US3670815A

US3670815A - Well packer

Info

Publication number: US3670815A
Application number: US108884A
Authority: US
Inventors: Cicero C Brown
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-01-22
Filing date: 1971-01-22
Publication date: 1972-06-20
Anticipated expiration: 1989-06-20

Abstract

A well packer employing a resilient cup-type seal member and releasable means for initially holding the seal member in a stretched condition to reduce its diameter sufficiently to clear the well wall during running of the packer whereby to obviate damage to the seal member.

Description

United States Patent Brown 1451 June 20, 1972 [541 WELL PACKER 2,980,185 4/1961 Daffin ..166/l25 x 2,988,148 6/1961 Conrad et a1. .....l66ll 18 X [72] Inventor: Cicero C. BMW, 5429 Sturbndge DI'IVC, 3 379 257 4/1968 Tamplen n 166/ 2 x Houston. 7727 3,593,784 7/1971 Brown ..l66/l25 'l 7 m] 19 1 Primary Examiner-David H. Brown [2]] Appl. No.: 108,884 Attorney-R. Werlin [57] ABSTRACT [52] US. Cl. ..l66/136, 166/125, 166/202 s1 1 1111. c1. ..E21b 23/02, E2 1 b 23/06, E21b 23/06, A Pack ''"F memwfmd E2") 33/126 releasable means for 1n1t1ally holding the seal member 1n a stretched condition to reduce its diameter sufficiently to clear Fidd 0' 136, l 18, the i g i g f the packer whereby to obviae damage to the seal member. [56] References Cited 6 China, 10 Drawing Figures UNITED STATES PATENTS 2,598,512 5/1952 Cypher ..l66/l21 X PKTENTEBaunzo m2 SHEET 10F 6/6550 BROWN INVENTOR.

BY Z

AT TORNEY PATENTEDJUH 20 1912 SHEET 3 OF 3 8/0580 0. BRO WN I NVEN'TOR.

ATTORNEY WELL PACKER BACKGROUND OF THE INVENTION Various types of packers are used in equipping oil and gas wells for sealing ofi' between strings of pipe in the well bore. A type widely used because of its simplicity and economy, while providing an efficient seal, is a so-called cup-type" packer in which the seal element is constructed of rubber or like flexible resilient material adapted to be expanded into sealing engagement by pressure of fluid entering its open end and extending the seal element into sealing engagement with the surrounding well wall.

One of the problems encountered with such packers is that in the relaxed or retracted condition the seal element will be radially expanded to a dimension such that it tends to rub against the wall of the metal pipe into which it is being run and is thereby frequently damaged by irregularities in the pipe surface and particularly by the spaced edges of pipe sections made up into their connecting couplings. The resulting damage frequently impairs the sealing efiiciency of the packer and in some cases may etfectively destroy the sealing element.

DESCRIPTION OF THE INVENTION The present invention contemplates an improved cup-type packer wherein means are provided to initially hold the seal element in an elongated or stretched condition to reduce its radial dimensions sufficiently to be clear of the wall of the pipe through which it is run. The packer includes means for releasing the stretching force on the seal element when the packer has attained the point in the well where it is to be set and has been anchored to the well wall.

The packer includes anchor dogs projectible into the collar recesses in the pipe wall to anchor the packer to the pipe, and setting means for the anchor dogs cooperating with the sealstretching and holding means to enable setting of the anchor dogs contemporaneously with the release of sealing-stretching means to allow relaxing of the seal element to its normal pipeengaging dimension. The seal-stretching means may then be removed from the well.

The packer may be released from withdrawal from the well by means of a retrieving tool operative to re-stretch the seal element while releasing the anchor dogs for retraction from the collar recess into which they had been projected.

The various other objects and advantages of this invention will become more readily apparent from the following detailed description when read in conjunction with the accompanying drawing which illustrates one useful embodiment in accordance with this invention.

In the drawing: 1

FIG. I is longitudinal quarter-sectional view of the packer with the parts shown in the running-in positions in a well pipe;

FIGS. 2 and 3 are views similar to FIG. 1 showing the parts in the positions occupied at successive stages in setting the packer,

FIGS. 4 and 5 are views similar to FIG. 1 showing the parts in the positions occupied at successive stages in releasing and retrieving the packer from the well pipe;

FIGS. 6 and 7 are crosssectional views taken respectively on lines 6-6 and 7-7 of FIG. 1;

FIGS. 8 and 9 are cross-sectional views taken respectively on lines 8-8 and 9-9 of FIG. 3; and

FIG. 10 is a detail of a latch element incorporated in the device.

Referring to the drawing, the packer is shown inserted in a well pipe R made up of threaded sections connected by conventional threaded couplings C to provide the annular recesses R into which the packer will be anchored, as will be described subsequently.

