Method Of Expanding A Liner

Abstract

A device and method for expanding a tubing liner having a preformed reverse bend by pulling the metal of the liner outwardly to expand the reverse bend and bring the liner into a substantially cylindrical shape inside of a well tubing or other pipe.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is an improvement over U.S. Pat. application, Ser. No. 749,711 filed Aug. 2, 1968, now U.S. Pat. No. 3,489,220, granted Jan. 13, 1970.

BACKGROUND OF THE INVENTION

The field of this invention is apparatus and methods for installing liners in well tubing or other pipe.

Apparatus for setting a liner or patch in a well tubing or pipe is disclosed in U.S. Pat. Nos. 3,191,677 and 3,424,244. Also, in said U.S. Pat. No. 3,489,220, an expander device was disclosed for expanding a liner having a reverse bend in it into a substantially cylindrical shape inside of a well tubing or pipe. Such expansion was accomplished by engaging the inside surface of the reverse bend with the surface of a tapered groove to push the metal outwardly to form a substantially cylindrical shape. It has been found that, using such expander device, occasionally the metal is folded over itself during the expansion of the liner, which results in an inadequate or defective seating and sealing of the liner in the tubing. Furthermore, since such expansion of the liner occurs down in the well and therefore cannot be observed, the occurrence of the fold-over cannot be readily detected.

SUMMARY OF THE INVENTION

The present invention relates to a new and improved device and method for expanding a liner having a reverse bend by pulling the metal outwardly to a substantially cylindrical shape, which obviates the occasional folding of the liner on itself as occurred with the device of said U.S. Pat. No. 3,489,220.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is an elevation, partly in section, illustrating the method and apparatus of this invention;

FIG. 2 is a front view of a portion of the expander device of the present invention;

FIG. 3 is an elevation, partly in section, taken on line 3-3 of FIG. 2, and illustrating the expander device of this invention;

FIG. 4 is a sectional view taken on line 4--4 of FIG. 3, with a metal liner shown in position thereon, as the expander device of FIG. 3 is being forced downwardly through the liner;

FIG. 5 is a sectional view taken on line 5--5 of FIG. 3 to illustrate the liner as it is expanded to an intermediate position during the movement of the expander device downwardly relative to the liner;

FIG. 6 is a cross-sectional view taken on line 6--6 of FIG. 3 to further illustrate the outward pulling of the liner to the expander position with the expander device as it is forced downwardly through the liner; and

FIG. 7 is a view on line 7--7 of the expander device, and showing it relative to the liner after the expander device has moved downwardly within the liner to the line 7--7 of FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the drawings, the letter E designates generally the expander device of this invention which is adapted to be lowered into a pipe or tubing T with a liner or patch P so as to position same opposite a hole 12 or other area of the tubing or pipe T which is to be covered or patched. The expander E is preferably lowered on a flexible line (not shown) which is a conventional wire line having therewith suitable wire line jars or other means for imparting downward jarring movement to the expander device E for driving same downwardly in the liner P when it is properly positioned in the tubing T.

Prior to lowering the expander E downwardly into the well, the defect or opening 12 is located by known means, and then a removable stop R of conventional construction is dropped or lowered into a seated position in one of the tubing joints 15, or at any other suitable point where the stop R may be releasably supported. A collapsible support S, an example of which is illustrated in U.S. Pat. No. 3,424,244, is suitably disposed in the tubing T above the stop R, and it may be located directly upon the stop R. As illustrated in FIG. 1 of the drawings, a spacer bar B, which is also disclosed in said U.S. Pat. No. 3,424,244 is disposed on the stop R to support the collapsible support S. As explained in said patent, more than one of the collapsible supports S may be employed and one or more of the spacer bars B may be employed. The collapsible support S is adapted to collapse when contacted by the lower end of the expander E so as to enable the expander E to move downwardly completely through the liner P to expand same throughout substantially its full length to a substantially cylindrical shape.

