US2726722A

US2726722A - Packing flow restricting devices

Info

Publication number: US2726722A
Application number: US325869A
Authority: US
Inventors: Reuben C Baker
Original assignee: Baker Oil Tools Inc
Current assignee: Baker Hughes Oilfield Operations LLC
Priority date: 1952-12-13
Filing date: 1952-12-13
Publication date: 1955-12-13
Anticipated expiration: 1972-12-13

Description

Dec. 13, 1955 R. c. BAKER Y PACKING FLOW RESTRICTING DEVICES Filed DeC. 15, 1952 ZEUBEN C, JgWER)I INVENTOR.

United States Patent O PACKING FLOW RESTRICITNG DEVICES Reuben C. Baker, Coalinga, Calif., assignor to Baker O il Tools, Inc., Los Angeles, Calif., a corporation of California Application December 13, 1952, Serial No. 325,869 12 Claims. (Cl. 166-204) 'I'he present invention relates to packing structures, and more particularly to the preventing of cold flow of flexible, pliable packing materials through substantial clearance spaces that might exist between the support for the packing structure and the wall of a confining enclosure, such as a well casing, liner, or similar well conduit.

The packing structures of oil and gas well packers are usually made of liexible, pliable materials, such as synthetic or natural rubber. There is a tendency for the packing material to cold ow through the clearance space ordinarily provided between the packer and wall of the well conduit in which the packer is run, when the packing structure is in sealing engagement with the conduit wall, especially when the packing structure is subjected to high pressures, high temperatures, or both. The cold owing through the clearance space may be of suicient extent to completely remove the packing material from its intended region of sealing against the well conduit, thereby resulting in failure of the entire well packer.

An object of the present invention is to preclude the cold ilowing of the packing materials from their intended sealing regions when they are subjected to high pressures, high temperatures, or both.

Another object of the invention is to provide an improved device for preventing the cold flowing of a packing of the retrievable type, which is expansible against the wall of a confining well conduit and which is also retractable therefrom.

A further object of the invention is to provide a well packer embodying an expansible and contractible device for preventing cold ow of packing material through the clearance space between the packer and wall of a conining well conduit, the device being positive in its operation, strong and sturdy, and relatively economical to manufacture.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of a form in which it may be embodied. This form is shown in the drawings accompanying and forming part of the present specification. It will now be described in detail, for the purpose of illustrating the general principles of the invention; but it is to be understood that such detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is a combined side elevation and longitudinal section through a portion of a well packer embodying the invention, the packing structure being disclosed in retracted position;

Fig. 2 vis a fragmentary longitudinal section, on anenlarged scale, of the device disclosed in Fig. l, with the packing structure expanded against the wall of a confining well casing;

Fig. 3 is an exploded, isometric projection of the device `2,726,722 Patented Dec. 13, 1955 ice for preventing cold owing of the rubber, or rubber-like, packing material.

The well packer disclosed in the drawings is generally of a known type, and may include an upper outer tubular body member 10 telescoped around an inner tubular body member 11. This inner tubular body member is slidable relatively along the inner surface of the outer tubular body member and may consist of several sections. As disclosed, it includes an upper section 12, which is threaded into a lower tubular body section 13, that carries the ow preventing ring structure 14. This structure 14 is engageable with one end, such as the lower end, of a packing sleeve 15 of rubber or rubber-like material that surrounds the upper section 12 of the inner tubular body 11. The upper end of the packing sleeve is preferably secured to an upper abutment structure 16 attached to the outer tubular body 10. When the upper body 10 is telescoped downwardly over the lower body 11, the packing sleeve 15 is foreshortened and is compressed radially outward and inwardly into sealing engagement with both the inner tubular body 11 and the wall of a well casing 17, or other coniining well conduit in which the apparatus is to be set. When expanded outwardly, the packing sleeve 15 must bridge the substantial annular clearance space 18` normally existing between the well packer and the Wall of the surrounding Well conduit.

More speciiically, the apparatus disclosed in the drawings includes an upper abutment ring member 19 having an upper portion 20 threaded onto the lower portion of the outer tubular body 10, the ring member including an inwardly directed flange 21 extending across the lower end of the outer tubular body 10 for reception under an external iiange 22 provided at the upper portion of the inner tubular body section 12. It is preferred to tirmly secure the upper end of the rubber packing sleeve 15 to the abutment ring 19. In the present instance, this is accomplished by molding an upward extension 15a of the packing sleeve within and to the inner surface of a tie ring 23 that is externally threaded for threaded reception within a threaded lower portion 24 of the abutment ring 19. When the tie ring 23 is threaded into the abutment ring 19, the upper end of the packing sleeve 15 is firmly attached to the abutment ring. However, the packing sleeve 15 and tie ring 23 are readily disassembled from the abutment ring 19 by unthreading the tie ring from the abutment ring.

