US3066690A

US3066690A - Well injection and bleed valve

Info

Publication number: US3066690A
Authority: US
Inventors: Gilbert H Tausch
Original assignee: Camco Inc
Current assignee: Camco Inc
Priority date: 1959-10-16
Filing date: 1959-10-16
Publication date: 1962-12-04
Anticipated expiration: 1979-12-04

Description

Dec. 4, 1962 ca. H. TAUscH 3,066,690

wELL INJECTION AND BLEED VALVE Filed oct. 1e, 1959 2 sheets-sheet 1 6. Tausch INVENTOR.

Y Qchawj Dec. 4, 1962 G. H. TAUSCH 3,066,690

WELL INJECTION AND BLEED VALVE Filed OCT.. 16, 1959 2 Sheets-Sheet 2 G. h. T cn/Jc INVENTOR.

BY Qc; /QM

United States Patent Oilice 3,056,690 Patented Dec. 4, i962 3,066,690 WELL llNltCTlN AND ELEED VALVE Gilbert H. Tausch, Houston, Tex., assigner to Camco, lncorporated, Houston, Terr., a corporation of Texas Filed (let. 16, 1959, Ser. No. 346,921 7 Claims. (Cl. 137-155) This invention relates to a well fluid production system having a production conduit communicating with the bottom of a storage chamber into which well huid from an adjacent formation enters through a standing valve and eriodically is lifted to the surface by pressure gas injection into the chamber above its point of communication with the production conduit, and more particularly to an improved pressure responsive valve operating automatically to vent the upper end of the collecting chamber between lift phases of the operating cycle and to close the vent and concurrently open the chamber for delivery thereto of pressure lift gas.

An object of the invention is to provide an improved well chamber installation by the use or a double acting valve which in the interval between gas lift periods closes the pressure gas passage and vents the top of the chamber into the production conduit to avoid air entrapment and resistance to free flow of well fluid into the chamber above the bottom of the production conduit but which valve acts in response to imposition thereon of a predetermined lift gas pressure and substantially simultaneously opens the pressure delivery passage and closes the vent so as to decrease and preclude pressure loss through the vent and make available full gas pressure for the utmost work of quickly evacuating fluid from the chamber and moving the fluid to the surface.

A further object of the invention is to provide an improved ilow control device in which a valve head is movably enclosed within a cage and has spaced apart and oppositely facing seats alternately engageable with a vent port seat and a pressure delivery passage seat.

Another object of the invention is to provide a valve normally yieldably biased away from vent closing position and toward pressure gas passage closing relation and has an area exposed within the passage to the action thereon of pressure gas and movement against the biasing force at a predeter iii-red gas pressure level, together with a valve engageable seat controlling the pressure gas passage and being itself movable in response to gas pressure for a folios -up action or unisonal movement with the downstream moving valve to maintain passage closing relation throughout an initial portion of the range of valve travel toward vent closing relation and which valve seat at the end or unisonal travel and upon occurrence of an open crack at the valve seat immediately exposes to the pressure gas a surface area larger and facing oppositely to the aforementioned face for overbalancing the latter and causing snap reversal of movement direction and a quick opening of the passage to maximum size and approximately coincident with vent closing action of the valve.

A still further object of the invention is to provide an assembly whose valve normally is positioned to open the vent and close the pressure gas passage in response to a biasinf7 force consisting of elastic gas confined under pressure within a variable volume chamber formed between relatively movable parts of the valve and valve housing and which chamber also confines a liquid to be forced upon variation in chamber volume through a constricted orifice for restricting the rate of chamber volume change and for minimizing violent valve seat pounding and attendant wear and vibration fatigue of the parts.

In the accompanying drawing, FIG. 1 is a vertical section of a fragment of the lower end of a well installation somewhat tdiagrammatically representing an application of the present invention; FIGS. 2A and 2B are companion views partly in side elevation and partly in vertical section of a valve unit retrievably located within a side tubular receiver of a tubing string section having a lateral offset and are on a large scale; FIGS. 3 and 4 show fragments of the valve unit in elevation and vertical section to illustrate parts positions different from one another and from FiG. 2B; FlG. 5 on a large scale shows a tubing mandrel in vertical section and a nonretrievable valve unit mounted exterior-ly thereof and FlG. 6 is a transverse section on line 6 6 of FIG. 3.

