US2945665A - Packer - Google Patents

Description

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United States Patent y,

PACKER L'ouis M. Regan, Redondo Beach, 'and Darrell L. Sims, Rolling Hills, Calif., assignors to Regan Forge and Engineering Company, 'San Pedro, Calif., a corporation of California Filed July 22, 1958, Ser. No. 750,243

4 Claims. (Cl. 251-1) The present invention relates in general to packers and, more particularly, toV expansible and contractible packers for closing annuli in oil Wells, or the like, to pack olf selected well zone, to prevent bloWouts, andV so forth.

A packer of the type to which the present `invention relates is disclosed in Patent No. 1,930,361 issued October l0, 1933, to F. M. Kilmer, Ir., and includes a housing having an annular chamber therein for an elastomeric sleeve which is secured to the housing at its end and which is adapted to be contracted or expanded by fluid pressure applied externally or internally thereof.

A serious disadvantage of a packer of the foregoing character when contracted into sealing engagment with a tubing string, or the like, is that the elastomeric sleeve tends to extrude into the clearance between the packer housing and the tubing string because of the tendency to fo mi@ embodiments of the invention described in detail hereinafter and illustrated in the accompanying drawing, in which:

Fig. 1 is a longitudinal sectional view of a contractible packer of the invention is uncontracted condition;

Fig. 2 is a view similar to Fig. 1, but showing the packer in contracted condition;

Fig. 3 is a transverse sectional view taken along the arroWed line 3-3 of Fig. 2; and

Fig. 4 is a longitudinal sectional view of another packer embodiment of the invention.

The packer of the invention illustrated in Figs. 1 to 3 of the drawing constitutes a blowout preventer 10 having a housing 12 adapted to be connected to an oil well casing, or the like, and provided therethrough with an axial passage 14 for a tubing string 16, or the like. The tubing string 16 may-be a drill string, for example.

Concentric with the passage 14 and located intermediate the ends thereof is an annular packer chamber 18 having a peripheral Wall 20 and end walls 22 and 24. In the construction illustrated, the peripheral wall 20 and the end wall 24 of the packer chamber 18 are formed contract the sleeve into a space having a volume less than the uncontracted volume of the sleeve as the result of securing the ends of the sleeve vto the housing. `Such extrusion of the elastomeric sleeve between the housing and the tubing string, or other structure engaged by the sleeve upon contraction thereof, frequently results in severe damage to the sleeve, which is obviously undesirable.

A primary object of the invention is to provide a packer similar to that hereinbefore discussed which avoids the disadvantage mentioned.

More particularly, a primary object of the invention is to provide a packer wherein at least one end of the elastomeric sleeve floats longitudinally of the packer chamber in the housing so that, when the sleeve is contracted into engagement with a tubing string, or other structure, therein, it is free to elongate so as to avoid extrusion of the material of the sleeve into the clearance between the housing and the tubing string.

Another object is to provide a packer wherein the floating end of the elastomeric sleeve has connected thereto an annular piston in slidable, fluid-tight engagement with the peripheral wall of the packer chamber, such piston reinforcing the iloating end of the elastomeric sleeve and confining the iluid utilized to energize the packer.

Utilizing 'the packer of the present invention with the floating end of the elastomeric sleeve thereof on the high pressure side of the packer results in an important ad vantage in that the high pressure acting on theannular piston attached to the floating end of the sleeve renders the packer self-energizing, the degree to which the elastomeric sleeve is contracted or expanded being increased by the high pressure.

Other objects of the invention are to provide packers wherein the elastomeric sleeves with voating ends are disposed in internal and external packer chambers, respectively, and are 'contractible and expansible, respectively.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will ,be apparent to those skilled in the packer art in the light of this disclosure, may be attained with the exemplary in a cup-shaped body portion 26 of the housing 12, the end Wall 24 of the packer chamber being provided by a closure 28 for the body portion which is suitably secured p thereto.

The axial passage 14 is formed by axial openings 30 and 32 respectively formed in the body portion 26 of the housing 12 and the closure 28 thereof.

Within the packer chamber 18 is an elastomeric sleeve 34, of rubber, or other material having similar characteristics, which is adapted to be .contracted into iluid-tight engagement with the tubing string 16, as shown in Fig. 2, by fluid pressure applied externally thereof through ports 36 in the peripheral Wall 20 of the housing 12. The elastomeric sleeve 34 may be provided with circumferentally staggered internal and external slits 38 and 40, as

taught by the aforementioned patent, to provide it with an accordion-like construction.

The end of the elastomeric sleeve 34 which is adjacent the end `Wall 22 of the packer chamber 18 has secured thereto, as by bonding, a rigid, annular mounting element 42 which is seated against the end wall 22 and which is secured to the housing 12 in any suitable manner, as by bolts 44. An O-ring 46 disposed in an external annular groove in the mounting element 42 and engaging the peripheral Wall 20 of the packer chamber 1-8 provides a fluid-tight seal between the mounting element and the housing 12 to conne fluid introduced through the ports 36.