As stated above, the other or lower end of the packing sleeve engages the lower abutment structure 14. This abutment structure is designed to occupy a normal or initially retracted position when the apparatus is .being moved through the well casing 17, but is expandible out-- wardly to bridge the clearance space 18 that usually exists between the well packer structure and the wall of the well casing, offering a barrier to the cold ow of the packing sleeve material through this clearance space. closed, the lower end of the packing sleeve 15 engages a solid thrust and supporting ring 25 whose upper travel along the inner tubular body 11 is limited by its engagement with a shoulder 26 formed on the tubular body, this shoulder being disposed at the lower end of the cylindrical portion 27 of the body 11 encompassed by the packing sleeve. The ring 25 has a depending or longitudinally extending boss 2S that provides a recess 29 with the remaining outer portion of the ring for the reception of an inner split ring 30 which inherently tends to occupy a contracted or retracted position, with its generallyvcylindrical inner surface 31 in engagement with the `cylind1 -ica l Y shoulder 32 defining the periphery of the boss 28.

of which projects a ange portion 34. The upper end of As dis-V this ange `34 is slidable along the lower surface of the ring 25.' This inner split ring 30 is disposed above and within an outer split ring 35 which inherently tends to contract. This outer ring, in effect, is nested within the inner ring 30, its longitudinally extending skirt or sleeve 36 having its inner surface 37 slidably engaging the outer surface of the skirt or-sle'eve 33 ofthe inner ring 30. The outer ring 35 is also provided with a flange portion 38 extending laterally outward from the skirt 36, and this tlange portion 38 is engageable with the lower surface of the inner ring ange 34.

As disclosed in the drawings, the

skirt portions

33, 36 of thetwo rings 31), 35 are preferably cylindrical andthe eoengaging slidable surfacesV of the

flange portions

34, 38 heretofore described are disposed generally at right angles tothe axis of the well packer. Y. `fThe lower endsV 40 ofthe inner and outer skirts V33, 36

' This expander member is also provided with a tapered Surface 44 at'its end parallel to the other tapered surface 41 and. engaging a tapered surface 45 on the lower Vside o'f the outer ring flange 38. Y

For the purpose'of increasing the flexibility of the inner and outer rings 3i), 35, their

ange portions

34 and 38 are provided .witha multiplicity of circumferentially spaced, generally radial slits: or-

slots

46, 47 extending from the peripheries of the flanges substantially to the respective skirt portions 33,. 36 of the rings. Thus, the

Vinner ring 30 has a large number of slits or slots 46, and

theY same is Atrue of the flange 38 of the outer expansible andlcontractibie ring 35, because of the slots 47. Accordingly,. both of the rings 3), 35 may expand outwardly.

with. facility from their initial contracted or retracted Y positions. VThe gaps provided by the slots 46,. 47 allow the. ange material onV opposite sides of the slotsto move toward each other, tending to close the slots. Y Y

The packer structure is mounted onthe body 11,V and the' partsV are initially arranged in the position disclosed in Fig. vl. In this figure, the solid, or circumferentially continuous, thrust and supporting ring 25 is in engagement with the shoulder 26, and this ring 25, in turn, has its outwardly extending portion andV also the periphery 32 of Y its boss 28 engaged by the inner expanding ring 36, which isY then in a retracted position. The outer expanding ring 35 is also in retracted position. However, its split 50 is preferably `angularly oifset with respect to the split 51 of therinner ring, to avoid alignment between the two splits orI slots, which would provide al gap through the expansibleabutrnent structure 14.` As an example, the splits 50, 51 of the rings may be substantially diametrically opposite one another. In addition, the two

split ring members

30, 35 are so arranged that their slits or

slots

46, 47 are out of alignment with each other, the slits or slots beingl disposed, for example,.in the relative Y positionV shown in elevation in Fig. 1, being offset or staggered with respect to one another. When the parts are in retracted position, there isV arsubstantial gap 52 between the skirt 36 of the outer ring member 35 and the skirt or sleeve portion 43 ofthe expander member 42, as clearly shown in Fig. l'. In addition, the radial dimensions of the two

anges

34, 38 are. such that their peripheries lie on substantially the same cylindrical surface.

