US3399729A - Retrievable well packer - Google Patents

Description

sept. 3, 1968 H. L. MCGILL RETRIEVABLE WELL PACKER Filed Dec. SO, 1966 5 Sheets-Sheet l Hon/afa M65/ INVENTOR.

sept. 3, 1968 H. MCG|| 3,399,729

RETRIEVABLE WELL PACKER ATTORNEY Sept. 3, 1968 H, McG|LL i 3,399,729

VRETRIEVABLE WELL PACKER Filed Dec. 30, 1966 3 Sheets-Sheet 5 Howe/'d L Mc 6'/// INVENTOR WMM/KWWL? ATTORNE Y United States Patent() 3,399,729 RETRIEVABLE WELL PACKE Howard L. McGill, Houston, Tex., assignorto Schlumberger Technology Corporation, Houston, Tex., a corporation of Texas Filed Dec. 30, 1966, Ser. No. 606,272 16 Claims. (Cl. 166-120) ABSTRACT F THE DISCLOSURE A well packer apparatus wherein the expanding anchor comprises two distinct means, one being mechanically actuated and adapted to anchor the packer against movement in one direction and the other being hydraulically` operated and adapted to anchor the packer against movement in the other direction. Structure is provided for positively preventing premature operation of either of the anchor means. Additionally, an integral bypass device is included for selective pressure equalization as well as a pressure balancing system.

This invention relates generally to subsurface well tools and more particularly to a new and improved retrievable well packer apparatus adapted to be positioned in a well conduit and anchored against longitudinal movement therein.

A typical retrievable well packerwhich can be used for performing pressure operations in a well generally includes normally retracted slips and packing which can be selectively expanded for respectively anchoring against downward movement in a well casing and packing off the annulus between the well casing and a tubing string on which the well packer is lowered into the well. A uid bypass can be provided which is normally open to facilitate rapid movement of the packer through the well fluids during lowering and retrieving and which can be utilized to equalize uid pressures on the packer after a pressure operation is completed. With the slips and packing expanded and the bypass closed, iluids can be displaced under pressure through the tubing string and well packer and into the well casing below the packer for performing various pressure operations common in the art, such as squeeze cementing, acidizing or hydraulic fracturing.

The pressures developed during such operations act as forces on the packer tending to shift it upwardly within the casing. Since upward movement can unset the packer, it is common practice to provide an auxiliary anchoring mechanism which functions to prevent upward movement. Typically, such auxiliary anchoring mechanisms include normally retracted gripping pistons or buttons which are actuated into gripping engagement with the Well conduit in response to fluid pressures developed during the abovementioned pressure operation.

During rapid descent into a well, fluid pressure surges can be created which cause premature operation of the gripping pistons. The gripping pistons are moved outwardly by the pressure surges and dragged along the well conduit wall untiltheir. gripping portions are dulled or otherwise damaged to an extent that they will not function properly when the packer is set.

An object of the present invention is to provide a new and improved well packer apparatus which can be set in a well conduit and anchored against movement in either longitudinal direction.

Another object of the present invention is to provide a new and improved well lpacker apparatus of the type described which is more positive in operation than has heretofore been known in the art in preventing premature actuation of hydraulically operated anchors.

Another object of the present invention is to provide ice a new and improved'well packer apparatus of the type described having auxiliary anchors for preventing upward movement under pressure, the anchors being structurally arranged in a manner to positively prevent their operation as the well packer is shifted in either longitudinal direction in a fluid filled well bore. Moreover, the well packer of the present invention can have an integral fluid bypass arrangement which will not be inadvertently opened during a pressure operation.

Yet another object of the present invention is to provide a new and improved well packer apparatus which is effective, simple and reliable in operation,

These and other objects are obtained in accordance with the present invention by providing an apparatus including an anchor body having expansible packing means mounted for sealing engagement with the well conduit and a mandrel movable in said anchor body. A first passageway between the mandrel and the anchor body is provided for bypassing well fluids through the packing means and a valve means is provided for selectively closing the first passageway, the valve means being actuated by movement of the mandrel. Normally retracted gripping members on the anchor body are shiftable outwardly of the anchor body into gripping engagement with the well conduit and a hydraulic member is movable in response to uid pressure for shifting the girpping members outwardly. A second passageway in communication with the rst passageway is provided to enable fluid pressure to act on the hydraulic member. Means on the mandrel is engageable with the hydraulic member to prevent movement of the hydraulic member, and thus actuation of said gripping member, when the bypass valve is in its open condition.

The present invention has other objects and advantages Which will become more apparent in connection with the following detailed description. The novel features of the present invention being set forth with particularity in the appended claims, the operation together with further objects and advantages thereof, may best be understood by way of illustration and example of certain embodiments and taken in conjunction with the accompanying drawings, in which:

FIGURES 1A and 1B are longitudinal sectional views, with portions in side elevation, of one embodiment of a well packer apparatus in accordance with the present invention and with parts in retracted positions for longitudinal movement in a well bore, FIG. 1B forming a lower continuation of FIG. 1A;

FIGURES 2A and 2B are views similar to FIGURES lA and 1B except with various parts in expanded positions and the well packer set in a well casing;

FIGURE 3 is a plan view of a J-slot which can be used in controlling relative movement of parts of the Well packer;

FIGURE 4 is a longitudinal sectional view, with portions in side elevation, of another embodiment of an apparatus in accordance with the present invention;

FIGURE 5 is a cross section online 55 of FIGURE 4 and;

FIGURE 6 is a fragmentary cross section online 6 6 of FIGURE 5.

