US2822050A

US2822050A - Well packer

Info

Publication number: US2822050A
Application number: US368769A
Authority: US
Inventors: Martin B Conrad
Original assignee: Baker Oil Tools Inc
Current assignee: Baker Hughes Oilfield Operations LLC
Priority date: 1950-11-25
Filing date: 1953-07-17
Publication date: 1958-02-04
Anticipated expiration: 1975-02-04

Description

Feb- 4, l1958- M. B. CONRAD f WELL PACKER l'originan Filed Nov. 25., 195o w Z @2 6 g BL Eff Feb. 4, 1958 M; B. CONRAD WELL PACKER x original Filed Nov. 25,1950

2 Sheets-Sheet 2 MAer//v CoA/@A0,

vIN V EN TOR.

' BY i 'rraeA/EYS United Sit-tes Patent WELL PACKER B. Conrad, Downey, 4Calif., assignor to Baker Oil liglisa, Inc., Los Angeles, Calif., a corporation of Calivf-.Uriginal :application November `25, 195i), Serial No. .197,541,41ow vPatent No. 2,681,114, dated .lune 15, 195.4. Divided and this application July 17, 1953, Seril'Nn.368,`769

'The ,present invention relates to Vsubsurface well ap- ,.paratua .and ,moreparticularly .to well packers to beset y.in boreholes.

This application is a division of my application for Well ,Packer-and Setting Apparatus, Serial No. 197,541, v.tiled November 25, 1950, now Patent No. 2,681,114.

fAnobject of `the vpresent invention is generally to improve inilatable types of `well packers to be set in bore holes.

Another object of `the invention is to provide a well v4packer-embodying an inflatable packing element, in which the-'ends of the element are iirmly secured to preclude @their `pulling out of their mounting or retaining members when subjected tocomparatively high ination pressures.

Yet another object of the invention is to provide a well Jfpackerembodying aninatable packing element, in which the v.endeportions of the element are pressed more rrnly nagainst theparts to which they are secured as the vinflal:"tioupressureincreases, in order to prevent leakage from `the interior ofthe packing element.

Still aurther object ofthe invention is to cause the end .portions of the inatable packing element of a well packer -to become more rmly `secured to the parts to which they :are anchored as the inilating pressure increases, thereby fprecluding the end' portions from pulling out of such parts.

Another object ofthe invention is to provide an inflat- `able packing `element in a well packer which expands againstcthe "wall of the well bore wall in such manner as to increase'the sealing eiectiveness of the packing element against the wall.

This invention possesses many other advantages, and thas 'other objects which may be made more clearly apparent `fnom a consideration of a form in which it may be embodied. Such form is shown in the drawings accomd panying and forming part of the present specification. Thisform will now be described in detail, illustrating the general principles of the invention; but it is to be understood-that such detailed vdescription is not to be taken in a limiting sense, since the scope of the invention is best `deiined `by `the appended claims.

Referring to the drawings:

Figure l is a longitudinal section through an apparatus disposed in the well bore prior to setting of the packer portion;

`Fig. 2. is a view similar to Fig. l, disclosing thepacker expanded against the well bore;

Fig. 3 is an enlarged longitudinal fragmentary section of ,aL-portion of the apparatus disclosed in Fig. 1;

Fig. 4 is anenlargedlongitudinal section through the lwacker" portionoflthe apparatus, with its parts in retracted position;

Lli)

C, such as a wire line.

aszaus Patented Feb. 4, 195.8

,a ICE Fig. 5 is a cross-section taken approximately along the line 5 5 on Fig. 4;

6 is a cross-section taken along the line 6--6 on 1g.

Fig. 7 isa fragmentary longitudinal section disclosing the manner in which an end of the packing element of the packer is anchored.

As described in the drawings, a Well packer A is provided whi'ch is releasably secured to a setting tool B that is, in turn, attached to ailower end of a running-in string The lower portion of the setting tool may be constituted as a bailer or container D capable .of retaining cementitious material E for deposit upon the packer, after the latter has vbeen set in the well bore F.

