US3057408A - Multiple unit well seal - Google Patents

Description

1962 s. L. GRIFFITTS 3,057,408

MULTIPLE UNIT WELL SEAL Filed Oct. 29, 1959 Fig-l 1 Fig. 2

Samuel L. Griff/ifs 1N VENTOR.

United States This invention comprises a novel and useful well casing packer or doirb\l: locking well seal and more particularly relates to a de .ice for sealing off the space between the casing and a wall of a well bore.

The primary purpose of this invention is to provide a packer capable of effectively sealing the space between a casing and a well bore wall in order to prevent communication between the spaces above and below the packer.

A further object of the invention is to provide a device whereby surface water and upper muddy streams may be more easily and effectively sealed from and prevented from coming into contact with and contaminating the water, oil or other fluid being produced from a well bore.

A further object of the invention is to provide a device in accordance with the foregoing objects which will effectively seal off mud, sand or gravel which may lie above the water or fluid to be produced from a well bore.

A further object of the invention is to provide a packing device which will make it possible by preventing the inflow of liquids to finish drilling the well bore with smaller diameter tools when it is found to be impractical or impossible to pull out the first casing and ream the well.

A further and more specific object of the invention is to provide an improved well packer which shall consist of a single integral sleeve of a deformable material.

Yet another object of the invention is to provide a well packer in accordance with the foregoing objects in which a one-piece sleeve of deformable material shall be so proportioned as to provide an improved fluid-tight seal of exceptionally great strength and endurance.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a view in vertical section of a fragment of a well bore having a first casing section therein and showing an inner casing with the packer device of the present invention applied thereto in operative position;

FIGURE 2 is a view in elevation, parts being broken away and showing in vertical section a portion of the inner casing of FIGURE 2 with the packer element thereon; and

FIGURE 3 is a view in horizontal section taken substantially upon the plane indicated by section line 3-3 of FIGURE 2.

The need frequently arises in the drilling of wells whether for water or deeper wells for petroleum or gas for a means to seal or pack off the casing from the well bore and thus separate the space below the packing such as a productive zone from contamination by fluids and materials from thereabove. The present invention is concerned with the provision of a packer construction adapted for use when such a requirement arises whereby the establishing of a seal between a casing and a well bore may be facilitated, and whereby the seal may be easily removed if such action is subsequently desirable.

Referring first to FIGURE 1 it will be observed that a well bore penetrates from the surface into a formation, passing through loose earth as at 12, a rock stratum as at 14, a porous or broken formation as at 16 until atent 3,5574% Patented Oct. 9, 1962 it reaches a productive formation 18 from which fluids are to be recovered. The upper portion of the well bore is shown provided with the usual surface casing 20 within which is received an inner casing 22. It is desirable to seal this casing within the well bore in order to separate the productive zone 18 in the well bore from possible contamination by or the inflow of fluids from some of the upper strata or zones of the formation.

When it is desired to seal an inner casing to the wall of a bore at a selected location a well casing packer in accordance with this invention is secured to the lower end of the casing string 22 for movement therewith. This packer assembly, designated generally by the numeral 30, includes a mandrel 32 preferably composed of a section of casing 22 which is adapted at its upper end to be secured to the end of the casing string as by welding at 34, by screw-threaded joint or any other suitable manner, The mandrel 32 is of any desired length, and its lower edge is provided with an internal beveled surface 36 to facilitate the removal of tools from the well bore from below the casing string.

Secured to the exterior surface of the mandrel 32 in any desired manner is a sleeve 40 of a resilient deformable material possessing the characteristics of being resistant to and not affected by minerals, chemicals or other elements normally found in the ground including water, gas or oil, and for this purpose may conveniently be of a number of plastic materials, compounded rubber, either natural or synthetic, or, any other flexible material suitable for the purpose intended.

In accordance with the principles of this invention the packer sleeve is of a particular configuration to be now described. A plurality of annular ribs or flanges project laterally from the sleeve and are integral therewith, these ribs being in longitudinally spaced relation. The ribs are of two different diameters, there being diametrically larger ribs 42 above each of which is disposed diametrically smaller ribs 44. The ribs are preferably disposed in longitudinally spaced sets, each set consisting of a large packer rib 42 and a smaller reinforcing rib 44. At this point it should be noted that the packer ribs will be of such size that the same will engage the wall of a well bore into which the packer device is inserted and be deformed and bent over the adjacent reinforcing ribs as shown in FIGURE 1.