Referring initially to FIGURE 1, a wellpacker apparatus 10 which 'embodies the principles of the present invention is illustrated with parts thereof in running-in positions. The wellpacker 10 includes a tubular mandrel 11 which is telescopically disposed within ananchor body 12 for sliding movement therein between the extended and contracted positions. The mandrel 11 has acentral bore 13 and extends throughout the full length of the tool. A threadedbox portion 14 at the upper end of the mandrel 11 is adapted for connection with a tubing string (not shown) and the lower end of the mandrel has a threadedpin portion 15 to which a section of pipe or another well tool can be connected. Themandrel bore 13 is arranged to continue the full bore size of the tubing string to which the mandrel is coupled.

Theanchor body 12 has a reduceddiameter compression sleeve 17 coupled to its lower end around which a pliant, elastomeric packing means 18 can be mounted. The upper end of the packing means 18 engages a downwardly facing annular shoulder orabutment 19 and the lower end engages the upper face of anannular abutment ring 20 which is slidable on thecompression sleeve 17. Theabutment ring 20 is connected to the upper end of asleeve 21 which extends downwardly to anexpander member 22. The packing means 18 can take any conventional form and is shown for purposes of illustration as comprising a plurality ofelastomeric packing rings 23 separated bymetallic gauge rings 24, the packing rings being adapted for lateral expansion upon compression thereof. Theexpander member 22 andsleeve 21 can be co-rotatively secured to thecompression sleeve 17 by means of coengagingsplines 25 or the like. Theexpander member 22 has downwardly and inwardly inclinedouter surfaces 26 thereon which are engageable with matinginner surfaces 27 on a plurality ofslip members 28 in a manner whereby downward movement of the expander member relative to the slip members will cause outward shifting of the slip members.

Movably mounted at the lower end portion of the mandrel 11 is atubular cage member 30. A J-slot 31 typically can be formed in the outer periphery of the mandrel 11 for cooperation with alug 32 extending inwardly from thecage member 30, the .I-slot and lug functioning to control relative movement between the cage member and the mandrel. The J-slot 31, shown in developed view in FIGURE 3, can have a longvertical segment 33 and a relatively shortvertical segment 35, thesegments 33 and 35 being connected by atapered segment 34. Thelug 32 engages in theshort segment 35 when the parts are in a running-in position as shown in FIG- URES 1A and 1B so that thecage member 30 cannot move substantially relative to the mandrel 11 in either longitudinal direction.

The cage member has a plurality of circumferentially spaced, radially directedrecesses 37 in its outer periphery, each of the recesses receiving atypical drag block 38. The drag blocks are urged outwardly bysprings 39 for frictional engagement with a well casing wall and function to retard movement of thecage member 20 within the well conduit in a conventional manner. Outward movement of thedrag blocks 38 can be limited byannular bands 40 and 41 which are arranged to engagetangs 42 and 43, respectively on eachdrag block 38.

Theslip elements 28 can be movably connected on the upper end of thecage member 30 by Tshaped extensions 44 which slidably engage incomplementary recesses 45 in thecage member 30. Moreover, a conventional dovetail flange andgroove connection 46 between eachslip element 28 and theexpander member 22 may be provided so that relative movement between the slip elements and the expander member will effect lateral movement of the slip elements to and from a well casing wall. Wickers orteeth 47 on the peripheral surfaces of eachslip element 28 are formed to face downwardly and are adapted to bite into and grip a well casing to anchor the well packer 10 against downward movement therein.

Anintermediate portion 50 of the mandrel 11 is spaced laterally away from the inner surface of thecompression sleeve 17 to provide an annularfluid bypass passageway 51. Thepassageway 51 extends from a plurality ofside ports 52 in theexpander member 22 to a plurality ofbypass ports 53 which extend through the wall of theanchor body 12 above the packing means 18. An internalannular recess 54 in theanchor body 12 adjacent to the upper end of thebypass passageway 51 is arranged to receive a seal ring '55. Theseal ring 55, in turn, has an internal groove 56 in which a suitablebypass seal element 57 is located. For selectively closing thebypass passageway 51, the mandrel 11 has anenlarged diameter section 58 to provide a valve head which is normally located above theseal element 57 and above thebypass ports 53 when the mandrel is in its extended position as shown in FIGURE 1A. In this relative position of parts, thebypass passageway 51 is open for bypassing well fluids through the packing means 18 as the well tool is shifted longitudinally in a well conduit. When the mandrel 11 is moved to a lower or contracted position relative to theanchor body 12, thevalve head 58 is moved adjacent to thebypass seal element 57 to block fluid ow through thebypass ports 53 and thus prevent any uid movement through thebypass passageway 51. Although theseal element 57 has been shown positioned on theanchor body 12, it will be appreciated that theseal element 57 could be alternatively arranged around thevalve head 58 and adapted to seal against an inner seal surface on the anchor body when the mandrel is moved downwardly.

