US3819192A - Well pressure sealing cup reinforcing structure and method of manufacture - Google Patents

Abstract

An improved reinforcing structure and method of making said structure are disclosed. The improved reinforcing structure is a polyfurcated cylinder having an integral base portion and a tines portion. The method of manufacture includes the steps of rolling a polyfurcated plate with an integral base and tines portion, rolling the base portion into a cylindrical shape and securing the abutting ends of the base.

Description

United States Patent [19] Berry et al.

[ WELL PRESSURE SEALING CUP REINFORCING STRUCTURE AND METHOD OF MANUFACTURE [76] Inventors: Robert F. Berry, l0318 Church Rd.,

ljallas Tex. 75 238 Henry W.

Blackwell, Rt. 1, Venus, Tex. 76084 [22] Filed: Jan. 8, 1973 [21] Appl. No.: 321,621

Related US. Application Data [62] Division of Ser. No. 166,171, July 26, 1971, Pat. No.

[52] US. Cl. 277/212 C, 29/1935 [51] Int. Cl F16j 9/08 [58] Field of Search 277/212 R, 212 C, 212 F, 277/181; 16/2; 92/241; 29/1935 [56] References Cited UNITED STATES PATENTS 665,873 1/1901 Budd 29/190 [45.] June 25, 1974 1,825,185 9/1931 Greenidge 277/212 C 2,619,393 11/1952 Wilson et al.... 2,799,237 7/1957 Martines 29/1935 X Primary Examiner-Samuel B. Rothberg Attorney, Agent, or Firm-William E. Johnson, Jr.; Michael J. Caddell; Morgan L. Crow 57] ABSTRACT Cl 9 W SF WS,

WELL PRESSURE SEALING CUP REINFORCING STRUCTURE AND METHOD OF MANUFACTURE CROSSREFERENCE TO RELATED APPLICATION This application is a divisional application of an original copending application, Ser. No. 166,171 filed July 26, 1971, by Robert F. Berry and Henry W. Blackwell; now U.S. Pat. No. 3,722,053 issued Mar. 27, 1973.

BACKGROUND OF THE INVENTION The field of invention relates to well operations in which a swabbing operation may be performed. Swabbing generally is the removal of liquid from a well by means of a sealing element mounted on a tool and lowered into a well by means of a wireline. The tool is lowered through a suitable amount of tubing and then lifted within the well effecting a seal with the pipe and lifting fluid above the tool to the surface. Packer cups are generally used to seal well pressure in one direction and are mounted on a well tool and positioned in a sealing engagement with well pipe. Packer cup application normally is a static or limited movement application.

There are a multitude of prior well swab bodies using a plurality of shaped wires held in base structures of various types as the reinforcing structure. See, for example, U.S. Pat. No. 2,887,347 issued to T. B. Losey. There are also prior well swabs employing metallic cones or corrugated cylinders as the reinforcing structure. See, for. example, US. Pat. No. 1,898,292 issued to C. S. Crickmer and US. Pat. No. 2,013,903 issued to F. A. Thaheld. There are also prior well swabs employing slotted metallic cylinders as wear protective structures. See, for example, US. Pat. No. 2,619,393 issued to R. E. Wilson and J. A. Wilson and US. Pat. No. 2,456,551 issued to R. A. Wilson.

Difficulty has been experienced in the past with such swab cup reinforcing structures constructed with a cylindrical base having upstanding tines or fingers pivotally attached to the base. Lack of cantilevered support from the base allowed the tines to become misaligned during the molding process, or required expensive fixtures and time consuming assembly of each finger.

Disadvantages with other unitary cup reinforcing structures made from tubular material are due to the time consuming machining operations and resultant high cost.

A primary object of this invention is to provide a method and structure for an improved pressure sealing cup reinforcing structure.

A further object is to provide a method and structure for producing a pressure sealing cup reinforcing structure at lower cost.

A further object is to provide an intermediate subassembly reinforcement structure for a well pressure sealing cup.

