US2330259A - Well packer - Google Patents

Description

Patented Sept. 28, 1943 WELL mom-1n Reuben C. Baker, Coalinga, Calif., assignor to Baker Oil Tools, Inc., Vernon, Calif., a corpora tion of California Application September 22, 1941, Serial No. 411,802

Claims.

This invention relates to well packers, and more particularly to packing devices forming a part thereof for efiecting a seal with the wall of a well casing 01 other confining enclosure;

The present application is a continuation-inpart of my application entitled Well packer apparatus, Serial No. 333,491, filed May 6, 1940, now Patent No. 2,275,935.

It is an object of the present invention to provide a well packer embodying a packing member which is held positively in sealing engagement with the wall of a confining enclosure, and in which the seal efiected with such enclosure is of more uniform character around the periphery of the enclosure than was heretofore obtainable.

Still another object of the invention is to provide an improved packing construction in a well packer of such character as to be capable of slidable leak proof movement on the supporting body of the packer with lesser resistance.

This invention has other objects that will become apparent from a consideration of the embodiment shown in the drawing accompanying and forming part of the present specification. This form will now be described in detail, but it is to be understood that such detailed description is not to be taken in a limited sense, since the scope of the invention is best defined by the claims appended hereto.

Referring to the drawing:

Figure 1 is a partial sectional and partial elevational view of part of a well packer embodying the present invention, with the packing member thereof disclosed in retracted position;

Figure 2 is a view similar to Figure 1, with the packing member disclosed in expanded position;

Figure 3 is a longitudinal section through the packing member per se; and

Figure 4 is a plane view of the packing member as seen from the bottom of Figure 3.

In the drawing, the invention is disclosed as forming part of a well packer mechanism particularly described in the patent to Reuben C. Baker et al., Patent No. 2,225,143, granted December 17, 1940, on Well packer mechanisms. This packer includes a generally tubular body III having a guide II threaded on its end. Also threadedly attached to the body is a conical expander I2 adapted to positively expand a cupshap d packing I3 against the wall of a casing I4, and to hold it positively in expanded position thereagainst.

One end of this cup-shaped packing I3 is secured to a packing retainer I5 slidable on the body I0. This retainer includes an inner sleeve I6 extending from its base portion I1, and an outer skirt I8 extending from its base portion and provided with an inwardly extending flange I9. The skirt I8 and sleeve I6 are spaced from each other to form a circular groove in which the fixed end of the cup-shaped packing I3 is positioned. This packing includes a base portion 2| abutting the end of the retainer skirt I8, with its inner surface snugly engaging the outer periphery of the retainer sleeve I6. Extending longitudinally outwardly from this base portion is a locking portion of the packing, consisting of a ring 22 having an outwardly directed flange 23, received within the circular groove 20 formed between the retainer sleeve I8 and skirt I8. The inwardly directed skirt flange I9 and outwardly directed packing flange 23 interlock to secure the packing I3 in the packing retainer I5.

While in retracted position, the free end 24 of the packing is preferably protected by an encompassing circular lip or ring 25 extending from the guide II. The free end of the packing is adapted to cooperate with the conical expander I2 to be forced thereby outwardly into contact with the casing I4. To accomplish this purpose, the free end 24 of the packing is provided with a plurality of inwardly directed and circumferentially adjacent fingers 2B capable of engaging the tapered surface of the conical expander to expand the end 24 of the packing outwardly against the casing. Such engagement and movement along the conical expander I2 toward its larger end takes place under the impetus of a helical spring 21 positioned within the conical expander. One end of the spring engages the base of this expander I2, while its other end engages the retainer sleeve l6.

As disclosed in Figure l, the helical spring 21 as held in contracted position, with the cupshaped packing I3 retracted and its free end 24 within the confines of the lip 25. The spring is prevented from expanding by any suitable means, such as a latching mechanism (not shown) acting directly upon the packing retainer I5 to prevent its movement along the body I0. Particulars of the latching mechanism are not essential to an understanding of the present invention, and may be found in the patent above referred to. It is suflicient to state that this latching mechanism prevents movement of the packing retainer I5 under the action of the spring 21, but when this mechanism is released, the spring may expand to move the packing retainer I5 and packing I3 along the body I0 and shift the inwardly directed fingers 26 along the conical expander I2 to force the free end 24 of the packing against the wall of the confining enclosure I4, as is represented in Figure 2.

The engagement of the packing with the casing prevents fluid from passing therebetween. Leakage between the packing retainer I5 and the body III of the packer is prevented by a seal ring 28 situated within an inner groove 29 in the sleeve I 6, and provided with a lip 30 engaging the exterior of the body. The pressure from within the cup packing I3 acts upon this seal lie.

ring and its lip to force and hold it in engagement with the body i0, thus preventing leakage therealong. As a result, it is evident that fluid is prevented from passing between the body l and easing I 4 through the sealing actions of the i cup-shaped packing [3 against the casing and of the seal ring 28 against the body.

