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Publication numberUS3658127 A
Publication typeGrant
Publication dateApr 25, 1972
Filing dateMay 13, 1970
Priority dateMay 13, 1970
Publication numberUS 3658127 A, US 3658127A, US-A-3658127, US3658127 A, US3658127A
InventorsCochran Chudleigh B, Manderscheid Phillip H
Original AssigneeBrown Oil Tools
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Well packer
US 3658127 A
Abstract
A well packer adapted to form a seal between the surrounding conduit of a well and a plurality of smaller conduits extending axially within the surrounding conduit. The packer is expanded into anchoring and sealing engagement with the surrounding conduit by hydraulic pressure applied through one of the smaller conduits and is locked in expanded position by one-way acting slips. Release of the packer from its expanded position is effected by non-rotational axial movement of one of the smaller conduits through the set components of the packer. Another of the smaller conduits is removably connected to the top of the packer and acts as a safety device preventing inadvertent release of the packer any time the conduit is connected to the packer body. A plurality of retaining rods provide axial support for the packer components to reduce the force required for release of the set packer and to protect the smaller conduits extending through the packer body from undesirable forces tending to release the packer from its expanded position or tending to cause leakage across the set packer. The release mechanism of the packer includes positive acting structure for extracting upper and lower spreading cones from under set anchor slips to assist complete release from the surrounding conduit.
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United States Patent Cochran et a1.

[54] WELL PACKER Chudleigh B. Cochran; Phllllp 1-1. Manderscheid, both of Houston, Tex.

[72] Inventors:

[73] Assignee: Brown 011 Tools, Inc.

[22] Filed: May 13, 1970 [21] Appl. No.: 36,770

Primary Examiner-David H. Brown 51 Apr. 25, 1972 Attorney-Carlos A. Torres 5 7] ABSTRACT A well packer adapted to form a seal between the surrounding conduit of a well and a plurality of smaller conduits extending axially within the surrounding conduit. The packer is expanded into anchoring and sealing engagement with the surrounding conduit by hydraulic pressure applied through one of the smaller conduits and is locked in expanded position by one-way acting slips. Release of the packer from its expanded position is effected by non-rotational axial movement of one of the smaller conduits through the set components of the packer. Another of the smaller conduits is removably connected to the top of the packer and acts as a safety device preventing inadvertent release of the packer any time the conduit is connected to the packer body. A plurality of retaining rods provide axial support for the packer components to reduce the force required for release of the set packer and to protect the smaller conduits extending through the packer body from undesirable forces tending to release the packer from its expanded position or tending to cause leakage across the set packer. The release mechanism of the packer includes positive acting structure for extracting upper and lower spreading cones from under set anchor slips to assist complete release from the surrounding conduit.

29 Claims, 12 Drawing Figures PAH-INTED APR 2 5 1972 SHEET 10F 5 A I i (palm-i M ,4 TTO/PNE) PATENTEU APR 2 5 I972 SHEET 2 OF 5 \\N FL? CHI/OLE [G H B. C'OCHRA/V PHIL LIP WDEESCHE ID I N'TOR.

wow ATM A T TORNE) PATENTS} APR 2 51972 SHEET 50F 5 (Imam-u A T TORNE) WELL PACKER BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to means for forming a seal between a surrounding conduit and a plurality of smaller conduits extending axially within the surrounding conduit. More specifically, the present invention relates to a packer which may be lowered into position within a conduit in a well bore and set to anchor against the conduit and to form a sealing engagement between the conduit and a plurality of smaller diameter tubing strings extending through the packet body with such anchoring and sealing engagement being releasable when desired so that the entire packer may be retrieved from the well.

It is often desirable or necessary to employ two or more separate conduits within a cased oil well for the purpose of simultaneously producing petroleum fluids from varying zones penetrated by the well. Where production is through two conduits, the well is referred to as a dual completion and the packer employed to form the desired seal between the two independent conduits and the surrounding well casing is referred to as a dual packer. As with single packers, the purpose of the dual packer is to form a pressure-tight, leakproof seal between the smaller conduits and the surrounding well casing for the purpose of isolating the internal casing zone above the packer from the zone below the packer. Once the requisite seal is effected by the packer assembly, production may be independently accomplished through each of the conduits extending through the sealed packer. Thereafter, when its function has been completed, the packer assembly is normally released from the casing and brought to the well surface.

2. Brief Description of the Prior Art Dual packers have a long and well known history in the art and have customarily been employed for the purpose of forming a pressure-tight seal in a well conduit with a plurality of smaller, independent tubing strings extending through and below the seal to communicate with vertically spaced production zones in a subterranean formation. Conventional packers of this type are generally secured to a tubing string and lowered into the casing of a well bore to the desired subsurface location. Then, by either mechanically manipulating the packer elements by means of a tubing string extending from the packer to the well surface or by pressurizing one of the smaller conduits extending through the packer, the packer is anchored or set in locking and sealing engagement with the surrounding casing. Once the packer and associated tubing strings have performed their desired function, the packer is released from its locking and sealing engagement with the surrounding casing which permits the packer and associated tubing strings to be retrieved from the well. Often, the release mechanism in a plural conduit packer is actuated by rotating one of the tubing strings to separate a threaded linkage formed in the body of the packer which thereby permits retraction of the packers anchoring and sealing means.