SUMMARY OF THE INVENTION These and other objects of the invention are generally provided by a well pressure sealing cup reinforcing structure having a body with a cylindrical base portion having a noncontinuous periphery, the body having a plurality of integral, upstanding tines and by the method including the steps of rolling a polyfurcated plate having an integral base and tines portion rolling the base portion into a cylindrical shape and securing the base portion in the cylindrical shape. As an additional feature, an intermediate subassembly is provided for use in a well pressure sealing cup including a unitary metallic plate with a first edge and an opposite edge and having a continuous portion along the first edge and integral tines extending from the continuous por tion to the opposite edge.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation view of an intermediate subas sembly for constructing a well pressure sealing cup reinforcing structure according to this invention.

FIG. 2 is an end elevation view of the subassembly illustrated in FIG. 1.

FIG. 3 is a view partially in elevation and partially in cross section of a well pressure sealing cup reinforcing structure according to this invention.

FIG. 4A is a cross section view of the preferred embodiment taken at section line 4-4 in FIG. 3.

FIG. 4B is an alternative embodiment of FIG. 4A.

FIG. 4C is still another alternative embodiment of FIG. 4A.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 illustrates an intermediate subassembly according to this invention wherein a flat metallic plate of the general shape illustrated may be used to construct the reinforcing structure. The length of a first edge 10 is determined as the approximate circumference for the base of the cup to be more fully described hereinafter. The opposite edge 14 from the first edge 10 is the starting point for sheared or sawed slots 16 which begin at opposite edge 14 and proceed to a point 18 near the first edge 10. With proper tooling known to those skilled in the art, all of the necessary multiplicity of slits 16 can be sheared or cut with a single stroke of a punch press although many other methods of manufacture are well known to those with skill in the art.

FIG. 2 illustrates an end view of the semifmished structure in FIG. 1 after bends running parallel to the edge 10 have been performed. Bend 20 and bend 22 achieve an offset from continuous portion 24 of plate 8 to a straight portion 26 of the tines 28 which were formed by slits 16. A bend 30 positions surface 32 on tine 28 at an angle which provides a chamfer or an an gular lead on surface to guide the resulting pressure sealing cup past joints, shoulders and other irregularities in the pipe (not shown) in which the cup will seal.

FIG. 3 illustrates a semi-finished reinforcing structure after continuous portion 24 has been rolled into a generally cylindrical shape. The outside diameter of cylindrical shape of continuous surface 24 is illustrated at 24 in FIG. 3. Straight portion 26 of the tines may be oriented parallel to central axis 34 or at an angle a of 0 to 15. Since the straight portion 26 is on a larger diameter than continuous portion 24, after forming continuous portion 24 into a cylindrical surface, there will be gaps between the tines since the circumference at a larger diameter 35 is greater than the circumference at diameter 7A. The circumferential length of metal at diameter 35 will be equal to the circumferential length of metal at diameter 24. However, since the circumference at diameter 35 is greater than the circumference at diameter 24, there will be circumferential gaps at diameter 35 since the tine or metallic portion will subtend a smaller angle of are at the larger diameter than the same width of metal at the diameter at surface 241. The slots or gaps between the tines provide for exposure of the elastomer as subsequently molded around the reinforcing structure according to this invention whereby the elastomer may feed through the slots between the tines responsive to pressure internal to the cup to maintain a seal between the cup and the pipe in which it seals while the cup may be performing in a static condition as a packer cup or in a dynamic condition as a swab cup. A cylindrical ring 36 may be placed in encircling relationship to cylindrical surface 24! to reinforce the structure and contain the base to prevent outward movement responsive to internal pressure in the finished cup. Tines 28 are thus cantilevered from continuous portion 24 and are flexible at the free end 38 which was originally the opposite edge M in H0. )1.

American Petroleum institute (AP!) tubing and casing threads represent the largest usage of threaded connections used in oil and gas wells. The basic distance is l inch between the ends of two pieces of pipe with API tubing or casing threads threaded into a coupling and tightened with the proper torque. Manufacturing tolerances can allow a particular joint dimension to vary plus or minus 0.5 inches, i.e., between 0.5 and 1.5 inches. Since the maximum allowable distance between the end of pipes in a joint is 1.5 inches, the straight portion of a well pressure sealing cup should be at least 1.5 inches so the cup may enter the end of one piece of pipe before leaving the end of the adjacent piece of pipe. A cup too short to span the gap between pipes could move laterally into the larger inside diameter of the coupling and allow the cup to become hung in the gap and could allow the cup to lose sealing engagement with the pipe.