There is contemplated the conventional surface controller for intermittently shutting olf and delivering pressure lift gas or air into a conduit leading downwardly to the well fluid collecting chamber and conveniently the conduit can be provided by the annular space l occuring between the production tubing string 2 and the well bore casing 3, as shown in FlG. l. The space between the exterior of Ithe casing and the well bore wall may be sealed by a cement liner 4 and the casing may terminate downwardly either to traverse the iluid containing formation or may end just above the formation. In the latter event, a smaller diameter casing section 5 may be secured and sealed to the lower end of the casing 3 to project downwardly to line the bottom hole and for communication through lateral perforations 6 through the cement liner 1i with the oil bearing stratum. As a part of the lower end of the string of `tubing 2, there is a bottom length of pipe 7 which, at its upper end and above the producing formation, is surrounded by an annular packer to seal oft the well from the annulus space l. At its lower end, the dependent tubing section 7 has a bottom closure wall in which is mounted an inwardly opening standing valve 9 which opens for the inflow of well fluid into the storage chamber lll afforded within the lower tubing section, so long as the pressure within the chamber is less than bottom hole pressure. Whenever the pressure relationships are reversed, the standing valve 9 closes against return flow from the chamber to the bottom hole.

An extension tube 11 is enclosed within and is of rsmaller diameter than the tube section 7 and at its upper end is secured and sealed olf by a suitable packer 12, with the tubing string a short distance above the annulus packer 8 so as to form a downward continuation of the production string extending downwardly thereto from the well head at the surface. At its lower end the extension tube il opens into the bottom of the storage chamber l!) and co-operates therewith in receiving and storing well uids and in providing an outlet from the storage chamber l0 when pressure gas is applied into the: upper end of the storage chamber. The co-operating walls of the tubing sections 7 and :il are imperforate throughout their length and together with the top packer 12 seal off the chamber 1t) except for the communicating opening at the lower ends of the tubes 7 and 11 and except for a pipe or passage F connection 13 in by-passing relation with the packer 12 for communicating the upper end of the closed storage chamber 10 alternately with a vent port leading to the interior of the tubing string 2 and a gas pressure supply passage afforded by one or more side wall ports 19a (FIG. 2B) through the wall of the tubing string and leading from the annular space 1. Such communication is under control of an automatic valving assembly 14- which, in the case of FIG. l, is a retrievable unit which can be raised or lowered through the tubing string and positioned in a laterally offset receiver positioned within an enlarged section `l5 of the tubing string 2.

In place of a retrievable valve unit accessible from the tubing interior, a valve unit llo, as shown in FIG. 5, may be mounted on external lugs 16 and 17 mounted on a production tubing section i8 and contained within the surrounding annulus space. A connecting pipe 113 communicates the top of a collecting chamber with the interior of the valve body and is for alternate venting into the production tube 1S through lateral ports 19 and for fluid pressure delivery from the annulus space through lateral ports 20.

Whether a retrievable valve unit as in FIG. 1 or a fixed mandrel unit as in FiG. 5, the detail control mechanism within the respective valve bodies is proposed, as best seen in FIGS. 2A and 2B. Here the valve body conveniently is made up of a succession of hollow or tubular sections 14a, idf), 14e, Md, 14e and lief joined together at final assembly in end to end succession, as by means of threaded joints. As a retiievable unit, upper and lower packing rings Zl-Zl are clamped between co-operating body sections above and below a pressure gas entry port 22 in the side wall of the body section 14e. In use, these packing rings peripherally on spaced apart internal regions of the offset receiver of the tubing section l and provide seals above and below the entry port 22 which is aligned with an annular internal groove formed in the receiver wall and provided with ported communication with the casing annulus l. Annular clearance between the wall and the inserted valve body above the packing 21 communicates the interior of the production string 2 with a lateral port or ports 23 of the body section idc for controlled venting of the otherwise closed top of the storage chamber 10, as will later be described. More particularly, the Vent port 23 is at the upper end of interior clearance space surrounding an elongated reciprocatory stern 24 fitted within the body section 14e and which clearance constitutes an interventing passage leading from a tapered valve seat 25 at the upper end of the space Z6 within a valve cage forming a part of the iiuid passageway through the valve. in constant communication with the valve cage space 26 is a longitudinal port or passageway 27 extending through the skirt of a cupped piston 23 and opening into the bore or passageway 2,9 extending downwardly through the body sections i4@ and 14f for open communication at all times with the upper end of the Weil fluid `storage chamber 1).

