US2589668A - Control governor for fluidoperated pumps - Google Patents

Description

March 18, 1952 c. J. COBERLY 2,589,668

CONTROL GOVERNOR FOR FLUID-OPERATED PUMPS Filed May 5, 1947 F'JC) [A/vE/vToR:

CLARENCE J. COBERLY By H15 ATTORNEYS HA RR/S, Mach, ESTER :3 HA R/P/S i a u M Patented Mar. 18, 1952 CONTROL GOVERNOR FOR FLUID- OPERATED PUMPS Clarence J. Coberly, Los Angeles, Calif., assignor, by mesne assignments, to Dresser Equipment Company, Cleveland, Ohio, a corporation of Ohio Application May 5, 1947, Serial No. 746,112

14 Claims.

This invention relates to the pumping art and more particularly to a method and governing apparatus for controlling the operation of fluidoperated pumps in wells and like bodies of liquid in which the pump is immersed.

My invention has particular application to the oil industry and will be described in connection therewith, but other applications will be obvious and I do not intend to be limited to that particular usage.

In the operation of oil wells it is common practice to install in the well a fluid-operated pump having a fluid motor to which operating fluij is pumped through a supply conduit from a pumping unit situated at the ground surface, the oil from the well being forced to the surface through a production conduit usually enclosing the supply conduit so as to leave an annular passage for the well product therebetween. Such fluidoperated pumps are ordinarily operated at relatively great depth in oil wells, und r. conditions not observable at the ground surface, and require means for governing their rate of operation which are automatic in action and preferably situated as close as possible to the pump so as to be immediately responsive to conditions existing there. Fluctuations in the pumping load may cause the pump to race when the load lightens and to incur hydraulic shock when the load returns, and to prevent such racing, shock, and

other detrimental effects, governor mechanisms 3 may be provided in the supply conduit conveying operating fluid to the pump immediately thereabove which will control the rate of flow to the .fiuid motor and prevent it from exceeding a safe limit of speed.

In my Patents No. 2,119,736, issued June 7, I

such pressure diiferential being dependent on the rate of flow of the operating fluid through the control orifice, and in turn being related to the pump load. Such governors act responsively to the effect upon the governor produced by the racing of the pump rather than responsively tothe cause for racing and, consequently, cannot be efiective until racing of the pump is actually started, which may be detrimental to the mechanism of the pump or to the operation of the pumping system.

Various factors may afiect the pump load, such as the entry of gas bubbles into the pump along with the oil, or a change in the hydraulic head or priming load on the intake side of the pump. Such factors may exist simultaneously and apply cumulatively, or act individually, as when gas enters the foot of the well casing at the pump level and momentarily forces the oil in the casing upwardly. In such an event the pressure of the hydraulic head would be constant or even increase at the pump level, and yet gas instead of oil would enter the pump. To control the operation of well pumps in accordance with the pressure of the hydraulic head, I have devised a governor, disclosed in my copending application Serial No. 747,233, filed May 10, 1947, in which a pilot valve is operatively connected to a member responsive to pressure in the well casing and in turn opens and closes a main valve as the pressure in the casing increases and decreases within a predetermined range. Such a governor, however, is not efiective to prevent racing of the pump in the event of gas entering the pump while suffic ent liqu d is in the casing to maintain the pressure at which the pilot valve is held open, and furthermore is sensitive to surging of liquid in the well casing which may have no direct detrimental effect upon the pump, but may .cause the governor unnecessarily to reduce the rate of pumping. None of the devices hereinbefore referred to meets all of the operating conditions hereinbefore described.

t is, therefore, a primary object of my invention to provide a methodof controlling the operation of a fluid-operated pump in which the rate of operation of the pump is regulated both in accordance with the depth of the liquid in the well in which the pump is immersed, as indicated by the pressure of that liquid, and in accordance with the load upon the pump, as indicated by the pressure of the operating fluid going to the pump.

It is a, further object of my invention to provide a flow governing device for the operating fluid of a. fluid-operated pump which is responsive both to external pressure conditions indicative of approaching detrimental operating conditions and to internal pressure conditions indicating that detrimental conditions presently exist at the pump.

It is another object of my invention to provide a governor which will gradually reduce the rat of pumping of a Well pump as the liquid level in the well falls and will immediately reduce the rate of pumping if the pump begins to A further object of my'invention is toprovide aceaeee a governor of the class described which is relatively nonresponsive to sudden surges of short duration in the liquid level of the liquid to be pumped, but is effective to maintain the liquid level at a safe operating mean.

