US 2449514 A
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Description (OCR text may contain errors)
Sept 14, 1948. E` scovlLLE, JR 2,44951'4 l OIL WELL PACKER.
Filed March 21, 1946 Y Patented Sept. 14, 1948 @IIL WELL PACKER Warren E. Scoviile, Jr., Nutley, N. J., assigner to United States Rubber Company, New York,
N. Y., a corporation of New Jersey Application March 21, 1946, Serial No. 656,069 Claims.V (Cl. 166-1-10) This invention relates to oil Well packers adapted to vbe lowered into a well and then expanded to shut off a portion of the well,` and more particularly to the so-called compression type of packer in which a reinforced rubberl "sleeve mounted on a drill pipe or well tubing is be lowered to a depth of 5,000 to 10,000 feet or` more are subjected to tremendous pressures during the well sealing period, and as constructed heretofore are short lived when used in deep wells. i
The purpose in using rubber packers is to sealoff a portion or portions of a well so that gas, water or other fluids present in such sealed-off area may be removed from the well for production or test purposes while excluding other fluids or gases. The rubber packer may, as above stated, be expanded to seal off a portion of the casing in the well or to engage the formation Walls of the hole. It is this latter use in which the packer is expanded suflicently to engage the formation walls of the hole with a sealing action that is most injurious to the packer.
In order to lower the packer assembly into the drill hole without undue diculty caused by its touching the casing Wall or swabbing the hole in the formation, certain allowance for clearance is usually provided for in designing the rubber packer. When a packer of the type herein contemplated is used in a portion of the well which does not contain a casing, it is lowered to the selected depth and then expanded laterally by a downward pressing force into sealing engagement with the formation of the walls of the hole. It is customary in rotary drilling to keep the hole filled with mud and water until the hole is cased. The weight of this long column of mud exerts a tremendous downward pressure upon the packer that tends to force the expanded outer Walls of the packer downwardly about the supported lower head of the packer with shearing action. It has been attempted heretofore to resist this shearing force by reinforcing the packer with cord fabric and woven duck, and by wrapping the end portions of the packer with wire, but lwith the Vpresent daytendency of drilling wells deeper and deeper there is ianurgentuneed of packers that are stronger and more serviceable than those available heretofore.
The present invention therefore relates to the compression type of oil well packer which is` so constructedthat itis much better adapted to withstand the tremendous shearing forces to which it is likely to be subjected in use than the packers manufactured heretofore.
The increased strength and wearing properties of the packers of the present invention are secured by providing a metal head at each end of the body portion `of the packer and by providing plies of cord fabric which surround this body throughout .the central portionof its length but taper inwardly near each Aend where they are iirmlyanchored tothe heads. In additionto this a number of metalrings are preferably provided near each head outside of the tapered portion of the cord fabric, and adjacent these metal rings are provided frustro-conical textile rings one of which fits in the space between the cord fabric and the metal rings and the other is positioned inside the tapered Wall formed by the plies of cord fabric. The arrangement is such that at the time the well packer is subjected to the most severe downward forces tending to rupture the same, the reinforcingplies will be firmly gripped between and supported by the frustro-conical rings and these rings are supported by 'the surrounding metal rings. The reinforcing plies of cord fabric may be rubberized cord fabric cut on the bias much the same as in the construction of tire carcasses.
The above and other features of the present invention will be more fully understood from the following description when read in connection with the accompanying drawings; wherein Fig. 1 is a vertical sectional View through the lower end portion of an oil well having the packer of the present invention positioned therein but not expanded.
Fig. Zona larger scale is a vertical sectional view of the pack-er of Fig. 1.
Fig. 3 shows the packer of Fig. 1 partly in full lines and partly in section and as expanded into sealing engagement with the formation walls of and the packer of the present invention is designated in its entirety by I2. The well is shown as having lowered therein the usual connected well pipes or tubings I3 and the lower end of this tubing is indicated by I4. The tubing I3 has slidably mounted thereupon the surrounding metal sleeve I and, the arrangement is such that the sleeve I5 may be slid longitudinally upon the lower end of the tubing I3 which extends downward from the upper end of the well and may be of great length. The tubing I3 is shown as having an outwardly extending pin I6 adapted to slide up and down in a J-shaped slot I6 formed in a wall of the sleeve I5. vThe tubing I3 has also a slot I1 through one wall and which may be brought into alignment with a hole I'i in a wall of the sleeve I5.
