US2720267A - Sealing assemblies for well packers - Google Patents

Description

Oct. 11, 1955 c. c. BROWN SEALING ASSEMBLIES FOR WELL PACKERS 5 Sheets-Sheet 1 Filed Dec. 12. 1949 A TTORNED J Oct. 11, 1955 c. c. BROWN SEALING ASSEMBLIES FOR WELL PACKERS 5 Sheets-Sheet 3 Filed Dec. 12, 1949 C/ cero C Brown INVENTOR.

A TTOfP/VEYS Oct. 11, 1955 C. C. BROWN SEALING ASSEMBLIES FOR WELL PACKERS Filed Dec. 12, 1949 I i ll /4 7 v H 5 A36 f A35 46 s h 1 u Ai/ci D O D O i /J/ A78 5 Sheets-Sheet 4 C/cero C. Brow/7 INVENTOR.

Oct. 11, 1955 c. c. BROWN SEALING ASSEMBLIES FOR WELL PACKERS l n U 0 o sw m WN H 5 6 a mowmm t N/ m wmfm M QMM Z e m m 5 MW. 0

Filed Dec. 12, 1949 United States Patent FSEALING ASSEMBLIES FOR WELL PACKERS Cicero C Brown, Houston, Tex. Application December 12, 1949, Serial No. 132,589

14 Claims. (Cl. 166--119) This invention relates to new and useful improvements in sealing assemblies for well packers.

OHC'IObjCCt Of the invention is to provide an improved :zsealing assembly for a well packer which may be effectively distorted 'into sealingengagementwith a well casing and which is so constructed that it will be readily removia ble regardl'ess of the length of time which it may have been in a set position within said casing.

A'nimport-ant object ofthe invention is to provide an improved sealing assembly for a well packer which is adapted to be distorted into sealing position by the imposition of the weightofthe well tubing or conductor and which has means incorporated therein for limiting the amount of weight which may be applied to the elastic {packing element of the assembly by the tubing or conductor, whereby the imposition of excessive weight on said element which may causedeformation of the well casing or extrusion o'f the ends of the element around the confining members of the assembly with a resultant sticking of thepacker, isobviated.

Another object -'is to provide a sealing assembly for well packers which is so constructed that the packing *element of the'assembly maybe initially distorted radially ou'twardly -b-y a coaction withthewell conductor by which the-packer is lowered and may thereafter be moved into a fina'l expanded sealing position by the application of weight of the lowering conductor; said assembly also lendingitself to the combination with a pressure seal means whereby it may be movedinto its final sealing fposition bythe fluid pressure in the annulus between the well casing and lowering conductor above the assembly.

Stillano'ther object "is toprovide an improved sealing assembly comprising an annular elastic sealing element having its upper and lower ends confined by segmental retaining members, with the segments of each member being displaceableradially outwardly, whereby a mechanical "radial pressure from within the bore of the sealing assenlbly may effect a radial displacement of the *segments simultaneously "with an outward displacement of theelastic sealingelement, whereby saidretaining members m'ay function to restrain "extrusion or flow of the "sealing element around said members through the space 'be'tween the members and the well casing.

further object is 'to provide a sealing assembly, of Ll'h'fl rcharacter described, wherein the upper segmental remaining member may be displaced radially into direct contact with the wall 'o'f ithe well casing to completely close the annular space between said member and the welltcas'ing andnthereby prevent the extrusion-or creeping of the material of r the packing element therearound.

A particular object is to provide fa sealing assembly, wherein the upper i radially expansible retaining member .is expanded into contact with the wall of the well casing rbyrimposing the weight of the well tubing or'conductor thereon, said retaining member functioning when in its fully expanded position engaging the casing to prevent the further application of tubing weight to the elastic ,sealinglor packi ng element of the assembly, wherebysaid 2,720,267 Patented Oct. 11, 1955 :element is protected from the imposition of excessive weight thereon.

Another object is to provide a sealing assembly, of the character described, which may be combined with any suitable type of anchor mechanism or device now in general use on well packers.