Still another object of my invention is to provide a governor of the class described which will respond automatically to increases in the depth of the liquid to be pump-ed so as to increase the rate of pumping to the maximum for which the input of operating fluid is capable, and which in the event of further increase in the depth of the liquid becomes receptive to gradual increases in the rate of input of operating fiuid.

Another object of my invention is to provide a governor of the class described having an orifice for controlling the flow of operating fluid which is automatically limited in area by pressure conditions in the liquid to be pumped, but which may be restricted within the limit so imposed so as to prevent an increase in flow therethrough such as might be caused by a pressure drop at the outlet of the governor, independently of the aforesaid pressure conditions.

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

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 valves thereof in partly opened,

or throttling, position;

' a casing head I 3 provided at its upper end.

Suspended from the casing head I3 is a production tubing l5 having secured at its lower end an intake check valve member 22 provided with an intake opening 24 communicating with a conical pump seat 20 adapted to receive in seating relation the lower tapered end of a fluid-operated pump !8. The intake check valve member 22 is so arranged in the intake opening 24 as to permit well fluid to flow into the fluidoperated pump 18, but to prevent a reverse flow thereof. The fluid-operated pump is may be of any'suitable type, but I prefer to use a fluidoperated pump such as shown in my above Patent No. 2,119,736, to which reference is hereby made for the details of construction thereof.

For illustrative purposes, a body of well liquid 2| is shown within the well casing 19, having a surface level I1, and it will be understood that the liquid 2| is to be pumped by the pump I3 and that the surface level 11 will var in height above the intake opening 24 according to the relative rates of influx through the well casing l9 and of output of the pump l8.

Connected to the upper end of the fluid-operated pump I8 is an inlet tubing it to which is connected the flow governor 23 of my invention at a height normally below the surface level H. Connected to the upper end of the flow governor 23 is a string of supply tubing !2 which extends through the casing head 13 to a surface pumping mechanism I! of any suitable type adapted to pump operating fluid, such as clean oil, under high pressure downwardly through the supply tubing E2, the flow governor 23, and the inlet pipe It to the fluid-operated pump l8 to actuate the same. Also connected to the casing head I3 and communicating with the production tubing [5 is a discharge pipe l0 adapted to convey fluid discharged therethrough to a point of discharge or use (not shown).

A special coupling It connects upper and lower units of the production tubing 15 at the level of the flow governor 23 and has, between said upper and lower units, an inwardly extending thickened portion 38 forming a guide surface 40 of sufiicient diameter to allow the pump 8 to pass downwardly therethrough to rest upon the conical pump seat 26, and fitting slida'bly upon a housing 34 which encases the hereinafter described members of the governor 23. Vertical passages 42 in the thickened portion 38 of the special coupling l4 connect the interiors of the upper and lower units of the production tubing l5 and permit the pump 8 to pump liquid upwardly past the housing 3:1.

The housing 34 comprises an upper coupling member 28 threadedly secured to the supply tubing I2, and a lower coupling member 86 threadedly secured to the inlet tubing 16, the coupling members 23 and 86 being threadedly secured to each other, and the upper coupling member 28 being externally proportion-ed to fit closely in the thickened portion 38 of the special coupling [4. The upper coupling member 23 has a coaxial bore 49, in the upper part of which is disposed a cylinder 33 housing a bellows member 36 of the type known as a Sylphon and longitudinally expansible and contractible in response to decrease and increase or" external pressure. The lower coupling member has a coaxial bore 64 housing a cylinder 7 3, which is proportioned externally to leave an annular passage 18 between its outer surface and the inner surface of the coupling member 86 and is threadedly secured to a downward extension 5B of the upper coupling member 28 of reduced diameter. A cylinder head 88 is threadedly secured in the lower end of the cylinder 14 and is provided with an extension 98 closely fitting within a guide collar 96 formed on the inner surface of the lower coupling member 86. The guide collar 93 serves to keep the cylinder 14 in alignment within the bore 64 to maintain uniform width of the annular passage 18.

The bellows member 36 is secured, as by soldering, to a head 29 which is threadedly secured to the cylinder 33 and to the upper coupling 28 and is provided with a nut extension 25 by which the cylinder 33 and the bellows member 36 contained therein may be detached from the housing 34 by application of a suitable wrench. The head 29 has a bore 23 forming a check valve chamber 3| in which is a ball check 3?), and the bore is closed by a threaded plug 21, which may be removed to permit the bellows element 36, to be filled with gas at a desired pressure, the ball check 30 retaining the gas while the plug 21 is being replaced. At its lower end the bellows member 36 is secured, as by soldering, to a plunger 44 proportioned to provide a working space 45 within the cylinder 33 to permit expansion and contraction of the bellows member 36. The plunger 44 has secured to it a rod 5| which extends downwardly with a close sliding fit through a guide collar 53 formed on the lower face of the cylinder 33.

