US2837108A

US2837108A - Combination self-cleaning constant and intermittent flow valve

Info

Publication number: US2837108A
Application number: US334561A
Authority: US
Inventors: James H Howard
Original assignee: Camco Inc
Current assignee: Camco Inc
Priority date: 1953-02-02
Filing date: 1953-02-02
Publication date: 1958-06-03
Anticipated expiration: 1975-06-03

Description

2 Sheets-Sheet 1 June 3, 1958 J. H. HOWARD COMBINATION SELF-CLEANING CONSTANT AND INTERMITTENT FLOW VALVE Filed Feb. 2, 1953 James H. H0 W-G/O/ INVENTOR.

BY M. 5 502% ATTORNEY United States Patent COMBINATION SELF-CLEANING CONSTANT AND INTERMITI'ENT FLOW VALVE James H. Howard, Houston, Tex., assignor to Cameo, Incorporated, Houston, Tex., a corporation of Texas Application February 2, 1953, Serial No. 334,561

7 Claims. (Cl. 137-155) This invention relates to a flow valve of the type generally disclosed in Well Flowing Patent No. 2,465,060 to W. C. Carlisle, et al., and of the type disclosed in copending Flow Valve application Serial No. 50,038, now Patent No. 2,668,553, February 9, 1954, by James H. Howard et al., particularly shown in Figs. 1 and 4 thereof, but varies from these disclosures in providing an annular flow passage around the valve tip of uniform cross-sectional area through a normally operating length of travel after the valve is opened.

It is therefore an object of this invention to provide a pressurized bellows type flow valve having an annular flow passage around the valve tip of uniform cross-sectional area through a normally operating length of travel after the valve is opened.

It is also an object of this invention to provide a flow valve of this type having a tip constructed to abruptly increase the flowpassage cross-sectional area through the valve seat when the valve stem is lifted above a normally operating length of travel.

It is another object of this invention to provide a flow valve of this type having removable and interchangeable tips.

, It is yet a further object of this invention to provide a flow valve of this type having large port openings in the housing wall, and a valve tip constructed to abruptly increase the flow passage cross-sectional area through the valve seat when the valve is lifted above a normally operating length of travel, whereby, as the valve is lowered into a well and subjected to the high well fluid pressures encountered therein, it will open, and its tip will travel above its normally operating length of travel, thereby insuring a large cross-sectional area path of flow through the valve so that fluids laden with large sized particle may pass freely and quickly through the valve.

It is also an object of this invention to provide a flow valve of this type in which the free flow passage area through the uniform cross-sectional area portion of the valve tip may be designed to be sized in equivalents of various diameter circles, .as 4", etc.

ICC

assembled with threadable valve stems, as of stainless It is yet another object of this invention to provide a flow valve of this type in which the valve is maintained seated when the force exerted by a pressurized bellows and a spring exceeds the fluid pressure in the casing annulus which acts within the valve body plus the fluid pressure in the tubing, which. acts against the valve seat.

It is also a further object of this invention to providea flow valve of this type in which the fluid passing fromv casing to, tubing when the valve is unseated is metered through a flow passage of reduced cross-sectional-area so that the fluid pressure on the tubing side of the valve seat is substantially at a pressure of the fluid .in the tubing,

of Fig. 7.

As shown in Fig. l, a well bore tubing string 1 hasused as an intermittent flow valve by the provision of an intermitter at the top of the well.

It is another object of this invention to provide a constant flow valve of this type providing a free flow passage area of uniform cross-sectional area surrounding ,a valve tip portion of uniform cross-sectional area extending thereinto, wherein such free flow passage cross-sectional area may be lesser than the cross-sectional area'of the opening into the housing on the opposite side of the valve seat from the extending tip portion.

It is yet a further object of this invention to provide a flow valve of this type having in one form a tip requiring no seal therearound, while insuring uniform fluid flow therearound during its normally operating length of travel.

It is also a further object of this invention to provide a flow valve of this type having in another form a tip and a seal therearound to insure uniform fluid flow therethrough during its normally operating length of travel while the seal also stabilizes the tip against vibration.

' It is yet a further object of this invention to provide a flow valve of this type having in one form a tip insuring a streamlined fluid flow through a length of uniform cross-sectional area therearound while also providing such a tip which is stabilized against vibration.