A still further object is to provide a sealing assembly wherein the segmental retaining members, which confine the ends of the elastic sealing or packing member and which are expansible radially, are formed with gripping surfaces or slips on their peripheral portions, whereby radial expansion of the retaining members moves the slips into gripping engagement with the well casing to lock the assembly therein; the construction completely eliminating the need for the usual separate anchoring mechanism.

The construction designed to carry out the invention will 'be hereinafter described together with other features thereof.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming apart thereof, wherein an example of the invention is shown, and wherein:

Figure 1 is an elevation of a well packer having a sealing assembly constructed in accordance with the invention 'and showing the packer being lowered in a well casing,

Figure 2 is an exploded view of the various parts of the sealing assembly,

Figure 3 is a view partly in section and partly in elevation illustrating the sealing assembly in a partially expanded position, t

Figure 4 is a similar view showing the assembly fully expandedinto its final set position,

Figure 5 is a horizontal cross-sectional view taken on the 'line:5-5 of Figure 4,

l-Figure 6 is a horizontal cross-sectional view taken on the line 66 of Figure 4,

ZFigure6a is an elevation of the sealing assembly illustrating a modified form of the confining or retaining members,

Figure .'7 is a'viewpartly in section and partly in elevation showing amodified form of the sealing assembly,

:Figure *8 is an exploded view-of the modification shown in Figure 7,

Figure9 is a view partly in section and partly in elevation and illustrating a seal cup on the upper end of the sealing assembly,

Figure 10 is :a horizontal cross-sectional view'taken-on the line 101'0 of Figure9,

Figure '11 is va horizontal cross-sectional view taken on the line 1 1-11 of Figure 9,

Figure 12 is a view partly in .section and partly in elevation of another modification of the sealing assembly wherein the gripping slips are incorporated into the assembly,

:Figure 13 is a horizontal cross-sectional view taken on the-line 1313of Figure 12, and

Figure '14 is a view partly in section and partly in elevation illustrating the sealing assembly of Figure 12 in "its fully expanded position.

In thedrawings, the numeral 10 desginates a welltubing which is adapted to be lowered through the usual well casing 1 1 within a well bore. A-sub 12 is threaded onto the lower-end-of the tubing and has its upper portionof a diameter substantially the same 'asthat of the well tubing with the .lower portion 12a of said sub being reduced whereby an-external annular shoulder13 which is preferably beveled is provided intermediate the ends of the sub. The lowerrend'of the sub is formed with a bevel or incline 14 and the upper end of a tubular mandrel or support is threaded into the lower portion of the sub whereby the mandrel is connected to the tubing string. The external diameter of the portion 12a of the sub is larger than the external diameter of the mandrel or support 15 so that the lower beveled end 14 of the'sub forms an external shoulder at the upper end of the mandrel. The lower end of the mandrel may be connected with a tail pipe 16 of any desired length.

The mandrel or support is formed with an axial bore 15a of constant diameter and fluid openings or slots 17 are formed in the upper portion of the mandrel while by-pass openings 18 are provided in the lower portion thereof.

The mandrel or support forms the main supporting element of a packer unit which includes an anchoring mechanism generally indicated at A and a sealing assembly generally indicated at B. The present invention resides in the sealing assembly B and any well known type of anchoring mechanism A may be employed. As illustrated the anchoring assembly comprises a slip carrying cage or sleeve'18 having radially movable slips 19 mounted within slots 20 formed in the cage. Friction springs 21 mounted on the cage normally ride the wall of the casing. The cage is adapted to be detachably connected with the mandrel 15 by a J-slot 22 formed in an upset'portion '23 on the exterior of the mandrel and a connecting lug 24 which projects inwardly from the inner wall of the cage or sleeve 18. When the lug is disposed within the lateral portion of the J-slot 22 the cage or sleeve 18 has connection with the mandrel and may be lowered and raised therewith within the well casing;

however, rotation of the mandrel to align the vertical portion of the J-slot with the lug 24 will permit the mandrel to be moved downwardly relative to the cage with said cage being held substantially within the well casing by the frictional engagement of the friction springs 21 with the wall of said casing.