'Thelower end ofthe bore -49 of the upper coupling 'member 28 is-closed by a cylinder head member 56 which forms also the head for the upper end of thecylinder 14. Fitting slidably Within the lower part of the bore 49 is a hollow plunger-52 adapted to be limited in its upward movement by engagement with the cylinder 33 and in its downward movement by engagement of the plunger head 54 with the cylinder head 56, and urged toward the latter position by a spring 56 reacting against the cylinder 33. The lengths of the rod 5| and plunger 52 are such, and the expansibility' of the bellows member 36 is so proportioned thereto, that the rod 5| makes contact with the inner face of the plunger 52 and holds the plunger head against the cylinder head56'when the bellows member 36 is expanded, and may lose contact with the plunger 52 when the bellows member 36 is contracted, depending upon forces hereinafter explained tending to raise the plunger 52 in follow-up of the rod 5|, with the sleeve 51 limiting the extent of such follow-up by making contact with the cylinder 33.

The cylinder head 56 is provided with an axial bore'adapted to receive slidably a metering orifice member 6| formed by a sleeve extending downwardly from the lower face of the plunger 52 and having V-notches narrowing upwardly in its walls. When the plunger 52 is in contact with the cylinder head 56, these V-notches are closed by the cylinder head, and as the plunger is raised, the V-notches extend above the cylinder head into the bore 49, thus forming a variablearea metering orifice 63 opening thereinto. The walls of the upper coupling member 26 contain a plurality of vertical passages 32 leading from the supply tubing l2 to the interior of the cylinder 14 below the cylinder head 56, and a plurality of radial passages 59 leading from the bore 49 to the annular passage 18. Passage for operating fluid is thus provided from the supply tubing l2 to the annular passage 18 and regulated bythe degree of opening of the variable-area metering orifice 63. High pressure operating fluid is-thus brought to bear against the lower face of the metering orifice member 6|, tending to raise the plunger 52 and to pass through the metering orifice 63 with a consequent pressure drop, creating a pressure differential across the orifice. The plunger 52 has a helical groove 55 formed on its outer surface and providing a restricted, twoway communication between the lower face of the plunger and the space 46 above and within the sleeve. 55 are filled with operating fluid, a dash-pot action is imposed on the plunger 52 retarding the movement thereof. As will be apparent, during downward movement of the plunger 52, fluid may flow from the lower end of the plunger into the space 48 at the upper end thereof through the helical groove 55. Conversely, during upward movement of the plunger 52, fluid may flow out of the .space 48 at the upper end of the plunger by way of the helical groove 55.

The cylinder 14 houses a dual valve system 13 for controlling the flow of operating fluid from the annular passage 18 outwardly from the governor to the inlet tubing I6 and the pump l8. divides the interior of the cylinder into an upper bore 61 and a lower bore l1 and which has a central guide boss 65 extending upwardly therefrom into the upper bore 61 and a lower boss '19 extending downwardly into the lower bore 11. A control piston 66 is fitted slidably in the When the space 46 and the groove The cylinder 14 has a partition 15 which upper bore 61 .so as'to be reciprocable therein. and is provided with an orifice '68 communicating through the wall of the cylinder 14 with the annular passage 18. A needle valve 16 is secured to the control piston 66 by a valve stem 62 slidably fitted within the guide :boss 65, so as to be moved by the piston 66 in .and out of contact with the valve seat formed by the walls of a passage 72 formed in the guide boss 19. A compression spring 66 is provided below the controlpiston 66 and tends to move it to the'position shown in Fig. 2, to retain the needle valve 76 in its open position. The relative strengths of the springs 66 and '56 and the relative areas of the control piston 66 and metering orifice member 6| are such that a somewhat higher pressure differential is required to act on the piston 66 to move it downwardly against the resistance of the spring 66 than is required to act on the metering orifice member 6| to raise the plunger 52 against the resistance of the spring 56.

A main valve piston 86 is slidably fitted in the cylinder 74 below the partition 15 and has'a sleeve 76 fitting slidably on the guide boss 19 and a valve stem 64 extending downwardly through the cylinder head 68. The guide boss 19 has a passage 8| in communication with the passage-l2 and communicating with a passage in the valve stem 84 and in the poppet head 69 of a main valve 9|. The poppet head 69 seats on a valve seat 93 in the extension 69 of the cylinder head 86, which extension has a discharge passage 99 communicating with the inlet tubing l6. An annular valve chamber 92 encompassin the poppet head 89 is in communication with the annular passage 18 through lateral passages 96 in the cylinder head 98 and an annular space 94 between the cylinder head 68 and the guide collar 96. The valve stem 84 fits loosely within the cylinder head 88 so as to provide an annular passage 81 therebetween leading to the interior of the cylinder 14 below the main valve piston 66. A restricted orifice 82 in the piston 86 provides a fluid path from the lower side of the piston to the upper side thereof, and thence a plurality of passages H in the guide boss 65 lead to a valve chamber 69 annularly surrounding the needle valve N. A spring 83, reacting against the partition 15, urges the piston 66 downwardly, tending to hold the main valve 9| closed.