The portion of theanchor body 12 above thebypass ports 53 is provided with a plurality of circumferentially spaced, generally rectangular shapedopenings 60 each of which receives a holdingslip 61. Each holdingslip 61 has an inner inclined surface extending downward and inwardly toward the mandrel 11 and has upwardly facing Wickers orteeth 62 on its outer surface. Eachslip 61 can be slidably connected to theanchor body 12 by anextension 63 which is received within aninclined groove 64 so that the holding slips can be shifted laterally between inner or retracted positions as shown in FIGURE 1A and outer or anchoring positions where theteeth 62 can grip a well conduit wall to prevent upward movement therein.

A hydraulically operatedslip expander member 65 is provided for shifting the holding slips 61 between their retracted and extended positions. Theexpander member 65 is generally tubular in form and is arranged for longitudinal movement within an internal annular recess orchamber 66 formed in theanchor body 12. Thechamber 66 is closed off at its upper end by an inwardly extending ange and aseal ring 76 sealingly engages the outer surface of the mandrel 11. Theexpander member 65 has outerinclined surfaces 67 at a lower portion extending downward and inwardly toward the mandrel 11. The inclined surfaces 67 are complementary in shape and engageable with inclined surfaces 68 on the holding slips 61 so that downward movement of theexpander member 65 will effect outward extension of the slips. Eachslip 61 can also have a conventional dovetail flange andgroove connection 69 to theexpander member 65 so that upward movement will effect retraction of theslips 61 away from a conduit wall.

The bore of theexpander member 65 is sized for sliding reception on the mandrel 11 and a suitable seal element such as an O-ring 71 seals between the inner periphery of the expander member and the outer surface of the mandrel. Anotherseal element 72 seals between the outer periphery of theexpander member 65 and the wall surface of thechamber 66. The cross-sectional area A between the twoseal rings 71 and 72 defines a differential area piston on which fluid pressure can act. An internal, elongatedannular recess 73 is formed intermediate the ends of theexpander member 65 and a shoulder orflange 74 on the mandrel 11 extends outwardly into therecess 73. Themandrel shoulder 74 is arranged to engage a downwardly facingshoulder 75 on theexpander member 65 when the mandrel is in its upper or extended position as shown in FIGURE 1A. In this manner, the engagedshoulders 74 and 75 can function positively to prevent any downward movement of theexpander member 65 relative to the holding slips 61. Accordingly, the holding slips 61 are positively prevented from being shifted outwardly as long as the parts of the well packer are in their relative positions for longitudinal movement in a well bore.

Theexpander member 65 is adapted to be hydraulically operated, when desired, to eiect outward shifting of the holding slips 61 into anchoring engagement with a well casing. For hydraulic operation, apressure communicating passageway 77 is formed in the mandrel 11 to extend from a location below thebypass valve head 58 to later-al ports 78 and 79 which communicate thepassageway 77 with theexpander member recess 73 and with theanchor body chamber 66 above theexpander member 65. When thebypass valve head 58 is engaged with thebypass seal element 57 by movement of the mandrel 11 to its lower or contracted position relative to theanchor body 12, thelower end 80 of thepressure communicating passageway 77 is disposed in a position below thebypass seal element 57. Accordingly, the fluid pressure which exists in thebypass pasageway 51 is communicated to thepressure communicating passageway 77 and into thebody chamber 66 to act on the upper side of theexpander member 65. The lower side of theexpander member 65 is in communication' with the well annulus above the packingelement 18 via the anchor body recesses 60. Therefore, a pressure difference between fluids in thebypass passageway 51 and in the annulus above the packingelement 18 can act on the dilerential area A as a force tending to move thehydraulic expander member 65 vertically relative to the holdingslip 61.

An upper internal annular recess in theanchor body 12 forms achamber 82 which receives abalance piston 83, the balance piston being integrally formed on the mandrel 11. Asuitable seal element 84 is positioned to seal between thebalance piston 83 and the w-all of thechamber 82.Several side ports 85 in theanchor body 12 enable annulus pressures above the packingelement 18 to `act on the lower face of thebalance piston 83. Thepressure communicating passageway 77 is arranged to extend upwardly to a port means 86 above thepiston 83 to enable fluid pressure in thebypass passageway 51 to act on the upper face of thebalance piston 83. Additionally, an annular floatingpiston member 87 is received at the upper portion of thechamber 82 for sliding movement between an upper position where the oating piston engages the inwardly extendingange 88 at the upper end of thechamber 82, and a lower position where the balance piston abuts against astop shoulder 89 formed on the mandrel 11. Inner andouter seal elements 93 and 94 prevent fluid leakage past the floatingpiston 87. Annulus pressures outside of theanchor body 12 can act throughside ports 90 on the upper face of ythe floatingpiston 87 while uid pressures in thebypass passageway 51, being reected in thepressure communicating passageway 77, can act on the lower face of the floatingpiston member 87. Accordingly, any pressure differential which may be developed can act on the area B of thebalance piston 83 and the area C of the floatingpiston 87 for purposes which will be subsequently described.