The anchoring mechanism also includes a tubular expander or cone member 25 which has a tapered expanding surface or cone 26 formed on its lower end. The upper portion of the expander or member 25 is cylindrical and at the intersection of the cylindrical portion and the expanding cone 26 the member 25 is formed with an external shoulder 27. The cage encircles the lower portion of the expander and has a retaining collar 28 threaded into its upper end. The collar 28 is slidable on the cylindrical portion of the expander and has its lower end adapted to engage the external shoulder 27 to prevent displacement of the slip carrying cage from the expander 25. The lower end of the expander or member 25 normally engages the shoulder 23a which is formed by the upper end of the upset portion 23 on the mandrel and with the expander so supported and with the slip carrying cage in connected position by means of the J-slot and lug arrangement, the slips are in their retracted position. The inner surface 19a of each slip is tapered complementary to the tapered surface 26 of the cone and when the mandrel is disconnected from the slip carrier and moved downwardly relative thereto the expander 25 moves downwardly within the slips to move said slips radially outwardly into gripping position with the well casing. It is noted that the anchoring device A shown and described herein is subject to some variation since any well known type of hook wall anchoring device may be employed.

The improved sealing assembly B is clearly illustrated in Figure 2 and comprises a main annular sealing ele ment 30 which is illustrated as formed of a trio of superposed elastic packing collars 30a which are constructed of rubber, rubber compound, or other suitable material. The lowermost collar 30a is molded to an end member 31 formed of a plurality of segmental arcuate sections 31a which sections are unconnected with each other except for the material of the elastic collar which is molded thereto. The lower retaining or confining member 31 is supported upon a coupling collar 32 which is threaded onto the upper end of the expander member 25. The coupling collar 32 is formed with a plurality of inverted T-shaped slots 33 which extend in a radial direction from the bore of the collar to the periphery thereof. As is clearly shown in Figure 2, each slot 33 is narrower at its upper end whereby lateral shoulders 34 are formed within each slot.

The upper end of the packing element 30 is confined by an upper retaining member 35 which is also formed of a plurality of arcuate segments 36. These segments are unconnected from each other and are therefore capable of radial expansion and contraction. The inner surfaces of the arcuate segments coact to form an axial bore 37 which extends through the member 35 and this bore is of substantially the same diameter as the bore of the packing collars 30a when the latter are in an undistorted position.

For connecting the retaining members 31 and 35 and the superposed packing collars 30a together as a single unit, through bolts 38 extend upwardly through openings 39 in the segments 31a and then upwardly through openings 40 provided in the collars 30a. The upper ends of the bolts thread into openings 41 which are provided in the under side of theupper retaining segments 36. The lower portion of each through bolt 38 extends below the lower confining member 31 and the annular head 38a of said bolt is adapted to be engaged within one of the inverted T-slots 33 in the coupling collar 32. It will be evident that the bolt head engages the shoulders 34 within its slot to firmly anchor the confining members and the sealing element 30 together. The bolt head engaging the shoulders 34 prevents upward displacement of the sealing assembly B from the coupling collar 32 and yet permits downward movement of the upper confining or retaining member 36 with respect to the lower confining or retaining element 31 which allows end-wise pressure to be applied to the elastic packing collars and thereby effect their radial distortion. At the same time the connection of the lower ends of the through bolts 38 with the coupling collars permits a radial movement of the through bolts with respect to the coupling collar 32.

In the operation of the sealing assembly said sealing assembly is connected to the expander or cone member 25 of the anchoring device A and the mandrel 15 is connected by means of the J-slot and lug to the slip carrier whereby the anchoring slips 19 are in a retracted position. At this time the bypass openings 17a are located below the anchoring device and the slots 17 are disposed above the sealing assembly whereby a fluid by-pass through the mandrel as well as around the packer unit may occur during the lowering operation.

When the position at which the packer unit is to be set is reached the mandrel 15 is rotated to align the vertical portion of the J-slot with the connecting lug 24 and the mandrel is moved downwardly with respect to the slip carrier whereby the expander 25 is moved within the slips 19 and functions to expand said slips into engagement with the wall of the well casing. As the slips move into gripping position further lowering movement of the expander 25 is halted and said expander thus provides a support for the lower end of the sealing assembly B since the upper end of said expander is coupled through the coupling 33 to the lower confining sectional member 31 of the sealing assembly.