It will be seen that operating fluid from the annular passage 78, that is, on the downstream side of the metering orifice 63, may flow through a flow channel comprising the annular passage 81, orifice 62, passage H, needle valve chamber 69, and the passages 72 and 6| to the inlet tubing l6 when the needle valve 76 is open. The orifice S2 is so proportioned as to impress a pressure drop on fluid flowing therethrough, and the resulting sharp pressure gradient acting o the piston 36 raises it against the resistance of the spring 36 to cause the main valve 9| to open. As fluid flows through the orifice82 only when the needle valve 76 is open, the needle valve acts as a pilot-for the main valve 9|.

As the cylinder 14 is not secured directly to the lower coupling member 66 surrounding it, but is only aligned therewith by the extension 98 closely fitting within the guide collar 96, the extension 93 is provided with an annular groove 6? and a sealing ring 65 sealing against the guide collar 96 to prevent leakage from the annular passage 78- to the inlet pipe I6 when the valves 76 and 9| are closed.

The bellows member '36, which, it hasbeen seen,

is capable of preventing the plunger 52 from riswhich therefore, it will be apparent, is capable of preventing the metering orifice 63 from opening, is operated by subjecting it externally to the pressure existing at its level in the well casing IS. The cylinder 33 is provided with a plurality of radial openings 39 communicating with an annular groove which registers with radial passages 43 in the upper coupling member 28. A relatively wide annular channel 41 is formed in the outer surface of the upper coupling member 28 with which the passages 43 communicate, and a plurality of radial passages 4| in the special coupling l4 complete the channel through which liquid in the well casing |9 may enter the cylinder 33, and the pressure in the well at the level of the passages 4| may be imposed upon the exterior of the bellows member 35. The annular channel 41 provides some leeway in the vertical placement of the housing 34 relatively to the special coupling I4, in a zone determined by placement of the pump l8 on the conical pump seat 20 and by the length of the inlet tubing I5. To isolate the passages 43 and 4| from the upper and lower units of the production tubing l5, which will contain liquid at a higher pressure than the pressure in the well casing I9, the outer surface of the upper coupling member 28 is provided with grooves 3'! above and below the annular channel 41, and the grooves 3'! are provided with sealing rings 35 which seal the housing34 to the special coupling l4 while permittin relative vertical movement thereof such as would be necessary in lowering the governor 23 and the pump I8 into position or in raising them for inspection or repair. The interior of the cylinder 33 is likewise sealed from the operating pressure fluid within the space 58 by a sealing ring 45 carried by the base portion of the cylinder 33.

Before installation of the governor 23 in a Well, the bellows member 36 is charged with a gas permitted by removal of the screw plug 21, following which the screw plug is replaced, as shown. The gas pressure with which the bellows member 35 is initially charged depends upon the level at which the governor 23 is to be installed in a well, as will be apparent to those skilled in the art from the following description of the operation of the governor.

In the operation of my invention, if the liquid in the well casing i9 is at a level above the radial passages 4| providing sufficient hydrostatic pressure to compress the bellows member 35 so as to lift the rod from the plunger 52 and allow the latter freedom of movement, the action of the governor 23 will be controlled by the pressure differential across the metering orifice. High pressure operating fluid, pumped through the supply tubing l2 and vertical passages 32, will create a high pressure zone in the upper end of the cylinder 14, exerting an upward force against the metering orifice member 5| and a downward force against the control piston 65. The plunger 52 will be lifted by this upward force against the resistance of the spring 50, the retarding action of the fluid in the helical groove 55, and such back-pressure as exists in the annular passage 18. As the needle valve i5 is normally open, this back-pressure will be the result of operating resistance of the pump l8. Lifting the plunger 52 will open the metering orifice 63 and permit fluid to flow therethrough, creating a fluid pressure differential across that orifice. The opening of the metering orifice 63 will take place slowly bethrough the helical groove 55, and when the opening is suflicient to bring the pressure diferential across the metering orifice 63 in balance with the spring 55 the opening movement will cease.