F [0. 4A illustrates the section 4-4 of FIG. 3. ln F lG. 1, ends 42 and 44 of continuous portion 24 are brought together as illustrated in FIG. 4A at joint ill. in this embodiment the continuous portion 24 is rolled into a substantially 360 cylindrical surface to form the reinforcing structure for a pressure sealing well packer cup or swab cup. The joint ill may subsequently be reinforced by the continuous ring 36 or it may be welded together.

DESCRIPTION OF ALTERNATE EMBODIMENTS FIG. 48 illustrates an alternate embodiment in which a plate with a first edge long enough to form onehalf the circumference of the base of a reinforcing structure is used. Two such base segments may each be formed into a 180 of cylindrical arc and then assembled with two joints as at 46 and 48 in H6. dB to form a completed reinforcing structure. Joints &6 and 48 may be reinforced by the addition of a ring 36 or each joint may be welded.

FIG. 4C illustrates another alternative in which each piece of reinforcing structure forms one-third of the base circumference so that three pieces are used to form a completed structure. The three segments are then assembled with three joints as at St 52, and 54 and may be reinforced by addition of ring 36. Alternative embodiments as illustrated in FIGS. 48 and 4C may lend themselves more readily to single stroke forming in a punch press operation and thereby offer economies of manufacture.

After considering these examples, skilled persons will understand that variations may be made without departing from the principles disclosed and l contemplate the employment of any structures, arrangement, or modes of manufacture that are properly within the scope of the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

ll. In an intermediate subassembly for use as a reinforcing structure in a well pressure sealing cup of the type having an elastomeric element bonded on all sides of said reinforcing structure, the improvement comprising:

a relatively flat, rectangular, unitary metallic plate having a first edge and an opposite, generally parallel edge, and having a continuous portion along said first edge with integral tines extending from said continuous portion to said opposite edge and with spaced longitudinal gaps between said tines; with said tines and said continuous portion remaining at least partially coplanar.

2. Apparatus according to claim I further comprising said plate having a plurality of bends parallel to said first edge.

3. Apparatus according to claim 2 wherein a substantially straight portion of said tines extends a distance of at least 1.5 inches.

4. Apparatus according to claim 3 wherein said straight portion of said tines forms an angle from 0 to 15 with said continuous portion of said plate.

5. Apparatus according to claim 3 with two of said plurality of bends located between said straight portion of tines and said first edge.

6. Apparatus according to claim 5 with another of said bends located between said straight portion and the free ends of said tines.

7. Apparatus according to claim 6 wherein said another bend is located from the free ends of said tines between 10 and 50 percent of the length of said tines.

UNITED STATES PATENT OFFICE" CERTIFICATE OF CORRECTION Patent No. 3 Dated June 51! lnventofls) Robert F. Berry & Henry WI Blackwell It is certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the Title page the following should be added:

-- ['75] Assignee: Dresser Industries, Inc,

Signed and sealed this 26th day of Noireiuber 19m (SEAL) Attest:

McCOY M. GIBSQN JR. 0. MARSHALL DANYN Attesting Officer Commissioner of Patents I USCOMM-DC 603764 69 FORM PO-IOSO (1069) V u,s. covsnuucm rmn'rms omcz; 930

Claims (7)

1. In an intermediate subassembly for use as a reinforcing structure in a well pressure sealing cup of the type having an elastomeric element bonded on all sides of said reinforcing structure, the improvement comprising: a relatively flat, rectangular, unitary metallic plate having a first edge and an opposite, generally parallel edge, and having a continuous portion along said first edge with integral tines extending from said continuous portion to said opposite edge and with spaced longitudinal gaps between said tines; with said tines and said continuous portion remaining at least partially coplanar.

2. Apparatus according to claim 1 further comprising said plate having a plurality of bends parallel to said first edge.

3. Apparatus according to claim 2 wherein a substantially straight portion of said tines extends a distance of at least 1.5 inches.

4. Apparatus according to claim 3 wherein said straight portion of said tines forms an angle from 0* to 15* with said continuous portion of said plate.

5. Apparatus according to claim 3 with two of said plurality of bends located between said straight portion of tines and said first edge.

6. Apparatus according to claim 5 with another of said bends located between said straight portion and the free ends of said tines.

7. Apparatus according to claim 6 wherein said another bend is located from the free ends of said tines between 10 and 50 percent of the length of said tines.

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