Lowering of the mandrel 15 is continued until the lower portion 12a of the sub attached to the upper end of the mandrel enters the bore 37 of the upper segmental retaining member 35 and because this portion is larger than the external diameter of the mandrel the segments of the member 35 are moved radially outwardly as shown in Figure 3, whereby the outer periphery of the member is moved into close proximity with the wall of the well casing. As the portion 12a of the sub moves downwardly through the elastic collars 30a such collars are also de- ;formed radially outwardly into close proximity with the wall .of the wel casing and subsequently the portion 12a will'similarlyzexpand or move the segments 31a of the lower confining member outwardly. It is thus apparent that the portion 12a of the sub 12 will function to initially irnpart'a-radial expanding movement to the segmental monfiningmembers 35 and 31 as well as to the elastic packing collars whereby positive mechanical pressure is utilized to initially deform the elastic packing collars in a radial direction.

Continued lowering of the tubing string will result .the external shoulder 13 of the sub 12 engaging @the upper surface of the upper retaining or confining element .35 sincethe external diameter of this shoulder is greater than the bore 37 through this upper member. Following engagement of the shoulder 13 with the upper confining ..member 35 the tubing 10 maybe slacked off to apply the desired weight .to the member 35 and this weight willbe transmitted .to thesealing element formed by the elastic ,packing collars whereby an end-wise compression is trans :mittedito thesealing-element to expand the outer peripheries of its collars into directsealing engagement with the wall of the well casing. At the same time the imposition .of weight upon the upper confining member 35 will, through the coactionof the beveled shoulder 13 with the upper inner surface ofthe segments, result in a further .radial expansion or movement of said segments so that the outer surfaces of the segments 36 will move into contact withithe wall of the well casing. Such outer movement of the upper confining member will result in the segments 36 .1 substantially closing the annular space between the segments and the wellcasing so that an extrusion or creeping of the :upper end of the material of the sealing element .30 around the segments will be prevented. Also, since ithe segments arein direct contact with the casing the im- :POSltlOII of any further weight by a further slacking oii on thetubing will be taken by :the metallicsegments and will vnot betransmittedto the elastic material ofthe packing element -30. The arrangement therefore provides for a Mprotectionof the sealing element against the imposition of-excessive weight and'this weightmay be controlled by tcontrolling the amount of radial movement which the segments 3'6must undergo before they actually moveinto .tlirect contact withthe wall of the well casing. It is aplparent tthat when the initial tubing weight deformed the relastic packing element 30 some radial movement was imiparted ltO the sealing element and this radial movementis :transmitted by means .ofthe through bolts to the lower segments so that said lower segments are actually expanded into substantial contactwith the wall of the casing. Thus, extrusion of the-packing element around the lowertconfiningmember 31 is also prevented.

Removal of thepacker is effected bymerely raising'the {tubing 10 and the mandrel 15 and .such lifting of the @mandrel retracts the portion 12a of the sub from within .ithersealing element and 'segrnents whereby these parts may return to 'a normal :inward undistorted position. The mandrel :is raised until the shoulder 23a formed by the .upset gportion strikes the lower end of the expander .25 audit the sealing. clement has not disengaged itself from the wallwof the well casing anupwardjarring on the seal- .ingassemblymay be efiected by jarring the shoulder 23a .against thejlower end of the expander. After thesealing element has been dislodged the mandrel may be rotated to reconnect the lug 24 of the slip carrying cage with the lateral portion of the J-slot after which removal of the unit may be effected.

From the foregoing it will be seen that the sealing element is arranged so that it is confined between radially i'expansible confining members and such members, as well .ast heisealing element itself, coact withthelowering conductorwhich includes the sub 12 so that the sealinge'lement and confining membersmay be initially mechanicallyexpanded. Following this initial expansion the tubing weight is employed tomove the sealing element and the "material which is 'molded thereto.

