BAKER HUGHES INCORPORATED
`Exhibit 1006
`
`Page 1 of 12
`
`

`
`4,018,272
`[11]
`[1,]
`United States Patent
` Brown et al. [45] Apr. 19, 1977
`
`
`[54] WELL PACKER APPARATUS
`
`A
`
`[57]
`
`ABSTRACT
`
`Disclosed is a retrievable,hydraulically set well paclcer
`which is locked in set position without need fortubing
`rotation and may be released from set position by
`shearing a retrieving link with either a straight pull on
`the productionjubing or by the application of high
`pressure through the tubing. Dual, opposed cones are
`employed for retaining the packer slips anchored irre-
`spective of the direction of the pressure differential
`acting on the packer and without need for an extra
`Sleeve to transmit Pressure induced forces to the coneS_
`Compression seals are employed to hold the slips firmly
`anchored against
`longitudinal displacement
`in both
`directions without reliance on the presence of a pres-
`sure differential across the set packer. The seals are
`employed as two separate assemblies which are posi-
`tioned above and below the slips to isolate a portion of
`the pressure induced forces from the retrieving link. A
`modified form of the invention employs the dual cone,
`dual sea] design on 3 packgr having multiple flow pas-
`Saga,
`
`[75]
`
`1m,emo,-S; Joe R_ Brown; wimam C_ Lindsey;
`phinip H. Mandel-scheid, an of
`Houston, Tex.
`'
`~
`_
`_
`173] AS51839‘? B|'°“'“ 0" T0015; ‘'19-, H0USt0naT3X-
`[22]
`Filed:
`Apr. 7, 1975
`
`[2l] Appl. No.: 565,385
`'
`[:2] $5.81; ................................ 166/119; 166/120
`[58%
`13"]d ‘f
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`3122111; 1331/
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`56
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`UMTED STATES PATENTS
`7/1961
`Brown ...... ..
`..
`2/1964
`Brown et al.
`8/1966
`Edwards, Jr.
`..
`. . . ..
`Brown . . . . .. . . . . .. . . .
`. . . .. 166/120
`Edwards, Jr.
`. . . . . .
`7/1968
`4/1972 Cochran et al. ................. .. 166/120
`
`[
`
`1
`
`2,990,882
`3,122,205
`3,265,132
`3,370,651
`3,391,740
`3,658,127
`
`155/119
`166/120
`166/120
`
`
`
`Primary Examiner—James A. Leppink
`Attorney, Agent, or Firm—Carlos A. Torres
`.
`
`‘
`
`T 22 Claims, 11 Drawing Figures
`
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`Page 1 of 12
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`

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`U.S. Patent
`
`April 19, 1977
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`Sheet 1 of 3
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`4,018,272
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`U.S. Patent
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`April 19, 1977
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`Sheet 2 of3
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`4,018,272
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`Page 4 of 12
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`1
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`WELL PACKER APPARATUS
`
`BACKGROUND OF THE INVENTION
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`The present invention relates to well devices em-
`ployed in the completion of oil and gas wells. More
`specifically,
`the present
`invention relates to a well
`packer which is retrievably anchored or “set” in a
`subsurface location within a well casing or other well
`conduit. When the packer is set, metal locking dogs or
`“slips” and annular resilient seal elements are extended
`radially to respectively anchor the packer to the casing
`and to form a pressure-light seal between the packer
`body and the surrounding well conduit or casing. A
`production tubing string connected to the packer con-
`ducts well efiluents which enter the casing below the
`packer to the well surface. A variety of well known
`techniques are employed to set the packer at the de-
`sired subsurface location. Manipulation of the tubing
`string or the application of fluid pressure through the
`tubing string are examples of two common techniques.
`Retrieval of the set packer requires that the radially
`extended seals and slips be retracted from engagement
`with the casing. Conventionally, a set packer may_ be
`released from its set position by manipulating the tub-
`ing string to cause mechanical components in the
`packer to sever or shift to a position which permits the
`slips and seals to retract. Once released, the tubing
`string and attached packer may be withdrawn from the
`casing.