In operation, the parts of the well packer are assembled as shown in FIGURES lA and 1B and the mandrel 11 coupled to a tubing string for lowering into a well casing. During lowering, thecage member 30 is retained in its lower position on the mandrel 11 by engagement of thelug 32 within the shortvertical segment 35 of the I-slot 31. The drag blocks 38 can slide along in frictional engagement with a well casing wall and the lower slips 28 are maintained in retracted -positions because thecage member 30 cannot move relatively upwardly toward theexpander member 22. The packing rings 23 are unexpanded and thevalve head 58 on the mandrel 11 is positioned above thebypass seal element 57 so that well fluids can enter thebypass passageway 51 through thelower side ports 52 and exit through theupper bypass ports 53.

Thehydraulic expander member 65 is held in its upper or inactive position by themandrel shoulder 74 and therefore cannot move downwardly in a manner to actuate the holding slips 61 outwardly. Accordingly, it will be appreciated that although the holding slips 61 can be eventually hydraulically operated, they are posiltively prevented from being prematurely operated by tluid pressure surges which can be developed within the it/ell packer during rapid descent into a fluid filled well ore.

At setting depth, the well packer is halted and a small upward movement coupled with right hand rotation of the mandrel 11 will position thelug 32 for entry into the long vertical J-slot segment 33 to permit substantial downward movement of the mandrel 11 relative to thecage member 30 for setting the well packer. During downward movement of the mandrel 11, theslips 28 and thecage member 30 are held against downward movement by the drag blocks 38. Downward movement of the mandrel 11 will advance theexpander member 22 downward relative to theslips 28 to shift them outwardly into gripping engagement with the well casing P as shown in FIGURE 2B. Further mandrel movement will move thevalve head 58 adjacent to thebypass seal element 57 to close the bypass passageway to fluid flow and to engage themandrel box portion 14 with theupper flange 88 on theanchor body 12.

Inasmuch as theabutment sleeve 21 is supported against further downward movement by theslips 28, the weight of the tubing string can be applied to the mandrel 11 and transmitted through theanchor body 12 to the upper end of thepacking element 18. As weight is applied, theupper abutment 19 is advanced toward thelower abutment ring 20` to compress and expand the packing rings 23 outwardly into sealing engagement with the surrounding well casing wall. The weight of the tubing string can be maintained on the well packer to maintain its set condition. It will be noted that when the well packer is set and thebypass ports 53 closed oi by thevalve head 58, the lower of thepressure communicating passageway 77 is disposed below thebypass seal element 57 so that whatever fluid pressures may exist within the mandrel bore 13 and in the annulus below the expandedpacking element 18 are communicated through thebypass passageway 51, thepressure communciating passageway 77 and to the upper side of thehydraulic expander member 65 via theports 78 and 79. Moreover, the pressure is also communicated to a location between thebalance piston 83 and theoating piston 87 via theports 86. As previously mentioned, whatever uid pressures may exist in the well annulus above the expandedpacking element 18 can act on the lower side of thehydraulic expander member 65 through the holding slip recesses 60, on the lower face of thebalance piston 83 through theside ports 85, and on the upper face of theoating piston 87 via theupper side ports 90.

A pressure operation such as squeeze cementing, acidizing, or hydraulic fracturing can now be performed in an interval below thepacker 10. If, as is usually the case, tubing pressure should exceed annulus pressure, the pressure difference will act as a force attempting to shift thewell packer 10 upwardly within the casing P as well as attempting to move the mandrel 11 upwardly. However, the high tubing pressure is also acting on the upper side of thehydraulic expander member 65, while the lower annulus pressure is acting on the lower side of the hydraulic expander member. Accordingly, the pressure difference acts on the area A as a downward force which moves thehydraulic expander member 65 downwardly to shift the holding slips 61 into 4gripping engagement with the well casing, thereby preventing any upward movement of thewell packer 10. Moreover, the higher tubing pressure is communicated into thebalance chamber 82 to act downwardly on the upper face of the mandrel.balance piston 83, while lower annulus pressures are acting on the lower face on the balance piston. Accordingly, the pressure difference can act across the area B as a downward force tending to counterbalance the upward force on the mandrel 11 due to high tubing pressure, thereby substantially minimizing the net upward force on the mandrel and preventing any upward shifting of the mandrel 11 during a pressure operation. The pressure differential is also acting upwardly on the area C of the floatingpiston 87 but the floating piston can merely shift upwardly into engagement with the anchor body flange '88. Since theanchor body 12 is anchored against upward movement by the holding slips 61, the upward force on the floatingpiston 87 is of no consequence.