"confining IIICmbGISIlIItO. their final expanded position. =-By radially expanding the confining :members extrusion or creeping of the packing material around said confining members is eliminated and also by radially expanding the upper confining member into contact with the well casing the imposition of excessive weight .upon the sealing element which might cause bulging or deformation of the well casing is prevented.

In-some instances, there may be a possibility of extruding the material of the upper sealing collar through the radial joints between the segments 31a and 3.6 and in order to overcome this possibility the segments may be provided with coacting overlapping lugs 36 and recesses 35' as shown in Figure :6A.. wtihrsuch structure the lugs '36 span the radial joints between the segments and prevent upward extrusion of material therethrough.

In Figures 1-6 the sealing element has been illustrated as formed of a plurality of superposed elastic packing collars but if desiredithe sealing element may be constructed of asinglepackingrsleeve, as shown in Figures 7 and 8. lnthis modificationtthe sealingelement is formed of a single annular elasticsleeve 42 which has its lower endmolded to a lower confiningmember 131 formed of arcuate unconnected segments 131a. The upper end of the sleeve 42 ismolded to an upper confining member 135 formed of arcuate segments 136 which are unconnected with each 'othertexcept for'the packing The upper member 135 "has an annular external groove '43 in its peripheral .surfaceand a-segrnental ring'44 is disposed in said groove.

The tjoints 45 between each 'segment of the ring 44 are located in oifset relationship to the radial joints between the segments 136 of the member and span said joints, whereby when endwise compression is applied to the sealing sleeve 42,-extrusion of the pacl-iing material upwardly through the joints between the .segmentsvis prevented.

The lower .confining member 131 has connection through headed bolts 138 with a coupling collar 132, with said bolts :138 beingtdisposed'within slots 133 formed in the couplingand extending inwardly from the bore thereof. An internal annular shoulder 1134 is formed :within 11116 coupling for engagement by the heads 138a of the member l35rto expand said member. The .portion 12a'then moves within the sleeve 42 to displace the same outwardly toward the wall of the well casing. The external shoulder 13on the sub 12 then'engages .the upper beveled surface of the seating ring 46 whereby the weight of the tubing maybe imposed downwardly upon the assembly tocause distortion of .the'sealing sleeve 42 into its final sealing position and also to finallyexpand the upper confining member 135 into contact with the well casing. It is evident that this form-of the invention has all of the advantages of the form wherein the sealing element is constructed of a pluralityof opposed packing collars.

"In some instances, it may be desirable :to utilize the 'PICSSUIC 'in the .annu'lusxbetween the casing and the well tubing Ito :impart a downward force 'to the sealing assemblyB and in Figures 9 to 11 such anarrangement is illustrated. in this :case,the structure is identical'to that shown in Figures 1 to 6 except that the 'upperretaining or confining element '35 is replaced by an upper confining member 235. The member 235 is constructed of arcuate segments 236 which are connected to 'the sealing assembly by the through bolts 38 in the manner hereseal cup 48.

inbefore described. The segments 236 are formed with an annular extension or collar 47 and this collar has the lower portion of a pressure seal cup 48 molded thereto. The seal cup is provided with upwardly directed flared sealing lips 49 and obviously the pressure in the annulus above the unit acts downwardly on the pressure Since this cup is directly connected to the sealing element a force will be imparted downwardly against the upper end of the sealing assembly and assist in causing a radial distortion of said sealing element. If this pressure is sufficient to distort the sealing element it is not necessary to impose the weight of the tubing upon the assembly although in most instances, it will be desirable to engage the shoulder 13 of the sub 12 with the upper end of the upper confining member 235. It might be noted that as the section 12a moves through the bore 48a of the sealing cup it will function to more firmly engage the sealing lips 49 of said cup with the casing and with the mandrel. After displacement of the sealing cup material radially outwardly by the portion 12a, the shoulder 13 and upper enlarged portion of the sub further displaces the cup, after which the shoulder seats upon the upper end of the arcuate segments 236 of the upper confining member 235 to finally set the unit in position in the well casing. Removal of this form is accomplished in the same manner as removal of the first form heretofore described.