In various dual packers found in the prior art, the operative components of the packer are coaxially mounted along and supported by one of the tubing strings which is used both to position the packer in the casing and to release it from its set condition. In one form of such prior art packers, a plurality of smaller tubing strings extend below the packer body with only a single, permanently connected string extending upwardly from the packer to the surface. The permanently secured string is the conduit normally employed to vertically position the packer in the casing and to release the packer after it has been set. Once properly positioned vertically, an additional tubing string (or strings as the case may be) is lowered into the well bore and secured to the top of the packer where it mates with the string extending below the packer. With the packer thus positioned, a plurality of tubing strings extend through the packer to provide the desired, separate communication between the vertically spaced production zones and the well surface.

Where the packer components employ the tubing string itself as an integral supporting structural member, undesired sideways or axial movement of the tubing string may be transmitted to the packer components which in turn may cause leakage through the set packer and, in severe cases, may also cause inadvertent release of the packer from its set position. In the past, it has been necessary to include force equalizing or force distributing means in such packers to prevent undesirable leakage or inadvertent release of the set packer.

In addition, packers employing the tubing string as an integral structural support are often difficult to release from the set position since the supporting tubing string is also the string which must be manipulated to effect the release. Thus, the

forces exerted against the supporting tubing string by the set components of the packer resist the relative component movement required to effect release of the packer from its set position. Often, with packers of this design, an undesirably great force may be necessary to release the packer especially after it has been set for a long period of time.

The anchoring mechanisms customarily employed with well packers and similar devices normally include a set of metal slips" which are radially movable members with locking teeth formed along their outer surfaces for the purpose of engaging and frictionally locking to a surrounding well casing. The slips are moved radially outwardly by means of a spreader having a conical spreading surface adapted to move axially and advance under the slip members forcing such members outwardly into engagement with the casing.

In some cases, dual, opposed, spreaders are employed to advance the slips radially outwardly into locking engagement with the casing. Where release of packers employing a single spreader is desired, the release mechanism withdraws one cone from under the slips which permits them to retract under a restoring bias force. Where dual cones are employed, the release sequence often requires retracting one of the cones and physically jerking the slip member off of the second cone by an axially directed force exerted through the manipulating tubing string. This brute force type of retrieval is often undesirable in that it may impose large forces on the manipulating pipe string and may also cause damage to the packer components and the surrounding casing.

The prior art also includes a variety of packers designed for use with single tubing strings which are adapted to be set or released by means of a direct vertical movement of the tubing string itself without any need for rotation of the string. Since straight pull" release devices of this type, require no rotation of the tubing string to efiect the desired axial movement, many of the difiiculties and undesirable aspects of rotatably set and released packers are eliminated. Such straight pull packers, however, are often subject to inadvertent release from their set position by pressure or temperature induced movement of the tubing string through the packer body.

SUMMARY OF THE INVENTION The well packer of the present invention is adapted to form a seal between a surrounding well conduit and a plurality of smaller tubing strings communicating with diflerent vertically spaced production zones in the well. While the present invention is described in detail for a "dual packer", i.e., one which provides the desired seal between the well bore casing and two tubing strings, it will be appreciated that the packer of the present invention may be adapted for use with any number of tubing strings.

The dual packer of the present invention includes a composite body supported axially by a plurality of retaining rods which extend through substantially the entire length of the well packer body. Because the packer body is self-supported, the tubing strings extending through the packer are protected from forces exerted by the packer when it is set. Thus, with the improved construction of the dual packer of the present invention, the pressure and temperature induced forces acting against the set components of the well packer act primarily against the packer components and the surrounding well conduit which prevents distortion of the tubing strings and thereby assists in preventing leakage through the packer. In addition, the reduction in structural forces acting against the tubing string also contributes to a reduction in the magnitude of the forces which must be transmitted through one of the tubing strings for releasing the set packer.

The packer of the present invention is set by hydraulic pressure introduced through one of the tubing strings which extends through the packer body. The increased pressure sequentially severs a series of shear pins causing the packer to seal against and then anchor firmly to the surrounding well conduit. Release of the well packer after the hydraulic pressure has been reduced is prevented by means of locking slips which engage the supporting retaining rods to prevent reverse movement of the packer components. The back-up or locking devices of the packer act against the retaining rods rather than the tubing strings to protect the tubing strings from the axial forces exerted by the set packer.

The set packer is released by a straight pull" exerted on one of the tubing strings from the well head. Undesired or inadvertent release of the tool from its set position by pressure or temperature induced movement of said one tubing string is prevented by the interlocking engagement formed between the well packer and a removable tubing string which may be selectively secured to or removed from the packer. The release mechanism of the packer can be actuated only when the removable tubing string is disengaged from the well packer to thereby provide a safety mechanism which prevents release of the well packer until such release is specifically desired.