The parts are shown in Fig. 1 with the pin i I5 at the top of the slot It so that the weight of the sleeve I5 is supported by the pin I6 through its engagement with the top of the slot I5. When the parts are in this position the-packer 2 is not expanded. To expand the packer I2 the parts are lowered in the well until a stop sleeve it attached to 'the lower end of the packer strikes the bottom II of the Well, whereupon the tubing "i3 is lowered further its pin I6 will engage the bottom of the slot I6' and push downwardly on the sleeve I 5 to expand the-'packer I 2. When it is desired to admit fluid into the bore of the tubing I3 from exterior of the sleeve I5, the pin It is moved into engagement with the part it of the slot I6.
The mechanism described so far-by reference numerals with the exception `of thepacker l2, is well known and forms no essential part of the present invention. Theoil well packer I2 being of the compression type is adapted to y-beexpanded by heavy pressure exerted upon the upper end `of the packer by the downward movement of the sleeve l5 while the lower end of the packe-r is supported by the sleeve I8. 11n the construction shown the lower end I4 of the tubing vI3 extends downwardly some distance into the stop sleeve it and this sleeve has a number of apertures it through which the fluid in the bottom of the well may pass into the interior 'of the sleeve. This sleeve E53 is provided at its upperend with an integral head-engaging flange 2t, and the lower end of the sleeve I5 is provided with a similar integral flange 2i. The packer I2 is, as above stated, expanded by lowering the sleeve 'I5 a few inches under the weight of thetubing I3 while the lower end of the packer'is supported by the stop sleeve I3.
The well packer I2 which forms the subject matter of the prese-nt invention will now be described in detail and since it is designed to withstand pressures `amounting to vmany tons without rupturing, its wallsare thick and it `is made very strong throughout. The packer as shown in the drawing comprises a tubular body "22 of vulcanized rubber and the inner boreof this tub-e and outer periphery vthereof are reinforced with plies of cord-fabric which may be very similar to the cord fabric used today in pneumatic vautomobile tires.
The reinforcing cord fabric usedilis fa weftless fabric formed of rubberized cord, and wherever such reinforcing fabric is used two plies are employed so that the cords of one ply may be disposed diagonally to the longitudinal axis of the packer in one direction and the cords of the other ply disposed diagonally to the longitudinal axis of the packer inthe opposite-direction. 'This is `fabric.
important in order that the cords may accommodate themselves to the bulging action of the packer as it is expanded from its cylindrical shape of Fig. 2 to the barrel shape of Fig. 3 where its side walls are expanded into sealing contact with the side walls I0 of the well hole. The thick tubular body 22 of rubber is reinforced adjacent its bore by the sheets of cord fabric 23 and this body 22 is reinforced at its outer periphery midway between its ends by several plies 24 of cord The packer I2 has the same construction at both ends so that if the lower end, which as will be presently pointed out is subjected to much more injurious forces than the upper end, becomes damaged the packer may be removed from the well and turned end for end for further use.
The packer I2 is formed at each end with what may be called a head and this head consists prii y marily of a heavy metal ring 25 having extending therefrom clamping bolts 26. These bolts are 'adapted to secure one end of the packer tothe flange 20 and the other end to the-f'angeI, by means of the nuts 2l'.
When the packer I2 has been expanded as shown in Fig. 3 to seal off a portion of the well, thus separating the column of liquid mud '28 above the expanded packer I2 from a lower well section to b-e worked or tested, the packer may support o. column of mud several thousand feet high which exerts a tremendous downward pressure upon the expanded packer. The effect of this is to subject the lower portion of the packer to a very severe shearing force as the Yweight 'of this column of mud Vtends to force the expanded portion of the packer downwardly about the head at the lower end of the packer. To' enable the packer of the present invention to resist the destructive action of this downward pressure the following construction is employed. The reinforcing plies 24 extend throughout the length of the packer and are strengthened from near the central portion of the packer to the ends thereof by the additional plies of cord fabric 29. These plies 2t and 29 converge inwardly near each end of the packer so Aas to pass inside the metal ring 25 and are folded about such ring and extend outwardly in a horizontal direction as indicated at 36, to thereby firmly anchor these plies to the lrings 25. At each end of the packer are provided a number of fabricv discs 3| that rest against the laterally extending portion 33 of the reinforcing plies, and the clamping bolts 25 pass through holes in these discs. The rings 25 it will be noted are surrounded by rubber to thereby provide a cushion between the parts and also to bond the plies to this ring.