When the pressure in the annular passage 18 is sumcient to cause operation of the pump l8, fluid will flow to the pump through the annular passage 81, the orifice 82, and the needle valve 10. Flow through the orifice 82 will produce a pressure gradient in the flow channel thus activated, acting upon the piston 85 and tending to raise the piston and open the main valve 9| against the resistance of the spring 83. As opening the main valve.9| opens a direct passageto the pump l3 and therefore tends to reduce flow through the needle valve 15, the main valve 9| will seek a balanced position in which it is sufiiciently throttled to maintain the flow through the orifice 82, which maintains it in that position. This throttled position of the main valve 9| and spring-opened position of the needle valve 10 may be called the normal operating position of these two valves, and a pressure differential across the metering orifice 63 suflicient to hold the metering orifice member 5| partly open against the spring 55 but insufficient to close the needle valve 10 may be called the normal operating pressure differential.

Now, if operating resistance to the pump l8 decreases, as might be caused by gas entering the ential back to its previous balancing degree. If I the increase in the pressure difierential is temporarily sufiicient to cause overbalancing of the spring 55 as it acts upon the control piston 60, it will move the needle valve i0 toward closed position and thus throttle the flow through the orifice S2 and cause the main valve 9| to move toward closed position. Throttling of thevalves 13 and 9| will restrict the outflow of fluid to the pump l8 and will increase the pressure in the annular passage 18, tending to restore the pressure differential across the control valve 6| to normal. Thus all three valves 6|, T0, and 9| tend to seek a stabilized position and to produce a stabilized normal pressure differential and to prevent a sudden outflow of fluid to the pump l8 such as would cause the pump to race.

On the other hand, a gradual increase in the rate of pumping is not prevented. If it is desired to increase the rate of operation of the pump I8, the rate of pumping of the surface pump may be gradually increased. This will cause an increase in pressure on the high pressure side of the metering orifice 53, which will be partly translated to the low pressure side thereof as an increase in pressure in the annular passage is due to increa ed back-pressure from the pump l8, and will act partly to increase the pressure differential acro s the metering orifice. The increase of the pressure differential across the metering or fice 53 will cause it to open gradually so as to restore the pressure differential-to normal, and this will permit an increased flow to the annular passage 78. The increase in pressure in the annular passage 18 will increase the pressure gradient across the orifice 82 and cause the main valve 9| to open wider to permit increased flow to the pump Hi and to restore the pressure diiierential across the control. valve 6| to normal. If the increase in the rate of pumping of the surface pump ii is so gradual as to permit the metering orifice member 6| and valve 9| to thus-act to restore the pressure differential to normal, without a sudden change sufflcient to unbalance the force holding the needle valve 1|] open, an increased rate of operation of the pump I 8 may easily be obtained.

, However, if the liquid level in the well casing I9 is so low as to place external pressure upon the bellows member 36 of less degree than will maintain the bellows member in contractedposition against the internal pressure of the gas charge within the bellows member, that is to say, of less degree than an amount predeterminable as representative of a satisfactory liquid level in the well casing Hi, the rod will be held against the upper face of the plunger 52, and freedom of action of the plunger in response to changes in the pressure differential across the metering orifice 63 will be prevented. Restrictive action of the bellows member 35 upon the degree of opening of the metering orifice 63 imposes a corresponding restriction upon the rate of supply of operating fluid from the surface pumping unit H which is a function of the amount that the fluid level in the well casing |9 falls below the predetermined or desired value. Under the aforesaid restrictive circumstances, an increase in the pressure differential across the metering orifice 63 will not avail to open the same, and it will not respond to tend to restore a normal pressure differential, and if the increase in pressure difierential is sufiicient to cause the piston oil to move downwardly, the needle valve 10 will move toward throttling position, causing the main valve 9! to move similarly. This action will occur whether the increase of. pressure differential across the control valve 6| is due to a pressure drop on the downstream side caused by decreased resistance at thepump It, or to an increase in pressure on the upstream side caused by an attempt to increase too fast the rate of pumping.

If the liquid level in the well l9, and thereby the external pressure on the bellows member 36, falls sufliciently low, the rod 5| will push the control valve 6| to closed position against all effort of the pressure differential across the control valve to open it, and this will cut off flow of operating fluid to the pump l8 until the liquid level'in the well casing I9 is restored to the desired operating level. As the bellows member 36 acts responsively to a change within a range of pressure rather than abruptly at a certain degree of pressure, and as the action of fluid in the helical groove 55 at all times presents a resistance to suddenmovements of the plunger 52, a continued fall in the liquid level in the well casing I!) would result in a gradual closing of the metering orifice 63 rather than a sudden closing of the same, and the throttling action on the metering orifice would produce only a gradual increase in the pressure differential across the orifice but at an accelerating rate of increase. As the metering orifice member 6| cannot respond under the stated conditions to restore the pressure differential to normal, the

pressure differential may increase to an ampli tude actuating the needle valve 10 to move toward throttling position, piloting the main valve 9| also to throttling position and thus further restricting flow to the pump l8 until-a balance of inflow and will remain within the limits within which the needle valve remains open. If the inflow to the well casing i9 increases and the liquidlevel therein rises, the bellows member 36 will removeits restriction upon the metering orifice member GI, and in response to a continued risein' the liquid level will permit it to open to the maximum amount at which it can maintain a normalpressuredifierential across the metering orifice 63, as determined by the input and outflow'of operating fluid existing at the moment.