It is yet a further object of this invention to provide a flow valve of this type which will easily close under force of a constant gas pressure in the casing annulus upon a reduction of pressure in the tubing, and which will easily and automatically open upon a subsequent increase of tubing pressure.

Other and further objects will be apparent when the specification is considered in connection with the drawings in which:

Fig. 1 shows a sectional elevation showing a flow valve, as included in this invention, installed on a tubing mandrel to be installed in the tubing string of a well.

Fig. 2 is a fragmentary, sectional elevation of a flow valve, showing one modification of valve stem tip.

Fig. 3 is a sectional plan view taken along line 33 of Fig. 2.

Fig. 4 is a fragmentary, sectional elevation of a flow valve, showing another modification of valve stem tip.

Fig. 5 is an enlarged, fragmentary, sectional elevation of the form of invention shown in Fig. 4.

Fig. 6 is a sectional plan view, taken along line 66 of Fig. 5.

Fig. 7 is a fragmentary, sectional elevation of a flow valve, showing still another modification of valve stem tip.

Fig. 8 is a sectional plan view taken along line 88 installed thereina tubing mandrel 2 which has a boss 3 thereon into which a flow valve 5 is threaded at 4. This flow valve 5 may be of a large variety of constructions, and in the form shown such valve has a body 6 comprising a bellows chamber 7 consisting of an upper section 8 and a lower section 6. A pressurized bellows 9 is connected at 10 to the upper section 8, and at its lower end the bellows is connected at 11 to'the top of a valve stem 12 The bellows chamber 7 has a valve chamber 14 connected thereto, which chamber comprises 'an upper section-IS and a valve seat section 16. A partition 17 separates thebellows chamber 7 fromthe valve chamber 14, and a spring 18 extends around the stem 12 and bears 3 upwardly on the partition 17 and downwardly on a nut 19,.whichis threaded onto the valve stem at 2.0. The valve stem 12 has a stop shoulder 21 thereon to serve a purpose to be hereinbelow described.

A valve tip 22, to, be hereinafter de scribed,, seats at,

23, which is a seating surface provided by the valve seat section 16.v

The bellows 9 has a pressurized fluid injectedinto its interior 24 through the valve cap 25. Thus the force of this pressurized fluid within the bellows and additionally the force of the spring 18 both combine in urging the valve tip 22 into seated position, and resist the unseating thereof due to the force of the fluid pressure entering the valve body through the ports 34, and due to the; tubing fluid pressure acting upwardly against the valve tip to unseat the valve.

A check valve chamber 26 is connected to the valve chamber 14 by means of the adapter 27, to whichthe check valve body 28 is connected. This check valve section 218 has a reduced-diameter threaded portion 29 for threaded engagement into the threaded section 4 of the boss 3. The check valve 30 normally floats in the check valve chamber 26 between its seat 27' in the adapter 27 and the shoulder 28, such floating being responsive to fluid pressure from the interior 31 of the mandrel 2, which communicates with such chamber by way of the passageway 32 through the boss 3. An increased velocity in the tubing fluid will cause the check valve 30 to seat on the check valve seat 27 to close off tubing fluid communication with the valve thereabove.

A protective lug 33 is installed on the mandrel 2 to over-extend the flow valve 5.

In well flowing practice, the flow valve is set to open at some predetermined pressure exerted by a gas injected into the well bore and into the annulus surrounding the tubing string 1 and entering the valve chamber 14 by way of the ports 34. When the valve tip 22 lifts from the seat 23, such gas may pass downwardly through the flow passage 35 in the valve seat section 16 and through the check valve chamber 26 land the check valve 30 will be forced downwardly to rest upon the shoulder 28' while the casing annulus fluid passes through the openings 30' in the check valve and through the passage way 32 into the interior 31 of the mandrel 2. This condition is set to occur preferably when there is a head of fluid, as oil, standing in the mandrel 2 and tubing string 1 above the passageway 32.

It is again stated herein that the flow valve 5, shown in Fig. l, is only one modification of a vast number of flow valves of various constructions which have been employed in practice for the purpose of flowing wells, as hereinabove described. Also, various types of tips or sealing elements have been provided for employment on the stems of flow valves with the areas of the ports 34, the areas of the flow passages 35, and the annular space 36 surrounding the valve tips, all bearing various ratios to each other, with the valve tips, valve seats, and ports, having various constructions and configurations.

