US2352812A - Swab cup assembly or packing element - Google Patents

Description

y 1944. R. e. TAYLOR, JR

SWAB CUP ASSEMBLY OR PACKING ELEMENT 3 d v M B S \\x Fmuww 4 m 2 r O 4 9 l 2 m a J d v m 7 9 8 m n, 7/// /7 w 7 W A 5 W WW .9 0 5 m W w 6 A M 3 RY Z 2 w B U M. M

. ,arl fi/llllllrllllvflllrd ATTORNEY. I

Patented July 4, 1944 UNITED STATES PATENT OFFICE SWAB CUP ASSEMBLY OR PACKING Raymond G. Taylor, In, Dalian Tex asslgnor to The Gulberson Corporation, Dallas, 'Iex. a corporatlon of Delaware Application January 27, 1940, Serial No. 315,929

16 Claims. (01. 309-33) The object of this invention is to improved type of swab cup.

As is well known in the art, swab cups are extensively employed in the oil well industry and are intended to seal thespace between the mandrel when being raised and the well casing so that the well fluid above the swab cup may be raised. The swab cup is, therefore, intended to make a seal-tight engagement with the well casprovide an ing. Rubber, DuPrene and other like substances which have been commonly employed in the construction of swab cups are generally employed for the reason that they will readily conformto Another 'form of the invention comprises the withstand pressure or approximately 6,000

the well casing and they are yleldable. However.

as is well known, these substances will flow when under great compression and to prevent this flowing, various devices have been used. For instance, in Crickmer 1,669,812 a wire basketor cage was employed which would support the yieldable swab cup. However, experiences show that the well fluid will leak past the wires forming such a cage when subjected to heavy pressures. They are also used as a packing element and when so used one cup faces upwardly and the other downwardly with the mandrel perforated between the cups so that cement may be pumped down the tubing, through the perforations between the cups and then through perforations in the casing and back into the formation. The cups, in this case, do no swabbing but they are generally termed swab cups. On such a cement squeeze Job where the pressures run up to 3,000 or 4,000 pounds per square inch itwas found that cups of the type shown in the Crickmer Patent 1,669,812 will leak around the wires. maintain these high pressures. It was further found that if you omit the wires the cup will seal oil perfectly without any leakage up to about 2,000 pounds per square inch but that a pressure in excess thereof would cause the cup to flow over the lower thimble and eventually rupture the cup. It is the object ofthis invention to pro- It was, therefore, very difficult .to-

"with the swab cupfiprovided with reinforcing vide a supporting means for a swab cup or packing element which will prevent such a flow of the material of which the swab cup is composed by eflectively supporting the same between the thimble and the well contacting portion of the swab and to provide the upper portion of the same with a continuous casing engaging portion which is free of wires around which the fluid might leak. I eifectively accomplish this by making the support terminate below the top oi the swab and embedding the supporting member in the swab cup. In other words, the supporting wires do not run to the top of the swab but extend inwardly below the top thereof leaving an upper lip which by well pressure will be tightly sealed against the casing without any obstructing wires or other material.

pounds per square inch without flowing. I found that linen thread is entirely suitable for this purpose. .v

Other objects and advantages of this invention will appear in the detailed specification and claims which follow.

Referring to the drawings,

Fig. 1 is a cross-sectional side elevational view of one form of the swab and its assembly,

Fig. 2 is a similar view of one form of the swab cup and its assembly, h

Fig. 3 is a similar view of a structure similar to Fig. 2 but with the inner reinforcing member and the lower threaded ring omitted and with another form of reinforcing cage- Fig. 41s a side elevational view in cross-section of a modification of the structure shown in Fig. 3,

Fig. 5 is a side elevational view in cross-section threads,

Fig. 6 is a perspective view of the type of reinforcing wires used in the structure shown in Fig. 2, and

Fig. 7 is a perspective view of the type of cage serving as the reinforcing member of the structure shown in Fig. 3. Such a cage might be also used in connection with the swabs shown in Figs. 1, 2, and 4.

