US2106859A - Hook wall packer - Google Patents

Description

Feb. 1, 1938. F. J. SPANG HOOK WALL PACKER Filed Aug. 27, 1956 INVENTOR ww Q. W WWWW Patented Feb. 1, 1938 UNITED STATES PATENT OFFICE 7 Claims.

This invention relates to well packers and more particularly to improvements in the slip assembly or actuating means for packers of the hook wall type.

In the drilling of oil and gas wells it frequently becomes necessary to pack the wells at a predetermined point to prevent fluid or gases passing up or down in the well at that point except through the string of easing or tubing by which the packer is carried either on the lower end or at a given positionat some intermediate point in the length thereof. The present invention relates to that particular class of packers which are adapted to be supported on the wall of the, well bore or on the interior wall of string of casing or tubing and are generally known in the art as a hook wall packer. In packers of this general type a friction slip assembly and a member having a conical surface are utilized to support the packer on the well wall and to expand the packer element thereof.

Ordinarily the slips of the assembly are held in an inoperative position by outwardly bowed friction springs attached at one end to the assembly and having their free ends pressing against the slip reins relatively close to the heels of the slips. Frictionally operated slip assemblies of this character have not proved entirely satisfactory in use, because, where unusual friction is required to set the packer, as for instance where the packer is being set on a smooth, slippery well wall, it is frequentlyimpossible to set the packer since the forcerequired to expand the slips into wedging action with the wall is considerably greater than the frictional grip of the spring on the wall of the well bore. Making the springs heavier so that they grip the well wall fails to solve the problem since, under the then existing conditions, it was impossible to apply sufficient force to expand the springs and permit the slips to be moved into wedging action by the conical surface.

Further, the slip assembly is often rendered inoperative by the wedging of foreign articles around the hook portion of the assembly and the strains resultingfrom the attempt to set such a wedged packer are sufficient to bend the hook out of shape and render it useless, and due to the limitation of space and general design as well as cost, it is impractical and impossible to make the hook section of heavier material.

Another objection to ordinary types of hook Wall packers is that the slips frequently pass over or above the conical surface of the member attached to the packing element and consequently the heels of the slip come into engagement with the soft packing element and look over the top of the member making it extremely diflicult if not impossible to remove the packer from the well.

The primary object of this invention is to provide a slip assembly for a hook wall packer in which the frictional operating springs are so arranged that they do not exert a hindering pressure on the slips and are of such capacity as will permit the packer to be actuated by the application of considerably less force than the force now required to operate or actuate this type of packer.

Another object of the present invention is to provide a slip assembly for hook wall packers in which the lower end of the hook is strengthened by means of the pressure of a portion of the friction springs and in which auxiliary means are introduced for supporting the open end of the hook member and for preventing it from spreading, whereby additional strength is given to the hook member. 0

A further object of the invention is to provide 2 a slip assembly for book wall packers having means for preventing the slips from passing above the corie member used to actuate the packing element. V 25 A still further object is to provide a hook wall packer which is simple to manufacture and which is positive in operation and requires considerably less force to expand the slips than is required in the conventional type of hook wall packer. 30

These and other objects which will be hereinafter made apparent to those skilled in this particular art are accomplished by means of this invention, one embodiment of which is described in the following specification, and illustrated in the accompanying drawing, wherein:

Fig. l is a view in elevation of a hook wall packer embodying my invention.

Fig. 2 is a View in elevation showing the packing elements in their set or expanded position. 40

Fig. 3 is a sectional view taken on line IIIIII of Fi 2.

Fig. 4 is a View in elevation of the slip assembly turned at substantially right angles to the position shown in Figs. 1 and 2. 5

Fig. 5 is a sectional view taken on line VV of Fig. 4.

Fig. 6 is a sectional view taken on line VI-VI of Figs. 2 and 3.

Referring to the drawing in detail, I0 indicates 50 a packer, made in accordance with my invention, having a tubular body H which is connected at its upper end to a coupling 12 by means of which the packer is connected to a suitable string of cas- H ing or tubing in which it is to be run. The outer 55 surface of the coupling I2 is provided with a series of serrations |2a to provide means for gripping the packer by a suitable grappling tool. Carried on the body of the packer is an expansible packing element l3 made of rubber or other suitable expansible material, having a ring-like member l4 secured to the upper end thereof in the usual manner, which is seated in a recess l5 formed in the outer surface of the coupling 2 adjacent its lower end and to which it is secured by screws IS. The lower end of the packing element I3 has a ring l1 secured thereto which is seated in a recess |8 formed in the upper end of an an-- nular member l9 and to which it is secured by means of the screws 20. The member I9 is slidably mounted on the body H, and has its lower end provided with a conical surface 2|, the purpose of which will be hereinafter explained.

In order to actuate or expand the packing element l3, a series of slips 22 having their inner surfaces tapered substantially the same as the conical surface 2| are provided which abut against the surface 2| and are carried by reins 23 having their lower ends secured to a ring-like member 24 that surrounds the body of the packer and is slidable thereon. The slips 22 are each yieldably held in engagement with the conical surface 2| of the member I9 by a relatively light outwardly bowed spring 25 having its lower end secured to the ring member 24 and its upper end bearing against one of the reins 23 at a substantial distance below the heel of the slip 22 which is carried thereby.