Should annulus pressure exceed tubing pressure, for example, where fluid is lifted within the tubing by swab- ,bing to test the success of an acidizing operation, the

higher annulus pressure acts downwardly on the well packer in a conventional manner to set the packingelement 18 and the lower slips 28 even more tightly within the well casing P. However, the higher annulus pressure will tend to lift thehydraulic expander member 65 upwardly within theanchor body 12 since the lower tubing pressure is acting on the upper side of thehydraulic expander member 65. Under this influence, thehydraulic expander member 65 can move upwardly until itsupper end surface 91 engages a downwardly facingshoulder 92 on theanchor body 12. This movement will retract the holding slips 61 and can occur without thehydraulic member 65 engaging themandrel stop shoulder 74. Since the lower tubing pressure is now acting on the upper 4face of thebalance piston 83 and the higher annulus pressure is acting on the lower face thereof, there is an upward force on the area B on thebalance piston 83. However, the pressure difference is now acting downwardly on the floatingpiston 87 which can move downwardly -to engage thestop shoulder 89 on the mandrel 11. The effective pressure areas B and C of the balance piston and oating piston respectively can be made substantially the same so that force on the mandrel 11 due to pressure acting on the pistons is counterbalanced. Accordingly, the mandrel 11 will not be moved upwardly to inadvertently open thebypass ports 53.

To release thewell packer 10 for retrieval to the surface it is only necessary to remove the tubing weight from the mandrel 11 and lift the mandrel upwardly. If the holding slips 61 are not already retracted by higher annulus pressure as previously described, upward movement of the mandrel 11 will engage themandrel shoulder 74 with thehydraulic expander member 65 and thus shift it upwardly to retract the holding slips 61. Also, upward movement of the mandrel 11 will position thevalve head 58 above thebypass seal element 57 to open thebypass ports 53 and permit equalization of any existing pressure differentials across parts of this packer. As compressive force is removed from the packing rings 23, they will inherently retract and eventually thelower expander member 65 will be moved upwardly relative to thelower slip elements 28 to cause their release and retraction. When sufllcient upward mandrel movement has occurred, the cage member will occupy its initial lower position relative to the mandrel 11 and thelug 32 will again engage in the slot segment to re-jay and lock the packer parts in retracted positions for longitudinal movement in the casing P.

An alternative embodiment of an apparatus which ernbodies the principles of the present invention is shown in FIGURE 4. Only the upper portion of the apparatus is shown for convenience of illustration and it will be appreciated that the lower portion can embody structural elements similar to those shown in FIGURE 1B or their equivalents. A mandrel 111 is telescopically disposed for movement inanchor body 112 between an extended position, as shown, and a. contracted position where abox portion 114 on the mandrel 111 engages an inwardly extendingflange 116 on the anchor body. The mandrel 111 has acentral bore 113 extending throughout its length which can continue the full bore of a tubing string (not shown) to which thebox portion 114 can be connected.

Theanchor body 112 has a reduceddiameter compression sleeve 117 threadedly coupled to its lower end', the compression sleeve having anelastomeric packing element 118 mounted around its periphery with its upper end engaging a downwardly facing shoulder orabutment 119 on theanchor body 112. The inner periphery of thecompression sleeve 117 is laterally spaced from the outer periphery of the mandrel 111 to provide anannular bypass passageway 120 which extends upwardly toseveral side ports 121 in communication with the well annulus above the packing element 11S. Abypass seal element 122 is disposed adjacent the upper end portion of thebypass passageway 120 and can be positioned within an internal annular groove formed in aseal ring 124 which is, in turn, located with an internal annular recess in theanchor body 112. Asuitable seal element 126 can be positioned adjacent to theseal ring 124 to prevent any fluid leakage past the seal ring.

Anannular valve head 128 is formed on the mandrel 111 by an enlarged diameter portion thereof. Thevalve head 128 is normally positioned above thebypass seal element 122 when the mandrel 111 is in its extended position so that fluids can flow freely through thebypass passageway 120 and theside ports 121. When the mandrel 111 is moved downwardly relative to theanchor body 112, the outer peripheral surface of thevalve head 128 can sealingly engage thebypass seal element 122 to block fluid flow from thebypass passageway 120 to the well annulus via theside ports 121.

Theanchor body 112 has upper and lowerannular chambers 130 and 131, respectively, formed therein and separated by an annular, inwardly extendingflange 132. The upperannular flange 116 extends inwardly to close the upper end of theupper chamber 130 and aseal element 134 sealingly engages the outer surface of the mandrel 111. Theupper chamber 130 is opened to the exterior of theanchor body 112 by a plurality of circumferentially spaced, generally rectangular shapedopenings 135 and each of the openings receive a holding member in the form of aslip element 136. Theslip elements 136 are each movable within a respective opening between a retracted position, as shown, and an extended position. Eachslip element 136 can be slidably connected to theanchor body 112 by a T shapedextension 137 at its lower end which engages in a matinginclined groove 138 in the inwardly extendingflange 132. Moreover, eachslip element 136 has innerinclined surfaces 139 which extend downwardly and inwardly toward the mandrel 111 and has upwardly facing wickers orteeth 140 on its outer periphery which are adapted, when the slip element is extended, to grip a well casing wall.

For actuating the holding slips 136 between retracted and extended positions, a hydraulic member is provided which is arranged for reciprocating movement within theupper chamber 130. Thehydraulic member 130 is generally tubular in form and has a bore therethrough which is sized for sliding reception on the mandrel 111. Aninner seal element 146 seals between the inner surface of the hydraulic member and the outer surface of the mandrel 111 while anouter seal element 147 seals between the outer periphery of the hydraulic member and the wall surface of thechamber 130. The crosssectional area A between the twoseal elements 146 and 147 defines a differential area piston on which fluid pressure can act.