As set forth hereinabove in the statement of objects of this invention, such invention relates to valves of the type generally described which have valve tips of uniform cross-sectional area through a normally operating length of travel when the valve is open; and in this invention such flow passage cross-sectional area is of a lower area than the cross-sectional area of the port space of the ports 34 through which the gas may enter the flow valve chamber 14 to act to lift the valve stem 12.

As shown in Fig. 2, one form of valve tip comprises the tip 22, as shown in Fig. 1, which has a threaded shank 37 which is threadable axially into a valve stem 12. In detail, this tip 22 has a flange 38 to which the shank 37 is connected, and a tapered or frusto-conical section 39 extending from the flange 38 to provide the seating surface which seats on the hardened metal seating surface 23 of the valve seat section 16.

A cylindrical portion 40 extends from the section 39 and is of. a uniform diameter, and of a smaller diameter than the flow passage bore41 through the seating element 23. As a terminal section, the valve tip has a cone 42 with base connected to the cylinder 40.

It can thus be seen that when the valve stem is lifted for a length of travel, the injected gas from the annulus surrounding the tubing 1 will flow through a flow passage annulus 44, of uniform diameter, and thereby a constant flow of gas is injected into the mandrel interior 31.

As the gas pressure increases, the valve stem 12 is lifted higher and higher until the cone base is at a level above the upper surface of the valve seat 23. Then, as

the valve stem continues to rise higher under increased pressure, the area through which the gas flows abruptly increases until, with the point 45 of the cone 42 above the upper surface of the seat 23, the whole cross-sectional area of the bore 41 through the seat 23 is opened to the How of gas. Thus, if any solid or particle-laden matter is carried by the gas, such may pass through the large port openings 34 and through the bore 41 with-minirnized danger of any stoppage or blocking of such gas flow being risked.

By this same procedure the valve may intermittently be opened wide to periodically allow large volumes of gas to pass into the tubing to provide intermittent lifting of the fluid in the tubing. The variation of the fluid pressure in the casing to intermittently operate the valve is controlled by an intermitter valve at the surface of the conventional type.

After the valve stem is lifted to the point immediately desecribed hereinabove, any continued lifting of the valve stem might subject the bellows 9 to pressure beyond its characteristic limits; and to avoid this, the distance between the shoulder 21 on the valve stem 12 and the partition 17, with the valve seated, is just slightly greater than the distance from the cone tip 45 to the topsurface of the seating element 23 when the valve is seated. Thus any tendency to lift the valve higher than the maximum desired opening of the seat bore 41 is avoided by the contact of the stop shoulder 21 with the partition 17.

A modification of valve tip is shown in Figs. 4, 5, and 6, which consists of a tip havingv a threaded shank 47 for connection to the valve stem 12, such shank being connected downwardly to a flange 48 which, in turn, is connected to a tapered or frusto-conical member 49 adapted to seat at 51 on the seating element 16'. Below the section 49 there is provided a cylindrical portion 52 of lesser diameter than the bore 53 of the flow passage 35. Then the tip terminates in a cylindrical portion 54, whichis of a diameter to have sliding engagement with the bore 53.

In order to avoid leakage around the portion 54, a flexible seal 56 is provided in the groove 57. The tip has the axial bore 58 therein, and extending radially therefrom to the periphery of the section 52 there are provided the ports 59.

With this type of tip, upon the lifting of the valve stem '12, a uniform flow of gas during a length of upward travel'is provided, the .bore 58 being the factor which insures this uniform flow. In this type of tip the seal 56 insures the accuracy of uniform flow, whereas the portion 54 stabilizes the valve stem against vibration, since it has sliding engagement with the bore 53.

A third modification of tip is shown in Figs. 7 and 8, in which a tip 6t] comprises a frusto-conical section 61 to seat at 62 on a seating element 16'. Such tip has a reduced-diameter, cylindrical section 63 connected to the section 61, and therebelow it has a section 64 of a diarneter to fit in sliding contact with the bore 65 'of a flow passage 35. To insure uniform flow, a plurality of is in sliding engagement with the bore 65. Also, because of this sliding engagement, the valve stem 12 is stabilized against excessive vibration.