It will thus be seen that as the needle valve 10 is free at all times to act in response to forces affecting its control piston 60, it will act promptly whenever called upon by those forces so as to prevent the pump l8 from racing, whether the liquid level in the well casing I9 is high Or low. The metering orifice member 6| will,,when permitted by the bellows member 36, act independently of it to allow an increase in flow to the pump l8 and can at all times act to restrict such flow. The bellows member 36 will prevent increases in flow to the pump when such increases are not justified by existing liquid levels in the well casing l9 and will forestall pumping tosuch lowliquid levels that the other members of the governor would be required to act to prevent the pump from pumping gas instead of liquid. Gas entering the well casing above the pump l8 may cause surging of the liquid level and sudden changes of pressure, without creating a condition justifying response by the bellows member 36, and the effect of such sudden fluctuations is minimized by the retarding action of the helical groove 55.

Because of the sealed construction afiordedby the sealing rings 35, the governor and the pump It may be drawn up to surface level through the production tubing |5 without disturbing the special coupling 4 and may be inspected, repaired, and returned to position. Changes in the pressure charge of the bellows element. 36 may readily be made by removing the plug 2 and'impressing or removing gas through the checkvalve chamber 3|, or the cylinder 33, containing the bellows element and entraining the rod 5|, may be removed from the governor by unscrewing the head 29 from the upper coupling member 28 and a new unit containing adiiferent pressure charge or including a rod 5| of different length may be installed. V I

It will be noted that correlation of themeter'ing orifice member BI and the valves 10 and 9|, and of the bellows element 35 and retarding helix groove 55, depends on correlation of theeifeetive areas of the various pistons, grooves, orifices, passages, and springs connected with and forming operating parts of said members, and that, for example, the correlation of the bellows member 36 to the metering orifice member 6| could be changed with respect to a desired rangeof operation of external pressure by changing-either the internal pressure of the bellows member, its rigidity, its length, or the length of the rod 5!. Changes in these areas and forces required to adapt my invention to various usages and operating conditions will be readily'apparent to one skilled in the art, and do not depart from the spirit of my invention.

It is also to be noted that, although I- have described the invention in connection with afluidoperated pump installation in which the production tubing and supply tubing l2 are concentric, making desirable a special form of coupling [4, the invention can readily be adapted by one skilled in the art for use in connection with a fluid-operated pump installation in which the production and supply tubings are side by side, such as is illustrated in my Patent No. 2,338,903, issued January 11, 1944, simply by connecting the flow governor 23 in the line of the supply tubing and omitting the coupling Hi from the production tubing. Consequently, I do not desire to be limited to the specific embodiment shown, but desire to be afforded the full scope of the following claims.

I claim as my invention:

1. In a fluid-operated pumping apparatus for use in wells, the combination of: a fluid-operated pump adapted to be submerged in well fluid in a well; supply tubing for conveying a high pressure operating fluid downwardly through the well to said pump to actuate it; production tubing for conveying the discharge from said pump upwardly through the well; governor means in the line of said supply tubing and adapted to control the rate, of flow of operating fluid therethrough, said governor means including a variable-area metering orifice means adapted to provide a fluid pressure differential thereacross, a pilot valve, a main valve, means for impressing said fluid pressure difierential across said pilot valve to tend to move said pilot valve. and means for operating said main valve in response to movement of said pilot valve; and means for closing said metering orifice in response to a predetermined decrease in the level of well fluid in the well.

2. In a fluid-operated pumping apparatus for use in wells, the combination of: a fluid-operated pump adapted to be submerged in well fluid'in a well; supply tubing for conveying a high pressure operating fluid downwardly through the well to said pump to actuae it; production tubing for conveying the discharge from said pump upwardly through the well; governor means in the line of said supply tubing and adapted to control the rate of flow of operating fluid therethrough, said, governor means including a variable-area metering orifice means adapted to provide a fluid pressure differential thereacross, a pilot valve, a main valve, means for impressing said fluid pressure difierential across said pilot valve to tend to move said pilot valve, and means for operating said main valve in response to movement of said pilot valve; and means for varying the effective area of said metering orifice in response to a predetermined decrease in the level of well fluid in the well.

