US3509913A

US3509913A - Rotary plug well safety valve

Info

Publication number: US3509913A
Application number: US655804A
Authority: US
Inventors: George E Lewis
Original assignee: Hydril LLC
Current assignee: Hydril LLC
Priority date: 1967-07-25
Filing date: 1967-07-25
Publication date: 1970-05-05
Anticipated expiration: 1987-05-05

Description

y 5, 1970 G. E. LEWIS 3,509,913

ROTARY PLUG WELL SAFETY VALVE Filed July 25, 1967 5 Sheets sheet 1 INVENTOR. GEO/26E E. LEW/s lay/4C4 4 firm/anew.

May 5, 1970 G. E. LEWIS ROTARY PLUG WELL SAFETY VALVE Filed July 25, 1967 3 Sheets-Sheet 2 INVENTOR. GEORGE E LEW/s y 5. 1970 G. E. LEWIS 3,509,913

ROTARY PLUG WELL SAFETY VALVE Filed July 25. 1967 i 5 Sheets-Sheet 5 lira. 4',

G502 65 E. LEW/5 United States Patent O US. Cl. 137614.11 9 Claims ABSTRACT OF THE DISCLOSURE The disclosed well pipe safety valve concerns a flow controlling plug stopper rotatable in a body passage enlargement by a crank which is subject to turning by a pressure responsive actuator outside the passage enlargement.

BACKGROUND OF THE INVENTION This invention relates generally to sub-surface valves for use in oil wells; more specifically the invention concerns pressure responsive, rotary plug, sub-surface safety valves.

US. Pat. 3,036,590 discloses a rotary plug safety valve connectible into a drilling or tubing string, and adapted to be closed for shutting off back-flow, as when a blowout threatens to occur. Rotation is transmitted to the stopper by means of a tool manipulable at the valve exterior to turn an operating stem projecting laterally through a side opening in a box member containing the stopper. Thus, in normal usage, the string section containing the valve must be located proximate the well head, so that the tool may be applied to the stem, for closing the valve. Such operation may in certain instances become disadvantageous; for example, when imminent blow-out threatens, there may be insufficient time to lift the string sufficiently, particularly when the valve is at a considerable distance below the well head.

Lifting of the string as described may be obviated by constructing the valve stopper to rotate in response to bodily movement, and wherein a fluid pressure responsive actuator is located interiorly of the string for bodily moving the stopper lengthwise of the string to effect stopper rotation; however, such an arrangement does not in a practical sense permit desirable isolation of the valve stopper and piston actuator structure, i.e. the latter must be introduced into the string interior along with the stopper so as to urge the stopper linearly in the string. Such a construction adds the problem of exposure of the actuator to the production fiow, which may subject the actuator to abrasion and wear from sand particles carried in the flow, increasing the risk of actuator malfunction, Also, the effective string bore size is reduced when the actuator is introduced into the string interior.

SUMMARY OF THE INVENTION It is a major object of the present invention to overcome the above problems through provision of a practical safety valve construction wherein the plug stopper or stoppers rotate without bodily translation; wherein the stopper or stoppers are rotated in response to bodily movement of fluid pressure responsive actuator structure; and wherein the actuator is isolated from the rotary stopper. Basically, the invention is embodied in a combination that includes a tubular body having a longitudinally extending flow passage and a passage enlargement; a plug stopper having a through opening and means mounting the stopper to rotate within the enlargement to bring the through opening into and out of registration with the flow passage; a crank operatively connected with the stopper and projecting outside the passage enlargement; an actuator such as a sleeve received within the body means 3,599,913 Patented May 5, 1970 to have operative engagement with the crank so that sleeve bodily movement coaxially of the flow passage acts to 1'0- tate the stopper, and the sleeve having oppositely facing surfaces to receive pressure acting to so move the sleeve coaxially of the flow passage. Typically, the sleeve and body form a pressure chamber outside the flow passage to receive fluid pressure acting againt one of the sleeve surfaces at one end of the sleeve, the sleeve extending about the plug stopper but confined outside the flow pasage.

Additional objects and unusual advantages of the invention include the provision of yieldable means acting against another of the sleeve surfaces at the opposite end of the sleeve to oppose movement of the sleeve induced by increased fluid pressure application to said one surface of the sleeve; the provision of a sleeve slot to receive the pivoted end of the crank accommodating sleeve movement relative to the crank, the sleeve also having a cam shoul der adjacent the slot and engagable with arm extent of the crank; the provision of a crank arm extending in an arc about the central axis defined by the fiow passage; the provision of an auxiliary chamber which may incorporate a bellows communicating with the other end surface of the sleeve to receive fluid displaced by that surface upon compression of the yieldable means or spring; the provision of a tandem stopper and crank arrangement operated by a single sleeve, as will be described; and the provision of an operating fluid pressure delivery line having a terminal connectible in series with body porting communicating with the pressure chamber, and guide means carrying that line and movable lengthwise of the tubing string in which the valve body is connected to guide the line terminal into connecting rotation with the porting.