The combination of apparatus disclosed is so devised 'that the setting tool B'will expand and set the packer A .in the well bore, becoming released when its pumps a prebody abutment 13 is threadedly, or otherwise, attached to the upper end -of the central body portion 1i? in longitudinal spaced relation to the lower body abutment 12,

providing a space around the central body for the accommodation of an inflatable packing element 1d, of rubber, or rubber-like, material. The ends 15 of the packing elementare secured to upper and lower retainers 16 engaging the upper and

lower abutments

13, 12, respectively. The element is also disposed around a retainer and spacer sleeve 17 engaging the upper and lower retainers and holding them in spaced relation.

The upper and 'lower packing element retainers 16 and the end portions 15 of the packing element are alike, although oppositely arranged. Each retainer 16 has a 'disc-like base portion 18 engaging the

body abutment

12 or 13, and is also provided with a longitudinally extending skirt4 portion 19 merging into an inturned ilange Ztl, forming a space 21 with the base portion 13 into which an external ilange 22 on the packing element extends. The inturned flange 20 ts into a circumferential space or groove 23 in ,the rubber packing element, the two

ilanges

20, 22, in effect, forming interlocking circumferential hooks anchoring the packing sleeve to the retainer.

The retainer and spacer sleeve 17 is mounted upon the central `body'portion 10, and may have a generally cylindrical external portion 24. The upper and lower portions 25 of the sleeve are concave, tapering inwardly toward the retainers 16. Each concave portion is spaced from kanadjacent vretainer flange 20, the distance between each concave portion and its adjacent retainer ilange decreasing in a direction away from the lbase portion lli.

Alsodisposed in each end portion 15 of the packing element 14 is a retaining ring Zo, which is spaced longitudinally from the retainer base 18, and which initially `occupies a position slightly longitudinally outward of .the

inturned flange 20. The outside diameter of this ring 26 is substantially equal to, but slightly less, than the inside diameter of the inturned flange 20, to function in the manner described below. The ring itself may initially be held coaxially with the well packer by a plurality of centering pins 27 welded to the ring and slidably received in companion vsockets 28 in the base 18 of the retainer 16.

As disclosed in the drawings, the packing element 14 is also provided with a central circumferential rib or flange .3, 29 received within a companion external groove 30 in the spacer sleeve 17. This rib or flange has the purpose of causing the packing to be expanded or inflated flatwise against the wall of the well bore F, rather than only a narrow longitudinal extent of contact being obtained, which occurs in the absence of the rib.

The entire packing structure may be made by mounting the upper and lower retainers 16 with the retainer sleeve, rings 26 and centering pins 27 in a suitable mold (not shown), and with the packing structure parts occupying the relative positions desclibed in Fig. 4. The packing element 14 may then be molded around the spacer sleeve 17 and in the spaces between the sleeve 17 and the upper and lower retainers 16, the retaining rings 26 being completely embedded in the rubber or rubber-like material. Of course the periphery of the rubber sleeve 14 may be molded to the desired form, such as the cylindrical surface disclosed in the drawings, substantially coinciding with the cylindrical surfaces of the retainers 16. Some of the rubber material may also extend into radial ports 31 disposed centrally in the spacer sleeve 17.

The packing element 14 is designed for outward expansion under the infiueuce of fluid under pressure pumped or forced into its interior. Such uid under pressure passes into a central passage 32 in the body, and through radial body ports 33 and the spacer sleeve ports 31 to the interior of the packing. The subjecting of the fluid to high pressure will stretch and inflate the packing element 14 in a lateral direction toward sealing engagement with the wall of the confining enclosure F, such as the wall of an uneased well bore. However, when such inilation takes place, the inflating Huid, or fluent material, must be prevented from owing back out of the inated sleeve 14. This action is forestalled by providing a check valve across the body ports.

As illustrated, the body ports 33 open into a peripheral or circumferential body groove 34 having tapered side walls 35 converging inwardly toward each other. The back pressure valve 36, in the form of a round rubber seal ring, or O ring, is disposed in the groove 34 and tends inherently to contract into snug sealing engagement with the tapered walls 35 of the groove. Such engagement occurs with the O ring 36 disposed somewhat outwardly of the outer ends of the body ports 33` When fluid under pressure is forced through the body passage 32 and ports 33, it will enter the inner portion of the peripheral groove 34. This pressure will then stretch the back pressure valve ring 36 outwardly, to allow the uid to pass around the ring and into the outer large portion of the tapered groove 34, from where it can flow through the spacer ports 31 to the interior of the packing sleeve 14. When the internal pressure is released, the valve member 36 contracts into snug engagement with the tapered walls 35 of the groove, and prevents the fluid from owing in a reverse direction through the body ports 33.