Above the side vent port 23, the body section 14C has an internal lug 3G having slide bearing engagement with the stern 24 and mounting an O-ring 31 for sealing between the adjoining slide bearing surfaces. As shown in FIG. 2A, a downwardly facing shoulder 32 on the stem Z4 is presented within the vent port and its size may be controlled by design `so that any head of Huid within the tubing string above the shoulder will exert a lifting force on the stern, which under some circumstances may be desirable. The area may be diminished or increased in relation to other surfaces carried by the valve stem for effecting imbalance or a balance. of opposing faces according to operating conditions in a particular well.

Spaced upwardly from the sealed stem bearing lug 30 is an adapter member 33 securely fastened as by means or" screw threads on the upper end of the Stem 24 and peripherally joined and sealed to the lower end of a iexible wall or metallic spring bellows 34 whose opposite end is sealed and joined to the bottom of the upper body or housing section 14a. The hollow interior of the body portion i4@ is closed at its lower end by the liexible wall 34 andthe upper surface of the valve stem adapter 33 and is closed atrits upper end by an inwardly opening check valve 35a through which the chamber may be charged with a pressure gas, preferably one that is inert, such as nitrogen. The compressed gas provides an elastic spring toact on the adapter 33 for biasing the valve stem downwardly. F or damping the rate of movement in either direction, a metering restriction or port 35 is provided in the lower end of a tubular partition 36 carried by the housing rsection 14a to separate the chamber space into upper and lower divisions in communication only through the constantly open orifice 35. In addition to the body of compressed gas, the chamber also confines a small liquid body, such as silicon oil, which separates by gravity from the gas and collects in the bottom of the chamber and to arlevel to extend intok the metering orifice at the maximum expanded volume of the chamber. Chamber volume changes will move the liquid in one direction or the other through the restricted orifice and control or damp the rate of change.

Since the liexible bellows wall encloses the upper side of the adapter 33, there is provided an unbalance of surface area in the space surrounding the adapter and above the sealed bearing surface 30 and the downwardly facing surfaces are of greater area. Such surrounding space communicates through a lateral port 37 in the valve stem above the sealed bearing surface Sil with a longitudinal bore 3S extending downwardly in the stem and through a valve head or tip 39 at the lower terminal of the stem. In the downwardly biased position of the parts, the head 39 has a downwardly facing hemispherical bottom surface in seating engagement with a downwardly tapered annular seat fil) at the upper internal corner of the circular skirt of the cupped piston 23. The downward areas of the adapter 33 and the valve tip 39 inwardly of the annular seat 4u are exposed to gas pressures within the hollow space of the cupped piston as communicated thereto through one or more lateral ports il extended through the wall of the piston skirt in offset or circularlyspaced relation with the longitudinal ports Z7. The two sets of ports may be formed by drilling round openings radially inwardly and longitudinally downwardly respectively through ditierent regions of the piston side wall or skirt. To the radial ports casing pressure gas flows from the side ports Z?, by way of annular clearance space surrounding the slide piston 2S and within the hollow body lids.

This `annular space about the piston is provided byari external stepped piston diameter with downwardiy facing surface areas at vertically spaced apart shoulders d2 and 43. The combined areas of these downwardly facing

shoulders

42 and 43 exceed theY upwardly facing surface on the bottom wall 44 of the piston cup. Confined to these opposing faces, as in the FIG. 2B relationship, the pressure of lift gas supplied from the casing annulus 1 through the ports 19a, Z2 and 41 and in opposition'to the valve closing force, will act on the piston with a lifting tendency while the valve tip 39 is seated at {it} on the piston skirt, since the upper skirt surface is within the vented passage and is occluded from action thereon of annulus pressure gas.