The packer itself comprises a tubular body 10 having an axial bore 11 formed adjacent its lower end to provide an upwardly facing annular shoulder 12. A downwardly opening cup-shaped seal element 14 has it s upper end molded to a metal end ring 15 and is held in sealed relation about the upper end of body 10 by means of a threaded bushing 16 screwed into the upper end of bore 1 I and over-hanging a portion of end ring 15. Seal element 14 is constructed of rubber or similar flexible, resilient composition and has its lower end defined by a lip 17 which is molded to a lower metal end ring 18. The latter has an internally threaded socket 19 adjacent its lower end to receive the upper end of a reducing collar 20 having an externally threaded pin 21 at its lower end for attachment to a tail pipe T or the like. Reducing collar 20 is formed to provide an upwardly facing internal shoulder 22 disposed in the path of movement of the lower end of body 10 to provide a limit stop for relative downward movement'of body 10. Lower end ring 18 is provided with a plurality of radial ports 23 to afford fluid communication between the interior of seal element and the interior of pipe P. A seal ring 24 is mounted between body 10 and lower end ring 19 to seal ofi therebetween below ports 23. This arrangement assures that pressure fluid entering through ports 23 will act effectively against the interior of seal element 14 to expand the same into sealing engagement with the wall of pipe P.

The upper end of upper end ring 15 is provided with an in ternally threaded socket 26 radially spaced from bushing 16 to threadedly receive the lower end of 'an anchor cage 27. The latter has a plurality of angularly spaced windows 28 through the wall thereof adapted to receive anchor dogs 29, each formed with an outwardly projecting boss 30 about its lower end and with an internal annular recess 31 defining spaced upper and

lower bosses

32 and 33 respectivelyrAnchor dogs 29 are arranged for radial movement in windows 28 to project boss 30 into collar recess R to anchor the packer to the well pipe, and to permit retraction of the anchor dogs to release the packer for withdrawal from pipe P as will be described subsequently.

A setting sleeve 34 is mounted coaxially in the bore of cage 27 for relative longitudinal movement, being formed with longitudinally spaced outwardly extending

bosses

35 and 36 separated by a transverse recess 37 and having a relief recess 38 above boss 35. The shape and arrangement of these elements on the setting sleeve are such as to urge anchor dogs 29 outwardly to project anchor bosses 30 into collar recess R when setting

sleeve boses

35 and 36 are moved into registration with boses 32 and 33 (FIGS. 2 and 3) of the anchor dogs and to permit retraction of the anchor dogs when recesses 37 and ,38 are disposed in registration with boss 33 (FIG. I). An abutment ring 39 is mounted in the inner wall of cage 27 above windows 28 to form a downwardly facing shoulder 40 adapted to cooperate with an upwardly facing external shoulder 41 onsetting sleeve '34 to limit relative upward movement of the latter to'the

position placing bosses

35 and 36 in registration with bosses 32 and 33 (FIGS. 2 and 3).

The upper end portion of setting sleeve 34 is-provided at a point above shoulder 41 with a plurality of angularly spaced windows 42 in which correspondingly shaped latch dogs 43 are mounted for radial movement for purposes to be subsequently described.

A tubular setting mandrel 45 extends slidably through the bore 11 of the packer body and has its upper end screwed into a collar 46 by which the mandrel is secured to the lower end of an operating pipe string 0. A latching sleeve 47 is mounted for longitudinal sliding movement on mandrel 45 between a lower shoulder 48 on the mandrel and an upper shoulder 49 formed by the lower end of collar 46. The upper end portion 50 of sleeve 47 is enlarged in diameter and is formed with an upper shoulder 51 adapted to overlie the upper end of setting sleeve 34 and an external annular recess 52 located below shoulder 51 to be in registration with latch dogs 43 to allow retraction of the latter when in" radially opposed relation to abutment ring 39 as seen in FIGS. 1 and 2. Shear screws 53 (one shown) extend through the upper end of setting sleeve 34 above windows 42 into end portion 50 of the latching sleeve to initially secure setting sleeve 34 in its lower inactive position (FIG. 1

The enlargement formed by upper end portion 50 defines a downwardly facing external shoulder 54-intermediate the ends of latching sleeve 47, the lower end of which carries an upwardly facing external shoulder 55 spaced from shoulder 54. A tubular collet 56 is slidably mounted about the lower portion of the latching sleeve between

shoulders

54 and 55 is normally biased upwardly against shoulder 54 by a coil spring 57 mounted about mandrel 45 in compression between the lower end of collet 56 and the upper end of bushing 16. Collet 56, a portion of which is shown in elevation in FIG. 10, is punched or otherwise formed to strike therefrom a plurality of fingers 58 formed with thickened heads 59 at their lower ends. When collet 56 is held in its upper position by coil spring 57 as seen in FIGS. 1 and 2, heads 59 will be thrust inwardly of the collet by inward thrust produced by engagement with the bore wall of setting sleeve 34, heads 59 being thus positioned above shoulder 55 of latching sleeve 47. The bore wall of setting sleeve 34 is provided with an annular recess 60 at an appropriate point just below windows 42 to receive heads 59 at a stage during release of mandrel 45 as will be described hereinafter.