The fluid is also prevented from escaping along the spacer sleeve 17 and body 10 to the exterior of the packer, by providing seal rings 38 in grooves 39 in the central body portion engaging the upper and lower retainers 16.

As duid is pumped into the packing sleeve 14, it is inflated and stretched outwardly into engagement with the wall of the well bore F. The central circumferential rib or flange 29 prevents the central portion of the packing element from rst engaging the well bore wall along a comparatively narrow wall length, such as tends to occur in the absence of the rib. The much thicker section of the packing element presented by the central rib 29 resists concentration of the expansible force at that particular portion of the packing sleeve, and causes expansion of the sleeve 14 to take place along an extended portion of its length in cylindrical fashion into sealing engagement with the wall of the well bore. As a result, a much greater area of sealing contact is obtainable between the exterior of the packing element 14 and 4 the wall of the well bore F, even under a comparatively low pressure and infanting condition, such as "occurs when the packing element is expanded outwardly to a comparatively large diameter, which, for example, may be two to three times its initial retracted diameter.

During the inflation of the packing element 14 there may be a tendency for its ends 15 to pull out of the retainers 16. As inflation occurs, the flange portions 22 of the packing element at each end move slightly toward each other (Fig. 7), shifting the rings 26 toward the inturned flanges 20 of the retainers 16, the pins 27 guiding and confining the rings 26 for movement parallel to the axis of the body 10.v Each ring 26 has a diameter that is only slightly less than the internal diameter of its associated flange 20. The movement of the ring 26 toward the flange 20 causes it to grip or pinch intervening rubber packing material between it and the inturned flange (see Fig. 7). In addition, as the ring 26 is moved longitudinally, it comes closer to the tapered portion 25 of the retainer and spacer sleeve 17, also pinching and clamping the rubber material' between it and the spacer sleeve. Thus, it is apparent that the rings 26 are effective in more securely anchoring the ends 15 of the packing sleeve to their

companion elements

16, 17, precluding pulling out of such ends under the normal pressures employed in fully expanding the packing 14 into sealing engagement with the wall of the Well bore F.

The flanged ends 22 of the packing sleeve 14 form a seal with the retainer flanges 20, to prevent leakage of fluid from the interior of the packing sleeve around its ends to the exterior of the packing sleeve. As expansion of the sleeve 14 takes place, the force of engagement between each inturned ange 20 and the packing sleeve increases, which increases the sealing effectiveness between these parts. Such sealing effectiveness is further enhanced by the clamping of the ring 26 upon the packing sleeve, forcing the latter more firmly against the inturned ange 20.

Ination of the packer A is accomplished through use of the setting tool B lowered with the packer into the Well bore F. This setting tool includes a cylinder'40, consisting of a cylinder sleeve 41 threaded onto an upper head 42 and also onto a lower head 43. The lower head is threaded into a coupling 44 threadedly receiving a lower setting sleeve D, or bailer or container, having a sleeve 45 threaded on its lower end and encompassing a cylindrical portion 46 of the upper body abutment 13. This sleeve 45 is initially secured to thje body abutment 13 by one or more shear vscrews 47. Leakage between such sleeve and the body abutment is prevented by a suitable seal ring 48, such as an O ring, mounted in the abutment 13 and engaging the inner wall of the sleeve 4S.

The cylinder 40 contains the fluent material G, Asuch as a liquid, which also fills the passage 49 ythrough a compression tube 50 extending centrally through the lower head 43. Leakage between the lower head and compression tube is prevented by use of a suitable seal 51 mounted in a groove 52 in the head 43 and slidably engaging the exterior of the compression tube 50. The compression tube is threaded onto the upper end of a tubular extension 53, which is, in turn, threaded into a thrust tube or nipple S4 extending into the upper end of the packer body lll. The nipple has a stop nut 55 threaded upon it engaging the upper end 10a of the body 10, the stop and thrust nut being locked in position on the nipple by a suitable lock nut 56.

The upper end of the compression tube 50 may have a cap 57 threaded directly into it; or a spacer member 58 may be threaded into the compression tube 50 and the cap 57 secured to the spacer member.