Considering the details of the expander device E, such device includes a body 20 which has its external surface 20a conically shaped, so as to have a taper upwardly and outwardly from the lower end 20b to an intermediate substantially cylindrical portion 20c, the intersection of which is formed at an edge 20d (FIG. 2). In the form of the invention illustrated in the drawings, the conical shape of the external surface 20a is offset with respect to the longitudinal axis of the body 20 so that the extreme edge 20e appearing at the right-hand side of FIG. 3, and also appearing in FIGS. 4-7, is substantially vertical so as to assist in the guiding of the expander device E during the lowering thereof. However, the conical shape of the surface 20a may be provided by having the conical shape formed on some other axis such as the same axis as the central axis of the body 20, in which case the surface 20e would also have a slight taper corresponding basically to the taper visible on both sides of the surface 20a in FIG. 2.

The conical shape of the external surface 20a is significant in the present invention because such conical shape enables the expander device E to pull the metal or other material of the liner P outwardly from its reverse bent position (FIG. 4) to the substantially cylindrical position of FIG. 7.

The liner or patch P has a reverse bend 30 (FIG. 4) pre-formed therein prior to the lowering of the liner P into the tubing T. The expander body 20 is provided with a groove 31 which is at least deep enough compared to the depth of the bend 30 in the liner P so that the surface of the groove 31 does not exert an appreciable pushing force on the liner P during the forcing of the expander E downwardly within the liner P. In fact, the surface of the groove 31 could be completely out of contact with the liner P at all times, since the liner P is expanded by the pulling of the material of the liner P outwardly due to the enlarging effect of the conical surface 20a, as previously explained.

On each side of the groove 31, tapered legs or cusps 32 are formed, each of which is curved and preferably corresponds with the curvature of the liner P in its initial reverse bent position of FIG. 4. The cusps 32 could be formed as a sharp point from a theoretical standpoint, since they merely retain the metal as it is being pulled outwardly by the external surface 20a, but to prevent a sharp bend in the metal of the liner P as it is being pulled outwardly, the cusps 32 are preferably rounded or curved as shown in the drawings so that as the metal or material of the liner P is pulled outwardly, the gentle curving of the cusps 32 facilitates the outward pulling of the metal. By comparing the sequence of views, FIGS. 4-7, the pulling action by the external surface 20a and the guiding action of the cusps 32 can be seen.

It is to be noted that the angle of inclination of the cusps with respect to the longitudinal axis of the body 20 of the device E should be greater than the angle the surface of the groove 31 makes with the longitudinal axis of the body 20 so as to avoid any pushing of the metal at the reverse bend 30 during the downward movement of the expander device E relative to the liner P. The reverse bend 30 is shown as spaced slightly from the surface of the groove 31 in FIG. 4, which is the initial starting position of the expander device E and the liner P, but it is not necessary for the reverse bend 30 to be completely out of contact with the surface of the groove 31, so long as the surface of the groove 31 does not contribute appreciably to the enlargement of the liner P.

It is to be noted that in the preferred form of the invention, the groove 31 is substantially vertical or stated differently, the inside or bottom surface of the groove 31 extends substantially parallel to the longitudinal axis of the body 20. Also, the groove 31 communicates with a central passage 35 in the body 20 and one or more inclined passages 36 which establish communication for the bypass of fluid through the body 20 to prevent a fluid lock during the movement of the expander device E downwardly through the liner P, should fluid be present in the tubing T.

The lower end of the expander device E has a recess 40 into which a portion of the upper end of the liner P is crimped or bent (FIG. 1) so as to releasably hold the liner P on the lower end of the expander E for the lowering of same into position on the collapsible support S (FIG. 1). In normal installations, the liner P may be as long as 10 feet, or even 12 feet. The length is of course not to be considered a limitation with respect to the invention, since the length of the liner P may be varied for different applications. In any event, the initial jarring of the expander device E releases the expander device E from its releasable connection at the recess 40 so as to permit the expander E to thereafter move downwardly in the liner P for expanding same, as will be more fully explained. It will also be appreciated that other suitable releasing means for releasably attaching the expander device E to the liner P may be employed. In some instances, the liner P may be lowered separately into the tubing T, and the expander device E may then be lowered subsequently for the insertion of the expander device E into the upper end of the liner P. However, due to the difficulties of alignment of the expander device E and the liner P, such a separate lowering of the device E and the liner P normally is not recommended.

