88 acting to equalize the rates of movement of the control piston 88 in both directions.

If it is assumed that operating fluid is being supplied to the now governor 38 at a predetermined constant rate such that the pressure differential across the metering orifice means 81 is such that the control valve means 48 is 25% opened, then. under this condition of operation themain valve means 38 will be entirely opened and there will be no movement of either means.

If the rate of flow is then slightly increased, for example by 10%, the control valve means 48 will gradually open until it will permit the passage therethrough of this increased amount or fluid flow without any increase in pressure differential across the metering orifice means 81, and there-- fore there will be no increase in pressure differential across the valve actuating means 88, and the main valve means 38 will remain in open position. If, however, an attempt is made to increase the rate' of flow of operating fluid by 50%, or if the flow tends to increase to such a value for any reason, the pressure differential across the metering orifice means 81 will exert a downward force on the valve actuating means 38 suflicient to move the valve piston 4| downwardly to close or partially close the main valve means 88 against the upward force exerted by the main valve spring 68 to a point where the rate of flow of operating fluid cannot exceed the original setting by more than 20%. This 20% increase in rate of flow of operating fluid, however, will increase the pressure differential across the meterof the fluid operated pump Q ing orifice means 91, resulting in a slow downward movement of the control piston 80 against the action of the control spring 88 and the dashpot efiect provided by the control cylinder 8| and associated passages, to open the control oriflce member Ml sufliciently to permit the 50% increase in rate of flow of operating fluid therethrough, but a considerable period of time will be required for this due to the throttling action of the control groove 83. It will be appreciated that the desired controlled changes in the rate of flow of operating fluid through the supply tubing 3| are accomplished by adjusting the rate at which the surface pumping mechanism 32 delivers operating fluid to the supply tubing.

It will therefore be apparent that the maximum instantaneous increase in operating speed 26 cannot be greater than in excess of the speed at which it was operating at the time the operating fluid flow conditions changed so as to tend to cause an increase in speed. For example, if the fluid operated pump 28 is receiving solid well fluid from the well on one stroke and all gas on the succeeding stroke, the rate of the stroke on which it receives all gas will not exceed by more than 20% the speed of the preceeding stroke on which it was pumping solid well fluid. It is therefore clear that the control valve means will automatically adjust itself either up or down between zero and its maximum capacity so as to limit the instantaneous increase in rate of flow of operating fluid therethrough so that the speed of the fluid operated pump 28 will never momentarily increase more than 20%, whether the fluid operated pump is running at one stroke per minute or one hundred strokes per minute.

In the above examples a flow governor designed for a 20% regulation with the same rate of change in both directions has been described. It will be apparent, however, that by changing the ratios of the springs to the projected areas which they balance, any desired per cent regulation may be obtained without departing from the spirt of the invention. To obtain the same rate of change in both directions, the oriflce 80 should communicate with the control groove 83 at a point measured from the top of the groove which is the same per cent of the total length of the groove as the per cent regulation desired. Moreover, different rates of movement of the control piston 80 in both directions can be obtained by changing the point -.at which the orifice 90 communicates with the control groove 83.

It is also to be noted that the flow governor ll reaches its maximum capacity when the control valve means 40 is in fully opened position. This top limit of capacity can be adjusted if desired by varying the area of the V-notches 93 or by varying the length of the tubular stem 85 or associated parts to provide a different limiting stop effect for the control piston 80. Such changes will be readily apparent to one skilled in the art, and do not depart from the spirit of my invention.

I claim as my invention:

1. In a device for governing the rate of flow of a high pressure fluid, the combination of walls forming a metering orifice through which said pressurefluid is adapted to flow so as to impress a pressure differential on said metering orifice, said orifice havng a variable effective metering area; throttle valve means through which said pressure fluid is adapted to flow, said throttle valve means being connected in series with said metering orifice; means for applying said pres- 5 sure diiferential on said metering oriflceto control the throttling action of said throttle valve means: and means for varying the eifective meterin area of said metering oriflce.