`~
`Manipulation of the tubing string may be difficult or
`impossible under certain circumstances such as when
`the well is severely deviated or contains an obstruction.
`These same conditions, as well as others, may also
`cause a well packer to set prematurely as it is being run
`into the well. When premature setting occurs, the grip-
`ping force exerted by the set packer slips and seals
`compounds the difficulty in manipulating or retrieving
`the packer and attached tubing. The same conditions
`which make it difficult to retrieve a packer by tubing
`manipulation also may make it difficult to lock the
`packer in set position if such locking requires rotation
`or other surface manipulation of the tubing.
`45
`For the foregoing reasons, and others, it is frequently 1
`desirable to set, lock and release the packer by non-
`rotative manipulation of the tubing string. It is custom-
`ary to design packers which are released by a straight
`upward pull of the tubing string. Such packers usually
`include shear pins or other frangible devices which
`rupture when a sufficient shearing force is imparted
`through the tubing string. The shear pins must remain
`intact while the packer is set in its normal operating
`position but must ‘be capable of rupturing when a pre-
`determined retrieving force is exerted on the tubing
`string.
`The pressure differential acting across the set packer
`imposes shearing forces on the release shear pins in a
`straight pull release packer. Accordingly, the shear pins
`must be of adequate strength to prevent pressure in-
`duced shearing which might inadvertently release the
`set packer. If the pins are too strong, however, an unde-
`sirably large upward pulling force may be required to
`shear the pins for retrieval of the packer. Such large
`pulling forces, in addition to requiring adequate surface
`equipment, also impose very strong tension forces on
`the mandrel itself requiring oversized mandrels with
`reduced dimension flow passages.
`
`2
`Since the direction of the pressure differential acting
`across the set packer may be exerted in either direction
`or may change, it is conventional in some packer de-
`signs to employ hydraulic hold-down buttons or dual
`opposed spreader cones to keep the packer set irre-
`spective of the direction of the pressure differential. In
`conventional dual cone designs, the seal if frequently
`above the slips and the pressure induced upward move-
`ment of the seal is transmitted past the slips to the
`lower cone by a tubular mandrel telescoped over the
`primary mandrel. The need for two mandrels in these
`packer designs reduced the space available for the
`packer flow opening. Dual cone designs are neverthe-
`less frequently more desirable than designs using hold-
`down buttons because of the increased danger of leak-
`age present with such buttons.
`Packers having dual flow passges which employ the
`dual opposed cone designs and a straight pull release
`usually require a strong primary mandrel which is
`strong enough to withstand very large tension forces.
`The need for a strong primary mandrel stems from the
`fact that all of the differential pressure acting on the set
`packer and all of the release forces employed to re-
`trieve the packer act through only one of the two man-
`drels extending through the packer. For these reasons
`also, the retrieving shear pin required in such packers
`must also be relatively strong.
`Moreover, the strength requirements imposed on the
`primary mandrel undesirably reduce the size of the
`flow opening which can be fonned through the man-
`drel. For the stated reasons, hold-down buttons, even
`with their inherent leakage problem, have been em-
`ployed more often than opposed cones in dual comple-
`tion, straight pull release packers.
`A variety of prior art packer designs have employed
`a twin seal, dual cone arrangement to remedy several of
`the previously noted problems. Examples of such
`packer designs are shown in U.S. Pat. Nos. 2,765,852;
`2,990,882; 3,142,338; and 3,331,440. While these
`prior art packers have particular desirable features and
`advantages, they are undesirable in some applications
`because they either require rotation of the tubing to
`effect setting or release of the packer or they rely on .a
`pressure differential across the set packer to keep the
`slips firmly set.