The axial length of the elastomeric sleeve 34 is less than i the axial length of the packer chamber 18 when the elastomeric sleeve is in its uncontracted state so that the other end of the sleeve is spaced from the end Wall 24 of the packer chamber, as shown in Fig. l of the drawing. Such other end of the elastomeric sleeve 34 is free to move or iloat longitudinally of the packer chamber 18 so that, when the elastomeric sleeve is contracted into sealing engagement with the tubing string 16, as shown in Fig. 2 of the drawing, the elastomeric sleeve may elongate to avoid extruding it into the clearance betweenV erally cup-shaped in cross-section and is provided wtih an end Wall 52 to which the corresponding end of the elastomeric sleeve 34 is secured, as by bonding. The piston 48 also includes a. peripheral skirt 54 which extends toward the opposite or anchored end of the elastomeric sleeve 34 and whichis provided with an annular rib. 56 in slidable engagement with the `peripheral Awall 20 of the packer chamber 18. Thus, the piston 48 slidably engages the peripheral wall 211 of the packer chamber' 18 in two axially spaced annular zones to provide stability and prevent binding, which is an important feature.

It is thought that the operation of the blowout pre- Venter 11i of the invention will be apparent so that only a brief description thereof is necessary. When it is desired to pack off the annulus between the blowout preventer and the tubing string 16 to prevent a blowout, fluid pressure isapplied to the exterior of the elastomeric sleeve 34 through the ports 36. This contracts the elastomeric sleeve 34 into fluid-tight engagement with the tubing string V16, the piston 48 moving axially of the packer chamber 1S in a direction away from the end wall 22 of such chamber as this occurs to permit redistribution of the material of the elastomeric sleeve 34 without extrusion thereof into the clearance between the housing 12 and the tubing string 16. In fact, the invention permits the elastomeric sleeve 34 to assume a smooth, hourglass-like configuration in cross-section 4with no abrupt changes in contour which might result in damage, this being an important feature of the invention.

Another important feature of the invention is that, when the blowout preventer 1) is utilized in the manner shown in the drawing so that the high pressure in the well is applied to the floating end of the elastomeric sleeve 34, the device is self-energizing. As will be apparent, the high pressure acting upwardly on the piston 48 tends to force the elastomeric sleeve 34 more tightly into engagement with the tubing string 16 to attain this self-energizing effect.

Referring to Fig. 4 of the drawing, illustrated therein is a packer 116 of the invention which is similar to the blowout preventer 10 and which operates in a similar manner so that only a brief description is necessary. The packer 110 includes a housing 112 comprising a tubing 113 having external collars 114 and 115 thereon, the

' housing being insertable into a casing 116, or the like. The

housing 112 provides an external packer chamber 113 having a peripheral wall 120 formed by the tubing 113 and end walls 122 and 124 respectively formed by the collars 114 and 115.

Within the packer chamber 118 is an elastomeric sleeve 134 adapted to be expanded outwardly into fluid-tight engagement with the casing 116 by applying fluid pressure internally thereof through passages 136 in the housing 112. The elastomeric sleeve 134 is connected at one end, as by bonding, to an annular mounting element 142 which is secured to the housing 112 adjacent the end wall 122 of the packer chamber 11S, as by threading the mounting element 142 onto the corresponding collar 114. A iiuidtight seal between the mounting element 142 and the housing 112 is provided by an O-ring 146.

The other end of the elastomeric sleeve 134 is secured, as by bonding, to an annular piston 148 which is slidable in the packer chamber 118 in engagement with the peripheral wall 120 thereof, a fluid-tight seal between the piston 148 and the peripheral wall 120 being provided by O-rings 150.

In the packer 120, the elastomeric sleeve 134 shortens as it is expanded outwardly into fluid-tight engagement with the casing 116, or the like. Consequently, the initial length of the elastomeric sleeve `134 is such that the piston 148 engages the end wall 124 of the packer chamber 118 prior to expansion. This is in contrast to the packer or blowout preventer 10 wherein the initial length of the elastomeric sleeve 34 is less than the length of the packer chamber 18 so that the piston 48 is out of engageg ment with the end wall 24 of the packer chamber v18 prior to contraction.

Although the invention as disclosed herein shows the elastomeric sleeve as fastened at one end and flo'ating at the opposite end and in most instances, as a matter of choice will be so constructed, the elastomeric sleeve will work equally well floating at both ends.

Although exemplary embodiments of the invention have been disclosed herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiments without departing from the spirit of the invention as defined by the claims which follow.

We claim:

1. In combination: a housing having a passage therethrough and having internally thereof an enlarged packer chamber between the ends of said passage; tubular packer means in said chamber in register with said passage and having an over-al1 length less than the length of said chamber, including an elastomeric sleeve, an annular piston connected to' one end of said sleeve and slidable in said chamber longitudinally thereof, and an annular member connected to the other end of said sleeve and engaging the peripheral wall of said chamber; and port means in said housing communicating with said chamber externally of said sleeve and intermediate said annular piston and said annular member for applying uid pressure to the exterior of said sleeve to reduce the diameter thereof.

2. The combination set forth in claim 1 wherein said piston is generally cup-shaped in longitudinal cross section andhas an end wall connected to said one end of said sleeve and a peripheral skirt encircling said sleeve and in slidable engagement with` the peripheral wall of said chamber.

3. The combination set forth in claim l wherein said piston is generally cup-shaped in longitudinal cross section and has an end wall connected to said one end of said sleeve and a peripheral skirt encircling said sleeve and in slidable engagement with the peripheral wall of said chamber, said sleeve being secured to said end wall of said piston only and being movable relative to said peripheral skirt thereof.

4. The combination set forth in claim 1l including means securing said annular member to said housing at one end of said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,108,128 Buifum Aug. 25, 1914 1,930,361 Kilmer Oct. l0, 1933 2,779,419 Mounce Jan. 29, 1957 2,786,642 Comb Mar. 26, 1957

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