As has been noted, any suitable anchoring device may be employed and in Figures 12 and 13 an arrangement is shown wherein the anchoring slips are incorporated into the sealing assembly B. As shown in Figure 12 the sealing element is formed of the superposed elastic packing collars 30a. A lower retaining or confining member 331 is molded to the lowermost packing collar while an upper retaining or confining element 335 is molded to the uppermost packing collar. The lower confining or retaining member is constructed of a plurality of arcuate segments 50and the inner surface of the segments which co-act to form an axial bore 51 through the member are provided with a groove 52 and screw and are engageable therewith while the upper thread 56 which is inclined upwardly and outwardly of the mandrel is engageable within the recess 52. The threads 53 and 55 are preferably left hand threads, and as is clearly shown in Figure 12, the co-action between the screw threads connect the mandrel to the segments whereby the assembly may be supported by the mandrel.

Disconnection of the mandrel from the member 331 is effected by rotating the mandrel to unscrew the threads 55 downwardly from the threads 52 of the lower confining member 331, after which lowering of the mandrel relative to the member may be accomplished. It is noted that as the upper thread 56 on the mandrel moves through the threads 52 it acts to spread the segments 50 in a radial direction.

A lower seal cup 57 has its upper portion molded to the segments 50 of the confining member 331 and has downwardly directed flared lips 58 whereby a pressure from beneath the cup will urge said cup and the confining segments in an upward direction. The seal cup 57 seals the annular space between the casing 11 and the mandrel 115.

The upper confining member 335 is also constructed of segments 60 and said segments are secured to the lower segments 50 by the through bolts 48, the head 48:; of said bolts being disposed in inverted T-slots 59 formed in the segments 50 of the lower confining member. A seal cup 61 having upwardly directed flared lips 62 has its lower portion molded to the segments 60 of the upper confining member.

The external or outer surface of each of the upper segments 60 is extended or amplified and is formed with gripping teeth 63 which are shaped to lock against upward movement when said teeth are engaged with the wall of the Well casing 11. The outer surface of the segments 56 of the lower member are also amplified and provided with gripping teeth 64 which are shaped to lock against downward movement when said teeth are engaged with the wall of the casing. The joints between the segments 60 of the upper member and the joints between the segments 50 of the lower member extend in a radial plane and it is preferable to offset the lower portion of each segment so that an overlapping joint indicated at 60a is provided for the upper segments 60 and an offset or overlapping joint 50a is provided for the lower segments 50. This overlapping joint functions to prevent extrusion of the material of the packing or sealing element through the spaces formed between the joints.

In operation the parts are in the position shown in Figure 12 and the assembly is lowered by means of the mandrel 115, with the pressure below the unit acting against the under side of the lower seal cup 57 and tending to urge said cup upwardly; however, the connection or interengagement of the threads 53 and 55 and the engagement of the upper thread 55 of the mandrel within the groove 52 of the segments prevents such upward movement. When it is desired to set the device the mandrel is rotated to unscrew the threads 55 from the threads 53 which results in a downward movement of the mandrel relative to the packer assembly. As the mandrel moves downwardly the pressure from below may urge the lower seal cup upwardly and at the same time pressure from above will impart a downward force to the upper sealing cup. Thus, an end-wise compression is applied to the confining members 331 and 335 and is also applied to the sealing element 30 to distort the latter radially outwardly. As the sealing element moves radially outwardly into contact with the wall of the well casing 11 such radial movement is imparted to the segmental confining members 331 and 335 whereby the gripping teeth 64 and 63, respectively, of said members are engaged with the wall of the well casing. Continued application of pressure against the seal cups 58 and 62 merely functions to move the gripping teeth 63 and 64 into tighter engagement with the well casing 11.