`SUMMARY OF THE INVENTION
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`50
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`The well packer of the present invention may be set
`without tubing rotation and may be unset by a straight
`pull on the tubing string or, using an appropriate plug-
`ging device, by the application of fluid pressure
`through the tubing string. For the straight pull retrieval,
`a shearable retrieving link is employed to connect the
`anchoring and sealing assembly of the packer to the
`packer mandrel. The retrieving link is shearable, once
`the packer is set, by pressure induced movement of a
`piston ring which_also sets the packer or by vertical
`movement imparted to the packer mandrel by the tub-
`ing. The packet is set at a hydraulic pressure value
`which is below the pressure value required to shear the
`retrieving link. The piston ring carries a split locking
`ring which holds the packer in set position after the
`setting pressure is relieved and without need for a pres-
`sure differential across the set packer.
`,
`The packer of the present invention employs double
`acting slips and twin compression seal assemblies, one
`above and one below the slips. By virtue of this design,
`a pressure differential acting upwardly against
`the
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`4,018,272
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`lower seal assembly forces the lower cone spreader up
`to increase the gripping force of the slips and a pressure
`differential in the opposite direction forces the upper
`seal assembly downwardly against
`the upper cone
`spreader to increase the slips’ gripping force. The need
`for a telescoping mandrel is thus eliminated so that a
`larger flow passage may be fonned through the packer.
`The use of locked compression seals, rather than swab-
`cup type seals or other seal assemblies which rely on a
`pressure differential, produces good pressure seals
`even when there is no pressure differential acting
`across the set packer.
`'
`The twin seal design also makes it possible to» isolate
`a portion of the pressure induced forces from the shear-
`able retrieving link. Since the anchored slips provide
`direct resistance to cone movement, the forces result-
`ing from the pressure differential acting across only the
`cross-sectional area of the mandrel are effective on the
`retrieving link. By contrast,
`in single seal assembly
`designs where the seal is above the slips and the pres-
`sure is highest below the set packer, the forces resulting
`from the pressure differential acting across the entire
`cross-sectional area of the casing, less that of the tubing
`bore, tend to sever the retrieving link. Since much
`smaller pressure induced shearing forces are exerted
`with the twin seal design, the strength of the shear pins
`or retrieving link may be reduced and the upward pull
`required on the tubing string to shear the link for re-
`trieval of the packer may also be reduced.
`In a dual packer, the twin seal design significantly
`reduces the tension forces exerted on the mandrels and
`the retrieving link so that the dual opposed cone design
`may be employed. In the dual packer of the present
`invention, both mandrels are connected to the packer
`headrand to the retrieving link so that either of the
`tubing strings connected into the packer may be used
`to renieve the packer. The two mandrels thus share the
`pressure induced tension forces so that the need for a
`strong primary mandrel is eliminated. As a result, rela-
`tively large flow openings may be provided in both
`mandrels.
`
`, Hydraulic pressure applied through a port in the
`mandrel to an expansion chamber in the well packer
`causes relative movement between the components in
`the anchoring and sealing assembly of the packer to
`effect radial expansion of the slips and seals. A split
`ring covers the port to prevent debris from entering the
`chamber when the packer is being run into the well and
`after the packer is set. The hydraulic setting pressure
`moves the split ring away from the port to provide
`pressure access to the chamber.
`The piston sleeve, which is temporarily fixed relative
`to the mandrel by the split locking ring, is responsive to
`the application of a sufficiently high pressure after the
`packer is set to sever the retrieving link. This action
`disengages the split locking ring and releases the assem-
`bly from its set position by permitting components in
`the anchoring and sealing assembly to shift relative to
`the stationary mandrel.
`_When the retrieving link is severed by a straight pull
`of the tubing string and attached mandrel, the locking
`ring remains engaged and the shearing of the retrieving
`link permits mandrel movement relative to the station-
`ary anchoring and sealing assembly which in turn re-
`leases the assembly from its set position.
`Other features, objects and advantages of the inven-
`tion will become more readily apparent from the ac-
`companying drawings, specification and claims.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`is an elevation, partially in vertical section,
`1
`FIG.