In order to hold the slips 22 in their inoperative position adjacent the conical surface 2| and to prevent them from being inadvertently wedged against the wall of the well or casing during the time that the packer is being lowered into the well, a hook member 21 is formed integrally with the ring 24'to which the slips are attached, and has a horizontally extending open ended slot 28 formed therein which is adapted toreceive a pin 29 on the body member of the packer to hold a slip assembly against movement thereof relative to the body of the packer I0. The bottom ends 30 of the hooks 21 are rounded to prevent the slip assembly from coming to rest on the pin and to provide direction finding points which will insure the positioning of the pin 29 in the slot 28.. To prevent the heels of the slips 22 from passing above the top of the member l9 when the packer is actuated, a sleeve 32 is formed integrally with the ring member which is adapted to engage the bottom of the member l9 and is of a length sufficient to prevent the slips from passing over the top of the cone member.

So that a greater frictional grip will be secured between the slip assembly and the wall of the well or the casing in which the packer is being lowered and, at the same time, todecrease the amount of force required to expand the slips 22 into wedging engagement With thewall being packed, a series of outwardly bowed springs 33 are provided having their lower ends attached to the hooks 21 and their upper ends bearing against the sleeve 32. These springs, which are relatively 7 heavy in comparison with the springs 25, materially increase the frictional engagement of the slip assembly with the well bore and, at the same time, they tend to support the directional finding points 39 of the hooks 2'L'holding them against the body of the packer and preventing them from being bent into an inoperative position and shape. The hook 21 isfurther supported by a strap 34 which spans the slot 28 adjacent the open end thereof and is secured to the hook 21 and the ring 24.

From the foregoing description it is apparent that when the packer I0 is lowered into the well with the hook 21 over the pin 29 the friction springs 25 and 33 tend to retard the movement of the slip assembly and exert considerable frictional pressure between the packer and the well bore. When the packer has been lowered to the desired setting position, the body of the packer is turned in a right-hand direction to move the pin 29 out of the hook slot 28 (the slip assembly being held against rotary movement by the frictional engagement of the springs 25 and 33 with the well bore or the casing). At the completion of this rotary movement, the body ll of the packer is lowered relative to the slips 2 2 and ring 24, which causes the conical surface 2| to expand the slips and move them into wedging engagement with the well bore, and since the springs 25 bearing against the slip rings are relatively light, the force required to move the slips into wedging engagement with the well bore is considerably less than that required where relatively heavy springs are used to frictionally engage the well bore. After the slips 22 have been moved into wedging engagement with the well bore, the downward movement of the packer body is continued, the member I9 then sliding on the packer body It and the packing element I3 is expanded and pressed into engagement with the well bore. When the packing element |3 has been set, the upper end of the sleeve 32 comes into engagement with the lower end of the member I9 tional pressure exerted by the slips on the conical surface of the member l9, thus making the packer positive in operation and permitting it to be actuated with a relatively light force. Fur- It is also apparent that I have provided ther, the hook is held in position by the auxiliary springs 33 and by supporting the nose of the hook, the slot is always held in correct position both vertically and circumferentially.

While I have described one embodiment of my invention, it is also apparent that certain modifications, additions, subtractions, and omissions may be made therein without departing from the spirit of my invention and the scope of the ap-' pended claims.

What I claim as new and desire to secure by Letters Patent is:

1. A packer comprising a tubular body, an expansible element carried by said body, a member having a conical surface carried by said body and engaging said element, a ring member slidable on said body, a slotted hook depending from said ring, a relatively heavy outwardly bowed spring secured at one end to said hook below the slot therein and having the other end engaging said ring, a series of slips carried by said ring and relatively light outwardly bowed springs secured to said ring having one end engaging said slips for holdingthe same against said conical surface.

2. In a hook wallpacker, a slip assembly comprising a ring section, a hook section depending" from said ring section, a sleeve section projecting above said ring section, a series of slips carried by said ring section, a spring yieldingly engaging each of said slips, and a pair of springs attached to the lower ends of said hook section and abutting against said sleeve section.

3. In a hook wall packer, a slip assembly comprising a ring member, a hook depending from said ring, and having a slot therein, slips carried by said ring, and a nose support for said hook end spanning said slot.

4. A slip assembly for a hook wall packer comprising a ring-like member having depending slotted hook portions and an upwardly projecting sleeve, a series of slips attached to said ring, a series of outwardly bowed relatively light springs each having one end secured to said ring and the other end bearing against one of said slips, and outwardly bowed relatively heavy springs each having its lower end secured to one of said hook portions below the seat therein and its upper end bearing against said sleeve.

5. A slip assembly for a hook wall packer comprising a ring, a slotted hook portion depending from said ring member, a sleeve projecting upwardly from said ring member, a series of slips, reins for attaching said slips to said ring, a series of outwardly bowed springs each having one end secured to said ring and the other end bearing against one of said slip reins, and a pair of outwardly bowed springs each having one end secured to one of said hook portions below the slot therein and the other end bearing against said sleeve for reinforcing said hook.

6. A slip assembly for a hook wall packer comprising a ring member, horizontally slotted hooks depending from said ring member, a sleeve projecting upwardly from said ring member, a series of slips, reins for attaching said slips to said ring member, a series of outwardly bowed springs each of which has one end secured to said ring and the other bearing against one of said slip reins, a series of outwardly bowed springs each having one end secured to the hooks and the other ends bearing against said sleeve for reinforcing said hook, and means for supporting the nose of said hook in fixed position relative to said ring member.

'7. In a hook wall packer, a slip assembly comprising a ring section, a hook depending from said ring and having a slot therein, slips carried by said ring, a support for said hook spanning said slot, and auxiliary means for reinforcing said hook.

FERDINAND J. SPANG.

CERTIFICATE OF CORRECTION.

Patent No. 2,106,859. February 1, 19

FERDINAND J. SPANG.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, line 11, claim 5, for the word nd" read and; and that the said.

Letters Patent shouldbe read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 8th day of March, A. D. 1958.

. Henry Van Arsdale (Seal) 7 Acting Commissioner of Patents.

Images