When annulus pressure rises )and overcomes valve closing force, the piston 2S follows the valve upwardly and maintains the seating engagement at 4u until stopped by the limit abutment 47 immediately in advance of vent closing engagement with the seat 25 by the upper seat shoulder 29 on the valve head. Separation from the seat 4h by the valve and its seating at 25 Occur in rapid succession and thereupon annulus gas pressure can act on the top surface of the piston skirt. Such upwardly facing surface, either `alone or combined with the upwardly facing surface on the bottom cupped wall 44, presents an area in excess of the oppositely facing combined areas of the

downward shoulders

42 and 43, whereby the action of pressure gas on the differential areas will depress the piston. A downward limit of piston movement is provided by Ian upwardly facing shoulder 45 of a counterbored portion of the body section 14e and the lower edge of a depending skirt portion of the piston which carries an 0-ring 46 for sealing purposes. The bottom surface 47 of the body section 14d provides a stop to limit upward travel of the piston by engagement therewith (see FIG. 3) of the top of the piston skirt, whose peripheral upper portion has slide bearing engagement internally of the body section 14e and is sealed therewith by an 0- ring 48. The range of piston travel upwardly is slightly less than that of the Valve tip 39 on the head of the Valve stem 24. Thisvalve head has an upwardly tapered seat 49 tov engage with the fixed annular valve seat 25 as a stop to upward valve travel and for closing the valve cage from vented communication with the tubing interior..

During gas lift operation of the well and while the surface intermitter is closed against delivery of pressure gas to the casing annulus, the vulve parts will be in the position illustrated in FIGS. 2A and 2B, whereby the valve 39 seated at itl cuts off the gas annulus from the chamber llt) and the top of the chamber l@ is vented into the tubing string 2 through the communicating

passages

29, 27, 26 and 23 so that well liquids admitted past the Standing valve 9 can readily rise in the storage chamber lll above the bottom of the production tube l1. When the intermitter delivers pressure gas, there will be a tendency for inward gas flow through the inlet ports 22 land all, as aforesaid, and the pressure acting on the under sides of the piston and valve parts will be yieldingly opposed by the compressed gas within the flexible walled entrapment chamber and once the depressing7 force is overcome, both the piston and the valve will rise toward the seat 25 'out with the seat 4t) remaining closed during the initial travel. Immediately the upward travel of the piston Z8 is stopped by the abutment 47, as seen in FiG. 3, the continued rise of the valve under the pressure force will crack the seal at the valve seat d@ and this action will take piace at about the same time that the clearance around the valve seat 25 is being restricted, whereby pressure will build up above the top of the piston skirt and reverse the direction of piston travel so that the piston and the valve tip 39 both move away from each other for a free passage of pressure gas from the entry port il and the valve cage space 26 `at approximately the same time as the vent port 23 is closed at the upper limit of valve travel by engagement of the complementary seating surfaces i9 and 25. With the separation of the seats 39 and and closure of the vent port 23, pressure of the casing lift gas can act on the upper face of the piston skirt within the cage space Z6 as well as on the upward face of the piston wall 44 and, the piston will now move downwardly from the upper limit of FIG. 3 to its lower limit, as shown in FIG. 4. From the Valve cage 26 and with the vent port Z3 remaining closed, the lift gas moves downwardly through the piston passage 27 and the body passage 29 into the top of the collecting chamber lil to depress the level of iuid therein and effect closing of the standing valve 9 and a substantially complete evacuation of the liquid from the chamber l@ upwardly through tne open bottom of the tube il and on through the production tubing string 2 to the surface. After a selected interval of pressure gas delivery to the annulus il, the surface controller will again shut oif further delivery of pressure gas and the resultant drop in pressure at the valve unit M- will allow the downward biasing force on the valve stem 24 to again do-minate and depress the valve tip 39 into seating engagement with the annular seat ttl of the depressed piston ZS, thereby sealing communication with the casing space l and lowering the valve surface 49 from its seat 25 for repetition of the chamber venting phase of the cycle.

