Title:
PACKER AND PACKER SETTING APPARATUS
United States Patent 3554279


Abstract:
A packer and packer setting apparatus including a packing element arranged to be deformed into sealing engagement with a well casing, a packing cup encircling the packer and sealingly engaging the casing, an annular packer deforming member engaging the upper end of the packing element, and a frangible connection member releasably connecting the packing cup to the packer deforming member whereby fluid pressure in the annulus can be utilized to apply a setting force on the packer. At least one recess extends longitudinally along the exterior of the packer deforming member and is initially located below the packing cup. The connection member is arranged to part upon the application of a predetermined hydraulic pressure on the packing cup whereby the cup is driven downwardly permitting flow through the recess to prevent the cup from "swabbing" as the packer is pulled from the well.



Inventors:
Meripol, Robert B. (Dallas County, TX)
Pumpelly, Robert C. (Dallas County, TX)
Application Number:
04/847224
Publication Date:
01/12/1971
Filing Date:
08/04/1969
Assignee:
DRESSER INDUSTRIES INC.
Primary Class:
Other Classes:
166/130, 166/202
International Classes:
E21B23/06; E21B33/126; (IPC1-7): E21B23/06
Field of Search:
166/121,130,202,183
View Patent Images:
US Patent References:
3316971Sand trap for use in well bores1967-05-02Brown
2990882Well packers1961-07-04Brown
2819762Bypass well packer1958-01-14Johnston et al.



Primary Examiner:
Brown, David H.
Claims:
We claim

1. In a packer arranged to be set in a well bore by a downward force exerted thereon through a tubing string, fluid pressure setting means for exerting an additional setting force on the packer, said packer having a mandrel extending therethrough connected with the tubing string and a deformable packing element encircling the mandrel, said pressure setting means comprising:

2. The packer of claim 1 wherein said seal means includes a cup member having an upwardly oriented flexible lip portion disposed in sliding and sealing engagement with the well bore wall when the packer is disposed in a well bore.

3. The packer of claim 2 wherein said seal means also includes:

4. The packer of claim 1 wherein said connection means includes a frangible member connecting said seal means and body, said frangible member having a predetermined parting value.

5. The packer of claim 3 wherein said connection means includes at least one frangible member connecting said annular member to said body with said annular seal disposed relatively above the recess in said body, said frangible member having a predetermined parting value.

6. A packer arranged to be set in a well bore by a downward force exerted thereon through a tubing string, said packer comprising:

Description:
BACKGROUND OF THE INVENTION

This invention relates generally to packer apparatus useful in well bores or the like. More particularly, not by way of limitation, this invention relates to a packer having improved setting apparatus thereon for deforming the packing element of the packer into sealing engagement with a well bore wall or the like.

In the so-called "compression-set" packers, movement of the wall engaging or anchoring members and the deformation of the packing element is accomplished by downward movement of the tubing string upon which the packer is run into the well bore. The downward movement of the tubing string must be sufficient to bring the wall engaging members into holding engagement with the well bore wall and to deform the packing element. To accomplish this, the weight of the tubing string is set down on the upper end of the packer.

Frequently, it is desirable to run the compression-set packers in relatively shallow wells. In such wells, the weight of the tubing string will oftentimes not be sufficient to deform the packing element into the desired sealing engagement with the well bore wall. Under such circumstances, a packer of this type cannot be used.

One object of this invention is to provide an improved packer setting apparatus for use with compression-set packers that will enable the packers to be set in shallow well bores.

Another object of the invention is to provide improved packer setting apparatus for use with the compression-set packers wherein the amount of force exerted thereon can be controlled, and thereby avoid damaging the packer through the use of excessive setting forces.

Still another object of the invention is to provide an improved compression-set packer wherein hydraulic force is utilized through a packer cup to provide the additional force necessary to obtain proper sealing and, yet, the packer can be retrieved without swabbing.

This invention then provides an improved packer and an improved pressure-actuated setting means for exerting an additional setting force on the packer. The packer has a mandrel extending therethrough connected with the tubing string and has a deformable packing element encircling the mandrel. The pressure setting means comprises: a hollow body encircling the mandrel and having an upper end engageable with the mandrel, a lower end engageable with the packing element, and having at least one recess in the exterior thereof; seal means sealingly engaging the body above the recess, the seal means being arranged to sealingly and slidingly engage the well bore wall; and, connection means releasably connecting the seal means to the above the recess whereby fluid pressure applied on the seal means exerts a force on the body to aid in setting the packer. The connection means is releasable when a predetermined force is exerted on the seal means to permit fluid to flow through the recess thereby permitting the packer to be retrieved without swabbing.