In order further to strengthen lthe end positions of the packer against severe outward `and downward forces the plies 24 and 29 are internally reinforced above the ring 25 by the frustroconical rings 'S2 vand are externally reinforced by a second frustro-conical ring 33. These rings 32 and 33 are preferably formed of a heavy ribbon Aof fabric wound one coil about the other in the are shown in Fig. 2 to `that in which they arel shown in Fig. 3 they will be `supported bythe metal annulus formed 'of the' rings 34,
All metal and fabric portions of the packer of the present invention are preferably surrounded by rubber as shown to provide a cushion action between the parts, and the bore of the packer and all exterior surfaces thereof are protected by a heavy film of rubber as indicated by 35. All rubber parts are properly vulcanized. Each of the head engaging flanges and 2| is given the hollow -construction shown so as to receive the end portion of the packer that is formed largely of the fabric discs 3|.
It will be seen from th'e foregoing that the construction of the packer is such that when the clamping nuts 21 are tightened the ends of the reinforcing plies 24 and 29 will be subjected to a strong clamping action between the ring 25 and flange 20 or 2l, and that a downward thrust exerted upon the packer by the weight of th'e column of mud 28 will be resisted by the coop eration of the rings 34 with the frustro-conical` rings 32 and 33 between which the reinforcing plies 24 and 29 are gripped. In this manner an exceptionally strong and serviceable packer is provided.
Having thus described my invention, what I claim and desire to protect by Letters Patent is:
1. A Well packer comprising, an expansible tubular body of elastic material, -a metal ring at each end of said body, plies of cord fabric surrounding said body and rmly anch'ored to each ring, a semi-rigid frustro-conical textile ring surrounding the cord plies near each metal ring and formed of a number of heavy fabric plies wound one over the other to produce a ring that is rigid enough to retain the frustro-conical shape under expanded Well closing conditionsI and a metal annulus adjacent each metal ring positioned to support the adjacent semi-rigid frustro-conical ring to thereby support the expanded cord fabric near the metal rings against rupturing forces.
2. A well packer comprising, an expansible tubular body of elastic material, a metal ring at each' end of said body, plies of cord fabric surrounding said body and firmly anchored to each ring, a semi-rigid frustro-conical textile ring surrounding the c ord plies near each metal ring and formed of a number of heavy fabric plies wound one over the other to produce a ring that is rigid each end of said body, plies of cord fabric surrounding said body and firmly anchored to each head, two semi-rigid frustro-conical rings `disposed one at each side of said plies near each head each' of these rings being formed of a number of fabric plies disposed one over the other to produce a ring that is rigid enough to retain enough to retain the frustro-conical shape under expanded well closing conditions, and va metal annulus adjacent each metal ring and surrounding a portion of the adjacent frustro-conical ring, to thereby support th'e expanded cord fabric near the ends of the tubular body against rupturing forces.
3. A well packer comprising, an expansible tubular body of elastic material, a metal head at its frustro-conical shape under expanded well closing conditions, and a metal annulus adjacent each head and positioned to support the adjacent frustro-conical rings to thereby support the expanded cord fabric near the ends of the tubular body against rupturing forces.
4. A well packer comprising, an expansible tubular body of elastic material, a metal head at each' end of said body, plies of cord fabric surrounding said body throughout most of its length and inclined inward near each head and anchored to the head and formed of a number of heavy fabric plies wound one over the other to produce a ring that is rigid enough to retain the frustro-conical sh'ape under expanded well closing conditions, a semi-rigid frustro-conical ring surrounding the inwardly inclined portion of said plies near each head, and a metal annulus -adjacent each head and surrounding a portion of the adjacent frustro-conical ring to thereby support the plies near the ends of the tubular body against rupturing forces.
5. A well packer comprising, an expansible tubularbody of elastic material, a metal ring at each end of said body, plies of cord fabric surrounding said body throughout most of its length and turned inwardly near eachl ring and folded about and anchored to the ring, a semi-rigid frustro-conical member surrounding the cord plies near each ring and formed of a number of heavy fabric plies wound one over the other to produce a ring that is rigid enough to retain its frustroconica1 shape under expanded well closing conditions, and a metal annulus adjacent each ring and positioned to support the adjacent frustreconical member to thereby support the expanded cord fabric near said rings against outward and downward forces.
WARREN E. SCOVILLE, JR.
REFERENCES CITED The following references are of record in the le of this patent:
UNITED STATES PATENTS Number Certificate of Correction Patent No. 2,449,514. September 14, 1948. WARREN E. SCOVILLE, JR.
It is hereby oertiied that error appears in the printed specification of the above numbered patent requiring correction es follows: Column 6, line 19, claim 4, beginning with the Words and forlned strike out all to and including conditions in line 23, and insert the same inline 25, after head and before the comme.; and that the seid Letters Patent should be read With this correction therein that the samemay conform to the record of the case in the Patent Office.
Signed and sealed this 30th day of November, A. D. 1948.
THOMAS F. MURPHY,
Assistant Oomm'issz'oner of Patents.