Auxiliary oil well tubing shut-off assembly

Abstract

An auxiliary oil well pressurized tubing string shut-off assembly that may be removably secured to a valve for control of fluid through the string, after the valve has been disconnected from an above ground piping system, and the valve placed in a closed position. After the assembly is secured to the valve, the valve is opened, and block and tackle means that form a part of the assembly are employed to force a radially expandable seal downwardly through the valve into the tubing string. Expansion of the seal is accomplished by rotation of a rod that forms a part of the assembly. After the seal has been radially expanded to block upward flow of pressurized fluid through the tubing string, the portion of the assembly used in positioning the seal within the tubing string is separated from the valve. The valve may now be disconnected from the tubing string for repair and maintenance work, or the maintenance work performed while the valve remains connected to the tubing string. After the repair work has been completed, the portion of the assembly removed from the valve is remounted thereon and the above described operation is repeated in reverse to retrieve the seal from the interior of the tubing. After the seal has been moved upwardly through the valve, the valve is placed in a closed position and the assembly completely separated therefrom, with the valve then being reconnected to the above ground piping system of which it forms a part. The valve may now be placed in the open position to permit pressurized fluid to flow from the tubing string to the above ground piping system.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

Auxiliary oil well tubing string shut-off assembly.

2. Description of the Prior Art

The repair or replacement of a valve that controls the pressurized flow of fluid through an oil well tubing string at a well head presents a serious problem. In the past there has been no device or method by which an auxiliary seal could be effected in the tubing string to permit such a valve to be replaced or removed in an easy and convenient manner.

The primary purpose in devising the present invention is to provide an assembly and method of using the same that permits a valve to be removed from a pressurized line after the latter has been temporarily sealed by use of a portion of the assembly.

A further object of the invention is to furnish a sealing assembly for a pressurized fluid line that has a simple mechanical structure, is easy and convenient to use, requires little or no maintenance attention, and can be retailed at a sufficiently low price as to encourage the widespread use thereof.

SUMMARY OF THE INVENTION

The valve that is to be replaced or repaired, is placed in a closed position, and the upper end thereof is disconnected from the above ground piping system. The assembly that comprises the present invention is now removably connected to the upper open end of the closed valve. The assembly includes a first tube that has first and second ends. First means are provided for removably connecting the first ends of the first tube to the upper end of the valve body. A second tube is longitudinally disposed in the first tube, with the second tube having first and second ends. The first end of the second tube has first threads formed thereon. Second means are mounted on the upper end of the first tube for slidably and sealingly engaging the second tube as the second tube is moved longitudinally relative to the first tube, as well as rotated relative thereto.

A rigid tubular body is provided that has a first externally threaded end that engages the first threads on the second tube, with the body including an intermediately disposed portion that defines a circular body shoulder on the downwardly disposed part thereof, and a tube that depends from the intermediate portion. The tube terminates at the bottom in a second end. A ring shape resilient packer that has first and second surfaces is provided and mounted on the depending tube with the first surface being in contact with the above mentioned body shoulder. A finger defining cylindrical shell is disposed below the packer, with the lower end of the shell being engaged by a nut.

A first rod extends downwardly through the second tube, with the first rod having an eye formed on the upper end thereof and a socket of noncircular transverse cross section on the lower end. The socket is adapted to removably engage a head of noncircular transverse cross section on a second rod that extends downwardly through the body and shell to engage the nut. A pin extends through one of the fingers of the shell to engage the tubular portion of the body, to prevent relative rotation between the shell and body.

After the first tube has been mounted on the valve, the valve is placed in an open position, and block and tackle means, or other force exerting means that form a part of the invention, are employed to force the second tube, and packer assembly supported therefrom, downwardly through the valve body against the fluid pressure in the bore hole. This operation is continued until the packer is disposed within the tubing string. The first rod is now used to rotate the socket and second rod in a direction to exert a longitudinally directed force on the packer to radially expand the latter into sealing contact with the interior surface of the tubing string.

After the packer has effected such a seal, the second tube is rotated in a direction to separate it from the packer assembly whereby the second tube and first rod may be drawn upwardly through the valve and separated therefrom. The valve may now be removed from the tubing string for replacement or repair purposes. After the valve has been replaced or repaired, it is again mounted on the upper end of the tubing string, and the second tube placed in engagement therewith. The repaired or replaced valve is now placed in the open position, and the block and tackle assembly is utilized to force the second tube and first rod downwardly into the confines of the tubing string. By rotation of the second tube, the lower end thereof is placed in engagement with the upper end of the body. The socket on the lower end of the first tube is now in engagement with the head on the second rod. By rotation of the first rod in an appropriate direction, the second rod is rotated to longitudinally separate the finger defining shell and the portion of the body that defines the shoulder, to allow the resilient packer to longitudinally expand and retract out of sealing engagement with the interior surface of the tubing string.