I 3. In a fluid-operated pumping apparatus for use in wells, the combination of a fluid-operated pump adapted to be submerged in well fluid in a well; supply tubing for conveying a high pressure operating fluid downwardly through the well to said pump to actuate it; production tubng concentric with said supply tubing and for conveying the discharge from said pump upwardly through the well; collar means in the line of said production tubing and having a lateral fluid passage communicating between the interior and exterior thereof, and having a longitudinal passage communicating between the upper and lower ends thereof so as to permit said pump discharge to -flow upwardly therethrough; governor means in the line of said supply tubing and adapted to control the rate of flow of operating fluid therethrough, said governor means includinga variable-area metering orifice means adapted to pro- 12 vide a fluid pressure differential thereacross, a pilot valve, a main valve, means for impressing said fluid pressure differential across said pilot valve to tend to move said pilot valve, and means for operating said main valve in response to movement of said pilot valve; and means for closing said metering orifice in response to a predetermined decrease in the level of well fluid in the well, including means connected to said metering orifice means and communicating with the fluid pressure in said lateral fluid passage, and responsive to changes in said fluid pressure in said lateral passage to move said metering orifice means to vary the effective fluid flow area thereof.

4. In a governor for governing the rate of flow of a high pressure fluid to a fluid-operated pump adapted to be operated below the surface level of a liquid to be pumped, the combination of means adapted to form a fluid metering orifice through which said fluid is adapted to flow so as to impress a fluid pressure differential on said orifice; pilot means adapted to move in response to variations in said fluid pressure differential; main valve means adapted to move in response to movement of said pilot eans and being adapted to control the flow of said fluid through the governor; and means responsive to changes in the hydrostatic pressure exerted by said liquid on said governor for varying the effective fluid flow area of said metering orifice so as to vary said fluid pressure differential.

5. In a governor for governing the rate of flow of a high pressure fluid to a fluid-operated pump adapted to be operated below the surface level of a liquid to be pumped, the combination of: means adapted to form a fluid metering orifice through which said fluid is adapted to flow so as to impress a fluid pressure diflerential on said orifice, including a movable member adapted to vary the eflective fluid flow area of said metering orifice so as to change said pressure differential; pilot means adapted to move in response to variations in said fluid pressure differential; main valve means adapted to move in response to movement of said pilot means and being adapted to control the flow of said fluid through the governor; and means connected to said movable member and responsive to changes in the hydrostatic pressure exerted by said liquid on said governor for moving said movable member.

6. In a device for governing the rate of flow of a high pressure fluid, the combination of: means adapted to form a fluid metering oriflce through which said pressure fluid is adapted to flow so as to impress a fluid pressure differential on said orifice, including a movable member adapted to vary the fluid flow area of said orifice; a pilot valve; 2. pilot valve piston connected to said pilot valve; means for impressing said pressure differential across said pilot valve piston to control the movement of said pilot valve; a main valve adapted to control the volume of said fluid flowing through the device; a main valve piston connected to said main valve; means for impressing a second fluid pressure differential across said main valve piston to control the movement thereof, movement of said pilot valve being adapted to vary said second pressure differential; and means for moving said movable member in response to variations in fluid pressure exterior of the device.

7.In a device for governing the rate of flow of a high pressure fluid, the combination of: means adapted to form a fluid metering orifice through which said pressure fluid is adapted to assesses flow so as to impress a fluid pressure differential on said orifice, including a movable member adapted 'to vary the fluid flow area of said orifice; a pilot valve; a pilot valve piston connected to said pilot valve; means for impressing said pressure diiferential across said pilot valve piston to control the movement of said pilot valve; a main valve adapted to control the volume of said fluid flowing through the device; a main valve piston connected to said main valve; means for impressing a second fluid pressure diiferential across said main valve piston to control the movement thereof, movement of said pilot valve being adapted to vary said second pressure differential; and fluid pressure responsive means operatively connected to said movable member and communieating with the exterior of the device, and being responsive to variations in fluid pressure exterior of the device to move sa d movable member.