2. In a device for governing the rate of flow o! a high pressure fluid, the combination of: means forming a metering orifice through which said pressure fluid is adapted to flow so as to impress a pressure diflerential on said metering oriflce; throttle valve means through which said pressure fluid is adapted to flow, said throttle valve means being connected in series with said metering oriflee; means for applying said pressure differential on said metering oriflce to control the throttling actionof said throttle valve means; and means for varying the effective flow capacity of said metering orifice, said means being responsive to changes in the rate of flow and being arranged and constructed so as to prevent the rate of flow from suddenly increasing by more than a predetermined amount above the then prevailing rate of flow, but thereafter automatically permitting a gradual increase-in said rate of flow above said predetermined amount.

3. In a device for governing the rate of flow of a high pressure fluid, the combination of:

valve means for throttling the flow of said high pressure fluid; a cylinder having a piston therein operatively connected to said valve means: means forming a metering oriflce through which said high pressure fluid passes 50 as to impress a pressure diflerential on said metering orifice, said metering orifice being connected in series with said valve means; means for applying the pressure diflerential on said oriflce to the faces of said piston so as to control the acton of said valve means; control means for controlling the pres-.

sure differential applied to said piston, said control means including means for restricting the rate of operation of aid control means and being responsive to changes in the rate of flow and being arranged and constructed so as to prevent the rate of flow from suddenly increasing by more than the predetermined amount above the then prevailing rate of flow, but thereafter automatically permitting a gradual increase in said rate of flow above said predetermined amount.

4. In a device for governing the rate of flow of a high pressure fluid, the combination of: valve means for throttling the flow of said high pressure fluid through said valve means; a cylinder having a piston therein operatively connected to said valve means; walls forming a metering oriflce through which said high pressure fluid passes so as to impress a pressure differential .on said metering oriflce, said metering oriflce being connected in series with said valve means; means for applying the pressure differential on said orifice to the faces of said piston so as to control the action of said valve means; and control means for controlling the pressure differential applied to said piston, said control means including a control piston adapted to vary the normally effective flow capacity of said metering orifice and a dash-pot for restricting the rate of movement of said control piston, said control means operating in response to a change in the rate of flow of said pressure fluid.

5. In a device for governing the rate of flow of a highpressure fluid, the combination of: valve means for throttling the flow of said high pressure fluid through said valve means; a cylinder having a piston therein operatively connected to said valve means; walls forming a metering orifice through which said high pressure fluid passes so as to impress a pressure diflerential on said metering orifice, said metering orifice being connected in series with said valve means; means for applying the pressure diflerential on said orifice to the'facesof said piston so as to control the action of said valve means; and control means for controlling the pressure differential applied to said piston, said control means including a control piston adapted to vary the normally eflective flow capacity of said meterin orifice, means for applying the force exerted by said'pressure differential on said metering orifice to said control piston tending to move said control piston in one direction, and means for exerting a force on said control piston tending to' move said control piston in a direction opposite to said first direction, said control means operating in response to a change in the rate of flow of said pressure fluid.

6. In a device for governing the rate of flow of a high pressure fluid, the combinaton of: valve means for throttling the flow of said high pressure fluid through said valve means; a cylinder having a piston therein operatively connected to said valve means; walls forming a metering orifice through which said high pressure fluid passes so as to impress a pressure differential on said metering orifice, said metering orifice being connected in series with said valve means; means for applying the pressure differential on said orifice to the faces of said piston so as to control the action of said valve means; and control means for controlling the pressure differential applied to said piston, said control means including a control piston adapted to vary the normally effective flow capacity of said metering orifice,

means for applying the force exerted by said pressure differential on said metering orifice to said control piston tending to move said control piston in one direction, means for exerting a i'orce on said control piston tending to move said control piston in a direction opposite to said first direction, and means for restricting the rate of movement of said control piston when said forces thereon become unbalanced, said control means operating in response to a change in the rate oi flow of said pressure fluid. a

7. In a device for governing the rate flow of a high pressure fluid, the combination of: valve means for throttling the flow of said high pressure fluid through said'valve means; a cylinder having apiston therein operatively connected to said valve means; walls forming a meterin orifice through which said high pressure fluid passes so as to impress a pressure diiferential on said metering orifice said metering orifice being connected in series with said valve means; means for applying the pressure differential on said orifice to the faces of said piston so a to control the action of said valve means; and control means for controlling the pressure dilerential trolling the effective metering area of said orifice, said control means including walls forming a cylinder having a control piston therein tending to move in one direction in response to force applied to said control piston by said pressure differential, means for exerting a force tending to move said control piston in a direction opposite to said first direction, and means for restricting the rate of movement of said control piston when said forces thereon become unbalanced.