In this form the mandrel is provided with the slots 17 and is also provided with the sub 12 so that initial displacement of the sealing member 30 as well as initial displacement of the confining members may be accomplished by the movement of the portion 12a of the sub through the assembly. It is noted that the frictional engagement of the seal cups 58 and 62 with the casing wall holds the assembly stationary while the mandrel is moved downwardly therethrough to accomplish initial radial displacement of the sealing element and the segmental end members. When the mandrel has been lowered sufficiently to engage the shoulder 13 with the upper confining member 335, the tubing weight is imposed upon the upper confining member 335 to assure that sufiicient end-wise compression is applied to the assembly to displace the gripping teeth 63 and 64 radially outwardly into gripping position and to move the sealing element into a final sealing position. As in the first forms heretofore described the by-pass or fluid openings 17 in the mandrel are moved below the lower sealing cup after the packer is in its sealing position and thus the differential in pressure above and below the packer acting upon the seal cups 57 and 61 will function to maintain the unit in its set position.

When it is desired to remove the packer it is only nec- ,essary to lift 1 the mandrel upwardly and -.due to t-the Tin- ,clination of the upper-thread -56i1=on,=the mandrel, theseg- .fbore. Of course, :if desired, reen-gagement of the threads 53 and 55 may be effected byrotation.

.It is notabsolutely, essential that thexthreads 55 and 56 of. the mandrel be I continuous since .said threads *could'rbe interrupted and .formed on two diametrically opposed lugs which replace the upset portion 54. .In such case, disconnection andrconnectionof thetthreads 55 and 56 would .be accomplishediin the manner hereinbefore described. It is, of course, understoodthat the ,tJ-slot connection showndn Figures 1 .to 6 may be substituted for the threaded connection between the mandrel ,1- and the lower confining member 331 shown in Figure 12.

From the foregoingit will be iseentthat this invention is one well adapted to attain all of theends and objects hereinabove set forth, together with other advantages which are obvious and which are inherent to the structure.

It will 'be understood that certain -features and subt combinations are of utility and may be employed without reference to other features-and subcombination. This is "contemplated by and -is within the scope of the claims.

iAs many possible embodiments mayfbe madeof the invention without departing-fromthe scope thereof, it is to be understood that all rnatterherein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having described the invention, I claim:

1. A sealing assembly for well packers including, an annular elastic sealing element having its ends confined by annular radially expansible retaining members, whereby the application of an endwise compressive force on the assembly distorts the sealing element radially and simultaneously expands the retaining members radially, pipeengaging means formed on the outer surface of the retaining members, whereby expansion of said members within a well pipe will move said pipe-engaging means into contact with the pipe to lock the assembly against displacement therein, a lowering pipe extending axially through said annular sealing element and said members, and interengaging threads on said pipe and one of said retaining members for detachably connecting the parts together.

2. A sealing assembly for well packers including, a support, a lower radially displaceable retaining member encircling the support, an upper radially displaceable retaining member encircling the support, said upper and lower retaining members each being formed of arcuate segments which co-act with each other to form a substantially annular member, an annular elastic sealing element surrounding the support and confined between said members, a coupling collar disposed below said lower member, and fastening means attached to the upper retaining member slidably extending through the sealing element and the lower member and slidably attached to said coupling collar, said fastening means being capable of radial and longitudinal movement relative to said coupling collar, whereby the members are fastened together and to the sealing element in a unitary structure and also whereby the application of a compressive force longitudinally of the structure results in a radial distortion of the sealing element and a radial displacement of the upper and lower retaining members.

3. A sealing assembly as set forth in claim 2, wherein the lower portion of the sealing element is molded to the segments of the lower member and its upper end is upper detaining, member zchanically displacing said "members and element sradialty outwardly when the support. is moved longitudinally with :respect totsaidmembersiandelement. I

5. A sealing assembly asset lforthiin claim .2, together with means on "thesupportzadzipted to :enter the ibore's of wthe:sealing elementandthe retaining members Ifor unechanically rdisplacing. said members and nelement iradiall y nontwardly "Wh6I1L the support is moved ilongitudinally with respect to said members and element, and additional means on. said support adapted "to engage the upper retaining'member, whereby said supportwmay be utilized .to impart .a longitudinal compressive force to the sealing element.

6. The sealing assemblyi set forth in claim .12, wherein said fastening means 'includes'a plurality "of bolts threaded to the segments of the 'upperl retainin'g member and slidwably @extending through longitudinal (openings :in vsaiid patileing'element and said lower retaininglmem'ber, ssaid hbo'lts having bolt heads slidably attached to :said coupling acollar.