What is claimed is:

1. A pressure responsive valve assembly adapted for alternately communicating the top of a well fluid collecting chamber with a vent means and a pressure gas supply source, comprising a valve element having a stern and a head, an upwardly facing valve surface on the head, a downwardly facing valve surface on the head in axially spaced relation to the upwardly facing valve surface, a hollow housing enclosing and slidably mounting said stem, yieldable means carried by the housing and active on the stem to bias the same downwarlly, a valve cage constituting a part of the housing and surrounding said head, a chamber communicating passage in the housing and opening into said valve cage, a pressure gas supply passageway in the housing leading to and terminating in an upwardly facing annular valve seat within the valve cage for engagement by said downwardly facing valve surface to close the supply passageway under biasing action of said yieldable means, said valve element having a downwardly facing area exposed to the passageway supplied pressure gas for passageway opening valve action in opposition to said bias means and a vent passageway in the housing leading from and terminating at the valve cage in a downwardly facing annular valve seat for engagement by said upwardly facing valve surface to close the vent passageway in response to valve element movement upon action thereon of said passageway supplied pressure gas.

2. A valve assembly as in claim l, wherein a piston carries the valve seat of the pressure gas supply passageway and is slidably mounted in said cage, a downwardly facing surface on the piston exposed at all times lto said passageway supplied pressure gas and for response and upward travel with the valve element, piston engageable abutment means carried .by the housing to define a limit of upward piston travel with said valve element and Ito an extent less than valve element travel toward said valve seat and an upwardly facing surface on Vthe piston and within said valve cage and of greater area than the area of said downwardly facing surface of the piston for exposure to passageway supplied pressure gas when upward piston travel is limited by said abutment means so as to effect quick downward piston travel away from said downwardly facing valve surface.

3. A well injection and vent valve assembly including a housing having a xed valve seat, a vent passage surrounded by said valve seat and extended therefrom through the housing to the exterior thereof, a piston slidably mounted in the housing for reciprocation toward and from said fixed valve seat, a pressure gas entry passageway in the housing and projected through the piston and into the space between the piston and said fixed valve seat, another passageway extending through the housing and opening into said space for alternate communication with the vent passage and the pressure gas entry passageway, oppositely facing surfaces on the piston adapted to be exposed to entry passageway `gas pressures and thereby control piston travel, a valve seat on one of said surfaces medially thereof to separate the same into two zones, a valve element movably carried `by the housing within the space between .said valve seats and provided with :a surface exposed in said entry passageway to pressure gas and movable in response thereto in a direction to engage and close said fixed valve seat, yieldable means contained in the housing and active on the valve element for biasing the same in the direction to engage the valve element with the piston carried valve seat and thereby to exclude one of said two Zones from action -thereon of pressure gas, the other of said two zones having an :area less than that of the `surface facing oppositely thereto, so that the action on piston and valve element surfaces exposed to entry passageway gas pressure in excess of yieldable means bias moves the valve element toward said fixed seat and also moves the piston in `follow-up relation to the valve element and maintains the entry passage closed in the initial portion of valve element travel, a housing carried abutment engageable -by the piston as a limit stop to such follow-up movement and for effecting opening of said entry passageway in the nal travel portion of the valve element into xed seat engagement, the combined areas of said two zones exceeding the area of said oppositely facing surface and serving in response to pressure gas action lthereon to shift the piston away from the valve element.

4. A combined well injection and vent valve assembly including a reciprocatory valve element `having axially spaced apart and oppositely facing valve seating surfaces, a housing slidably mounting the valve element and providing a cage surrounding said seating surfaces, port means in said housing having constant communication with lthe interior of said cage, a vent passage extending within the housing to the interior thereof and leading from and having a xed valve seat at one end of the cage engageable 'by one of the valve seating surfaces to close the vent passage and also to define one limit of spaanse reciprocation of the valve element, means on the valve element responsive to the action thereon of pressure gas within the housing, a pressure gas delivery passage projecting into the housing and leading to said cage, a reciproc-atory piston slidably mounted in axial relation to said valve element and within said cage and formed with a passage constituting a part of said gas delivery passage, oppositely facing surfaces on the piston of differential areas, one surface being exposed within the delivery passage and the other surface being exposed partly within the delivery passage `and partly within said cage, a valve seat on the piston surrounding the passage therein and engageable by the other of said valve seating surfaces to occlude the ow of pressure gas into the cage, piston engageable stop means on the housinfy confining the range of piston movement to less than that of the valve element and yieldable means carried by the housing tand active on the valve element in a direction to bias the same into engagement with the piston in opposition to action of pressure gas on the valve element and on the piston within its range of valve engaging movement.