Although not shown, the tip 60 may be adapted for threaded engagement with the valve stem 12 rather than formed integrally therewith. Obviously, such may be accomplished simply by providing a threaded shank on the tip above the frusto-conical section 61.

As shown in Fig. 5, the tip 50, in detail, may include a polygonal adapter 67 into which the flange 48 of the tip may be pressed and welded.

In both the modification of Figs. 4-6, and in the modification of Figs. 7-8, it is noticeable that the terminal portion .70 of these tips is tapered to a reduced diameter.

. Thus when an excess of gas pressure in the casing or well bore annulus may lift the stem 12 or valves on which these tips are installed, to a position above the top surface of the seating element thereof, there is an abrupt increase of the cross-sectional area through which fluid may flow to an area equal to the cross-sectional area of the bore 53 'or 65.

It can be seen that this invention is adapted to maintain a constant flow after the valve is lifted and then to abruptly increase the cross-sectional area of flow when the valve stem is further lifted under excessive pressure.

It is also pointed out that the constant flow'takes place through a cross-sectional area of the flow passage 35, which is always of a lower cross-sectional area than the area of the opening space, as the ports 34, through which gas may flow into the housing and valve chamber of a flow valve 5.

Insomuch as it is necessary to have some measure of the free cross-sectional area through the flow passage in which the uniform cross-sectional area portion of the valve tip extends, it has been found practical to design such free area in the equivalents of various diameter circles, as ,4 etc.

As regards the design of the tips, where excessive velocities and pressures may occur, a construction as shown in Fig. 5 may be preferred, in which a valve tip, as of tungsten steel, is pressed and then Welded into an adapter portion which can be of a threadable metal, as stainless steel, through the threads of which the tip may be connected to the valve stem.

The ports 34, shown and described throughout this invention, have been stated to amount to a greater crosssectional area than the area of the free flow passage in which the uniform cross-sectional area portion of the valve tip extends, but it is not necessary to have ports 34 of such large area, and in excess of such free flow passage area, and the principle of this type of valve may operate where such area of the ports 34 may be lesser than such free flow passage area while still maintaining the inherent benefits of a free flow passage area of uniform cross-section in which a valve tip portion of uniform cross-sectional area extends.

Broadly this invention considers a constant flow valve having a stem tip with a portion extending into the flow passage on the opposite side of the valve seat from the resilient means urging said valve closed, with the crosssectional area of said portion, over a length thereof, bearing a constant ratio to the free flow passage area through which said tip portion extends, and with said housing.

having port means therein on the resilient means side of said valve seat, such port means being of a greater crosssectional area than said free area. This invention also broadly considers such a construction wherein such port means area may be of lesser cross-sectional area than said free area.

What is claimed is:

l. A flow valve comprising, a housing, a valve seat adjacent one end of said housing, a flow'passage in said housing extending through said valve seat, a valve stem in said housing having a valve tip on one end thereof to seat upon said valve seat in a downstream flow direcin a predetermined range of fluid pressure for a given extent of tip travel slightly less than the maximum range of tip travel under fluid pressure in excess of said predetermined range, said tip having a flow metering portion extending in. said flow passage for a length corresponding to the aforesaid given extent of tip travel for obstructing free flow through the passage, the cross-sectional area of said portion over said length bearing a constant ratio to the free flow passage area through which said portion extends for a uniform obstruction and said cross sectional area abruptly decreasing beyond said length, said metering'portion being fixed with the tip for movement outside the passage in response to fluid pressure increase above said predetermined range for the abrupt removal of restriction to free passage flow, said housing having inlet port means therein on the resilient means side of said valve seat of a greater cross-sectional area than said free area.

2. A flow valve comprising, a housing, a valve seat adjacent one end of said housing, a flow passage in said housing extending through said valve seat, a valve stem in said housinghaving a valve to seat upon said valve seat, resilient means in said housing to urge said valve to closed position, said valve having a flow restricting cylindrical portion extending into said flow passage and of a cross-sectional area over a length thereof of a constant ratioto the free flow passage area through which said portion extends for a uniform metered flow at a rate substantially less than the unrestricted flow rate of the passage, said length corresponding to the travel range of the valve in its normal flow control operation, said resilient means including a pressure responsive bellows connected at one end to said stem and at the other end to said housing and responsive to normal operating pressures to unseat the valve without removing said cylindrical portion from the passage and responsive to abnormally high pressure to remove said cylindrical portion from the passage for unrestricted flow therethrough.