These and other objects and advantages of the invention, as well as the details of illustrative embodiments, will be more fully understood from the following detailed description of the drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical elevation taken in section and showing the valve assembly internal construction, the valve stopper being in open position;

FIG. 1a is a fragmentary elevation illustrating the crank and sleeve interconnection;

FIG. 2 is an elevational view of the valve, cut-away to show the valve stopper rotated to open position;

FIG. 3 is a sectional view taken on line 33 of FIG. 1;

FIG. 4 is a sectional view taken on line 44 of FIG. 1;

FIG. 5 is a vertical section, partly cut-away to ShOW interior construction of a tandem valve embodying the invention; and

FIGS. 6 and 7 are fragmentary views showing modifications.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1, the safety valve assembly is indicated at 10 as connected in a well pipe string 11, for controlling flow through the string. The valve assembly includes tubular body means such as parts 12, 13- and 14 defining a longitudinally extending flow passage 15 and a passage enlargement 16. In this regard, the

cap parts

12 and 13 may have threaded connection with cylindrical part 16 at the

locations

17 and 18 as shown.

The assembly 10 also includes a plug stopper, such as is seen at 19, having a through opening 20, together with means mounting the stopper to rotate within the passage enlargement to bring the through opening 20 into and out of registration with the flow passage 15. In this regard, FIGS. 1 and 2 respectively show the stopper out of and in registration with the passage. The mounting means typically includes a pair of opposed

bearing plates

22 and 23 retained between and seating against the

terminal shoulders

24 and 25 of the

parts

12 and 13, as is clear from FIG. 4. The stopper rotates on hearing balls 26 retained within longitudinally planar and parallel annular grooves or

ball races

27 and 29 respectively cut in laterally opposite sides 28 of the stopper and lateral sides 30 of the

plates

22 and 23. The latter contain lateral openings or bores 34 loosely receiving the oppositely extending

projections

35 and 36, which do not transmit loading from the stopper to the plates. In contrast, all stopper loading is transmitted through the bearing balls to the

plates

22 and 23, whereby very low resistance to stopper rotation is imposed by the mounting structure, irrespective of loading conditions. Note further that the annular portions, i.e. major extents, of the

plates

22 and 23, are received in notches 37 cut in opposite sides of the generally spherical stopper.

Means for rotating the stopper includes a crank 38 operatively connected with the stopper, and projecting outside the passage enlargement 16. Such operative connection is for example brought about via

stems

39 and 40, the former received in bore 34 of plate 23, and the stem 40 received in bore 41 and counterbore 42 formed in cylindrical part 14. When the stopper is in open position, a key 43 on projection 36 extends longitudinally for reception in a keyway 44 in stem 39. Similarly, a key 45 on stem 39 is received in a keyway 46 formed in stem 40; however keyway 46 extends laterally when keyway 44 extends longitudinally, and vice versa. Accordingly, a universal joint is formed between the stopper and stem 40, to accommodate any slight misalignment of the stopper and its rotating and mounting means, to prevent binding.

Rotation of the stopper is effected by means of an actuator, as for example, sleeve 50 received by the body means to have operative engagement with the crank such that sleeve bodily movement coaxially of the flow passage acts to rotate the stopper. In this regard, the sleeve contains a slot 51, as seen in FIGS. 1 and 1a, to receive the end portion 38:; of the crank pivotally supported by the stem 40 at 52, whereby sleeve longitudinal bodily movement relative to the crank is accommodated. Note the longitudinal elongation of the slot 51, for this purpose, and the curvature of both the slot and crank about the principal longitudinal axis '53 defined by passage 15. Axis 53- is normal to the transverse axis about which the stopper and crank rotate.

The sleeve also has

cam shoulders

54 and 55 at longitudinally opposite sides of an auxiliary slot formed in the sleeve and receiving arm extent 38b of the crank. Such extent may typically be formed in the shape of a head or ball received between

cam shoulders

54 and 55 for actuation thereby as the sleeve moves longitudinally, thereby to rotate the stopper between open and closed positions. The extent of stopper movement, or stopper positioning, may be determined as by means of the indicator 57 attached to stem 40 and projecting outside the assembly, particularly where the device is used above ground. Note seals at 88 and 89 sealing off between the stem 40 and sleeve. Seal 88 is compressed by the float of stem 40 in response to internal pressure in enlargement 16, as accommodated by the universal joint. A vent 90 relieves any fluid pressure build-up between such seals, for conducting same to the exterior.