With the second tubing string removed from the well packer, a straight pull exerted on the main tubing string releases shear pins securing portions of the retaining rods to permit axial movement of the packer body components which in turn permits retraction of the resilient seals in the packer body. Continued upward force exerted on the manipulated tubing string pulls a first cone away from a set of anchor slips formed in the packer body with continued upward movement of the tubing string acting to pull the slips away from the lower cone to permit retraction of the slips into the packer body and thus provide full release of the packer and tubing assemblies. The packer includes means for providing a positive withdrawal of the lower cone from under the anchor slips in the event release cannot easily be effected by the upward pull. This positive cone withdrawal is effected by exerting a downward or tapping force on the tubing string which is transmitted through the retaining rods to the lower cone to extract the cone from under the anchoring slips.

From the foregoing it will be appreciated that one of the primary objects of the present invention is to provide a well packer for use with plural tubing strings having structural supports formed as an integral part of the packer body in such a way as to free the supporting tubing strings from structural forces imposed by the set packer components.

An additional object of the present invention is to provide a plural string well packer which may be released from its set position by means of a non-rotational straight pull release motion imposed through one of the strings.

Still another object of the present invention is to provide a plural string well packer wherein positive extraction of a spreader from under expanded slip members may be effected by exerting a downward, non-rotational movement to one of the strings extending through the packer body.

A further object of the present invention is to provide a well packer adapted to form a seal between a plurality of tubing strings and a surrounding well conduit wherein such packer may be released by a straight pull" exerted on one of said tubing strings with such packer including means for preventing inadvertent or undesired release of said packer by pressure or temperature induced movement of said one tubing string.

Still another object of the present invention is to provide a well packer substantially free from leakage caused by pressure or temperature induced movement or distortion of the tubing strings extending through the set packer body.

The foregoing and other objects and advantages of the present invention will becomemore apparent from the following specification and the related drawings.

BRIEF DESCRIPTION OF THE'DRAWINGS FIG. 1 is a longitudinal sectional view in two non-coincident planes illustrating the dual production well packer of the present invention in its unset condition. The sectional view of FIG. 1 is taken substantially along the lines 1-1 of FIG. 7 for the purpose of showing the cooperating action of the packer components in a single figure;

FIG. 2 illustrates the well packer of FIG. 1 with its sealing assembly moved to the set position;

FIG. 3 illustrates the well packer with its anchoring assembly partially set;

FIG. 4 illustrates the anchoring assembly fully set;

FIG. 5 illustrates the seal and anchoring assemblies fully released;

FIG. 6 illustrates the seal assembly released with the anchoring assembly being partially released;

FIG. 7 is a cross-sectional view taken along the line 7-7 of FIG. 1;

FIG. 8 is a longitudinal sectional view taken along the line 8-8 of FIG. 7;

FIG. 9 is a cross-sectional view taken along the line 9-9 of FIG. 1;

FIG. 10 is a cross-sectional view taken the line 1010 of FIG. 1;

FIG. 11 is a cross-sectional view taken along the line 11- 11 of FIG. 4; and

FIG. 12 is a cross-sectional view taken along the line 12l2 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the dual production well packer of the present invention indicated generally at 10 is illustrated in position within a surrounding well conduit C. The conduit C may be the well casing or any other tubular conduit'disposed within a well. Two production tubing strings indicated generally at T-l and T4 extend axially through the body of the packer 10 to provide fluid or gas conducting communication across the packer body as required for production from different zones within the subterranean formation.

The packer body includes a radially expandable sealing means indicated generally at P employed for forming a pressure-tight seal between the surrounding casing C and the dual tubing strings T-l and T-2. A radially movable anchoring assembly indicated generally at A is included with the packer assembly for mechanically locking the packer body and the associated tubing strings T-l and T-2 against the surrounding walls of the casing C. As will be hereinafter explained in greater detail, setting" of the packer l0 first forces the resilient sealing assembly P radially outwardly against the surrounding casing C and thereafter moves metallic slip members radially outwardly into locking engagement with the surrounding casing C to provide the desired sealing and anchoring functions of the packer.

As best illustrated in FIG. 8, the packer body is formed from a plurality of cooperating members which are confined axially by two retaining rods 11 and 12 which extend between a lift plate 13 at the top of the packer body and a retaining plate 14 at its bottom. As best indicated in FIGS. 10 and 12, various components of the packer are essentially cylindrical in external shape to conform to the internal cylindrical wall of the surrounding conduit C. The packer body components include axially developed bores or openings through which the retaining rods 11 and 12 and the tubing string T-l and T-Z extend. With reference to FIG. 8, the retaining rods 11 and 12 include upper section components 11a and 12a, respectively which are threadedly engaged with the lift plate 13. Nuts 11b and 12b are threadedly engaged to the lower end of the rods 11 and 12 to draw the retaining plate 14 toward the lift plate 13 to position and axially retain the various body components of the packer l0.