The lower end portion of thehydraulic member 145 can have a .plurality of longitudinally extendingpockets 150, each of which receives a wedge-shapedexpander insert 151. The expander inserts 151 can be rigidly but removably connected to thehydraulic member 145 by suitable fasteners such as threadedstuds 152. Each insert can have an inwardly extendinglip 153 which engages in arecess 154 to further secure the inserts for longitudinal movement with thehydraulic member 145. Theouter surface 155 of eachexpander insert 151 is formed to incline downwardly and inwardly toward the mandrel 111 and is complementary in shape to the innerinclined surfaces 139 on the holding slips 136. Eachslip 136 is arranged to engage arespective insert 151 in a manner whereby downward movement of thehydraulic member 145 will effect outward movement of the slips. Each holdingslip 136 can further be sldably connected to arespective expander insert 151 by a conventional dovetail ange andgroove arrangement 156 so that upward movement of the hydraulic member '145 will elect inward retraction of the slips.

To enable uid pressure to act on thehydraulic member 145, a pressure communicating passageway 160' can be formed to extend along the mandrel 111 from anopening 161 below thevalve head 128 to anopening 162 which is in communication with theupper chamber 130 above thehydraulic member 145. Thus it will be appreciated that whatever uid pressures exist in thebypass passageway 120 are reflected in theupper chamber 130 to act on the upper side of thehydraulic member 145 whether thevalve head 128 is in its open or closed position. Also, whatever fluid pressure may exist in the well annulus above thepacking element 118 is communicated through theanchor body openings 135 to act on the lower side of thehydraulic member 145. Accordingly, whenever the iiuid pressure in the bypass passageway 120' exceeds the annulus pressure, the pressure difference acts on the area A' as a force in a downward direction tending to move thehydraulic member 145 downwardly and to expand the holding slips 136.

In order to prevent premature expansion of the holding slips 136 when the mandrel 111 is in its extended position for lowering or retrieving in a well bore, the mandrel is provided with several outwardly extending lugs orshoulders 164 as shown in FIGURES 5 and 6 which can be circumferentially offset relative to theslips 136. Theshoulders 164 are sldably received ingrooves 165 which extend longitudinally in thehydraulic member 145, the upper end of eachgroove 165 defining a downwardly facingshoulder 166 against which the upper face of a respect-ive mandrel lug 164 can engage when the mandrel 111 is in its extended position. Accordingly, thehydraulic member 145 is positively retained in an upper or inactive position and cannot move downwardly to shift the holding slips 136 outwardly. It will be appreciated that this structural arrangement prevents any possibility of premature actuation of holdingslips 136 when the parts of the well packer are in relative positions for longitudinal movement in a well. However, when the well packer is set and the mandrel 111 is in its contracted position within theanchor body 112, the mandrel lugs 164 are moved downwardly away from the groove shoulders 166 a suiiicient distance to permit free longitudinal movement of thehydraulic member 145 as it functions to actuate the holding slips 136.

, The pressure differential necessary to operate thehydraulic member 145 and thus the holding slips 136 is derived from the high tubing pressures normally developed during a pressure operation. The high tubing pressure is communicated from below the well packer upwardly through theclosed bypass passageway 120, through thepressure communicating passageway 160, thepassageway opening 162 and into theupper chamber 130 to act on the upper side of thehydraulic member 145. As the tubing pressure exceeds the annulus pressure which is acting on the lower side of thehydraulic member 145, downward force is developed to reciprocate thehydraulic member 145 downwardly and thereby shift the holding slips 136 outwardly to anchor the Well packer 110 against upward movement in response to high pressure from below.

The higher uid pressure within the mandrel 111 also acts on the mandrel in an upward direction and tends to turely. Accordingly, a balancing system is included in accordance with the present invention and comprises apiston 168 which can be integrally formed on the mandrel 111 and arranged for reciprocating motion within thelower chamber 131. Aseal element 169 in a suitable groove around the outer periphery of thepiston 168 engages the wall surface of thechamber 131 to prevent fluid leakage past the piston. An annular floatingpiston member 171 is also positioned within thechamber 131 above thebalance piston 168 and inner andouter seals 172 and 173 prevent uid leakage past the lioating piston. It will be appreciated that theiloating piston 171 is free to move lonigtudinally within thechamber 131 between limits defined by thelower face 174 of theange 132 and the upper face of thebalance piston 168. The chamber space located between thebalance piston 168 and the floatingpiston 171 is placed in communication with thepressure communicating passageway 160 by a lateral port means 176.