As stated above, the liquid G fills the cylinder 40, being capable of passing through ports 59 in the compression tube above the lower cylinder head 43 into the central gaseoso passage 49 through the compression tube 50, tubular extension 53, nipple 54 and bodypassage32, .as well as the ports 33 in the latter, the tapered groove' 34 and the sleeve port 31. A tloating or pumping piston 66 rests upon the upper end of the liquid G inthe cylinder 40, suitable piston rings 67 vbeing provided on the piston for sliding engagement with the cylinder sleeve 41. The piston` 66 is H-shape in cross-section, providing a lower chamber 6i? into which some air may be compressed upon filling the cylinder 40 with the liquid G; so as to allow increases in temperature of the liquid to increase the volume of the liquid without subjecting the packing sleeve 14 to any material pressure. It is apparent that as the oating piston 66 is forced downwardly in the cylinder sleeve 41, the liquid G is yforced `out of the cylinder and through the

tubular members

50, 53, 54 into the packer body 10, passing into the interior of the packing sleeve 14, inllating the latter to a desired extent. Y

The parts are originally held in place as illustrated in Fig. l, with the screws 47 intact, the appropriate location of the parts being insured by engagement of a shoulder 69 on the compression tube 50 with the underside of the lower cylinder head 43. Downward movement of the floating piston 66, for the purpose of forcing the liquid G downwardly and inllating the packing element 14, is provided as a result of the combustion of la power charge 7 0 containing its own source of oxygen. This power charge rests upon the floating piston 66 within an upper recess 71 of the latter, and is initially disposed within a compres sion chamber 72 in the upper cylinder head 42. The upper end ofthe power charge is ignited by firing a cartridge 73 disposed within a gun barrel 74 clamped between the cylinder head 42 and a cable head 75 threaded into the latter. The wire line cable C is attached to the cable head 75, in a known manner, and has an electrically` conductive wire or core 76 connected to a heating filament 77 in the cartridge.

During lowering of the apparatus-through the fluid in the well bore, the hydrostatic head acting on the exterior of the packing element 14 increases. It is desired to neutralize the hydrostatic head, and for this reason the well liuid is allowed to enter the

tubular members

50, 53, 54 through ports 7 8 that may be provided in the compression tube 50 below the lower cylinder head 43. Thus, the well fluid can pass through a window or opening 79 in the dump bailer container D and thence through the ports 78, this pressure being exerted upon the liquid G in the

tubular members

50, 53, 54, as well as within the packing 14 itself. However, when pressure is being applied by the oating piston 66V to the liquid G in the apparatus, the ports 78 are to be closed, to prevent escape of iluid G from the apparatus. For this reason, the ports are controlled by a one-way check or back pressure valve S0, which may be similar to the check valve 36 located in the packer A, although acting in a reverse direction.

The compression tube 50 may be provided with an inner circumferential groove 81 communicating with the radial ports 78. This groove has tapered side walls 82 converging in an outward direction toward each other. The ring check valve member 80 is disposed within this groove 81 and tends to expand outwardly into engagement with the tapered side walls 82. Pressure exerted within the compression tube 50 in excess of the hydrostatic head externally thereof forces the O ring against the tapered side walls 82 and prevents the fluid from flowing outwardly through the ports 78, but when the hydrostatic head or fluid in the well bore overbalances the iiuid pressure within the tubular members t), 53, 54, the O ring is urged inwardly out of the sealing engagement with the tapered side walls 82, and allows the hydrostatic pressure to be exerted upon the liquid G in the apparatus.

The apparatus is assembled with the parts occupying the relative position illustrated in Fig. l. Prior to attachment of the setting tool B to the well packer A, the liquid G is placed inthe setting tool, with the floating piston 66 adjacent the upper cylinder head 42. Since the upper and lower portions of the piston are symmetrical, it. is im; material which end of the piston is first placed in the cyl'- inder 40. The end 66a of the piston will engage the upper cylinder head 42, with the power charge "resting1within the upper cup portion 71 of the piston. They lower cup portion 68 of the piston will provide the'desired air cham ber that will allow expansion of the fluid G upon increase in its temperature.