With joint reference to FIGS. 1 and 8, the component sections of the packer body positioned between the two end plates 13 and 14 include a top body 15 constructed of metal. The packing assembly P positioned immediately below the top body 15 includes a top backup plate 16 of metal, a first resilient packer seal 17 constructed of rubber or other suitable material, a spacer plate 18, a second resilient seal 19, and a compression plate 20.

The anchoring assembly A positioned immediately below the packing assembly T includes a spreader cone 21, a slip cage 22, a plurality of metal slip members 23 and a lower cone spreader 24.

The lower portion of the packer 10 includes a tubular sleeve 25 which encircles a portion of the lower cone 24 and a bottom body 26 which is threadedly engaged with the sleeve 25.

With reference to FIG. 1 of the drawings, it is seen that the tubing string T-l includes a mandrel section 27 which extends completely through the packer 10. The lower end of the mandrel is provided with external threads which engage and connect with internal threads formed in a lower tubing section 28. The upper axial end of the tubing section 28 is provided with an externally tapered surface 28a and an under cut shoulder 28b which are adapted to permit the section 28 to be raised into and locked within the lower body 26 as required during the release movement of the packer.

The tubing string T-2 includes a mandrel section 29 which extends downwardly from the base of the top body 15 through the lower retaining plate 14. The upper portion of the tubing string T-2 includes a sleeve section 30 which is removably seated within the top body 15. The sleeve 30 includes a J-slot 31 which is designed to mate and lock with a pin 32 secured to the top body. Packing 33 extends about the sleeve 30 to form a leakproof seal between the sleeve 30 and the surrounding bore of the top body 15. A hold-down coupling 34, threadedly secured to the top of the sleeve 30, is provided with a retaining shoulder 34a which prevents release of the packer from its set position until such time as the top portion of the string T-2 is removed from the packer 10. The tubing string T-2 is completed by an upper tubing section 35 which is threadedly engaged with the coupling 34 and extends upwardly to the well surface.

It will be evident from an inspection of the connecting structure between the top body 15 and the sleeve 30 that a clockwise rotation of the tubing string T-2 (as viewed looking down in FIG. 1) coupled with a simultaneous lifting of the tubing string would permit the upper portion of the string to be released from the top body 15 of the packer 10. When it is desired to mount the top of string T-2 in the top body 15, the string is lowered down to the lift plate 13 which is provided with a tapering upper surface to direct the lower end of the sleeve 30 into the receiving bore. As the sleeve 30 is lowered through the receiving bore, the pin 32 engages the opening portion of the J-slot 31 and the string is permitted to rotate until the pin 32 is at the top of the J -slot where it prevents undesired separation of the two mating components.

SETTING OF THE PACKER In the use and operation of the packer 10 of the present invention, the packer is initially lowered into the well casing C by means of the tubing string T-l. During this lowering procedure, the tubing string T2 is normally removed from the packer. When the appropriate vertical position in the casing C has been reached, the tubing string T-2 is lowered into the casing and locked into the top body 15. Once the tubing string T-2 has been secured to the packer 10, the packer assembly appears as illustrated in FIG. 1.

The packer 10 is hydraulically set by pressurizing a fluid contained within the tubing string T-2. For this purpose, a ball B is pumped down through the tubing string T-2 until it engages and seals against a seat formed below the packer. Once a suitable seal has thus been formed, the fluid pressure within the tubing string T-2 is increased causing the fluid to enter an expansion chamber 36 through ports 37 extending through the wall of the mandrel 29. A plurality of O-rings are disposed between mating components in the packer body for the purpose of maintaining a pressure-tight, slidable seal which permits the chamber 36 to expand without loss of pressure.

The expansion chamber 36 is formed between the base of the lower cone spreader 24 and the top of the lower body 26 and expands under the influence of the hydraulic pressure by forcing the lower cone spreader axially away from the lower body. Upward movement of the lower body along the mandrel 29 is prevented by a snap ring 29'. Thus, the hydraulic pressure in the chamber 36 exerts a resultant upward force on the base of the lower cone spreader 24 which eventually causes a shear pin 38 to sever which in turn permits the cone 24 to be advanced upwardly through the surrounding sleeve 25.

The initial expansion of the chamber 36 following severance of the shear pin 38 is illustrated in FIG. 2. The packer components are axially constrained between the lift plate 13 and the retaining plate 14 so that the movement of the lower cone 24 through the surrounding sleeve 25 produces an upward motion which is transmitted from the lower cone 24 to the cage 22, upper cone 21 and the compression plate 20. The upward movement of the compression plate 20 axially foreshortens the packer seals 19 and 17 causing them to expand radially outwardly into sealing engagement with the surrounding walls of the casing C. Shear pins 39 and 40 extending between the cage 22 and the lower cone 24 and upper cone 21 respectively, prevent any relative axial movement of the pinned components during the initial upward movement which follows severance of the first shear pin 38.