The foregoing and additional objects and advantages of the invention will become more apparent as the following detailed description is read in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a view, partly in elevation and partly in cross section, of a compression-set packer disposed in a conduit and setting means thereon constructed in accordance with the invention.

FIG. 2 is an enlarged view, partly in cross section and partly in elevation illustrating, in more detail, the setting means constructed in accordance with the invention.

FIG. 3 is a view similar to FIG. 2 but illustrating the packer setting means in another operating position.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawing and to FIG. 1 in particular, shown therein and generally designated by the reference character 10 is a packer assembly located in a conduit or casing 12. Although not shown, and during normal use, the conduit 12 will be located in a well bore.

The packer assembly 10 includes a hollow mandrel 14 threadedly connected at its upper end to a valve member 16 that is threadedly connected with the lower end of a tubing string 18. The tubing string 18 extends to the surface of the well.

The valve member 16 includes an annular seal 20 that is arranged to be received in sealing engagement with the upper end of an upper thimble 22. The valve member 16 also includes an exterior annular flange 24 that is engageable with the uppermost end of the thimble 22.

The thimble 22 encircles the mandrel 14 and is threadedly connected with a packing sleeve 26 that extends downwardly through an annular deformable packing element 28. The packing element 28 is constructed from any suitable material that can be deformed into sealing engagement with the conduit 12 through a series of manipulations to be described.

The upper end of the packing element 28 is in engagement with the lower end of the upper thimble 22 and the lower end of the packing element 28 is in engagement with a lower thimble 30. The lower thimble 30 is slidingly disposed on the packing sleeve 26 and has a lower end that is engageable with a flange 32 projecting radially from the sleeve 26.

An abutment 34 is mounted on the exterior of the mandrel 14 below the flange 32. The abutment 34 is located within a slip expander 36 which has its upper end threadedly connected with the lower thimble 30. The expander 36 has an exterior, frustoconical surface 38 that is adapted to mate with tapered inner surfaces 40 located on a plurality of slips 42. The slips 42 are circumferentially spaced about the expander 36 and are connected at their lower ends with a drag spring assembly 44.

The drag spring assembly 44 includes a plurality of drag springs 46 that frictionally engage the interior wall of the casing 12. The drag spring assembly 44 includes a J-slot body 48 having a J-slot 50 therein that is sized to receive a J-slot pin 52. The pin 52 is threadedly attached to and projects radially outward from the mandrel 14. An abutment 54 is provided on the lower end of the mandrel 14 below the J-slot body 48 for purposes that will become more apparent hereinafter.

As may be seen more clearly in FIG. 2, an upturned packer cup 56 encircles the upper thimble 22. To maintain the cup 56 in the position illustrated, a shear pin 58 extends therethrough into threaded engagement with the thimble 22. The shear pin 58 is designed to part at a predetermined value which will be slightly above the force required to set the packer assembly 10. The outer diameter of the cup 56 is greater than the inner diameter of the casing 12 so that the packer cup, which is constructed of a resilient material, slidingly and sealingly engages the casing 12.

An O-ring seal 60 is located within the packer cup 56 in sliding and sealing engagement with the exterior of the upper thimble 22. As may be seen in FIG. 2, the shear pin 58 retains the packer cup 56 in a position wherein the O-ring seal 60 is located above the upper end of longitudinally extending recesses 62.

The recesses or slots 62 are circumferentially spaced about in the exterior of the upper thimble 22. The lower ends of the slots 62 extend into a shoulder 64 formed on the thimble 22 and are of such length that when the pin 58 has parted and the packer cup 56 moves downwardly, fluid will flow through the recesses past the O-ring seal 60 and outwardly through the lower ends of the slots 62 in the shoulder 64.

OPERATION

In operation, the packer assembly 10 is connected with the lower end of the tubing string 18 and lowered into the casing 12 which is disposed in a well bore (not shown). As the packer assembly 10 passes downwardly through the casing 12, the drag springs 46 are in engagement with the casing 12 and the packer cup 56 is also in engagement with the casing 12 except as it is deformed by fluid passing between the packer cup 56 and the casing 12.

