US2390372A - Open hole sleeve packer - Google Patents

Description

Dec. 4, 1945,

M. O. JOHNSTON ET AL PEN HOLE SLEEVE PACKER Filed June 18, 1941 J a" MLrfeLM/TH,

nnentors,

Cttomeg Patented Dec.; 194s l Mordlca 0.

Johnston and Thomas A. Andrew.

Glendale, and Adelbert M. Graham and Walter G. L. Smith, Los Angeles, Calif.

Application June 1s, 1941, sgi-laine. 398,624

-2 claims. (ci. icc-71o) This invention relates to oil well tools, and particularly pertains to an open hole sleeve packer.

In oil .well operations where itis desired to pack off the well at a particular point, it has been common to use a' sleeve type packer which is expanded into the well bore or casing and forms a seal therewith. Various types of packers have been Y employed in this manner including multiple ring packers and sleeves which represent an entire cylindrical packer wall of a desired length. Due to the simplicity of operation and relative cheapness of this last named type of packer its use is desirable. It has been found, however, that` in using a deformable sleeve packer in an open hole that due to the irregularities in the walls of the well bore the longitudinal compression yoi! the packer will deform and expand it and will cause the packer to expand unduly in the less confined areas of the well -bore, thus tending to permanently stretch and deform certain parts of the Packer, and at the same time making it necessary to increase the length of the packer to get a proper seal. When the length of the packer sleeve is increased under the conditions specified, it is found that the rate of expansion in various sections of the packer proceeds at a rate in excess of that existing at other points, and that when excessively stretched or expanded the rubber does not have suilicient strength to limit this expansion and will transfer the force to other points so that expansion throughout the length of the sleeve will be at a substantially'uniform magnitude. In fact, the impression has been given to some observers that vin some cases Where abnormal expansion starts at any particular point it accelerates, comparatively speaking, rather than decelerates, imparting to the packer a corrugated o'uter surface as represented by portions of the packer which have expanded more than others, with the result that the packer operates ineffectively and after a small amount of use may lose its usefulness. It is the principal object of the present invention, therefore, to provide a packer of the sleeve type which, while relatively small in diameter, may be expanded due to longitudinal compression -to a much greater expanded diameter than is now the case, while the expansion longitudinally of the packer is uniformly controlled to prevent inequality in expansion action at given sections of the packer, thereby insuring a maximum sealing action and a'minimum amount of destructive wear.

The present invention contemplates the construction of a sleeve packer having a wall of deiormable material, such for` example as rubber,

and within which a helical strengthening and equalizing element is incorporated 'to control and distribute compressive and expansive forces in the structure.

The invention is illustrated by way of.examplo n in the accompanying drawing, in which:

Figure l is a View in elevation showing the apl plication of the present invention.

Fig. 2 is an enlarged view in vertical section showing the packer construction.

Fig. 3 is a view in transverse section as seen on the line 3-3 of Fig. 2 showing the packer construction and its reinforcing and equalizing ele ment.

Referring more particularly to the drawing. I0 indicates a sub having a box II at its upper end to receive a'supportingstring or pipe I2 and a pin I3 at its lower end to connect with a tubular extension I4. The lower end of the tubular extenv sion is internally threaded and receives an upper pressure element I5 of the packer structure generally indicated at I6. A lower pressure element I1 is disposed at the lower end of the packer structure and is tted with a pin I8 which is.` threaded into an anchor pipe I9. .The upper pressure element I5 is formed with an upwardly projected threaded extension 20 which engages the tubular extension I4. The pressure element I5 is formed with a central bore 2| extending longitudinally therethrough. VThe diameter of the bore 2l is less than the inside diameter of bore 22 extending through the tubular extension I4, with the result that an upwardly presented shoulder 23 is formed on the member 20 and within the bore 22. Resting normally on this shoulder is a stop nut 24 carried by a tubular mandrel'25 onto the upper end of which the nut is threaded. This mandrel extends downwardly and its lower end is threaded at 2B to engage a complementary threaded portion in the lower pressure element, I1. A circulation passageway 21 is formed through the lower circulation element and completes fluid circulation from 'the tubular mandrel. interposed between the upper pressure element I5 andthe lower pressure element I1 is a cylindrical sleeve 28 which is made of deformable material such as rubber and constitutes the packer sleeve. This sleeve has a Wall of a thickness as represented by the opposite ends of the sleeve -position by screws 36.

