US3286772A

US3286772A - Well packer

Info

Publication number: US3286772A
Application number: US473263A
Authority: US
Inventors: Solari Joseph; Darrell C Gallear
Original assignee: Chevron Research and Technology Co
Current assignee: Chevron USA Inc
Priority date: 1961-06-29
Filing date: 1965-06-04
Publication date: 1966-11-22
Anticipated expiration: 1983-11-22

Description

Nov. 22, 1966 J. SOLAR! ET AL 3,286,772

WELL PACKER Original Filed June 29. 1961 A q M A FIG.2

FIG.4-

INVENTORS DARRELL C. GALLEAR JOSEPH C. SOLAR/ ATTOB'N EYS United States Patent 3,286,772 WELL PACKER Joseph Solari and Barrel] C. Gallear, Taft, Califi, as-

signors to Chevron Research Company, a corporation of Delaware @riginal application June 29, 1961, Ser. No. 120,603. Dr-

vided and this application June 4, 1965, Ser. No.

1 Claim. or. 166-179) This-application is a divisional application of application Serial No. 120,603, filed June 29, 1961, now U.S. Patent No. 3,240,273.

This invention relates to packing apparatus and more particularly, this invention relates to apparatus for packing off a well, said apparatus including means for alternatively setting and freeing a packing member while said apparatus is located in the well.

It is an object of the present invention to provide apparatus for packing off a well, which apparatus is easily positioned and removed from locations in the well.

Additional advantages and objects of the present invention will become apparent from the following detailed description and the accompanying drawings which are made a part of the present specification.

FIG. 1 is an elevational view partly in section of the preferred embodiment of apparatus assembled in accordance with the present invention.

FIGS. 2, 3, and 4 are unrolled views of an improved locking cage in the packer illustrated in FIG. 1.

FIG. 1 is a vertical view partially in section illustrating an improved packer useful in the present invention. The improved packer is particularly useful when it is desired to stimulate at different producing horizons in a well without having to pull the tubing string out of the well after each stimulation. The packer as here shown may be run in on the tubing string with a stimulator tool, such as described in parent application Serial No. 120,603, and the packer set, stimulation accomplished, the packer freed, the tool moved to a new location in the well and the cycle repeated.

The packer illustrated in FIG. 1 is similar to a CO packer of the valveless, hook-wall type manufactured by Lane-Wells, Incorporated, and shown on page 2916 of the Composite Catalog of Oil Field Equipment and Services, 1958-59, published by World Oil. Two important improvements, however, have been incorporated into that design to prepare the packer for use with the stimulator assembly.

In order that the packer may be set and then released it is necessary that the packer mandrel 83 is free to turn when the rubber packing rings 53 are expanded against the well wall or the casing. To allow the packer to rotate when the packing rings are expanded, bushings 81 are inserted between the mandrel 83 and the packing rings 53. The bushings 81 are preferably sized so that when the packing rings are fully expanded the bushings 81 contact each other and thus substnatially completely separate the packing rings 53 and the mandrel 83.

The second improvement in the packer in FIG. 1 comprises important modifications in the locking cage 88.

The locking cage 88 is a flat curved surface extending around mandrel 83. The improvement in the locking cage 88 and the manner of utilizing the improved packer in the invention can be better understood by reference to FIG. 2, FIG. 3 and FIG. 4 along with FIG. 1. FIG. 2,

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FIG. 3 and FIG. 4 are views of the locking cage 88 as it would look if it were cut at A-A on FIG. 1 and unrolled from its position around mandrel 83. The improvement in locking cage 88 comprises constructing the locking cage with a flat lower surface indicated at 90. A notch 92 is the only break in the flat lower surface 90 of locking cage 88. The notch 92 is provided with rounded corners to facilitate engaging and disengaging dowel pin 87 when mandrel 83 is rotated inside the locking cage 88.

In operation, the packer is connected to the stimulator tool '60 by collar 52 and positioned at a desired location in a well bore. The slips 82 are locked in a retracted position by dowel pin 87 held in the angular notch 92 as illustrated in FIG. 2. The slips 82 are unlocked from this retracted position by turning mandrel 83 about oneeighth turn counterclockwise. Friction spring 86 then forces slips 82 against the casing 50 as mandrel 83 is lowered. Continued lowering of mandrel 83 with resulting application of weight sets the slips 82 firmly against the casing 50 and expands the packing rings 53 to form the pack-01f. By rotating mandrel 83 counterclockwise about one-fourth turn, the locking cage 88 and dowel pin 87 are in the relative position illustrated by FIG. 3 and the slips 82 and the packing rings 53 are locked in expanded position.

After the completion of the well stimulation procedure the mandrel 83 is rotated clockwise until the slips 82 are unlocked by dowel pin 87 engaging the angular notch in locking cage 88 as illustrated in FIG. 4. The slips may be disengaged by an upward motion of the tubing string and then retracted by the spring collar to the original retracted position. The slips 82 and the packing rings 53 are now again locked in a retracted position. The stimulator assembly is ready to be repositioned and the operation repeated.

As is evident from the specification, the invention provides a novel apparatus for packing off a well. The invention having been fully described and illustrated, we claim:

An improved packer comprising a mandrel, at least one packing ring on the exterior of said mandrel, bushing means between said mandrel and said packing ring, said bushing means providing for rotatable motion between the mandrel and the packing ring when said packing ring is expanded, means for expanding said packing ring, said means operably positioned on the exterior of said mandrel, a pin on said mandrel, a locking cage operably connected to said expanding means contacting said pin, said locking cage characterized by a fiat lower surface and an annular notch adapted to engage and disengage said pin on said mandrel, said notch being the only break in said flat lower surface, whereby said mandrel can be rotated to move said pin int-0 and out of said notch and along said flat surface and resilient means keeping said pin into contact with said flat surface when said pin is out of said notch.

References Cited by the Examiner UNITED STATES PATENTS 2,053,065 9/1936 Crowell 166-210 2,106,859 2/1938 Spang 166-138 2,160,515 5/1939 Pranger 166-130 2,855,051 10/1958 Holloway 166-118 3,083,770 4/1963 Villalon et al 166-237 X CHARLES E. OCONNELL, Primary Examiner. T. A. ZALENSKI, J. A. LEPPINK, Assistant Examiners.