The setting tool B is then assembled appropriately on the packer A, the nipple 54 being piloted in the central body bore 32 until the stop nut 55 engages the upper end 10a of the body. A seal ring 35 is disposed in a nipple groove 86 and engages the wall of the body bore, to prevent leakage of fluid in an upward direction around the nipple. The screws 47 are. then threaded into the setting sleeve 45 and upper abutment 13. The apparatus is then lowered into the well bore F. InV the event that the bore hole contains fluid, the hydrostatic head is equalized by the luid pressure being imposed upon the liquid G, through the expedient of passing through the ports 78 and unseating the upper check valve 80. As a result, the pressure both internally and externally of the packer portion A of the apparatus, as well as the setting tool portion B, is equalized until the well packer is being set.

When the setting location in the well bore F is reached, the electrical circuit through the filament 77 is completed, tiring the cartridge 73 and causing the llame issuing from it to ignite the upper end of the power charge 70. This latter combustible fuel commences burning and generates a gas at a gradually increasing pressure. This gas under pressure acts downwardly on the floating piston 66, which begins to move downwardly in the cylinder sleeve 41, forcing the liquid G ahead of it. The liquid in the tool is subjected to pressure, as a result of the movement of the floating piston 66, greater than the hydrostatic head of fluid in the well bore F. This pressure holds the upper check valve ring 89 in closed position against the tapered walls S2 of the circumferential groove 81 and effectively closes the upper ports 78. The pressure also acts in an outward direction upon the lower check valve O ring member 36,V urging the valveu 36 out` of engagement with the tapered seats 35, and allowing the fluid toflow around the valve 36, through the spacer sleeve ports 31 into the interior of the packing element 14. As the pressure in*- creases, the uid G pumps or inates the packing element 14 in an outward direction, until it contacts the wall of the well bore F along an extended longitudinal length, whereupon the packing element may elongate along the well bore wall in up and down directions.

As the loating piston 66 moves downwardly, because of the continued burning of the power charge 70, it forces the liquid G ahead of it, and approaches the stop cap 57 at the upper portion of the compression tube 50 or spacer member S8. When the oating piston 66 engages the cap 57, a predetermined volume of iluid G has been pumped into the packing element 14. As the power charge 70 continues to burn, it buildsup an increasing pressure in the cylinder 40 above the piston 66. This pressure is now exerted directly uponthe cap 57, spacer member 58 (if one is used), compression tube 50, tubular extension 53, nipple 54 and stop nut 55 directly upon the packer body 10. When the gaseous pressure force exceeds the shear strength of the screws 47, it dis- -rupts them, thereby releasing the setting tool B from the well packer A. After the shear screws 47 have been disrupted, the setting tool B may be elevated to the top of the hole and used again with another packer in another well bore. If the setting tool B includes the bailer portion D containing cementitious material E, the elevation of the setting tool B, following shearing of the screws 47, will allow the cementitious material E to be dumped from the bailer upon the set packer A.

It is to be noted that a certain quantity of liquid G remains below the lioating piston 66 upon its contact with the compression tube cap 57, and that the piston and compression tube move downwardly after the shear screws 47 have been disrupted, until the piston 66 engages the lower cylinder head 43. Inasmuch as it is desired to inflate the packing element 14 to a predetermined extent, by pumping only a xed volume of fluid G into it, substantially all of the fluid G below the piston, following its engagement with the cap 57, is bled to the exterior of the apparatus. As a result, the volume of fluid G pumped into the packing 14 is the volume of liquid displaced by the piston 66 in moving from its uppermost position to a position in engagement with the cap 57. By varying the length of the spacer member 58 secured to and between the compression tube 50 and cap 57, the displacement volume of the piston 66 can be varied, which correspondingly alters the volume of fluid G pumped into the packing element 14. Of course, the spacer member 58 may be eliminated and the cap 57 screwed directly into the compression tube 50, under which condition the floating piston 66 will pump a maximum quantity of fluid G into the packing 14.

The excess fluid G below the piston 66, upon its engaging the cap 57, is bled to the exterior of the apparatus after shearing of the screws 47, which allows the compression tube 50 to move downwardly in the lower cylinder head 43. During the downward movement of the piston 66 in the cylinder 40 to inflate the packing element 14, the seal ring l. prevents leakage of the fluid downwardly around the exterior of the compression tube 50. However, the upper portion 50a of the compression tube has a reduced diameter and the lower cylinder head portion 43a below the seal ring has a larger diameter; so that the downward movement of the compression tube 50 will bring its smaller diameter portion 50a adjacent the seal ring 51, which cannot engage it, and which will, therefore, allow the excess iluid G to ilow between such portion and the seal ring and then downwardly through the annular space 90 between the cylinder head 43a and the compression tube 50 into the bailer portion D of the apparatus. The longer the spacer member 58 the greater will be the quantity of iluid that must be bled out between the compression tube 50 and the lower cylinder head 43. When the cap 57 is threaded directly into the compression tube 50, in order to obtain maximum expansion of the packing element 14, there is very little fluid G remaining below the piston 66, following its engagement with the cap 57, and the bleeder or by-pass feature may be omitted, if desired.