The portion of the assembly below the valve is now moved upwardly therethrough into the confines of the second tube, and the valve now placed in the closed position. The second tube may now be disconnected from the valve, and the entire assembly moved to a position remote from the valve. The upper end of the valve is now connected to the above ground piping system, and the valve placed in an open position to effect communication between the interior of a pressurized fluid tubing string and the piping system to which fluid is supplied.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a conventional piping combination at an oil well head that controls the flow of pressurized fluid upwardly from a tubing string by means of a valve;

FIG. 2 is the same side elevational view as shown in FIG. 1, but with the overhead piping system having been disconnected from the valve, and the temporary shut-off assembly that forms the subject of this invention having been mounted thereon;

FIG. 3 is a side elevational view of the valve, after the assembly has been mounted thereon, and with the assembly in a first position;

FIG. 4 is the same elevational view as shown in FIG. 3, but after a block and tackle that forms a part of the assembly having been employed to force a sealing portion of the assembly downwardly through the open valve into the confines of the pressurized tubing string;

FIG. 5 is an enlarged side elevational view of the sealing portion of the assembly disposed within the confines of a tubing string;

FIG. 6 is an enlarged fragmentary longitudinal cross sectional view of the sealing portion of the assembly disposed in a tubing string, but prior to the packer that forms a part of the assembly having been radially expanded into sealing engagement with the interior of the tubing string; and

FIG. 7 is the same view as shown in FIG. 6, but after the packer has been radially expanded into sealing engagement with the interior surface of the tubing string.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In FIGS. 1-4 inclusive it will be seen that a tubing string A is concentrically disposed within a casing B, with both of the previous mentioned tubing string and casing being situated in an oil well bore hole C. The upper end of the tubing string A and casing B are in communication with a conventional above ground fitting D, and the fitting having a section of the tubing string A situated thereabove that is connected to a valve E. The valve E includes a valve body 10 that has a first tapped upper fluid discharge end 12 that is screw threaded to a pipe 14 that has a union 16 therein, and the pipe 14 being connected to a conventional oil field assembly F that includes a pressure gauge and the like.

The invention G is removably secured to the upper tapped end of the valve E after the pipe 14 is disconnected therefrom, and with the valve E being in the closed position. The invention G as may be seen in FIGS. 3 and 4 includes a first tube 18 that by threaded means 20 is removably secured to the tapped upper fluid discharge end 12 of a valve body 10. The first tube 18 as may best be seen in FIG. 2 has a cross piece 22 secured thereto that rotatably supports laterally separated first pulleys 24. A second tube 26 extends longitudinally into the first tube 18, with the second tube slidably and rotatably engaging a seal 18a mounted on the upper end of the first tube 18. A cross member 28 is secured to the upper portion of the second tube 28 and supports a pair of second pulleys 30. A rope or cable L is provided that has a first end 31 thereof secured to the first tube 18, with the cable extending over the pulleys as shown in FIG. 3 and 4, to provide in effect a block and tackle assembly.

A first rod 32 as shown in FIGS. 2, 3, 4 and 5 extends downwardly in the second tube 26, with the rod on the upper first end thereof being provided with an eye 34 for rotating the same.

The second tube 26 has an upper first end 26a adjacent the pulleys 30 and a second lower end 26b of enlarged transverse cross section that has first thread 36 formed on the interior surface thereof as best seen in FIG. 5. The shut-off assembly H, later to be described in detail, is removably supported in the tubing string A by the thread 36, and this shut-off assembly capable of being lowered through the interior of the valve body 10 when the valve member (not shown) in the valve body is in the open position. Shut-off assembly H as can be seen in FIGS. 5-7 inclusive, includes a rigid tubular body 38 that has a first upwardly disposed, externally threaded portion 40 that engages the thread 36. An externally threaded neck 42 extends upwardly from the first portion 40, and engages a tapped recess 46 formed in a bottle shaped, tubular member 44.

The tubular body 38 includes an intermediate portion 48 which on the lower portion thereof defines a body shoulder 48a from which a tube 50 depends. A resilient ring shaped packer J, best seen in FIGS. 6 and 7, is mounted in an encircling position on the upper portion of the tube 50. The packer includes a first upper end surface 52 that is in abutting contact with the body shoulder 48a. The packer J also includes a second lower end surface 54.