The next step of the setting sequence is illustrated in FIG. 3. Increased hydraulic pressure shears the pin 40 securing the cage 22 to the upper cone permitting the cage to move upwardly over the upper cone 21. As the cone spreader 21 moves downwardly through the cage 22, the tapered, conical surface of the spreader slides along an internally tapered cooperating surface formed on the slip members 23. The cooperating surfaces between the slip member 23 and the cone spreader 21 are best illustrated in FIG. 8. The slip members 23 are biased toward a normally retracted position as illustrated in FIG. 8 by means of helical springs 23a positioned between the inner wall of the cage 22 and the base portion of the slip members. FIG. 9 of the drawings also illustrates the spring biased mounting of the slips 23 within the mounting cage 22.

As the upper cone 21 moves downwardly into the cage 22, the top portion of each of the slip members 23 is forced radially outwardly against the restraining baising force of the springs 23a. FIG. 3 of the drawings illustrates the semianchored position of the slips 23 following severance of the shear pin 40. It should be noted that the slip member 23 shown in dotted line in FIGS. 3 and 4 is included for the purpose of better illustrating the initial anchoring movement of the slip members and is not actually positioned in the location indicated in the figures. The actual, preferred positioning of the slip members may be seen by reference to FIGS. 8, 9 and 11.

Once the slip members 23 have partially anchored as illustrated in FIG. 3, continued upward movement of the cage 22 over the upper cone spreader 21 is resisted and the force exerted by the pressurized fluid in expansion chamber 36 severs the shear pins 39 which permits the lower cone spreader 24 to move upwardly through the cage 22. An externally tapered, conical surface formed on the lower cone spreader 24 engages the internally tapered surface at the lower end of the slip members 23 so that upward movement of the cone spreader 24 moves the slip members 23 outwardly into full anchoring engagement with the walls of the surrounding casing C. The complete seal and anchoring engagement of the packer 10 is illustrated in FIGS. 4 and l l of the drawings.

After the hydraulic pressure in the tubing string T-2 has been reduced, the components of the well packer 10 are retained in set position by means of segmented locking slips 45 and 46 best illustrated in FIGS. 8 and 10. The locking slips 45 and 46 are set within conical depressions formed in the base of the lower cone 24 and include downwardly directed teeth which engage and lock with the retaining rods 11 and 12 to prevent the lower cone 24 from moving axially downwardly along the retaining rods. It will be understood that the slip members 45 and 46 are forced inwardly against the retaining rods which they encircle by means of the cooperating conical surfaces formed on the slip segments and the bore in which they are set. As the retaining rods 11 and 12 tend to move axially upwardly through the lower cone spreader 24, the frictional engagement of the internal teeth formed in the locking slips tends to draw the slips upwardly through the lower cone spreader which in turn forces the slips more tightly against the retaining rods which increases the locking engagement. Movement of the cone spreader 24 upwardly along the retaining rods is permitted since the downwardly directed teeth formed within the slips 45 and 46 slide when moving upwardly over the external surfaces of the two retaining rods.

The locking slips 45 and 46 are held in position by sealing rings 47 and 48 which in turn are held in position by resilient snap rings 49 and 50. Thesealing rings 47 and 48 are provided with resilient O-rings along their internal and external cylindrical surfaces. The O-rings provide a sliding seal between the retaining rods 11 and 12 and the lower cone spreader 24 to accommodate the expansion of chamber 36 and to permit the slips 45 and 46 to move axially through the cone spreader 24.

When the packer has been set as illustrated in FIG. 4, the ball B or other sealing means is floated up to the well surface through the tubing string T-2. Thereafter, the desired production of the well is effected through the two tubing strings T-l and T-2. In its sealed position, the packer 10 forms a pressuretight, leakproof seal between the zone Z-l contained within the casing C above the packer and the zone Z-Z contained within the casing below the set packer. The continuity of the seal across the packer body is ensured primarily by means of the expanded packer seals 17 and 19 which form a seal between the internal casing walls and the external surfaces of the two tubing strings T-l and T-2. The seal is further maintained by O-rings which are carried by the spacer plate 18 and form a sliding seal between the tubing strings T-l and T-2 and the retaining rods 11 and 12. Similarly, the compression plate 20 carries resilient O-rings which encircle and seal against the external surfaces of the tubing strings Tl and T-2 and the retaining rods 11 and 12. Thus, a pressure-tight seal is formed by the set packer assembly P completely isolating casing zone Z-l from casing zone Z-2.

As previously indicated, the expansion chamber 36 includes seal forming means which maintain a continuous sea] as the chamber is expanded. For this purpose, the base portion of the expansion chamber 36 is sealed by means of O-rings carried in the lower body 26 which form a stationary seal between the lower base and the retaining rods 11 and 12 and the sleeve 25. A sliding seal between the lower cone spreader 24 and the surrounding sleeve 25 is provided by means of dual O-rings carried in the outer circumferential surface of the cone spreader 24 which mate with and seal against the internal surface of the sleeve 25. As best illustrated in FIG. 1, the lower cone spreader 24 also carries dual sets of O-rings which encircle and seal against the tubing string T-l and T-2.