The length of mandrel 45 is made such that when fully inserted in bore 1 1, its lower end 61 will be in downward thrusting engagement with shoulder 22 whereby to apply a stretching force to seal element 14 to elongate the latter and correspondingly reduce its diameter sufiiciently to be clear of the wall of pipe P when the packer is run through the pipe. Shear screws 53 serve to initially hold the parts in the seal element-stretching relation during running of the packer to its setting position.

A rubber gasket 61 is mounted in the upper end of cage 27 to extend radially outwardly into sealing engagement with the inner wall of pipe P and inwardly over the upper end of setting sleeve 34. The gasket serves to close off the annular spaces between the well wall and the anchor cage and between the latter and the setting sleeve to prevent scale and other detritus from falling into the spaces where such detritus might hinder the movements of the anchor and latch dogs both during setting and release of the packer.

OPERATION The packer, assembled as shown in FIG. I, will be run into the well pipe P on operating string 0. With mandrel 45 holding seal element 14 in the stretched position, as shown, the seal element will be clear of the well pipe and thus not subject to abrasion. When a point in the well has been reached at which the packer is to be set, an upward pull is applied through the operating pipe until anchor dogs 29 are opposite a collar recess R freeing them for radial outward movement into the recess. At this point the upward pull combined with the force of spring 57 will move setting

sleeve bosses

35 and 36 into registration with

bosses

32 and 33 of the anchor dogs thereby locking the latter into the collar recess as seen in FIG. 2. At the same time shoulder 48 on the mandrel will be raised into engagement with the lower end of latching sleeve 47.

With the anchor dogs locked in the collar recess, upward jarring applied through operating string will break shear screws 53 (FIG. 3). This will allow mandrel 45 to move upwardly carrying latch sleeve 47 upwardly and out of the bore of the packer. At the same time collet 56 will be raised by the engagement of shoulder 48 with heads 59 until the latter come into registration with recess 60 into which the heads will now enter (FIG. 3), thereby freeing the mandrel and latching sleeve so that they can be fully withdrawn from the packer. The pressure of spring 57 will keep the collet fingers latched into recess 60 and produce the upward force on setting sleeve 34 sufficient to hold anchor dogs 29 fimily anchored in collar recess R. When collet 56 is raised to the latching position, it also acts to push latch dogs 43 outwardly to project over the upper end of abutment ring 39 and to hold these dogs in that position, in which dogs 43 function to hold setting sleeve 34 in the set position shown in FIG. 3 and prevent accidental release of the setting sleeve as a result of vibration or other unintended action on the tool.

The withdrawal of mandrel will release the stretching force on seal element 14, allowing the latter to retract and expand radially into engagement with the wall of well pipe 0 (FIG. 3). Fluid pressure from below will enter ports 23 and will act to force seal element 14 into tight sealing engagement with the pipe wall.

When it is desired to retrieve the packer. a pulling tool K of any suitable design adapted to re-stretch or extend seal element l4 and at the same time free anchor dogs 29 from collar recess R will be run into the bore of the packer. An exemplary form of tool K is shown in FIGS. 4 and 5 but does not form a part of this invention.

As shown, tool K includes a tubular mandrel 65 adapted to be run into the bore of the packer and secured at its upper end to a running string A. A releasing sleeve 66 is slidably mounted on mandrel 65 and connected thereto by a cross pin 67 which extends through an elongate slot 68 in the upper portion of the mandre. A coil spring 69 is mounted in compression between an external shoulder 70 on the releasing sleeve and a shoulder 71 of the running tool and acts to bias sleeve 66 downwardly relative to mandrel 65. At a point below cross pin 67, setting sleeve 66 is provided with a downwardly facing external shoulder 72 adapted to abut the upper end of collet 56 in order to force the latter downwardly when the retrieving tool is inserted into the packer. At a suitably spaced point below shoulder 72, sleeve 66 is provided with openings 73 in which dogs 74 are mounted for radial movement to be projected outwardly by an enlargement 75 located on mandrel 65 near its lower end. 1