A portion 56 of tube 50 below the packer J as may be seen in FIG. 6 tapers downwardly and inwardly for reasons that will later be explained.

A nut 58 is provided as shown in FIGS. 5, 6 and 7, which nut has external thread 60 formed thereon that engage a tapped recess 62 formed in a bottom 64 of a cylindrical shell 66. The cylindrical shell 66 has a number of circumferentially spaced, longitudinally extending slots 68 defined therein which subdivide the shell 66 into a number of longitudinally extending fingers 70 that terminate on the upper end in inwardly extending lugs 72 best seen in FIGS. 6 and 7.

In FIGS. 6 and 7 it will be seen that a second rod 74 extends downwardly through member 44, body 38, and shell 66, with the rod having thread 76 formed on the lower portion thereof that engage a tapped interior bore in the nut 58. Rod 74 as shown in FIG. 6 has a first upper end 74a that is secured to a head 78 of non-circular transverse cross section, which head may be removably engaged by a socket 80 having an interior of like configuration. Socket 80 is secured to the lower second end of the first rod 32.

By use of a cable L in cooperation with the first and second pulley 24 and 30, the sealing assembly H may be forced downwardly through the valve body 10 into the interior of the tubing string A to overcome the fluid pressure therein, and position the sealing assembly H in the tubing string as shown in FIG. 5. After the sealing assembly H has been disposed within the tubing string A as shown in FIG. 5 and 6, the first rod 32 is rotated in an appropriate direction by means of the eye 34, with this rotation of the first rod causing rotation of head 78 and second rod 74. Rotation of the second rod relative to the nut 58 causes the shell 66 to move longitudinally upward towards the body shoulder 48a, and in so doing the resilient packer J is longitudinally compressed. As the packer J is longitudinally compressed it expands radially from the position shown in FIG. 6 to that shown in FIG. 7 where it is in pressure sealing contact with the interior surface of the tubing string A.

The second tube 26 is now rotated in an appropriate direction to cause the first threads 36 to separate from the externally threaded portion 40 of body 38, and after the threads are so separated, the second tube together with the first rod and the first and second pulleys 24 and 30 and cable L may be separated from the valve by unscrewing the threaded portion 20 therefrom. Valve E may now be removed from the upper end of the tubing string A to be replaced or repaired.

After a valve E, either a replacement or a repaired valve, is remounted on the upper end of the tubing string A, the portion of the invention shown in FIG. 2 is mounted on the upper end of the valve by means of the threaded portion 20. The cable L and the first and second pulley 24 and 30 are now used to force the second tube and first rod 32 downwardly through the valve body 10 after the valve E has been placed in the open position. After the thread 36 are adjacently disposed to the externally threaded end portion 40 of body 38, the second tube is rotated in an appropriate direction to cause the threads 36 to engage the body as shown in FIG. 6. The socket 80 is now in engagement with head 78. The eye 34 of first rod 32 is now rotated in an appropriate direction to cause the nut 58 and shell 68 to move downwardly relative to body shoulder 48a and allow the packer J to contract radially out of sealing engagement with the interior surface of the tubing string A. The shut-off assembly H shown in FIG. 5 together with a portion of the second tube 26 are now moved upwardly through the valve body 10 into the confines of the first tube 18. Valve E is now placed in the closed position, and the shut off assembly as a whole is disconnected from the valve by means of the threaded portion 20. The valve E is now reconnected to the pipe 14, with the valve then being placed in the open position to establish communication between the tubing string A and pipe assembly F.

The shell 66 is prevented from rotating relative to the tube 50 when the sealing assembly H is being moved from the non-sealing position shown in FIG. 6 to that shown in FIG. 7 by a pin or screw 82 that extends through one of the lugs 72 to engage a longitudinally extending slot 84 formed in the tube 50. When the shut-off assembly H moves from a nonsealing position shown in FIG. 6 to the sealing position shown in FIG. 7 it will be seen that the interior faces of the lugs 72 are in slidable contact with the tapered surface 56, and as a result as the shell 66 moves upwardly the fingers and lugs are moved outwardly relative to the second surface 54 of the resilient packer J to provide maximum surface contact therewith. The neck 42 is provided with an internal groove as may be seen in FIGS. 6 and 7 in which an O-ring 84 or other sealing ring is disposed to at all times maintain pressure sealing contact with the external surface of the second rod 74, and prevent upward flow of pressurized fluid between the rod and the bore 86 in the neck 42 in which the rod is rotatably mounted.

The use and operation of the invention has been explained previously in detail, and need not be repeated.