`illustrating the well packer of the present invention in
`its unset position;
`FIG. 2 is a vertical, quarter sectional view illustrating
`the packer in set position;
`FIG. 3 is a vertical, quarter sectional view illustrating
`the packer in partially unset position;
`FIG. 4 is a vertical quarter sectional view illustrating
`the packer in fully unset position;
`FIG. 5 is a vertical quarter sectional view illustrating
`the packer being withdrawn upwardly through the well
`as it is being retrieved;
`FIG. 6 is a horizontal cross—sectional view taken
`along the line 6-6 of FIG. 1;
`FIG. 7 is a horizontal cross-sectional view taken
`along the line 7—7 of FIG. 2;
`FIG. 8 is a horizontal cross-sectional view taken
`along the line of 8-8 of FIG. 2.
`FIG. 9 is a longitudinal sectional view of a second
`embodiment of the invention;
`FIG. 10 is a transverse sectional view taken on line
`10—l0 of FIG. 9; and
`FIG. 11 is a transverse sectional view taken on line
`11-11 of FIG. 9.
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`10
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`DESCRIPTION OF THE ILLUSTRATED
`EMBODIMENT
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`The well packer of the present invention, indicated
`generally at 10, is illustrated in FIG. 1 as it appears
`when being run into the well through a surrounding
`well conduit or casing C. The packer includes a central
`mandrel 11 which supports an anchoring and sealing
`assembly indicated generally at 12. The mandrel 11 is
`connected to a production tubing string T which ex-
`. tends to the well surface.
`Included in the assembly 12 are compression seal
`elements 13 and 14 and a plurality of slip elements 15.
`When the packer 10 is set, as illustrated in FIG. 2, the
`seals 13 and 14 are compressed axially causing them to
`expand radially to seal the annular area A between’ the
`packer body and the casing C, and the slip elements 15
`anchor the packer to the casing. The compression seal
`elements 13 and 14 may be any suitable seal means
`which are locked in to provide a pressure tight seal
`between the packer body and the casing without reli-
`ance on a pressure differential across the set packer.
`With reference to FIG. 2, the packer 10 is set by the
`application of fluid pressure through the tubing T to an
`expansion chamber 16. The pressure is communicated
`from the tubing to the chamber 16 through a mandrel
`port 17 which is covered by a resilient metal snap ring
`18. The ring 18 is spring biased radially inwardly into
`an annular recess formed on the mandrel. The ring 18
`functions as an upper retaining member and also resil-
`iently covers the port 17 to prevent debris from enter-
`ing the chamber. Thus, the ring does not form a pres-
`sure tight seal over the port opening so that the pres-
`sure of the hydraulic fluid used to set the packer may
`be effectively transmitted past the ring into the cham-
`ber 16.
`
`_5s
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`Setting pressure applied to the chamber 16 forces an
`annular piston ring 19 upwardly over the mandrel 11
`toward a retaining end piece 20 which is threadedly
`fixed to the upper end of the mandrel. This movement
`compresses the seals 13 and 14 and moves them into
`sealing engagement with the casing C. Movement of
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`the piston ring 19 toward’ the end piece 20 also acts_
`through the seal 14 to ‘force a lower cone spreader
`element 21 toward an-upper cone spreader element 22.
`As the two cones 21 and 22 approach each other, they
`wedge ‘the intermediate slip elements 15 outwardly into
`anchoring engagement with the casing C.
`Once set, the packer 10 is firmly anchored to the
`casing C to prevent either up or down movement of the
`packer and attached tubing T. The dual cone configu-
`ration holds the packer in place irrespective of the
`direction of the pressure differential acting on the
`packer. The upper and lower seals 13 and 14 form a
`seal between the mandrel and the casing to prevent
`fluid flow in the annular area A. The seals also isolate
`
`When the packer-10 has been lowered to a desired
`subsurface location within the casing C, a ball B is
`pumped down through the tubing string T into sealing
`engagement with a seat S formed at the lower end of
`the mandrel 11. Once the ball B has seated, the pres-
`sure in the tubing string'T increases in the expansion
`chamber 16 to drive the piston 19 upwardly relative to
`the lower sleeve ring 30. This upward movement serves
`the shear pin 23 which connects the housing 29 to a
`lower tubular retaining piece 39. Once the pin 23 is
`sheared, the retaining member 38 falls downwardly
`into the position illustrated in FIG. 2.