When the packing sleeve 15` is to be expanded, the lower tubular body 1 1 is held stationary by some other portion of the well packer, such as. a; lower setV of slips (not shown), that are movedintd anchoring engagement with` the wall offthe well casing, 1777.Y Since the inner 4 tubular body 11 is now held stationary, the packing sleeve 15 can be expanded by moving the outer tubular body 10 and its abutment ring .19 downwardly toward the expander member 42 of the inner tubular body 11. Such downward movement is transmitted through the packing Y sleeve 15 to the solid thrust ring 25,. This solid thrust ring then transmits the movement to the inner and oute'row preventing rings 3l),V 345, sliding them downwardly along the tapered surfaces 41, 44 of the Vexpander member 42 and in a radial outward direction intor rm engagement with the wall of the well conduit 17. When engaged with the wall ofthe wellconduit, the split ring members 30,V

35 bridge the'annular space 18 between the solid ring 25 and the casing wall (Fig. 2'). Y

Y The inner and

outer rings

30, 35 canexpand outwardly Vin view of the fact that they are split. This'expansionis allowed to occur, despite the relatively thick sections of their

ilange'portions

34, 38, because of the provision of the

radial slots

46, 47. During thev expansion, `and after the full expansion of the two ringsinto. engagement with the wall of the well conduit 17, the .split portions 50, 51-

of the rings Vremain in their oset relation to each other,

and this is also true of thev staggered relation between i the

radial flange slots

46, 47. .Y Y An increase in the downward force imposed, on the outer tubular body 10 will now shift the upper abutment ring 19 toward the expanded lower flow preventing ring structure 14, foreshortening thevr packing sleeve and expanding it radially into firm sealing engagement with they wall of the well conduit 17, asf well; as against the periphery of the inner tubular body '11 (see Fig. 2). If the endwise force; on the rubber packing sleeve is excessive,v then some of the packing` material willl ow around the exterior of the solid thrust ring 25 and` through the'clearance space 18. VHowever, this rubber packing materialV cannot pass beyond the flange 34 ofthe inner split ring i 30, since it is bridging the clearance space just referred to. Pressures imposed on the packing sleeve`15, suchas those that might be due to thefhydraulic pressureV in the annulus 18 above the packing sleeve 'and between the outer tubular body 10 and the well conduit 17, may be' sorhigh (for example, it may be 8,000 p. s. i.) and the Vwell temperatures may also be comparatively high (of the order of 300 degrees F.) that the packing material may even ow through the split 51 of the upper a'ngef 34. However, the packing material will then engage the flange 38 of the outer ring 35 therebelow, and cannot ow longitudinally to any further extent.. Inraddition, Vthe radial slots 46, 47.V in the flanges will notpermit any ex.-V cessive flow of packing material thereinto, since they, are.,

relatively narrow and the slots themselves close to a certain extent as a result of the outward expansion

ofthe ring angcs

34, 38 into engagement' with the wall of the well conduit 17.

When it is desired to retract the packing structure, theV outer tubular member 10 is elevated with respect tothe inner tubular member'- 11, the packing sleeve 15 inherently"V assumingitsv initial position. When the endwise force is removed from the thrust ringV 25 andthe split rings 30, 35, then the split rings, due to` their inherentvcontractibility, will retract to their initial posit'ons, moving radially in-'- ward and upwardly along the expander surfaces 41, 44 back tothe positionsshown inFig. 1 The packing sleeve 15 and the cold flow preventing structure'14` may againY be expanded and retracted a plurality of times, the'ilow preventing ring structure at all times bridging the annular clearance space 18 between the metallic packerpart 42 and the wall ofthe. wellca'sin'g 17, to prevent cold flow ofthe packing material through'` the Vclearance space;

The inventor claims:

l. in a packing structure: a pliant packing lada'pted to* be expanded laterally; abutment means adjacentisaid p'ayck'-v ing anda having innerY andl outer: inclined exygsanrder"sur-v faces; and' a iiow .preventing ring' device engaging said packing and abutment means, said device including an inner splitting engaging said inner expander surface,.a'nd

an outer split ring encompassing said inner ring and engaging said inner and outer expander surfaces.

2. in a packing structure: a pliant packing adapted to be expanded laterally; abutment means adjacent said packing and having inner and outer inclined expander surfaces; and a flow preventing ring device engaging said packing and abutment means, said device including an inner split ring having a skirt portion engaging said inner expander surface and a flange extending outwardly from said skirt portion, and an outer split ring having a skirt portion encompassing said inner ring skirt portion and engaging said inner expander surface, said outer ring having a flange extending outward from the outer ring skirt portion and engaging said outer expander surface.