the middle of the mass of material forming the wall of the packer sleeve 28. Imbedded in the 28 are cylindrical thimbles 30 and 3| which are vformed of suitable material, such as brass, and have .an annular groove 32 in their outer circumferenceand into t which the ends of the helical' element 29 are fitted and thereafter held in place by brazing or the like. Thus, the helical member will be fas tened by its opposite ends to the thimbles, which in turn are imbedded within the packer sleeve. At the outer ends'of the thimbles an annular shoulder 33 is formed. yFitting around this shoulder andV also into grooves 34 formed around the circumference of the pressure elements I5 and I1 are split fasteningy rings 35. These rings are channel shape in cross-section and are' held in The split rings act to embrace the ends of the pressure elements I and I1 contiguous to the packing sleeve 28 and to embrace the ends of the packing sleeve, thus reinforcing and protecting the same and positively securingy the packer sleeve to the pressure elements I5 and I1. square ends of the thimbles 3II and 3| rest directly against the elements I5 and I1 so that longitudinal force is applied directly to the thimbles and then to the packer sleeve 28. The tubular mandrel is guided within the upper pressure element I5 by a suitable bushing 31. 'Ihe bushing 31 is fixed upon the tubular mandrel and moves therewith. Extending transversely through the tubular mandrel and the upper end of the bushing and also into the upper pressure element I5 is a shear pin 38. This pin element I 5 in xed relation to the lower pressure element I1 without imposing compression upon the packer sleeve 28 until it is desired to set the sleeve.

In operation of the present invention the structure is assembled as shown and lowered into the well Auntil the anchorpipe I9 strikes the bottom of the well. Suflicient weight is then applied to the drill string I2, the sub I0, the tubular extension I4, and the upper pressure element I5 to shear the shear pin 33. Further downward force exerted by the aforementioned elements will impose a longitudinal compressi-on strain upon the packing .sleeve 29 and compress the same while deforming it in a lateral direction. The rubber which occurs between the convolutions ofthe helical element 29 and the tubular mandrel will be compressed and forced outwardly between the convolutions of the element ,29 and against the wall of the well bore. There will therefore be a. tendency to distribute the compression force` and control the deformation of the packer uniformly throughout the length of the packer. It will be seen that if at any single convolution of the reinforcing element 29 there is a greater expansive stress than at some other point in the length of the' sleeve, pressure will be.

set up in the mass of rubber adjacent to that point in excess of that present in any adjoining convolution and will confine. the rubber so that further compression will not take place.r r-,This

insures that theL rubber in the area between the tween the Within the By this arrangement the square ends of the pressure acts to hold the upper pressure material due to longitudinal compression will be equalized throughout the length of the packer sleeve 29 and uniformly therearound. It will further be noted that the reinforcing vhelix 29 will tend to limit the amount of expansion to which the sleeve can be forced, and will also act to contract and restore the packer to its original form. It has also been found that due to the strength given by the helix 29 the ability ofthe rubberto the tubular mandrel throughout a compression and de-compression cycle is greatly increased, and that a larger amount of expansion of the rubber sleeve can be obtained without danger. This last named'feature makes it possible for the packer sleeve to be of a smaller diameter than usual,

to facilitate in lowering the packer linto the well. When the packer is inserted and set and when it isbeing withdrawn from the Well it will be noted that the weight of the string of pipe below the packer will place the helical element 29 under tension and will tendl to contract the packer,l since the helical member which is imbedded packing sleeve will be contracted. This is due helical element are xed. The upper end is xed with relation to the upper pressure element I5 and the lower end with relation to the lower pressure element I1. By this arrangement it is insured that the packer will be contracted as it is unseated so that the packer may be withdrawn easily without unduly abrading or tearing it.

It will thus be seen vthat by the structure here shown a suitable sleeve type packer of any desired length may be obtained to pack on diilicult formations and to operate efficiently with long life.

While we have shown the our invention as now known to us, it will be understood that various changes may be made in 4 and positively secured by its ends to said elements,

and helical reinforcing means imbedded within and extending longitudinally of the sleeve and permitting longitudinal compression of the sleeve between said pressure elements while restraining expansion of the packer sleeve at intervals in the length of the sleeve, said helical means being likewise positively secured by its ends to said pressure elements.

2. A sleeve-type Well Ipacker, comprising al tubular mandrel, a lower pressure element fixed thereon, an upper tubular pressure element telescopically connected with the mandrel, interengaging means retaining themandrel and upper .tubular pressure element in telescopic connection, a tubular deformable packer sleeve mounted onthe mandrel between the pressure elementsl I maintain its form and properly embracel thereby increasing the flow space bepacker and the wall of the well bore to the fact that both ends of the preferred form oi mandrel, interenand being positively secured by its ends to said elements, a helical reinforcing member imbedded within and extending longitudinally of the sleeve and permitting longitudinal compression of the` sleeve between said pressure elements while restraining expansion of the packer sleeve at intervals in the area of the sleeve within which the helical member is directly imbedded, the ends `of said helical member vbeing positively secured to the upper and lower pressure elements. and

means temporarily holding the mandrel and the upper tubular `pressure element against relative longitudinal movement.

' MORDICA O. JOHNSTON.

v THOMAS A. ANDREW.

ADELBERT M. GRAHAM. WALTER/G. L. SMITH.

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