`Upward movement of the piston sleeve 30 is pre-
`vented by the split ring 18 while downward movement
`of the piston sleeve is prevented by a circumferential,
`shearable split ring or retrieving link 39. As the housing
`29 moves upwardly over the piston sleeve 30, the lock-
`ing ring 27 is urged upwardly against the spring 37 out
`of its wedging position to produce a ratchet-like action
`which permits the upward movement ofthe housing 29.
`Reverse movement of the housing relative to the sleeve
`30 is prevented by the ring 27 which is moved down-
`
`
`
`the slip elements and thus function to prevent debris in
`the annulus from ‘accumulating about the slip and cone
`assembly.
`During the described setting procedure, shear pins
`23, 24, 25 and 26 sever in the stated order to permit
`relative movement of the pinned components as re-
`quired to expand the slips and seals. The pins are em-
`ployed to prevent inadvertent setting of the packer
`while it is being run into the casing before the desired
`subsurface location is reached.
`_
`The packer is held in the set position illustrated in
`FIG.- 2 by a split, annular lock ring 27 which has a
`wedge shaped cross-section. Circumferential gripping
`teeth 28 formed along the outer surface of the ring 27
`anchor into a surrounding tubular housing 29 to pre-
`vent the attached piston ring 19 from returning to its
`original unset position. The housing 29, a lower piston
`sleeve 30, the mandrel 11 and the piston ring 19 coop-
`erate with annular, resilient O-ring seals 31, 32, 33, and
`34 to form the expansion chamber 16.
`Referring jointly to FIGS. 2 and 8, it may be seen that
`the piston sleeve 30 is provided with an annular recess
`35 which carried the split lock ring 27. As the housing
`29 attempts to move downwardly relative to the sleeve
`30, a tapered surface 36 on the sleeve wedges the ring
`27 into tight gripping engagement with the surrounding
`housing. A spring element 37 resiliently biases the ring
`22 down into its wedging position between the inclined
`surfaces 36 and the housing 29.
`SETTING THE PACKER
`
`wardly into itswedging position by any such reverse
`movement.
`.
`
`After the pin 23 severs, the upward movement of the
`piston ring 19 compresses the seal 14 which in turn
`urges the lower cone element 21 upwardly causing the
`shear pin 24 to sever. This frees the lower cone 21 for
`upward movement which in turn forces the slips 15
`outwardly. The slips 15 are held in a floating assembly
`by a slip mounting ring 40. The assembly is temporarily
`secured relative to the mandrel 11 by the shear pins 25.
`When the cone,21 moves upwardly relative to the slip
`assembly, the resulting force exerted on the slip ele-
`ments 15 forces the‘ shear pins 25 to sever and causes
`the slip assemblyito be driven radially outwardly into
`anchoring engagement with the surrounding well cas-
`ing C. Once the slips are anchored, the forces exerted
`by the setting fluid-cause the mandrel 11 to move
`downwardly relative to the slips. This motion pulls the
`upper cone into firm engagement with the slips 15.
`Continued downward movement of the mandrel after
`the upper cone 22 engages the slips 15 severs the shear
`pin'26 and moves the end piece 10 toward the cone 22
`to radially expand the seal 13. This downward move-
`ment of the mandrel is permitted by either stretching
`the tubing T or moving it downwardly from the well
`surface. While the shear pins 24, 25 and 26 have been
`described as sequentially shearing in that order, the
`actual shearing occurs almost simultaneously.
`Setting pressure is released when the components of
`the well packer 10 have been moved into the relative
`positions illustrated in FIG. 2. Once such pressure is
`relieved, the normal resiliency of the seals 13 and 14
`tends to move the lower piston head 19 downwardly
`along the mandrel 11. This downward movement is
`prevented by operation of the locking cone 27 so that
`the packer remains set.