In the set position illustrated in FIG. 4, the pressure differential exerted across the packer l0 acts only against the retaining rods 11 and 12 which provide the primary structural support for the packer 10. It will also be appreciated that the illustrated construction of the packer l0 directs the pressure induced forces exerted against the components of the packer body to the slip members 23 tending to increase the anchoring force against the surrounding well casing C as the pressure differential against the set packer increases. The packer therefore tends to become more firmly set and to increase the sealing engagement with the surrounding well casing as pressures increase. Additionally, the illustrated structure protects the tubing string mandrels 27 and 29 from the distorting forces exerted by the set packer components. Similarly, the structural independence between the packer components and the tubing string mandrels extending through the packer body prevents distortion or movement of the tubing strings T-l and T-2 from causing leakage across the packer or from inadvertently releasing the packer from its set position.

RELEASING THE SET PACKER In releasing the set packer from the position illustrated in FIG. 4, the upper portion of tubing string T-2 is removed by applying the appropriate rotational and lifting movement from the well surface to release the J-slot connection between the sleeve 30 and the pin 32. Once the top of tubing string T-2 has been removed, an upwardly directed force (straight pull) is exerted on the tubing string T-l from the well surface. The straight pull exerted on the tubing string T-l is transmitted to a snap ring 54 carried by the mandrel 27 to the lift plate 13 which in turn transmits the forces to the retaining rods 1 1 and 12. Upward movement of the rods through the cone spreader 24 is prevented by the locking slips 45 and 46. When the lifting force exerted on the tubing string T-l is sufficiently great, shear pins 55 and 56 connecting the top rod component 1 la to the rod body 11 and pins 57 and 58 connecting the top rod component 12a to the retaining rod 12 are severed. Severance of the shear pins 55 through 58 permits the upper rod components 11a and 12a to be drawn upwardly through the receiving bores in the top body 15. Raising the two rod members 11a and 11b to the position illustrated in FIG. 5 releases resilient snap rings 11c and previously confined within the upper rod sections 11a and 12a respectively to mechanically lock the upper sections to the main bodies of the retaining rods. With the snap rings 11c and 12c disengaged from the lower portion of the rods 11 and 12 as illustrated in FIGS. 5 and 12, the top body 15 is free to move upwardly with respect to the axially fixed rods 11 permitting the top spacer plate 16 to move upwardly which in turn permits the two packer seals 17 and 18 to contract radially into their unexpanded position as illustrated in FIG. 5. It may be appreciated that the relative movements required in the described release sequence cannot be completed when tubing string T-2 is locked into the packer 10 since the upward forces exerted by the string T-l are transmitted directly to the top body 15 through the J-slot and pin linkage. Thus, the presence of the string T-2 acts as a safety mechanism preventing undesired release of the set packer.

In continuation of the release sequence, the tubing string T-1 is raised, drawing the upper rod sections 11a and 12a against an internal shoulder formed in the top body 15 which in turn raises the top body and the mandrel 29 of tubing string T-2. A resilient snap ring 60 carried on the external surface of the mandrel 29 is drawn upwardly into engagement with an internally formed shoulder on the upper cone spreader 21 as the tubing string T-l continues to be raised. The lifting movement of the mandrel 29 and snap ring 60 is transmitted to the upper cone 21 drawing it out from under the top of slips 23 to partially release the slips from their radially expanded position. Continued upward force exerted through the upper cone spreader 21 is directed against the cage 22 and slips 23. In many cases, the upwardly directed pull on the slips 23 is sufficient to pull the slips 23 off the lower spreader 24 permitting the slips to completely retract under the restoring force of the springs 23a.

If the lower end of the slips 23 do not completely release from the lower cone spreader 24, jars or other suitable means may be employed to impart a downwardly directed tapping force against the tubing string T-1. The force is transmitted downwardly through the mandrel 27 and the lower tubing section 28. During the initial lifting sequence, the lower tubing section 28 was drawn upwardly into the lower body with the conical surface 28a acting to spread a resilient snap ring 70 carried in the retainer 14 and the downwardly directed shoulder 28b acting in cooperation with the snap ring 70 to prevent the lower tubing section from withdrawing from its raised position within the lower body 26. The downward force exerted on the mandrel 27 is thus transmitted through the lower tubing section 28 to the retaining plate 14 which in turn imparts a downward force on the nuts 11b and 12b on the two retaining rods. The retaining rods are thereby forced downwardly, sliding through the locking slips 45 and 46 until shoulders 11d and 12d on the rods 11 and 12 respectively are drawn into engagement with the lower cone spreader 24 to pull the cone spreader from under the lower portion of the slip members 23. Thus, it will be understood that the well packer of the present invention includes a positive, straight movement type release for extracting the lower cone spreader from underneath the slips 23 to permit full retraction and release of the packer from engagement with the surrounding well casing The foregoing disclosure and description of the invention is illustrative and explanatory thereof, and various changes in the size, shape and materials as well as in the details of the illustrated construction may be made within the scope of the appended claims without departing from the spirit of the invention.