Because of the manner of mounting the packing l3 in the retainer i5, very little resistance is encountered to sliding movement of the retainer and packing along the tool body l0 under the influence of the helical spring 21. The seal ring 28 is effective to prevent leakage between the retainer sleeve i6 and body without creating sumcient friction to materially impede movement of the retainer. The cast iron or other comparatively rigid material of which this packing retainer may be constructed produces very little friction against the cast iron or other metallic material of the packer body l0. Substantially the full force of the helical spring 21 is therefore available for expanding and holdingthe free end 24 of the packing against the wall of the casing. This is a better arrangement than the one disclosed in the above-mentioned patent, in which the base of the packing itself engages the packer body, creating a great amount of friction and resistance to movement of the packing along the body with respect to the conical expander.

The employment of the inwardly directed fingers 26 which are preferably molded as an integral part of the packing so as to be separated from one another by slots 3| extending to the skirt 32 of the packing, enables the free end 24 of the packing to expand orbe stretched outwardly with greater facility to the increased diameter disclosed in Figure 2. If, instead of employing the separated fingers 28, a continuous inwardly directed flange were used, a much greater resistance to outward expansion of the free end of the packing would beencountered. The fingers can separate readily and will enable outward expansion of the free end of the packing to take place without undue restraint.

Although the use of the inwardly directed fingers 26 possesses the above-noted advantage, it is sometimes noted that the free end 24 of the packing fails to make a uniform sealing contact with the wall of the casing. The contact is apparently intermittent in character. Efl'ective sealing engagement occurs at the fingers 26, but the packing material between the fingers is sometimes spaced from the casing, offering regions through which fluid may leak. The spaced, inwardly directed fingers therefore might produce a corrugated or rippled surface on the exterior of the packing.

For the purpose of guarding against the occasional occurrence of this rippled effect, an outwardly directed packin lip 33 is formed onthe free end 24 of the packing. This lip is separated from the fingers 26 by a generally V-shaped groove 34 and preferably extends outwardly beyond the transverse plane in which the fingers As a result of this construction, the greater pressure exerted by the fingers 26 against the packing end 24 and casing over that existing in the packing between the fingers has no effect upon the packing lip 33 due to the separation mentioned. Upon expansion of the packing, the lip 33 engages the wall of the casing uniformly around its entire circumference. Following the engagement of the packing lip with the casing, pressure in the casing acts within the packing to expand it against the casing over a greater poruniform seal desired.

It is therefore apparent that a well packer has been provided embodying a packing device which is readily movable along the supporting packer body, and which eflects an efficient seal with the wall of a confining enclosure.

Iclaim:

1. A cup-shaped packing adapted to be expanded laterally outwardly by a conical expander, said packing comprising a plurality of inwardly directed fingers arranged circumferentially adjacent one another around the interior of said packing at its free end, said fingers lying in a plane substantially at right angles to the axis of the packing for engagement with the tapered surface of said expander to expand said free end of the packing laterally outwardly.

2. A packing adapted to be moved into sealing engagement with a member by an expander, said packing comprising a plurality of juxtaposed separated fingers engageable with the tapered surface of said expander to force said packing laterally into sealing engagement with said memher, said packing also including an annular lip adapted to make a uniform circumferential seal with said member whose uniformity is substantially unaffected by said fingers.

3. A packing adapted to be moved into sealing engagement with an enclosure by a conical expander, said packingcomprising a plurality of inwardly directed fingers arranged circumferentially in juxtaposition around the interior-of said packing and engageable with the tapered surface of said expander to expand said packing laterally outwardly, said packing also including an annular lip spaced from said fingers so as to make a uniform circumferential seal with said enclosure whose uniformity is substantially unaffected by said fingers.

4. A cup-shaped packing adapted to be moved laterally outwardly by a conical expander, said packing having a plurality of inwardly directed fingers arranged circumferentially adjacent one another around the-interior of said packing at its free end, said fingers lying in a plane substantially at right angles to the axis of the packing for engagement with the tapered surface of said expander to expand said free end of the packing laterally outwardly, the free end of said packing also including a lip spaced from said fingers to define a circumferential groove therebetween.

5. A cup-shaped packing adapted to be moved laterally outwardly by a conical expander, said packing having a plurality of inwardly directed fingers arranged circumferentially adjacent one another around the interior of said packing at its free end, said fingers lying in a plane substantially at right angles to the axis of the packing for engagement with the tapered surface of said expander to-expand said free end of the packing laterally outwardly, the free'end of said packing also including a terminal circumferential lip extending longitudinally from the plane of said fingers.

REUBEN C. BAKER.

Images