The balancing system operates in the following manner. When there exists high tubing pressure, the pressure is communicated through thebypass passageway 120, past thevalve head 128 via thepressure communicating passageway 160 and into the chamber space between the twopiston members 168 and 171. The pressures in theannulus above the packer are communicated to the upper face of the floatingpiston 171 through theanchor body openings 135, and to the lower face of thebalance piston 168 through thebypass ports 121. The pressure difference will act on the balance piston area B as a downward force on the mandrel 111 tending to counterbalance the upward force on the mandrel due to high pressure from below. Accordingly, thebypass valve head 128 will not be lifted to an open position by the high tubing pressure. Under these conditions, theoating piston member 171 can merely move upwardly until Iit engages theanchor body ilange 132. Forces on the floatingpiston 171 cannot cause upward movement of theanchor body 112 because it is anchored against upward movement by holdingslips 136.

Moreover, should annulus pressure exceed tubing pressure, the pressure difference will act upwardly on the hydraulic member to shift it upwardly until itsupper end surface 178 engages the lower surface 179 of the upperanchor body ange 116. This movement will retract the holding slips 136 and can occur without transmitting any force directly to the mandrel 111. Since the upper end of theanchor body 112 is engaging thebox portion 114 on the mandrel 111, theanchor body 112 cannot move upwardly relative to the mandrel 111 responsive to high annulus pressures. Also, the directions are reversed in which pressure forces are acting on thebalance piston 168 and theioating piston 171. That is to say, should annulus pressure exceed tubing pressure, the pressure difference acts on the area B as an upward force, and on the area C as a downward force. Under these influences, theoating piston 171 can move downwardly to engage thebalance piston 168 and the areas B and C can be made the same so that the net force is zero due to pressures acting on the oating and balance pistons.

The various parts of the apparatus shown in FIG- URE 4 can be operated to retracted positions for retrieval from the well by upward movement of the mandrel 111 in the same manner as described relative to the apparatus shown in FIGURES lA and 1B. Upward movement of the mandrel 111 will open the bypass passageway 129 to equalize pressures and permit retraction of thepacking element 118 as well as engaging the mandrel lugs 164 with the hydraulic member shoulders 166 to retain thehydraulic member 145 in its upper or inactive position. The well packer 110 can then be retrieved from the well bore or moved to another setting position.

A new and improved well packer has been disclosed which can be anchored in a well conduit against movement in either longitudinal direction. The well packer has an integral bypass and pressure equalizing means as well as a pressure balancing system. The well packer is structurally arranged to prevent premature operation during lowering or retrieving.

Since certain changes or modifications may be made in the disclosed embodiments of the present invention without departing from the inventive concepts involved, it is intended that the appended claims cover all such changes or modifications falling within the true spirit and scope of this invention.

I claim:

1. A well packer for use in a well bore comprising: a body member; a mandrel movable in said body member and adapted for connection to a running-in string, said mandrel having a bore; packing means on said body member adapted for sealing off said body member in a well bore; slip means movable between retracted and expanded positions for anchoring said body member in a well conduit against substantial movement in either direction, at least one of said slip means disposed on said body member on one side of said packing means; hydraulic means for actuating said one slip means; passage means extending from said hydraulic means to the other side of said packing means along said body member said mandrel and externally of said bore to enable fiuid pressure on said other side to act on said hydraulic means; and means on said mandrel engageable with said hydraulic means for releasably holding said slip means in a retracted position.

2. The well packer ofclaim 1 further including chamber means between said mandrel and said body member; balancing means on said mandrel and movable in said chamber means; and means to enable said fluid pressure to act on said balancing means.

3. A well tool comprising: an anchor body having expansible packing means mounted thereon for sealing engagement with a well conduit; a mandrel movable in said anchor body; a first passageway between said mandrel and anchor body for bypassing well fluids through said packing means; passageway closing means actuated by movement of said mandrel for selectively closing said first passageway; a second passageway in communication with said first passageway; normally retracted gripping members on said anchor body shiftable outwardly of said anchor body for gripping a well conduit; hydraulic means movable in response to pressure in said first and second passageways for shifting said gripping members outwardly; and means on said mandrel engageable with said hydraulic means for normally preventing movement of said hydraulic means to actuate said gripping members when said passageway closing means is open.

4. The well packer ofclaim 3 including piston means on said mandrel subject to fiuid pressure to said first and second -passageways when said passageway closing means is closed for exerting a force on said mandrel in a direction to maintain said first passageway closing means closed.

5. A well tool comprising: an anchor body; a mandrel telescopically arranged in said anchor body; expansible packing means on said anchor body adapted for lateral expansion to pack off a well conduit; a bypass passageway between said packing means and said mandrel and extending along said mandrel between locations above and below said packing means; valve means actuated by telescoping movement of said mandrel and arranged to close said bypass passageway adjacentan end portion thereof; holding means on said anchor body shiftable outwardly thereof for gripping a well conduit to prevent movement in one longitudinal direction; hydraulic means movable between said mandrel and said anchor body for shifting sai-d holding means outwardly; pressure communicating means for enabling fluid pressure in said bypass passageway to act on said hydraulic means; and means on said mandrel engageable with said hydraulic means for selectively preventing operation of said hydraulic means, thereby selectively preventing operation of said holding means.

6. The well tool ofclaim 5 further including cylinder means in said anchor body; balance means on said mandrel and sealingly engaging said cylinder means; and means to enable fluid pressure in said bypass passageway to act on said balance means.