The inventor claims:

l. In a wel] packer: a body; an expansible packing element around said body; a retainer on said body; said retainer and element having interlocking circumferential portions securing said element to said retainer; and an annular member embedded in said packing element, said annular member being located adjacent said interlocking portion of said retainer and on the same side thereof as said interlocking portion of said packing element, whereby upon expansion of said packing element said annular member is moved toward said retainer interlocking portion to prevent disconnection between said interlocking portions.

2. In a well packer: a body; an expansible packing element around said body having a laterally extending surface; a retainer on said body having a portion thereof adjacent to said surface and having a surface opposing and contacting said surface; an annular member embedded in said packing element adjacent to and to one side of said contacting surfaces, whereby upon expansion of said packing element said annular member is moved toward said contacting surfaces.

3. In a well packer: a body; an expansible packing element around said body and having an external groove providing a laterally extending surface; a retainer on said body having a circumferential inturned flange received within said external groove, said flange having a surface opposing and contacting said other surface; and an annular member embedded in said packing element adjacent to and to one side of said contacting surfaces, whereby upon expansion of said packing element said annular member is moved toward said contacting surfaces.

4. In a well packer: a body; upper and lower longitudinally spaced retainers on said body having opposed portions providing inwardly directed flanges; an expansible packing sleeve around said body and having external grooves receiving said flanges, whereby portions of said sleeve interlock with said flanges; and annular members embedded in said packing sleeve, each of said annular members being located adjacent one of said flanges on the same side thereof as said portion of said packing sleeve, whereby upon expansion of said packing sleeve said annular members are moved toward said flanges to prevent disconnection of said sleeve portions from said flanges.

5. In a well packer: a body; upper and lower longitudinally spaced retainers on said body having opposed portions providing inwardly directed anges; an expansible packing sleeve around said body and having external grooves receiving said flanges, whereby portions of said sleeve interlock with said flanges; a spacer member around said body and within said sleeve, said spacer member having tapered portions; and annular members embedded in said packing sleeve, each of said annular members being located adjacent one of said flanges on the same side thereof as said portion of said packing sleeve and also being located adjacent one of said tapered portions, whereby upon expansion of said packing sleeve said annular members are moved toward said flanges and tapered portions to prevent disconnection of said sleeve portions from said flanges and disengagement of said sleeve from said tapered portions.

6. ln a well packer: a body; an expansible packing element around said body and having an external groove providing a laterally extending surface; a retainer on said body having a circumferential inturned flange received within said external groove, said flange having a surface opposing and contacting said other surface; a member around said body and within said element, said member having a tapered portion; and an annular member embedded in said packing element adjacent to and to one side of said contacting surfaces and adjacent said tapered portion, whereby upon expansion of said packing element said annular member is moved toward said contacting surfaces and tapered portion.

7. A packing structure, including a packing element having an external groove providing a laterally extending surface; a retainer having a circumferential inturned flange received within said external groove, said flange having a surface opposing and contacting said other surface; and an annular member embedded in said packing element adjacent to and to one side of said contacting surfaces, whereby upon expansion of said packing element said annular member is moved toward said contacting surfaces.

8. A packing structure, including a packing element having an external groove providing a laterally extending surface; a retainer having a circumferential inturned flange received within said external groove, said ilange having a surface opposing and contacting said other surface; a member within said element and having a tapered portion, and an annular member embedded in said packing element adjacent to and to one side of said contacting surfaces and adjacent said tapered portion, whereby upon expansion of said packing element said annular member is moved toward said contacting surfaces and tapered portion. v

9. A packing structure, including upper and lower longitudinally spaced retainers having opposed portions providing inwardly directed flanges, an expansible packing sleeve having external grooves receiving said flanges,

portions from said anges.