The arrangement and spacing of the parts of the retrieving tool are such that when it is run into bore 11 of the packer, shoulder 72 on sleeve 66 will first engage the upper end of collet 56 (FIG. 4) and push fingers 59 downwardly out of latching recess 60, at the same time pushing setting sleeve 34 downwardly to the position releasing anchor dogs 29 for retraction from collar recess R (FIG. 5). This downward movement will be such as to cause the lower end of releasing sleeve 66 to engageand push downwardly on shoulder 22 to an extent sufficient to re-stretch seal element 14 out of engagement with the wall of pipe P. Also the extent of this downward movement will position dogs 74 below the lower end of bushing 16. At this point, an upward lift on the running tool will pull mandrel 65 upwardly relative to releasing sleeve 66 which will be urged downwardly by spring 69. This relative upward movement of mandrel 65 will move enlargement 75 behind dogs 74 (FIG. 5), thereby holding the latter in abutting engagement with the lower end of bushing 16. Continue upward pull on the running string will pull the packer upwardly out of pipe P.

It will be understood that various changes and modifications may be made in the details of the illustrative embodiment within the scope of the appended claims but without departing from the spirit of this invention.

What I claim and desire to secure by Letters Patent is:

1. A well packer, comprising:

a. a tubular body;

b. anchor means on the body for releasably anchoring the body to a surrounding well wall; a resilient cup-type seal member disposed about the body with its upper end fixedly secured thereto and its lower end free for movement between a relaxed position allowing the seal member to radially expand into engagement with the surrounding well wall and a longitudinally stretched position clearing said well wall; and

d. means releasably secured to said body initially holding said seal member in said stretched position.

2. A well packer according to claim 1 wherein said lastmentioned means comprises:

a. a tubular mandrel extendible through the bore of said body into stretching engagement with the lower end of said seal member; and

b. means releasably securing said mandrel to said body in the seal-stretching position.

3. In a well packer according to claim 1:

a. a metallic collar member secured to the free lower end of said seal member and defining an upwardly facing annular shoulder below the lower end of said body;

b. said releasably secured means including a tubular mandrel extendible through the bore of said body into thrusting engagement with said shoulder to stretch said seal member; and

c. means releasably securing said mandrel to said body in the seal-stretching position.

4. A well packer according to claim 1 wherein said anchor means comprises:

a. anchor dogs mounted on the body for radial movement between advanced anchoring position and retracted release position;

b. a setting sleeve member slidably disposed in said body cooperable with said anchor dogs to effect said radial movement thereof between said positions;

c. said releasable holding means also initially holding said setting sleeve member in said dog-releasing position.

5. A well packer according to claim 4, including:

a. latch means mounted on said body to releasably secure said setting sleeve member in the dog-advancing position.

6. A well packer according to claim 5 wherein said latch means comprises:

a. a collet member slidably mounted in the bore of said setting sleeve for movement between upper and lower positions;

b. flexible latch fingers carried by the collar for engaging a recess in the inner wall of said setting sleeve member when the collet member is in said upper position; and

c. spring means normally urging said collet member to said upper position.

Claims

1. A well packer, comprising: a. a tubular body; b. anchor means on the body for releasably anchoring the body to a surrounding well wall; c. a resilient cup-type seal member disposed about the body with its upper end fixedly secured thereto and its lower end free for movement between a relaxed position allowing the seal member to radially expand into engagement with the surrounding well wall and a longitudinally stretched position clearing said well wall; and d. means releasably secured to said body initially holding said seal member in said stretched position.

2. A well packer according to claim 1 wherein said last-mentioned means comprises: a. a tubular mandrel extendible through the bore of said body into stretching engagement with the lower end of said seal member; and b. means releasably securing said mandrel to said body in the seal-stretching position.

3. In a well packer according to claim 1: a. a metallic collar member secured to the free lower end of said seal member and defining an upwardly facing annular shoulder below the lower end of said body; b. said releasably secured means including a tubular mandrel extendible through the bore of said body into thrusting engagement with said shoulder to stretch said seal member; and c. means releasably securing said mandrel to said body in the seal-stretching position.

4. A well packer according to claim 1 wherein said anchor means comprises: a. anchor dogs mounted on the body for radial movement between advanced anchoring position and retracted release position; b. a setting sleeve member slidably disposed in said body cooperable with said anchor dogs to effect said radial movement thereof between said positions; c. said releasable holding means also initially holding said setting sleeve member in said dog-releasing position.

5. A well packer according to claim 4, including: a. latch means mounted on said body to releasably secure said setting sleeve member in the dog-advancing position.

6. A well packer according to claim 5 wherein said latch means comprises: a. a collet member slidably mounted in the bore of said setting sleeve for movement between upper and lower positions; b. flexible latch fingers carried by the collar for engaging a recess in the inner wall of said setting sleeve member when the collet member is in said upper position; and c. spring means normally urging said collet member to said upper position.