3. in a packing structure: a pliant packing adapted to be expanded laterally; abutment means adjacent said packing and having inner and outer inclined expander surfaces; and a ow preventing ring device engaging said packing and abutment means, said device including an inner split ring having a skirt portion engaging said inner expander surface and a iiange extending outwardly from said skirt portion, and an outer split ring having a skirt portion encompassing said inner ring skirt portion and engaging said inner expander surface, said outer ring having a ange extending outward from the outer ring skirt portion and engaging said outer expander surface, said iianges being provided with a plurality of circumferentially spaced generally radial slots to increase the iiexibility of the rings.

4. ln a packing structure as defined in claim l, wherein said rings inherently tend to contract from outwardly expanded positions.

5. In a packing structure: a pliant packing adapted to be expanded laterally; abutment means adjacent said packing and having inner and outer expander surfaces inclined laterally outward in a direction leading away from said packing; and a ow preventing device engaging said packing and abutment means, said device including an inner split ring having a skirt portion provided with an inclined end engaging said inner expander surface and a ange extending outward from said skirt portion, and an outer split ring having a skirt portion encompassing said inner ring skirt portion and provided with an inclined end engaging said inner expander surface, said outer ring having a ange extending outward from the outer ring skirt portion and provided with an inclined surface engaging said outer expander surface.

6. in a packing structure: a pliant packing adapted to be expanded laterally; abutment means adjacent said packing and having inner and outer expander surfaces inclined laterally outward in a direction leading away from said packing; and a liow preventing device engaging said packing and abutment means, said device including an inner split ring having a skirt portion provided with an inclined end engaging said inner expander surface and a iiange extending outward from said skirt portion, and an outer split ring having a skirt portion encompassing said inner ring skirt portion and provided with an inclined end engaging said inner expander surface, said outer ring having a flange extending outward from the outer ring skirt portion and provided with an inclined surface engaging said outer expander surface, said anges being provided with a plurality of circumferentially spaced generally radial slots to increase the iiexibility of the rings.

7. In a packing structure: a pliant packing adapted to be expanded laterally; abutment means adjacent said packing and having inner and outer inclined expander surfaces; a circumferentially continuous ring engaging said packing; an inner split ring engaging said circumferentially continuous ring and inner expander surface; and

8. In a packing structure: a pliant packing adapted to be expanded laterally; abutment means adjacent said packing and having inner and outer inclined expander surfaces; a circumferentially continuous ring engaging said packing; an inner split ring having a skirt portion engaging said inner expander surface and a iiange engaging said circumferentially continuous ring and extending outwardly from said skirt portion; and an outer split ring having a skirt portion encompassing said inner ring skirt portion and engaging said inner expander surface, said outer ring having a flange extending outward from the outer ring skirt portion and engaging said outer expander surface. A

9. In a packing structure: a pliant packing adapted to be expanded laterally; abutment means adjacent said packing and having inner and outer expander surfaces inclined laterally outward in a direction leading away from said packing; a circumferentially continuous ring engaging said packing; an inner split ring having a skirt portion provided with an inclined end engaging said inner expander surface and a ange engaging said circumferentially continuous ring and extending outward from said skirt portion; and an outer split ring having a skirt portion encompassing the inner ring skirt portion and provided with an inclined end engaging said inner expander surface, said cuter ring having a ange extending outward from the outer ring skirt portion and provided with an inclined surface engaging said outer expander surface.

l0. In a packing structure: a pliant packing adapted to be expanded laterally; abutment means adjacent said packing and having inner and outer expander surfaces inclined laterally outward in a direction leading away from said packing; a circumferentially continuous ring engaging said packing; an inner split ring having a skirt portion provided with an inclined end engaging said inner expander surface and a iiange engaging said circumferentially continuous ring and extending outward from said skirt portion; and an outer split ring having a skirt portion encompassing the inner ring skirt portion and provided with an inclined end engaging said inner expander surface, said outer ring having a iiange extending outward from the outer ring skirt portion and provided with an inclined surface engaging said outer expander surface; said flanges being provided with a plurality of circumferentially spaced generally radial slots to increase the exibility of the rings.

11. In a packing structure: a pliant packing; a threaded ring surrounding and molded to a portion of said packing, said portion being disposed interiorly of said ring; and an abutment member threadedly receiving said ring while engaging said packing.

12. in a packing structure: a pliant packing having a terminal portion and an adjacent portion spaced longitudinally from the end of said terminal portion and having a greater external diameter than the external diameter of said terminal portion; a threaded ring surrounding and molded to said terminal portion, said terminal portion being disposed interiorly of said ring; and an abutment member threadedly receiving said ring while engaging the end of said terminal portion and the end of said adjacent portion.

References Cited in the file of this patent UNITED STATES PATENTS 2,368,928 King Feb. 6, 1945 2,555,647 King .lune 5, 1951 2,603,294 Barnes July 15, 1952 2,604,946 Sweet July 29, 1952