7. The well tool ofclaim 5 wherein said hydraulic means has inclined surfaces slidably engageable with inclined surfaces on said holding means for shifting said holding means outwardly.

8. The well tool of claim 7 further including coengageable means on said inclined surfaces for shifting said holding means inwardly to retracted positions.

9. The well tool ofclaim 5 further including first cylinder means in said anchor body, and wherein said hydraulic means includes seal means slidably and sealingly engaging said first cylinder means.

10. The well tool of claim 9 further including second cylinder means in said anchor body; balancing means on said mandrel and sealingly engaging said second cylinder means; and means to enable fluid pressure in said bypass passageway to act on said balance means.

11. A well packer comprising: body means having expansible packing means mounted thereon for sealing engagement with a well conduit; a mandrel adapted for connection to a pipe string and movable in said anchor body between first and second positions; a bypass passageway between said mandrel and body means and extending along said mandrel between locations above and below said packing means; bypass passageway closing means actuated by movement of said mandrel for closing said bypass passageway in one of said positions, said bypass passageway being open in the other of said positions; another passageway in communication with said lbypass passageway when said mandrel is in at least one of said positions; normally retracted gripping members on said body means and shiftable outwardly thereof for gripping a well conduit; hydraulic means actuated in response to pressure in said other passageway for shifting said gripping members outwardly; and means including a shoulder on said mandrel engageable with said hydraulic means for holding said hydraulic means against movement when said bypass passageway is open to positively prevent outward shifting of said gripping members.

12. A well packer apparatus comprising: a body; a mandrel telescopically disposed in said body for movement between extended and contracted positions; normally retracted slips and packing means lfor respectively anchoring in a well conduit and packing off well conduit, said slip means -being arranged to prevent movement of said apparatus in one longitudinal direction; a bypass passageway between said packing means and said mandrel; valve means operable when said mandrel is in said contracted position for closing said bypass passageway; normally retracted gripping members on said Ibody for anchoring said apparatus against movement in the opposite direction; hydraulic means for actuating said gripping members into anchoring engagement with a well conduit; means for enabling tiuid pressure in said bypass passageway, when closed, to act on said hydraulic means; and means on said mandrel engageable with said hydrulic means when said mandrel is in its extended position for preventing operation of said hydraulic means.

13. A well packer comprising: an anchor body; a sleeve coupled to the lower end portion of said anchor tbody; elastomeric packing means mounted around said sleeve and adapted for expansion to pack ofi a well bore; a mandrel adapted for connection to a tubing string and extending concentrically through said anchor body and sleeve, said m-andrel being arranged for telescoping movement therein between extended and contracted relative positions; Ia bypass passageway between said sleeve and said mandrel and extending between locations above and below said packing means; bypass closing means operated by movement of said mandrel to said contracted position for selectively closing said bypass passageway; slip members on said anchor body and shiftable outwardly thereof for anchoring against movement in a well casing; hydraulic means for shifting said slip member outwardly, said hydraulic means being movable along said mandrel and said anchor Ibody; means to enable iluid pressure to act on said hydraulic means including a pressure communicating passageway extending between locations below said bypass closing means and yabove said hydraulic means; yand means engageable with said hydraulic member when said mandrel is in said extended position for preventing movement of said hydraulic means, thereby `to prevent outward shifting of said slip members.

14. The well packer ofclaim 13 further including chamber means between said anchor body and said mandrel; a balance piston coupled to said mandrel and movable in said chamber means; and means to enable iluid pressure in said pressure communicating passageway to act on said balance piston for exerting a balancing force on said mandrel when said hydraulic member is actuating said slip members.

15. The well packer ofclaim 14 further including a iloating piston member movable in said chamber means relative to Iboth said mandrel and said anchor body; and means to enable uid pressure to act on said floating piston member for balancing force on said balance piston when said hydraulic member is not actuating said slip members.

16. A we-ll packer comprising: an anchor body; a mandrel movable in said anchor body between exten-ded and contracted positions; expansible packing means mounted on said lanchor body and arranged to pack oi a well bore; means operable when said mandrel is in said contracted position for expanding said packing means; holding means on said anchor body and shiftable between extended and retracted positions for anchoring against movement in one longitudinal direction; hydraulic means between said anchor body and mandrel and movable relative to both said anchor body and said mandrel for shifting said holding means between extended and retracted positions; means for enabling fluid pressure to act on said hydraulic means including a normally open bypass passageway between said mandrel and said anchor |body 'and extending between locations above and below said packing means; valve means operable when said mandrel is in said contracted position for closing off said bypass passageway, said enabling means being in communication with said bypass passageway when closed; and means engageable with said bydraulic means when said mandrel is extended for holding said 'hydraulic means in an inactive position so that sai-d hydraulic means cannot function to shift said holding means.

References Cited UNITED STATES PATENTS 2,878,877 3/1959 Baker 166-120 X 3,020,959 2/ 1962 Nutter 166-134 3,233,675 2/1966 Tamplen et al. 166-134 X 3,283,819 11/1966 Tausch 166-120 3,283,824 11/1966 Hoiman et al. 166-120 X 3,338,308 8/1967 Elliston et al. 166-120 DAVID H. BROWN, Primary Examiner.

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