`PRESSURE RETRIEVAL OF THE SET PACKER
`
`If, during the setting or running in procedure, the
`well packer should prematurely anchor to the sur-
`rounding well casing,
`it may be released by merely
`supplying sufficient pressure to cause the element 39 to
`sever permitting the piston sleeve 30 to move down-
`wardly. This is accomplished without any movement of
`the tubing T. Complete movement of the elements to
`their unset position usually requires that the tubing
`string T be raised which in turn draws an annular split
`ring 42 on the mandrel 11 into engagement with the
`upper cone 22. Further upward movement withdraws
`the cone 22 from under the slips 15. Continued upward
`pull draws a second annular slip ring 43 into engage-
`ment with the lower portion of the slip elements 15 to
`pull such elements off of the lower cone 21. Helical
`springs 41 positioned between the slip mounting ring
`40 and each slip element 15 return the slip elements to
`a normally retracted position out of engagement with
`the surrounding casing wall once the cones 21 and 22
`have been returned to the position illustrated in FIG. 1.
`The normal resiliency of the seals 13 and 14 returns
`them to their retracted position. The described proce-
`dure thus permits the seals and slip elements to return
`to their normally retracted position so that the well
`packer 10 may be completely withdrawn from the well
`casing.
`Although the described pressure retrieving release of
`the well packer is considered to be an emergency mea-
`sure, itmay be desirable under some circumstances to
`retrieve the well packer under normal circumstances
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`4,018,272
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`8
`initiated in a customary manner. The construction and
`operation of the assembly 110 is analogous to and will
`be understood from the previous description of the
`construction and operation of the well packer 10.
`Retrieval of the packer 110 from its set position is
`effected by a straight upwardly directed pull on either
`of the tubing strings extending to the surface to shear
`the retrieving links 139a and l39b. As with the packer
`10, the links 139a and 139b can also be severed by the
`application of high hydraulic pressure with a setting
`plug or ball (not illustrated) suitably placed below the
`port 117a for plugging the flow passage of mandrel
`llla.
`
`The twin seal design in the packers 10 and 110 func-
`tions such that only that portion of the force resulting
`from the pressure differential across the cross-sectional
`area of the mandrel acts against the shear links 39 in
`the packer 10 and 139a and 13% in the packer 110.
`The force from the pressure differential across the
`packer seals is not transmitted to the retrieving link
`since it is applied directly to the spreader cones. For
`example, with specific referenece to FIG. 2, it may be
`noted that if the pressure below the seal 14 is greater
`than that above the seal 13, the pressure differential
`tends to force the seal 14 upwardly. This upward force
`is transmitted to the cone 21 which in turn transmits
`the force to the slips 15. This portion of the pressure
`induced force is not exerted against the mandrel 1 1 and
`accordingly is not exerted against the retrieving link 39.
`If the seal 14 were omitted however, the pressure dif-
`ferential would apply an upward force on the seal 13
`which in turn would exert an upward force on the man-
`drel 11. In a straight pull release packer, this upward
`force would have to be resisted by the same device that
`must be severed to retrieve the packer. As a result, the
`use of only a single seal in a straight pull release packer
`' requires a stronger shear pin or retrieving link than that
`required with the dual seal design of the present inven-
`tion.
`
`While hydraulic setting is employed in the preferred
`form of the present invention, it will be appreciated
`that the advantages of the dual seal design may also be
`applied to mechanically set packers. Other modifica-
`tions of the present invention will suggest themselves to
`those having ordinary skill in the art. By way of exam-
`ple, rather than limitation, the dual seal, opposed cone
`design may be employed in any multiple bore packers
`and is not limited to the single and double bore exam-
`ples specifically described herein.
`The foregoing disclosure and description of the in-
`vention is illustrated and explanatory thereof, and vari-
`ous 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. By way of
`example rather than limitation, the seals 13 and 14 may
`be omitted and, with other obvious minor changes, the
`device 10 may be employed to function as an anchor to
`hold or position a liner or other well device or assembly
`within the well.
`We claim:
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`using the pressure release. Following the setting of the
`packer or retrieval of the packer through the applica-
`tion of well pressure, the ball B is returned to the sur-
`face by any conventional procedure so that well fluids
`may flow freely through the tubing T.