9. In a device for governing the rate of flow of a high pressure fluid, the combination of: walls forming a variable. area metering orifice through which said high pressure fluid passes to create a pressure differential on said orifice; control mean movable between open and closed positions in said orifice for controlling the effective area of said orifice in response to a change in the rate of flow of said pressure fluid; and means for equalizing the rates of movement of said-control means both toward and away from said open position.

10. In a device for governing the rate of flow of a high pressure fluid, thecombination of: walls forming a metering orifice through which said pressure fluid is adapted to flow so as to impress a pressure diflferential on said metering orifice; throttle valve means through which said pressure fluid is adapted to flow, including a valve chamber, a plurality of valve ports leading into said chamber, and valve closure means for closing said valve ports, said valve ports being disposed so as to equalize the fluid pressures on said closure means, said throttle valve means being.

' ble'area metering orifice connected to said valve,

so constructed and arranged as to permit an increase in the flow of said operating fluid to said pump at a predetermined controlled rate but preventing sudden substantial increases in said rate of flow, so as to prevent racing of said pump upon a sudden decrease in the pumping load thereon but permitting substantial increases in the production capacity of said pump during pumping thereof in response to a gradual increase in said rate of flow; and means on the surface of the ground for supplyingsaid operating fluid to said pump through said tubing.

applied to said piston, said control means including a control piston in acontrol cylinder, the

lower end of the cylinder forming a dash-pot for walls forming a variable maximum capacity metering orifice through which said high pressure fluid passes to create a pressure differential on said orifice, said orifice having avariable efiective metering area; and control means for-com 12. In a device 'for governing the rate of flow ofv a pressure fluid, the. combination of: means formingv ,a'metering orifice through which pressure fluidpas'ses to create apressure differential on said orifice, said. orifice having a variable .eifective metering area; movable control means connected with an element of said orifice forming means, said control means being movable for increased to rates above said predetermined amount; and means for restricting the rate of movement of said control means.

13. In a fluid operated pumping system for wells, the combination of: a fluid operated pump disposed in a well and adapted to pump well fluid therefrom; tubing means extending downwardly through said well and connected to said pump; means for supplying operating fluid under pressure through said tubing to said pump; and means in said well and in said line of tubing, including a valve and control means provided with a variable area metering orifice connected to said valve, so constructed and arranged as to prevent the rate of flow of said operating fluid through said tubing from suddenly increasing by more than a predetermined amount above the then established rate of flow but immediately thereafter automatically permitting a gradual controlled increase in said rate of flow above said predetermined amount, whereby the production capacity of saidpump can be substantially increased during operation thereof and said pump at all times is prevented from racing at excessive speed upon a sudden reduction in pumping load thereon.

14. In a device for governing the rate of flow oi fluid under pressure, the combination of: valve'means adapted to control a flow oi. fluid under pressure therethrough; and valve control means in series with said valve means and connected thereto, said valve control means including a variable area metering oriflce and being so constructed and arranged that it controls said valve means so as to prevent the rate of flow of said fluid from suddenly increasing by more than a predetermined amount above the then established rate of flow, but immediately thereafter automatically permits a gradual increase in the rate of flow above said predetermined amount.

15. In a device for governing the rate of flow oi fluid under pressure, the combnaltion of: valve mean adapted to control a flow o1 fluid under pressure therethrough; control means for said valve means including a varable-area metering orifice in series with said valve means, the effective area of said metering oriflce being variable in response to fluctuations in the rate of flow of fluid therethrough; and means for preventing the fluid pressure drop across said metering oriflee from momentarily exceeding a predetermined maximum."

16. In a device for governing the rate of flow of fluid under pressure, the combination of: valve means adapted to control a flow o1 fluid under pressure therethrough; piston means operatively connected to said valve means; and control means operatively connected to said valve 'means and including a variable area metering orifice in series with said valve means and adapted to impress the pressure diflerential thereon on said piston to tend to cause said piston to actuate said valve means, the effective area of said metering orifice increasing gradually in response to an increase in the rate of flow of said fluid therethrough, but said control means being so constructed and arranged as to prevent a sudden increase in the effective area of said metering orifice.

CLARENCE J. COBERLY.