Upon reaching the desired location in the well bore for setting the packer assembly 10, the tubing string 18 and the connected mandrel 14 are rotated, moving the pin 52 in the J-slot 50 to a position wherein the pin 52 can pass downwardly through the lower end of the J-slot body 48. The J-slot pin 52 is moved downwardly by lowering the tubing string 18 and mandrel 14.

As the mandrel 14 moves downwardly, the slips 42 are retained in a fixed position by the frictional engagement of the drag springs 46 with the casing 12. The seal 20 enters the upper thimble 22 closing the passageway between the mandrel 14 and the packing sleeve 26. Farther downward movement brings the flange 24 on the valve member 16 into engagement with the upper end of the upper thimble 22.

After engagement between the flange 24 and the upper thimble 22, additional downward movement of the tubing string 18 forces the upper thimble 22, packing sleeve 26, packing element 28, and expander 36 downwardly relative to the slips 42.

Relative movement between the expander 36 and the slips 42 brings the surfaces 38 and 40 on the expander 36 and slips 42, respectively, into engagement moving the slips 42 radially outwardly and into holding engagement with the casing 12. When this occurs, further downward movement of the expander 36 is prevented.

Since the expander 36 is now retained in the fixed position, the threadedly connected lower thimble 30 is also fixed relative to the casing 12. Continued downward movement of the mandrel 14 forces the upper thimble 22 and the connected packing sleeve 26 downwardly relative to the lower thimble 30, deforming the packing element 28 outwardly and into engagement with the casing 12 as is illustrated in FIGS. 2 and 3.

As previously mentioned, the weight of the tubing string 18 may not be sufficient to completely deform the packing element 28 into full sealing engagement with the casing 12. When this occurs, fluid pressure is increased in the annular space located between the tubing string 18 and the casing 12. This fluid pressure exerts a downward force on the packing cup 56 thereby increasing the downward force on the upper thimble 22 and further deforming the packing element 28 until the desired sealing effect is attained.

After the operations have been performed in the well through the packer assembly 10, and it is desired to remove the packer assembly 10 from the well bore, the fluid pressure in the annulus is increased until sufficient force is exerted on the packing cup 56 to shear the shear pin 58. After the shear pin 58 parts, the packer cup 56 moves downwardly along the upper thimble 22, as illustrated in FIG. 3, until the lower end of the packer cup 56 engages the shoulder 64.

With the packer cup 56 in this position, the upper end of the slots or recesses 62 are located above the O-ring seal 60 carried by the packer cup 56. It will be noted that the lower ends of the slots 62 extend through the shoulder 64 so that the lower end of the slots are open despite the engagement of the packer cup 56 with the shoulder 64. Since the lower and upper ends of the slots 62 are open, fluid flows from the annulus above the packer cup 56 to the annulus therein below thus equalizing the pressure across the packer cup 56 and relieving any pressure exerted thereby on the packing element 28.

To complete the removal of the packer assembly 10 from the well bore, an upward pull is taken on the tubing string 18 moving the value valve 16 upwardly out of the upper thimble 22. Continued upward movement of the mandrel 14 brings the abutment 34 thereon into engagement with the flange 32 on the lower end of the packing sleeve 26, forcing the upper thimble 22 relatively away from the packing element 28 and permitting the packing element 28 to return to its undeformed condition.

Additional upward movement of the mandrel 14 brings the flange 32 into engagement with the lower thimble 30, raising the expander 36 out of engagement with the slips 42. The slips 42 then return to a position out of engagement with the casing. When this occurs, the packer assembly 10 is free and may be pulled upwardly through the casing 12.

As previously mentioned, the packer cup 56 is in sealing engagement with the casing 12 and as the packer assembly 10 is raised upwardly, the sealing engagement is increased due to the weight of the fluid column in the well above the packing cup 56. To avoid having to lift this column or "swabbing" the well, the slots 62, which are in the open-flow condition as described in connection with FIG. 3, permit fluid flow past the packer cup 56 and thereby prevent the swabbing of the well by the packer cup 56. Thus, it is possible by use of the packer assembly 10 constructed as described to obtain the desired sealing effect in shallow wells wherein the tubing weight is not sufficient to set the packer and, yet, maintain the ease of retrieval of the packer assembly.

Having described but one embodiment of the invention, it will be understood that many changes and modifications can be made thereto without departing from the spirit and scope of the invention.