`STRAIGHT PULL RELEASE OF THE WELL
`PACKER
`
`FIG. 3 of the drawings illustrate the well packer 10 as
`it is being released from its set position by an upward
`pull exerted on the tubing string T. The upward pull is
`transmitted through the mandrel l 1 to the outer assem-
`bly l2 through the retrieving link 39. When a sufficient
`upward pull is exerted on the tubing, the link 39 severs
`permitting the mandrel to be raised upwardly relative
`to the anchored slip segments 15. This upward move-
`ment engages the lock ring 42 with the upper cone 22
`which in turn pulls the cone out from under the set
`slips. At this point, the components of the assembly are
`in the positions illustrated in FIG. 3.
`FIG. 4 illustrates the well packer as it appears follow-
`ing continued upward movement of the tubing T which
`pulls the split ring 43 into engagement with the slips 15
`to pull the slips off of the lower cone element 21. Once
`the cones 21 and 22 have been spread apart and the slip
`elements 15 have been retracted, the components of
`the outer assembly 12 move into the fully retracted
`position illustrated in FIG. 5. Thereafter,
`the well
`packer 10 may be withdrawn to the well surface.
`DUAL STRING WELL PACKER
`
`FIGS. 9 through 11 illustrate a modified form of the
`invention, indicated generally at 110 in FIG. 9, em-
`ployed for establishing fluid connection between the
`surface and two separate subsurface locations. Unless
`otherwise noted, components of the well packer 110
`are substantially similar in function and operation to
`those of corresponding components of the invention 10
`and are identified by reference characters which are
`higher by 100 than those for corresponding compo-
`nents in the well packer 10. The subscript a is em-
`ployed to identify components associated with one of
`the flow passages and the subscript b is employed with
`the same reference number to identify the same com-
`ponents associated with the second flow passage in the
`well packer 110.
`The well packer 110 includes a conventional, dual
`connecting head CH with openings CHa and CI-lb. The
`well packer is releasably connected through opening
`CHa to a tubing string (not illustrated) by which the
`assembly is lowered into the well bore. Setting of the
`packer 110 is effected in the manner previously de-
`scribed for the packer 10 by the application of fluid
`pressure through the tubing string employed to lower
`the well packer into place. The fluid pressure acts
`through radial bore 117a in the mandrel llla to ex-
`pand chamber 116.
`Components 113, 114, 119, 121, 122, 130, 138 and
`140 are constructed in the fonn of cylindrical bodies
`having parallel openings extending longitudinally for
`receiving the mandrel 111a and lllb. A ring 140 se-
`cured to the body 140' by screws 140" holds the slips
`115 in position. The ring 118b cooperates with the ring
`118a to form an upper stop for the piston ring 130.
`Once the packer is set, a second tubing string (not
`illustrated) is lowered through the casing and con-
`nected into the free opening CHb in. the connecting
`head CH. Production from two zones may then be
`
`1. A retrievable well device which may be set to
`anchor to a surrounding well conduit at a subsurface
`_65 location comprising:
`a. a mandrel assembly;
`b. an anchoring assembly carried on said mandrel
`assembly;
`
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`4,018,272
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`c. friction gripping elements included in the anchor-
`ing assembly, said gripping elements being expand-
`able radially into a set position to anchor said well
`device to said surrounding well conduit;
`d. setting means including means movable in a first
`longitudinal direction relative to said mandrel as-
`sembly for moving said gripping elements into said
`set position;
`e. locking means between said mandrel assembly and
`said movable means permitting movement of said
`movable means relative to said locking means in
`said first direction but preventing movement of
`said movable means relative to said locking means
`in a second direction opposite to said first direction
`and movement of said locking means relative to
`said movable means in said first direction for main-
`taining said gripping elements in said set position;
`f. said mandrel assembly, said setting means and said
`locking means at least partially defining an expan-
`sion chamber in communication with the interior
`of said mandrel assembly, said movable means and
`said locking means defining respective opposed
`axially facing pressure reaction surfaces within said
`chamber, said movable means being so movable in
`said first direction responsive to the application of
`fluid pressure above a first limit from said mandrel
`assembly to said expansion c