The sleeve 50 has oppositely facing surfaces to receive pressure acting to move the sleeve coaxially of the flow passage 15 and enlargement 16. In this regard, fluid pressure may be receivable within a pressure chamber 58 formed by the sleeve and body means outside the flow passage 15, such pressure being applicable against one of the sleeve surfaces at one end of the sleeve, as indicated at 59. Note in this regard the fluid pressure source 60', and linefitla connected into body cylinder part or hous ing 61 spaced outwardly from part 14, and confined between

flanges

62 and 63 on parts 12- and 13. Similarly, fluid pressure may be introduced to a chamber 64 at the opposite end of the sleeve, for applying actuating pressure to sleeve end surface 65. A pressure duct for this purpose is indicated at 66 communicating with chamber 64 via fitting 66a.

In addition, or alternately, yield'able means such as springs 67 may be located in chamber 64 to transmit pressure to sleeeve 50, for returning the sleeve upwardly to stopper closed (rotated) position, as seen in FIG. 1. Guide pins 69 project through the springs to maintain them against extreme lateral deflection.

Returning to FIG. 1, rings 75 and 76 have lips '77 and 78 engaging the spherical surface of the stopper, at longitudinally opposite sides thereof. The rings respectively have slip fits with

counterbores

79 and 80 in

body parts

12 and 13. Also, the rings are urged toward the stopper by corrugated

flat springs

81 and 82, whereby lips 77 and '78 fit sealingly against the stopper surface as it rotates, preventing leakage past the stopper in closed position as seen in FIG. 1. Finally, lateral access to passage enlargement 16 for lubrication purposes is afforded by ducting 85 passing through another longitudinally elongated slot 86 in the sleeeve. A threaded plug 87 closes the ducting, and may be removed to facilitate lubrication of the stopper exterior in enlargement 16. Opposite sides Q1 and 92 of the ducting provide stops engageable with the sleeve surfaces 93 and 94 to limit axial displacement of the sleeve, the ducting being retained by

body parts

61 and 14. Also, ducting 85 prevents rotation of the sleeve 50.

Referring to FIG. 6, the fitting 99, which is adapted to take the place of fitting 66a, defines a chamber containing a piston 161. Space 102 above the piston contains compressible fluid such as air, and space 103 below the piston communicates with chamber 64 for receiving fiuid displaced therefrom as actuator sleeve 61 moves downwardly. Accordingly, pressure developed by compression of air in space 102 may be communicated to the lower end surface 65 of the actuator sleeve. FIG. 7 illustrates another modification wherein the auxiliary chamber takes the form of a bellows 104 the interior of which communicates with chamber 64 to receive displaced pressurized fluid. The exterior of the bellows is exposed to the exterior 105, which may for example comprise the subsurface ocean water in off-shore well environments. Therefore, the pressure of the fluid at the exterior 105 tends to collapse the bellows and is transmitted to the lower end surface 65 of the sleeve, for balancing the static pressure in line 60a, the springs then closing the valve assembly, in the event of failure of above static pressure in line 60a.

The modified assembly seen at in FIG. 5 is especially well adapted for running on a tubing string 111 into sub-surface location in a well, as for example within well casing 112. The assembly includes tubular body structure comprising cylindrical part 113 into which

tubular cap parts

114 and 115 are thread connected; and outer cylindrical housing part 116 endwise confined between flanges on

parts

114 and 115.

Tubular elements

117 and 118 are respectively connected with the cap parts, for connecting the assembly in series with the string 111.

Tandem plug stoppers

119 and 120 are mounted to rotate within the

enlargements

122 and 123 of the flow passage 124, the construction of the stoppers with their through openings and mounting structure being the same as described previously in FIGS. 1-4. Means to rotate the stoppers includes the

cranks

126 and 127, each of which is connected with its respective stopper as described in FIGS. 1-4. The cranks project outside the

passage enlargements

122 and 123 and in the

slots

128 and 129 formed in the actuator sleeve 130. The slots and cam surfaces 131-134 are constructed as before, and the sleeve is movable longitudinally in the chamber defined by the body parts 113416, thereby to rotate the stoppers in synchronism, both stoppers opening and closing together. Typically, the longitudinal spacing of the cam shoulders 131 and 132 from the cam shoulders 133 and 134 may be such as to initiate rotation of one stopper slightly before initiation of rotation of the other stopper, thereby to reduce the frictional resistance to starting, imposed by the assembly. The use of two stoppers adds redundancy to the system, for assuring closure of at least one stopper upon movement of the sleeve to uppermost position.