Claims

We claim:

1. In combination with a pressurized oil well tubing string that extends upwardly through a bore hole to communicate with a valve having a first fluid discharge end, an auxiliary tubing string shut-off device that permits said valve to be removed from said tubing string for repair or replacement, or repaired while in communication with said tubing string free of fluid pressure, said device including:

a. a fluid shut off assembly that includes a tubular body having an engageable upper portion, an intermediate portion that defines a body shoulder, a tube depending from said intermediate portion; a resilient ring shaped packer that encircles the part of said dependent tube most adjacent said body shoulder; a finger defining cylindrical shell having first and second ends, said first end of said shell in contact with said packer; a nut secured to said second end of said shell; a rod that extends longitudinally through said body and shell, said rod having threads defined thereon that engage said nut; a head secured to the end of said rod most adjacent said engageable upper portion; first means for maintaining said head at a fixed longitudinal position relative to said body as said head and rod are rotated; and second means that prevent rotation of said shell relative to said body but permits longitudinal movement of said shell towards and away from said body as said rod is rotated by said head in opposite directions, said fluid shut-off assembly of such transverse cross section as to be movable into and out of said tubing string through said valve when the latter is in an open position;

b. a first tube having first and second end portions, said second end portion removably securable to said fluid discharge end of said valve;

c. a second tube longitudinally slidable and rotatable in said first tube said second tube having first, and second ends;

d. a socket supporting rod rotatably disposed in said second tube, said rod having a first end portion that projects from said first end of said second tube;

e. third means for rotating said first end of said socket supporting rod;

f. engaging means on said second end of said second tube that removably engage said engageable upper portion to removably support said fluid shut off assembly from said second tube; and

g. power means for forcing said fluid shut off assembly, second tube, socket supporting rod downwardly through said valve into said tubing string against the fluid pressure in the latter, with said socket supporting rod being rotated when said shut-off assembly is disposed in said tubing string and said socket is in engagement with said head in a direction to so rotate said rod connected to said head relative to said nut that said finger defining shell moves towards said body shoulder to radially expand said packer with the interior surface of said tubing string, said second tube thereafter being rotated in a direction to separate said engaging means from said engageable portion of said body to permit said second tube and socket supporting rod to be drawn upwardly into said second tube, said second tube thereafter being separated from said valve to permit the latter to be replaced or repaired, said valve after being replaced or repaired having said first tube connected thereto, said second tube and socket supporting rod thereafter being lowered relative to said tubing string to a position where said engaging means engage said engageable portion of said body and said socket engages said head, said socket supporting rod then being rotated in a direction that said nut engaging rod rotates and longitudinally separates said shell and body to the extent that said resilient packer contracts out of sealing engagement with the interior of said tubing string, said second tube, socket supporting rod and shut-off assembly being moved upwardly to dispose said shut-off assembly in said second tube, said valve now placed in a closed position, and said second tube and the balance of the elements comprising said shut-off device separated from said valve.

2. A tubing string shut-off device as defined in claim 1 which in addition includes:

h. sealing means on said first tube that movably engage said second tube to permit longitudinal and rotational movement of the latter relative to said first tube.

3. A tubing string shut-off device as defined in claim 1 in which the fingers of said shell include lugs on the ends thereof adjacent said packer, said tube including a downwardly and inwardly tapered surface that is contacted by said lugs, and said fingers and lugs moving outwardly to provide support for said second surface of said packer as said shell moves towards said body shoulder to radially expand said packer into sealing contact with said tubing string.

4. A tubing string shut-off device as defined in claim 1 in which said first means is a rigid tubular member secured to said engageable upper portion and extending upwardly therefrom, said tubular member defining a flat upper surface against which said head can rotate.

5. A tubing string shut-off device as defined in claim 1 in which said second means is a pin that extends transversely through said shell and an end portion of said pin slidably engaging a longitudinal slot formed in said depending tube.

6. A tubing string shut-off device as defined in claim 1 in which said third means is an eye on said first end of said socket supporting rod.

7. A tubing string shut-off device as defined in claim 1 in which said engaging means are threads formed on said second end of said second tube and said engageable means are threads formed on said upper portion of said body.

8. A tubing string shut-off device as defined in claim 1 in which said power means are:

h. first pulley means rotatably supported on said first tube;

i. second pulley means rotatably supported on said second tube; and

j. an elongate pliable member having first and second ends, said first end secured to said first tube, and said pliable member engaging said first and second pulleys means, and said first end of said second tube being moved towards said first tube when said pliable member is tensioned by a force applied thereto adjacent said second end thereof.