3. A gas lift Well flow control assembly for the flow of pressure gas through a connecting passage between a pressure gas conduit and a liquid production well conduit, including a conduit connecting passage whose flow area exceeds that required for normal operation of elevating an accumulated head of liquid Within the production conduit, an annular valve seat in the passage, a valve therefor, yieldable valve seating means exerting valve closing force in the downstream direction of pressure gas flow through said passage, a gas presstue responsive device exposed to upstream lift gas pressure above the valve and operably connected with the valve to unseat the same in opposition to downstream force exerted by said yieldable means, said valve and its seat being of such size as not to offer appreciable flow resistance within a predetermined operating range of valve movement in response to gas pressure below a given value on said pressure responsive means, a flow metering shank projecting from said valve and Within said passage as a choke thereof, said shank being so constructed and arranged in relation to the passage as to choke the passage to a substantially constant flow metering area suflicient for elevating liquid in the production conduit above the valve so long as the valve is unseated within said predetermined operatingrange of movement and being of a length to remain within said passage during said operating range of the valve toward and away from its seat and to clear the passage as the valve moves beyond said operating range on an abnormal gas pressure rise for an abrupt transition of passage area to substantially unrestricted gas flow between said conduits.

4. A flow valve as in claim 1, said housing having an annular groove therein spaced from said valve. seat on the opposite side thereof from said resilient means, and a flexible seal ring in said groove of slightly lesser inner diameter than the diameter of said flow passage, said valve tip comprising means to connect said tip to the. adjacent end of said valve stem and a section inwardly tapered from said connection means toseat upon said valve seat, said flow metering portion including a first cylindricalsection connected to said tapered section and of a lesser diameter than the diameter of said flow passage therearound, a second cylindrical section connected to said first cylindrical section and of a larger diameter than said first cylindrical section and said seal ring inner diameter to sealably slide against said seal ring, said flow metering portionhaving an internal passage means from the end of said tip opposite said connection means and communicating with said flow passage surrounding said first cylindrical section as a flow metering orifice around said seal ring.

5. A flow valve as in claim 1, said valve tip comprising means to connect said tip to the adjacent end of said valve stem and a section inwardly tapered from said connection means to seat upon said valve seat, saidflow metering portion including a firs-t cylindrical section connected to said tapered section and of a lesser diameter than the diameter of said flow passage therearound, a second cylindrical section connected to said first cylindrical section and of a diameter to slide within the bore of said flow passage, said second cylindrical section having axially extending groove means therein to comprise a flow metering area.

6. A gas lift Well flow control assembly as set forth in claim 3, and a flow metering passage extending axially through said shank from a point immediately adjacent said valve and controlling gas flow through the passage when the valve is unseated within. said predetermined operating range of movement but which pressure control metering passage becomes inefiective Whenever said shank moves out of the passage.

7. A gas lift Well flow control assembly as in claim 3, said flow metering shank having an external groove ex.- tending axially to the end thereof and defining said constant flow metering area so long as valve movement is within said predetermined operating range, said yieldable means being yieldable to abnormal flow pressures in permitting valve movement beyond said predetermined operating range and the withdrawal of said shank from the passage to remove passage choke action and effect fully open valve position.

References Cited in the file of this patent UNITED STATES PATENTS 1,328,653 Ferris Jan. 20, 1920 1,344,854 Berg June 29, 1920 1,743,350 Hopkins Jan, 14, 1930 1,882,060 Boynton Oct. 11, 1932 2,144,144 Crickmer Ian. 17, 1939 2,203,957 Glitsch et al. June 11, 1940 2,339,487 King Jan. 18, 1944 2,465,060 Carlisle et al. Mar. 22, 1949 2,519,242 Garrett et al. Aug. 15, 1950 2,573,110 Robison Oct. 30, 1951 2,646,062 Nixon July 21, 1953 2,668,554 Seyfiert Feb. 9, 1954 2,685,294 Gold et al. Aug. 3, 1954