What is claimed is:

l. A well packer means for forming a seal between a first well conduit and at least one smaller, second conduit extending within the first conduit comprising:

a. a packer body including first and second axially spaced ends;

b. anchoring means and sealing means disposed between said spaced ends;

c. setting means for respectively anchoring and sealing said anchoring means and said sealing means against said first well conduit;

d. retaining means extending between said spaced ends of said body for holding said first end fixed axially relative to said second end, said retainer means axially supporting the components of said well packer means independently of any conduits passing therethrough;

. release means for releasing said anchoring means and said sealing means from said first well conduit; and

. extension means included with said release means for selectively permitting said spaced ends of said body to separate axially away from each other during the release of said packer from said first well conduit.

2. The well packer as defined in claim 1 and further including operative connecting means between said second conduit and said release means whereby said extension means is operable by manipulation of said second conduit for initiating said axial separation of said spaced packer body ends.

3. The well packer as defined in claim 1 wherein said extension means includes means operable by axial movement of said second conduit.

4. The well packer as defined in claim 1 further including operative connecting means between said second conduit and said release means whereby said extension means is operable by non-rotational, axial movement of said second conduit for permitting said axial separation of said spaced ends.

5. The packer as defined in claim 1 further including anchor release connecting means between said second conduit and said release means for effecting positive release of said anchoring means when said second conduit is moved axially downwardly with respect to said packer body.

6. The packer as defined in claim 2 further including operative connecting means between said second conduit and said release means whereby said extension means is operable by nonrotational, axial movement of said second conduit for permitting said axial separation of said spaced ends.

7. The packer as defined in claim 3 further including anchor release means between said second conduit and said release means for effecting positive release of said anchoring means when said second conduit is moved axially downwardly with respect to said packer body.

8. The well packer as defined in claim 1 wherein said extension means includes pin means severable by axial movement of said second conduit with respect to said packer body whereby axial separation of said spaced ends is permitted by severance of said pin means.

9. The well packer as defined in claim 1 wherein:

a. said anchoring means includes metallic anchoring slip means and at least two spreader means axially movable toward each other for moving said slip means into anchoring engagement with said first conduit; and

b. said release means includes means for moving each of said spreader means axially away from the other spreader means while said slip means are in anchoring engagement with said first conduit.

10. The well packer as defined in claim 9 further including:

a. a third conduit extending within said first conduit through said packer;

b. selectively operable locking means for preventing undesired release of said packer; and

c. connection means included with said third conduit for attaching or releasing a top portion of said third conduit from engagement with said packer whereby said locking means is operable by said third conduit to prevent release of said packer when said top portion of said third conduit is engaged with said packer.

11. A well packer for forming a seal between a first well conduit and second and third, smaller conduits extending within said first conduit through said packer comprising:

a. a packer body having first and second axially spaced ends;

b. anchoring means included in said packer body for selectively anchoring said packer body to said first conduit;

c. sealing means included in said packer body for selectively sealing against said first conduit;

d. setting means included with said packer body for selectively moving said anchoring means and said sealing means into engagement with said first conduit;

e. release means included with said packer body for selectively releasing said anchoring means and said sealing means from engagement with said first conduit;

f. retaining means extending between said first and second axially spaced ends for selectively maintaining the axial spacing between said spaced ends; and

g. extension means included with said retaining means and operable by said release means for selectively permitting said spaced ends to axially separate.

12. The well packer as defined in claim 11 in which said third conduit is provided with locking means preventing operation of said release means until at least a portion of said third conduit is disengaged from said well packer.

13. The well packer as defined in claim 11 further including connecting means between said second conduit and said release means for operating said release means to release said anchoring means and said sealing means from engagement with said first conduit by manipulation of said second conduit.

14. The well packer as defined in claim 1 1 further including connecting means between said second conduit and said release means for operating said release means to release said anchoring means and said sealing means from sealing engagement with said first conduit by axial, non-rotational movement of said second conduit with respect to said packer.

15. The well packer as defined in claim 11 wherein:

a. said anchoring means includes metallic anchoring slip means and at least two spreader means axially movable toward each other for moving said slip means into anchoring engagement with said first conduit; and

b. said release means includes means for moving each of said spreader means axially away from the other spreader means while said slip means are in anchoring engagement with said first conduit.

16. The well packer as defined in claim 15 further including connecting means between said second conduit and said release means operable by non-rotational, axial movement of said second conduit relative to said packer for initiating the release function of said release means.

17. The well packer as defined in claim 16 in which said third conduit is provided with locking means preventing operation of said release means until at least a portion of said third conduit is disengaged from said well packer.

18. The well packer as defined in claim 11 further including selectively operable locking means for preventing undesired release of said packer.

19. The well packer as defined in claim 18 wherein:

a. said third conduit includes connection means for attaching or releasing a top portion of said third conduit from engagement with said packer; and

b. said locking means is operable by said third conduit to prevent release of said packer when said top portion of said third conduit is engaged with said packer.

20. The well packer as defined in claim 19 further including connecting means between said second conduit and said release means operable by non-rotational, axial movement of said second conduit relative to said packer for initiating the release function of said release means.