For this purpose, it is preferred to space the reinforcing ribs unevenly from the two adjacent packer ribs. Thus the distance A between each packer rib 42 and the reinforcing rib 44 immediately adjacent thereabove is less than the distance B between the reinforcing rib and the packer rib 42 immediately adjacent thereabove.

Further, each reinforcing rib 44 is convex in shape, while in contrast with this, each of the packer ribs has flat angular top and bottom surfaces.

Preferably, the ribs 42 are about of an inch in thickness as measured longitudinally of the sleeve, and are of such length and the spaces A and B are so proportioned that when the device is inserted in a well bore as shown in FIGURE 1, each of the packer ribs 42 will be folded over and bent upwardly over the adjacent reinforcing rib 44. The reinforcing ribs will thus strengthen and stiffen the packer ribs and hold them into tight resilient engagement with the walls of the well bore in order to establish a fluid-tight seal therebetween. This seal is established by merely pushing the packer device downwardly in the well bore by lowering therein a casing string 22 to which the packer assembly is attached. However, owning to the greater space B as compared to the space A, when it is desired to remove the casing string 22 from the well bore, there is ample space provided to permit the packer ribs 42 to fold downwardly into the space and thus disengage from the well bore as illustrated in dotted lines in the upper portion of FIGURE 2.

Obviously, the packer device can be formed in any desired size and any desired length. Inasmuch as the packer element, consisting of the sleeve 40 with the longitudinally spaced sets of longitudinally spaced packer and reinforcing ribs 42, and 44 is of integral construction, it may be readily replaced in the well bore, when desired.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A well casing packer comprising a hollow mandrel adapted for securement to a casing string and a sleeve of a resiliently deformable material receiving and embracing the exterior of said mandrel, said sleeve having a plurality of sets of longitudinally spaced, radially projecting packer and reinforcing ribs, said packer ribs being of sufiiciently greater diameter than said reinforcing ribs whereby each of said packer ribs may be folded over and into engagement with an adjacent reinforcing rib and in tight engagement with the wall of a well bore into which said packer is inserted.

2. The combination of claim 1 wherein the longitu dinal spaces between a reinforcing rib and the two adjacent packer ribs is unequal.

3. The combination of claim 1 wherein each reinforcing rib is in closer relation to the packer rib adjacent therebeneath than to the packer rib adjacent thereabove.

4. The combination of claim 1 wherein the opposite ends of said sleeve terminate longitudinally inwardly of the adjacent ends of said mandrel.

5. The combination of claim 1 wherein each of said packer ribs in longitudinal section have a fiat substantially radially extending side surface and said reinforcing ribs in longitudinal section each have a convex radially outer surface which engages the fiat side surface of an adjacent packer rib when the packer rib-s are deformed in packing position.

6. A packer for well casings comprising a hollow rigid member adapted to be secured to a well casing string and a hollow sleeve of resiliently deformable material telescopically receiving and embracing the hollow rigid member, said sleeve having a plurality of longitudinally spaced packer ribs and reinforcing ribs extending around its periphery and projecting radially outward therefrom, the reinforcing ribs being of smaller diameter than said packing ribs, each pair of packing ribs having a reinforcing rib spaced therebetween, a peripheral groove formed between each packer rib and an adjacent reinforcing rib whereby each of said packer ribs may be folde over and be compressed between the walls of a well bore an the outer surface of one of said reinforcing ribs. 7. The structure as defined in claim 6 wherein the reinforcing rib directly above each packer rib is spaced less therefrom than the reinforcing rib directly below.

References Cited in the file of this patent UNITED STATES PATENTS 1,771,556 Cox July 29, 1930 1,924,020 Bihet Aug. 22, 1933 2,032,492 Nathan Mar. 3, 1936 2,451,070 Chamberlain Oct. 12, 1948 2,452,466 Iaswell Oct. 26, 1948 2,813,589 Woodrufl Nov. 19, 1957

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