'7. Thesealingassembly set forth in claim' 2, wherein 1 said fastening :means includes a plurality df bolts threaded to the segments of the :upper retaining member and slidably extending through longitudinal openings in said wpaolcing element and said lower detaining member, said bolts having 'bolt heads slidably attached to sa'id'coup'ling collar, and also wherein 'said coupling co'llar has 'a *plurality of longitudinalsloits each having *an erilarged lower =slo't portion in which; said bolt heads are slidably 'eonfined for limited longitudinal movement relative to said collar.

8. A sealing assembly for well packers including, an upper annular packing cup, a lower annular packing cup, said cups being radially expanded upon the application of an endwise compressive force thereto, an annular sleeve disposed between said cups, means connecting said sleeve and said cups together, pipe-gripping means formed on the external surface of said upper cup, another pipegripping means formed on the external surface of said lower cup, whereby expansion of said cups within a well pipe will move said pipe-gripping means into contact with the well pipe to lock the assembly against displacement therein, a lowering pipe extending through said annular cups and said annular sleeve, and interengaging threads on said lowering pipe and said sleeve for detachably connecting the lowering pipe to said sleeve and cups.

9. The structure set forth in claim 8, wherein said lowering pipe has passage means for establishing fluid communication between the area in the well pipe below said lower cup and the area in the well pipe above said upper cup when said threads are connected, and means for closing said passage means when said threads are disconnected and said lowering pipe is moved longitudinally relative to said cups and said sleeve whereby a differential in fluid pressure above and below said cups eifects an expansion of said cups and said pipe-gripping means on said cups into gripping contact with the well pipe.

10. The structure set forth in claim 8, wherein said pipe-gripping means on said cups each comprises a plurality of arcuate segments having teeth thereon, said teeth being adapted to engage the well pipe when said cups are expanded.

11. A sealing assembly for well packers including, an upper annular radially expansible packing element, a lower annular radially expansible packing element, means connecting said elements together to form an annular unit, pipe-gripping means formed on the external surface of each of said elements, a lowering pipe extending through said annular unit, means detachably connecting said lowering pipe to said annular unit, detachment of the connecting means permitting longitudinal movement of-said lowering pipe relative to said annular unit, said packing elements being radially expansible upon the application of an endwise compressive force to saidannular unit, the expansion of said elements effecting a radial movement of said pipe-gripping means into contact with a well pipe for locking the annular unit against displacement in the well pipe.

tially annular member, means for attaching the retaining members and element to each other to form a unitary structure surrounding the support, an enlarged external diameter portion on the support adapted to enter and move within into contact with the inner surfaces of said sealing element and retaining members when the support is moved longitudinally with respect to the element and members to initially impart radial expansion to said element. and the segments of said members, and an annular shoulder on the support above said enlarged external diameterportion engageable with the upper end of the segments of the upper retaining member for applying a compressive force through said upper retaining member to the sealing element and lower retaining element to further radially expand said element and the segments of said members.

14. A sealing assembly for well packers including, an annular elastic sealing element having its ends confined by radially expansible retaining members, said members each being formed of arcuate segments disposed to form an annular member, whereby the application of an endwise compressive force on the assembly distorts the sealing element radially and simultaneously expands the segments of the retaining members radially, a support on which the element and members are mounted, an enlarged external diameter portion on said support movable within into contact with the inner surfaces of said element and retaining members to co-act with the element and the segments of the members to effect initial radial expansion thereof, and an annular shoulder on the support and engageable with one of the retaining members for imparting a longitudinal compressive force to the element and members to effect further radial expansion thereof.

References Cited in the file of this patent UNITED STATES PATENTS Re. 13,457 Hovis Aug. 13, 1912 820,149 Spang May 8, 1906 1,804,818 Spang May 12, 1931 2,216,336 Barnes et al. Oct. 1, 1940 2,220,359 Tschappat Nov. 5, 1940 2,241,561 Spencer May 13, 1941 2,352,423 Church June 27, 1944 2,368,928 King Feb. 6, 1945 2,382,455 Turechek Aug. 14, 1945

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