The actuator sleeve has an upper end surface 140 to which fluid pressure is communicable from a line 141 to which pressure is applied from a source 142 at the surface. The line includes

fittings

143 and 144, with the latter having a reduced width terminal projection 145 connectible in series with porting 146 in the body cap 114, porting 146 communicating with chamber 135 at the top of the sleeve 130. For this purpose, guide means such as bracket 147 is mounted on fitting 143 and embraces the tubing 111 for movement lengthwise thereof as the line 141 is lowered, whereby the terminal 145 may be guided toward connection with porting 146. As the terminal 145 approaches the body structure, tapered shoulder 151 on fitting 144 engages the cam surface 149 on tubular section 150, the latter being mounted on the body cap 114. Surface 149 spirals downwardly to guide tapered shoulder 151 toward and into the position seen in FIG. 5, wherein the terminal 145 has dropped into socket 153, formed in cap 114. The socket and porting 146 are initially filled with grease to block access of sea water or other fluid substance to the chamber 135; however, as the terminal 145 penetrates the socket, grease in the latter is displaced via vent 156 to the exterior. When shoulder 151 engages seat 157, the porting 146 communicates with the tubular passage 158 in fitting 144, to which fluid pressure is supplied via line 141, for operating the actuator sleeve 130.

I claim:

1. In a safety valve assembly connectible into well pipe for controlling flow therethrough,

tubular body means having a longitudinally extending flow passage and a passage enlargement,

a plug stopper having a through opening and means including transversely spaced bearings carried by the body means mounting the stopper to rotate within said enlargement to bring said through opening into and out of registration with said flow passage,

means to rotate the stopper including a crank operatively connected with the stopper and projecting outside said passage enlargement, and

an actuator received within said body means to have operative connection with the crank such that actuator bodily movement relative to said flow passage acts to turn the crank and thereby so rotate the stopper, the actuator having oppositely facing surfaces to receive pressure acting to so move the actuator relative to the flow passage,

said actuator comprising a sleeve movable coaxially of the flow passage, the sleeve and body means forming a pressure chamber outside said flow passage to receive fluid pressure acting against one of said sleeve surfaces at one end of the sleeve, the sleeve extending about the plug stopper but confined outside said passage, and said sleeve at all times remaining out of fluid transfer communication with said flow passage, said passage enlargement and said stopper through opening.

2. The combination of claim 1 including yieldable means acting against another of said surfaces at the op posite end of the sleeve.

3. The combination of claim 1 wherein the crank has a pivoted end and the actuator contains a slot extending sufiiciently in the direction of actuator movement as to receive and accommodate the pivoted end of the crank throughout the range of actuator movement, the actuator having a cam shoulder engageable with arm extent of the crank to rotate said arm extent in response to said actuator movement.

4. The combination of claim 3 which the flow passage defines a central longitudinal axis and the plug stopper defines a transverse axis normal to said central axis and about which the stopper is rotatable, the crank extending in an arc about the central axis from a locus proximate said transverse axis, the crank terminating proximate said cam shoulder.

5. The combination of claim 1 including means to supply actuating fluid pressure to said pressure chamber.

6. The combination of claim 2 including an auxiliary chamber communicating with said other surface to receive pressurized fluid displaced by said other surface upon compression of said yieldable means.

7. The combination of claim 6 in which said auxiliary chamber includes a bellows the exterior of which is exposed to pressure of exterior fluid.

8. The combination of claim 1 including a second plug stopper having a through opening and means mounting the second stopper to rotate within the body means, a second crank operatively connected with the second stopper to project outside the passage enlargement, and said actuator having operative connection with the second crank such that actuator bodily movement coaxially of the flow passage acts to rotate the second stopper to bring its through opening into and out of registration with the flow passage substantially in synchronism with the first-mentioned stopper.

9. The combination of claim 1 including tubing connected in series with the body means to communicate with said passage, a fluid pressure line having a terminal connectible in series with body means porting communicating with said pressure chamber, and guide means movable lengthwise of said tubing and carrying said line to guide said terminal toward connecting relation with said porting.

References Cited UNITED STATES PATENTS 2,501,957 7/1951 Teague 251-57 X 2,894,715 7/ 1959 Bostock 166-224 X 2,982,305 5/1961 Grove 137--6l4.l1 3,100,531 8/1963 Brown.

3,163,985 1/1965 Bouyoucos 9l4 ALAN COHAN, Primary Examiner H. M. COHN, Assistant Examiner US. Cl. X.R.