In Fig, 1" the mandrel l is provided with a shoulder 2 which receives a downwardly extending thimble 3. The mandrel is screw. threaded as indicated at 4 to receive an adjustable threaded sleeve 5 on which rests an upturned thimble 6. The swab l is\nested in the thimbles I and 6.

A wire support or reinforcing member 8 extends from within the thimbles following the outer contour of the swab I and at its upper end is turned inwardly as indicated at 9 within the upper thimble 3. By screwing upwardly on the threaded sleeve 5 the distortion of the swab may be varied or adjusted.

In Fig. 2 the mandrel I0 is provided with a shoulder II and with screw threads l-Z. A retaining nut 13 is screwed on the screw threads I 2 and supports a thimble II; An open ended swab cup I! is nested in the thimble H. A sleeve 16 surrounds the mandrel i0 and at its upper end abuts against the shoulder II and at its lower end rests on the thimble II. *It is provided with an outwardly extending apron or flange ll.

The sleeve i6 and flange I1 is substantially simi-' lar to the parts it and I! of the Crickmer Patent 1,735,264. Within the thimble It is a retaining ring it which, ii desired, may be rigidly secured to the sleeve 10 by welding or otherwise.

A reinforcing wire support I! has at its lower end a J-shaped extension 20 adapted to engage the retaining ring is. The wire support rests against the upper inner surface of the thimble i4 and follows the outside contour of the swab cup it, that is, it is provided with an outwardly sloping part 2| so as to fit that part of the swab cup extending from the upper end or the thimble to the part engaging the well casing 22 and thence having a vertically'extending portion 23 which engages the well casing and serves as a bearing for the swab cup so as to eliminate much of the wear which would otherwise be imposed upon the swab cup. It will be noted from an inspection oi Fig. 6 that the support It consists of what would be in eiIect two wires united at the upper end by what in reality is one wire bent Q so as to form duplicate convoiutions above described with a U-shaped part 24 at the upper end, which U-shaped part is bent inwardly and embedded within the swab cup, thereby leaving a lip 25 above and outwardly from the U-shaped part 24 so that this lip portion forms a continuous and uninterrupted seal with the well casing thereby preventing the leakage of well fluids downwardly past the wire support. It will, therefore, be noted that this type of swab cup is not only supported internally by the flange H but that the part 2| eil'ectiveiy supports the swab cup so that it cannot flow downwardly into the space between the thimble it and the well casing 22 while the part '22 provides a bearing to take up the wear between the swap cup and the well casing and the lip 2s eflectively seals the upper portion 0! the swab cup so that no leakage could occur by well fluid passing downwardly by the wires. Of course, it is understood that the well fluid when the mandrel is raised is in the swab cup and above the same 'and that it presses with great iorce depending upon the weight of the fluid or the force of the cement when used as a packer on a cement squeeze job so as to expand the swab cup outwardly into contact with the well casing, 'butii there would otherwise be any leakage. downwardly past the wire support the lip 25 being in continuous engagement with the well casing absolutely prevents such leakage. Such a swab cup has been tested up to approximately 6,000 pounds ,per square inch without noticeable leakage.