8. A flow governing device adapted to be installed in the line of two concentric tubings in a well, including: an outer tubular member adapted to be connected in the line of the outer of said tubings, said tubular member being provided with a lateral port communicating between the interior and exterior thereof; a tubular housing adapted to be connected in the line of the inner of said tub ngs and adapted to be received within said tubular member in fluidtight re ation therewith, said housing having an annu ar channel on the periphery thereof adapted to register with said lateral port, and having a fluid passage communicating between the interior of said housing and said channel; variable-a ea metering orifice means in said housing through which said pressure fluid is adapted to flow to impress a first fluid pressure different al on said orifice, incIuding a movable member adapted to vary the effective area of said orifice; main valve means in said housing and adapted to control the flow of said fluid therethrough in response to variations in said pressure differential; and pressure-responsive means in said housing and connected to said movable member. said pressure-responsive means communicating with said fluid passage whereby a variation in the fluid pressure in said passage causes movement of said pressure-responsive means.

9. A flow governing device adapted to be installed in the line of two concentric tubings in a well, including: an out r tubular member ada ted to be connected in the line of the outer of said tubings. said tubular member being provided with a lateral port communicating between the interior and exterior thereof; a tubular housing adapted to be connected in the line of the inner of said tubings and adapted to be received within said tubular member in fluid-tight relation therewith, said housing having an annular channel on the periphery thereof adapted to register with said lateral port, and having a fluid passage communicat ng between the interior of said housing and said channel; variable-area metering orifice means in said housing through which said pressure fluid is adapted to flow to imoress a first fluid pressure differential on said orifice, including a movable member adapted to vary the effective area of said orifice; main valve means in said housing and adapted to control the flow of said fluid therethrough, said main valve means being movable in response to variations in fluid pressure differential thereacross; pilot means movable in response to variations in said first pressure diiferential to vary said pressure differential across said main valve means; and

pressure-responsive means in said housing andconnected to said movable member, said pressure-' responsive means communicating with said fluid passage whereby a variation in the fluid pressure in said passage causes movement of said pressure-responsive means.

10. In a governor for regulating the rate of flow of an operating fluid, the combination of: metering orifice means having a variable effective flow area and adapted to produce a pressure diiferen tia1 in response to flow therethrough; means exposed to fluid pressure obtaining exteriorly of the governor for varying the effective flow area of said metering orifice means so as to vary said pressure diiferential; and control valve means actuable by said pressure differential for regulating the rate of flow of the operating fluid, said control valve means being in series with said metering orifice means so that the operating fluid flows through both said control valve means and said metering orifice means.

11. In a governor for regulating the rate of flow of an operating fluid, the combination of: a first valve adapted to produce a pressure differential in response to flow therethrough; means responsive to fluid pressure obtaining exteriorly of the governor for operating said first valve to vary said pressure differential; a second valve operable by said pressure difierential; and a third valve operable in response to flow through said second valve for controlling the rate of flow of the operating fluid.

12. In a governor for regulating the rate of flow of a fluid, the combination of a first valve adapted to produce a pressure differential in response to flow of the fluid therethrough; means exposed to fluid pressure obtaining exteriorly of the governor for operating said first valve to vary said pressure differential; a second valve in series with sa d first valve and operable by said pressure difierential; and a third valve in series with said first valve and in paralel with said second valve for regulating the rate of flow of the fluid, said third valve being operable in response to flow of the fluid through said second valve.

13. In a governor for contro ling the rate of flow of fluid, the combination of: a main valve for regulating thevrate of flow of the fluid; a pilot valve in parallel with said main valve so that part of the fluid flows through said pilot valve and the remainder through said main va ve;

pressure actuable means responsive to flow through said pilot valve for operating said main valve; a metering valve in series with said main and pilot valves; pressure actuable means responsive to a pressure differential across said metering valve for operating said pilot valve; and pressure responsive means exposed to fluid pressure obtaining exteriorly of the governor for operating said metering valve.

14. In a fluid-operated pumping system for wells, the combination of: a fluid-operated pump adapted to be installed in a well; supply tubing adapted to convey operating fluid under high pressure downwardly through said well to actuate said pump; production tubing in said well and adapted to convey the discharge from said pump upwardly through the well; a fluid flow governor disposed in the line of said supply tubing and adapted to control automatically the rate of flow of said operating fluid therethrough in response to changes in rate of flow of such operating fluid to said pump; and means for controlling the operation of said governor automatically in response 15 to variations in the level of liquid in the well, UNITED STATES PATENTS including a fluid passage communicating between Number Name Date the interior of said governor and said liquid in 493 774 Howes Mar 21 1393 the wellat a point adjacent to said governor. 1:976:82) wettstegn 1934 5 2,119,736 Coberly June 7, 1936 CLARENCE COBERLY- 2,119,737 Coberly June 7, 193a 2,208,554 Price July 16, 1940 REFERENCES CITED 2,266,356 Coberly Dec. 16, 1941 The following references are of record in the 2277746 Downs Man 31, 9 file of thls patent: 2,333,903 Coberly Jan. 11, 1944

Images