5. in a combined well injection and vent valve, a :housing having a flow passageway and pressure `gas entry means thereto, a piston slidably mounted in the passageway and movable in response to the action of pressure gas on oppositely `facing surfaces thereof, one of which surfaces is of larger area than the other, the larger surface being downstream and the smaller surface being upstream of the passage and in relation one to another, piston engageable stop `surfaces on the hou-sing defining opposite ylimits of piston movement, a reciproca-tory valve mounted in the housing for travel through a range greater than the travel range of the piston and provided with a seating surface exposed within the passageway, a seat on said larger surface of the piston engageable by said seating surface of the valve to seal the passageway lagainst pressure gas fiow from said entry means and to occlude a portion of said larger surface from pressure gas action, said housing having la vent port therein leading from the passageway, a valve seat in the housing surrounding the passageway vent port in downstream `relation with the valve engageahle seat on the piston and being engageable by said valve for establishing a limit of travel therefor and for closing the vent port, yieldable means carried by the housing Iand active on `the valve in the direction to seat the valve on said piston and resist movement of the valve and the piston away from one limit of piston movement and yieldable in response to gas pressure for piston and valve movement in downstream direction tto :the other limit of piston movement and for further valve movement out of engagement with the piston and into engagement with the valve seat of the vent port.

6, ln a pressure responsive vent and gas injection valve for Wells, a housing having a well communicating chamber, a pressure gas delivery passage in said housing 4and leading to the chamber, a movable valve within the chamber having a surface exposed to pressure gas in :the

passage and responsive there-to for movement in downstream direction, yieldable means carried by the housing and active on the valve in opposition to pressure gas thereon, ta pair of spaced apart seats in the chamber alternately engageable by said valve at opposite limits thereof, one of said seats being xed in the housing to establish valve travel limit in downstream direction, said housing having a vent port therein and surrounded by the last mentioned valve seat, la slidable piston contained in the chamber and carrying the other of said seats and having oppositely yfacing surfaces of unequal areas for exposure to pressure gas, one of said surfaces being upstream `of the piston carried seat and responsive to pressure gas to effect piston travel in follow-up relation to valve travel in downstream direction and the other of said surfaces having a portion thereof on the downstream side of the piston carried seat to be occluded from action .thereon of pressure gas while the valve is engaged with the pis-ton carried seat and stop means engageable by the piston Ito limit its downstream ltravel to less than valve downstream travel, said other of said surfaces in relation to the oppositely facing surface presenting to the pressure ygas a smaller area while the valve is engaged with the piston and a larger area upon disengagement of the valve and piston.

7. 1n a pressure responsive vent and gas injection valve for wells, a housing having a pressure gas flow passage, a pair of valve members movably mounted in the housing and one thereof comprising a head positioned within the passage and having a surface exposed to pressure `gas action for response thereto in moving the head in downstream direction, yieldable means contained in the housing and active to resist such movement, oppositely facing seating surfaces on said head, said housing having a vent port therein leading from the passage, a fixed seat surrounding the vent port and engageable by the valve head to close the port and .to limit valve head movement in downstream direction, the other of said valve members having a central opening forming a part of said passageway and also having an annular valve seat surrounding the passageway at one end and engageable by said valve head and oppositely facing surfaces on said other of the valve members, one in upstream relation to the annular valve seat and the other in downstream relation to the annular valve seat, the downstream surface being of larger area than the upstream surface and said surfaces serving to control movement of said other valve member by exposure of the respective surfaces to pressure gas within said passage.

References Cited in the tile of this patent UNITED STATES PATENTS 1,794,427 White Mar. 31, 1931 2,142,484 Jennings Ian. 3, 1939 2,142,485 Stephens Jan. 3, 1939 2,213,372 Aucoin Sept. 3, 1940 2,229,914 Boynton Jan. 28, 1941 2,556,867 `Carlisle June 12, 1951 2,573,110 Robinson Oct. 30, 1951