In Fig. 3 the mandrel Ill, shoulder ll, sleeve l3 and thimble. is are of identical construction with the construction described in Fig. 2. In this ilgure the sleeve It and flange l1 are omitted but they may be used if desired. Likewise, the sleeve It and flange I! may be omitted from the structure shown in Fig. 2. The essential diflerence between the structure shown, in Fig. 2 and that shown in Fig. 3 is that a diflerent form of wire support is employed, the details oi which are shown in Fig. '1. This wire support 2! is preferably composed of a continuous wire which may have its ends united so as to make the wire continuous or in case the ends of the wire are not united it would not be continuous but would be in one piece. Of course, if desired, it may be made in a plurality of parts according to the desire of the particular manufacturer. This is in the 1' iorm=of a basket as is shown in Fig. I which is nestedwithin the thimble I4 and extends on the outside oi the swab cup 21. A cross-sectional view of a contour of this wire'support is substantially the same as that oi the wire support is as will be noted from a comparison of Figs. 2 and 3 except that at the lower end 01' the wire support 20 instead oi being provided with a J-shaped portion it is bent laterally to form a U-shaped portion 2' at the bottom thereof. These U-shaped portions 2s serve as the connecting means between'the upwardly extending portions of the basket. It would be noted that such a basket readily adapts itself to radial expansion except that the lower portion is retained by the thimble I I so that this basket is as readily expanded radially as would be the wire support ll of Fig. 2.

In Fig. 4 the mandrel II is provided with a shoulder Ii and with the retaining nut it which supports the thimble l4. Resting in the thimble l4 and extending to the shoulder I i is a retaining ring 28 which receives an inwardly. bent portion 30 of a wire support II which wire support may be of the same construction as the wire support it oi Fig. 2, except that instead of having the J-shaped lower portion, it is provided with the inwardly extending bent portion It. The function oi the swab cup would be the same in Figs. 2, 3, and 4.

Fig. 5 is oi the same construction as shown in Fig. 3 except that instead oi the basket wire support a I insert in the swab cup as a mass 0! thread 33 extending from the thimble II to the casing contacting portion of the swab cup. I have found linen thread to be particularly useful to: this purpose although I do not wish to limit myself to the particular thread employed. The cup shown in Fig. 5 may also be provided" with the wire supports shown in Figs. 8 and 7. These threads do not have to be laid lengthwise or crosswise or in any particular position and I found it entirely satisfactory to use simply a mass of thread extending in virtually every direction such as would be obtained ina tangled mass of thread. This thread is vulcanized into the swab cup itseli and forms an integral portion thereoi. It serves the important function of preventing the downward flow oi the swab cup between the well casing and 'the thimbl for it supports all that portion oi the swab cup between the thimble and the casing but it leaves the upper end of the swab cup entirely free to radially expand and to make a leak-tight engagement with the well casing. Such a type of swab cup has been tested up to which could be noticed.

It will, therefore, be noted that in Figs. 2, 3, 4,

and 5 the swab cup is readily radially expansible in its upper portion and makes a continuous and leak-tight engagement with the well casing while the swab cup is adequately and eilectively supported so as to prevent any downward flow of the swab cup between the thimble and the well casing. In using the word casing I, of course, do not wish to limit myself to well casing but I mean this term to be as broad as the word pipe, for obviously, swab cups oi this type could be used to swab or pack of! in any type oi pipe regardless oi whether it is well casing or not. It is also obvious that the sleeve it and the supporting flange ll may be used in connection with the structure shown in Figs. 3, 4, and 5 just as well as it could be used in connection with that shown in Fig. 2. Likewise the wire basket shown in Fig. 7 could be used in connection with Figs. 2. 3,

the specific form of the invention shown by way of illustration herein and I therefore desire to claim the same broadly except as I may limit myself in the appended claims.

Having now described my invention I claim:

1. A cup assembly adapted to engage a well pipe including a cup. a reinforcement for the cup embedded in the cup and supporting the lower portion of the cup on the outside thereof up to a point beyond the point of contact of the cup with the pipe. the-upper portion of the cup above the reinforcement being in direct and unbroken engagement with the pipe.

2. A cup assembly adapted to engage a well pipe including a cup. reinforcing wires embedded in the cup and extending from the lower portion thereof and on the outside oi said cup to the point above where the cup would contact the pipe. the upper portion of the cup being in direct and unbroken engagement with the pipe 3. A cup assembly adapted to enga e a well pipe includ ng a cup. a reinforcement for the cup extending along the outer. lower and intermediate part of the cu and being bent inwardly at its upper end and embedded in the cup.