21. The well packer as defined in claim 20 wherein:

a. said retaining means includes a plurality of rod means;

b. said extension means include top and bottom rod portions included with each of said rod means; and

c. said top rodportions are releasably secured to said bottom rod portions by shear pin means whereby said rod means are extendable axially upon severance of said shear pin means.

22. A well packer means for forming a seal between a first well conduit and at least one smaller, second conduit extending within the first conduit comprising:

a. a packer body including first and second axially spaced ends; I

vb. anchoring means and sealing means disposed between said spaced ends;

0. setting means for respectively anchoring and sealing said anchoring means and said sealing means against said first wellconduit;

d. retaining means extending between said spaced ends of said body forv holding said first end fixed axially relative to said second end;

e. release means for releasing said anchoring means and said sealing means from said first well conduit;

f. extension means included with said release means for selectively permitting said spaced ends of said body to separate axially away from each other'during the release of said packer from said first well conduit; and

g. operative connecting means between said second conduit and said release means whereby said extension means is operable by manipulation of said second conduit for initiating said axial separation of said spaced packer body ends.

23. The well packer as defined in claim 22 wherein said extension means includes means operable by axial movement of said second conduit.

24. A well packer means for forming a seal between a first well conduit and least one smaller, second conduit extending within the first conduit comprising:

a. a packer body including first and second axially spaced ends;

b. anchoring means and sealing means disposed between said spaced ends;

c. setting means for respectively anchoring and sealing said anchoring means and said sealing means against said first well conduit;

d. retaining means extending between said spaced ends of said body for holding said first and fixed axially relative to said second end;

e. release means for releasing said anchoring means and said sealing means from said first well conduit; and

extension means included with said release means for selectively'permitting said spaced ends of said body to separate axially away from each other during the release of said packer from said first well conduit, said extension means including means operable by axial movement of said second conduit.

25. The packer as defined in claim 24 further including anchor release means between said second conduit and said release means for effecting positive release of said anchoring means when said second conduit is moved axially downwardly with respect to said packer body.

26. The packer as defined inclaim 24 further including operative connecting means between said second conduit and said release means whereby said extension means is operable by non-rotational, axial movement of said second conduit for permitting said axial separation of said spaced ends.

27. A well packer means for forming a seal between a first well conduit and at least one smaller, second conduit extending within the first conduit comprising:

a. a packer body including first and second axially spaced ends;

b. anchoring means and sealing means disposed between said spaced ends;

c. setting means for respectively anchoring and sealing said anchoring means and said sealing means against said first well conduit;

. retaining means extending between said spaced ends of said body for holding said first end fixed axially relative to said second end;

e. release means for releasing said anchoring means and said sealing means from said first well conduit;

f. extension means included with said release means for selectively permitting said spaced ends of said body to separate axially away from each other during the release of said packer from said first well conduit; and

g. operative connecting means between said second conduit and said release means whereby said extension means is operable by non-rotational, axial movement of said second conduit for permitting said axial separation of said spaced ends.

28. A well packer means for fonning a seal between a first well conduit and at least one smaller, second conduit extending within the first conduit comprising:

a. a packer body including first and second axially spaced ends;

b. anchoring means and sealing means disposed between said spaced ends;

c. setting means for respectively anchoring and sealing said anchoring means and said sealing means against said first well conduit;

. retaining means extending between said spaced ends of said body for holding said first end fixed axially relative to said second end;

c. release means for releasing said anchoring means and said sealing means from said first well conduit;

f. extension means included with said release means for selectively permitting said spaced ends of said body to separate axially away from each other during the release of said packer from said first well conduit; and

g. anchor release connecting means between said second conduit and said release means for efi'ecting positive release of said anchoring means when said second conduit is moved axially downwardly with respect to said packer body.

29. A well packer means for forming a seal between a first well conduit and at least one smaller, second conduit extending within the first conduit comprising:

a. a packer body including first and second axially spaced ends;

b. anchoring means and sealing means disposed between said spaced ends;

c. setting means for respectively anchoring and sealing said anchoring means and said sealing means against said first well conduit;

d. retaining means extending between said spaced ends of said body for holding said first end fixed axially relative to said second end;

e. release means for releasing said anchoring means and said sealing means from said first well conduit; and

f. extension means included with said release means for selectively permitting said spaced ends of said body to

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4018272 *Apr 7, 1975Apr 19, 1977Brown Oil Tools, Inc.Well packer apparatus
US4505332 *Oct 21, 1982Mar 19, 1985Ava International CorporationWell packers
US4745971 *Jun 3, 1985May 24, 1988Ava International CorporationMultiple string well packer
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Classifications
U.S. Classification166/120, 166/134
International ClassificationE21B33/122, E21B23/00, E21B23/06, E21B33/12
Cooperative ClassificationE21B23/06, E21B33/122
European ClassificationE21B23/06, E21B33/122
Legal Events
DateCodeEventDescription
Apr 5, 1982ASAssignment
Owner name: HUGHES TOOL COMPANY A CORP. OF DE
Free format text: MERGER;ASSIGNOR:BROWN OIL TOOLS, INC. A TX CORP.;REEL/FRAME:003967/0348
Effective date: 19811214