4. A cu assembly adapted to en a e a well pipe includin a cup. a thimble in which the cup is nested. a reinforcement for the cu extendin along the outer. lower and intermediate part of the cup and being bent inwardly at its upper end and embedded in the cu the lower end of said re nforcement bein within said thimble.

5. A cu assembly adapted to en a e a well pipe including a thimble. a cup supported by the thimble. a wire reinforcement for the cup and supporting the outer. lower and intermediate portion of the cup and forming a bearing between the cup and the pipe. said reinforcement being the cup and the lower portion of said wire reinforcement extending downwardly within the th mble.

-'l. A cup assembly adapted to engage a well pipe including a thimble. a cup supported by the thimble, a radially expansible wire cage supporting the outer. lower and intermediate portion of the cup and forming a bearing between the cup and the pipe. said reinforcement be'ng bent inwardly a distance below the top of the cup and embedded within the upper part of the cup.

- 8. A cup assembly adapted to engage a well pipe including a cup. a retaining rin in the cup. a plurality of. substantially U-shaped wires having their lower ends bent so as to be held by the retaining ring and extending along the outer lower portion of said cup and having their upper ends bent inwardly so as to be embedded in the cup.

9. A cup assembly including a thimble, a cur supported by the thimble, a retaining ring in the cup. a plurality of substantially U-shaped wipes having their lower ends bent so as to be held by the retaining ring and extending along the outer lower portion of said cup and having their upper ends bent inwardly so as to be embedded in the cup. 7 1

10. A cup assembly adapted to engage a well pipe including a cup, a continuous wire cage supporting said cup on the outer lower surface thereof and having th upper portion of said cage bent inwardly so as to be embedded in the cup.

11. A cup assembly adapted to engage .a well pipe including a cup, a radially expansible wire cage supporting said cup on the outer lower portion of said cup and having the upper portion of said cage bent inwardly so as to be embedded in the cup.

12. A cup assembly including a thimble. a cup nested in the thimble, a radially expansible wire cage supporting said cup on the outer lower surface thereof and having the upper portion of said cage bent inwardly so as to be embedded in the cup and a fibrous material embedded in the cup within the cage.

13. A cup assembly adapted to engage a well pipe including a thimble, a cup mounted within the thimble and a fibrous material embedded in the swab cup and extending from a point within the thimble to the part of the cup which would contact the well pipe and a wire cage supporting said cup and fibrous material on the outer lower portion of the cup and having the upper portion of said cage bent inwardly and embedded in the cup.

14. A cup assembly including a thimble. a cup nested in the thimble. and a fibrous material embedded in the cup and extending from. a point within the thimble to anintermediate portion of the cup and a wire cage supporting said cup and ilbrous material on the outer lower portion of the cup and having the upper portion of said cage bent inwardly and embedded in the cup.

15. A cup assembly adapted to engage a well pipe. including a supporting element. an upwardly opening thimble on said supporting element, a cup having its lower end nested within the thimble and its upper portion being adapted to engage the well pipe, a flexibl reinforcement extending from the part nested in the th mble to the pipe contacting part of the cup. and an expansible wire cage supporting said cup and reinforcement on the outer lower surface of the cup and having the upper portion of said cage bent inwardly so. as to be embedded in the'cup.

16. A cup assembly adapted to engage a well 4 pipe. including a supporting element. an upwardly opening thimble on said supporting element. a cup having its lower end nested within the thimble and its upper portion being adapted to engage the well pipe and a reinforcement extending from the part of the cup nested in the thimble to the pipe contacting part of the cup. said reinforcement consisting of a fibrous material and a null-- ally expansible wire cage supporting said cup and fibrous material on the outer lower surface of the cup and having the upper portion of said cage projecting inwardly so as to be embedded in the cup a substantial distance below the upper extremity of the cup so that the cup is provided with a flexible lip above the cage.

- RAYMOND G. TAYIDR, Ja.

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