The expander device E has a tapered or reduced body portion 50 above the substantially cylindrical portion 20c, through which the fluid discharge or bypass passages 36 extend. An upper stem 51 extends upwardly from the body portion 50, and preferably a centralizing means 52, which in the preferred form of the invention, includes a plurality of ribs 52a, is mounted. Such centralizing means 52 may be formed by machining a part of the stem 51 so that the ribs 52a are actually integral with the stem 51. The upper end of the stem 51 has a fishing neck 53 to which a conventional running-in tool is releasably attached for lowering the device E to the position shown in FIG. 1. Thereafter, the running-in tool is released and withdrawn from the well, and link jars or rein jars, or other suitable jarring devices which are supported on a wire line (not illustrated) are lowered, usually together with a finishing tool such as shown in U.S. Pat. No. 3,191,677 for providing a downward jarring action on the expander device E to drive same downwardly in the liner P.

In the operation or use of the apparatus of this invention, the removable stop R is initially placed in position in the tubing T at a point below the hole or other defect 12 which is to be patched or covered by the liner or tubing patch P. Then, as explained in said U.S. Pat. No. 3,424,244, the spacer or spacers B and the collapsible support S are lowered into position in the manner illustrated in FIG. 1. Thereafter, the expander device E with the liner P releasably attached at its lower end are lowered into the tubing or pipe T with the running-in tool on the wire line until the lower end of the liner or patch P engages the upper surface of the collapsible stop S.

After the liner P has contacted the upper end of the collapsible support S, the running-in tool is released and withdrawn from the well, leaving the device E as shown in FIG. 1. Thereafter, the jars are lowered on a wireline, as explained above, so that the jarring of the expander device E may be accomplished. The initial jarring releases the crimped connection at the recess 40, permitting the expander device E to move downwardly and to expand the liner P outwardly by pulling same outwardly due to the tapered or conical surface 20a of the body 20, as previously explained. The expander device E moves downwardly through the liner P until the lower end thereof reaches the upper end of the collapsible support S, at which time the collapsible support S is caused to collapse, at least partially, as explained in said U.S. Pat. No. 3,424,244, and this permits the expander device E to move completely through the liner P for expanding the liner P to its substantially cylindrical shape (FIG. 7) throughout substantially the full length of the liner P.

Additional expanding tools for a final expansion of the liner P may be employed, an example of which is shown in U.S. Pat. No. 3,191,677, for forcing the liner out to form a seal with the inside of the tubing T so as to prevent leakage through the hole 12 or other defect in the pipe T.

With the present invention, the liner is expanded without any danger of a fold-over of the metal on itself during the expansion and therefore, the expansion to the substantially cylindrical shape illustrated in FIG. 7 of the drawings is assured under a normal operating condition. The term "cusp" and "cusps" as used herein and in the claims is intended to and does include the rounded shape or lobes shown in particular at 32 in FIGS. 4-7 of the drawings, and it should be understood that such cusps are not sharply pointed in practice.

The foregoing disclosure and description of the invention are illustrative and explanatory thereof, and various changes in the size, shape, and materials as well as in the details of the illustrated construction may be made without departing from the spirit of the invention.

Claims

I claim:

1. A method for expanding a metal liner in a tubing or pipe, wherein the liner is preformed with a reverse bend in it, comprising the steps of:

preforming a reverse bend in a liner

inserting in the upper end of the liner, a portion of an expander device having a conically shaped body with a groove therein forming longitudinally extending rounded cusps on each side of the groove;

positioning the reverse bend in the liner in said groove so that there is no appreciable contact between the bottom of the groove and the inside surface of the reverse bend; and

gradually pulling the metal of the liner from its reverse bend shape to a substantially cylindrical shape in the tubing or pipe without any appreciable pushing of the metal of the liner at the reverse bend, by forcing the expander body downwardly in the liner with only the external surface of the conically shaped body and the cusps engaging the inside of the liner and with no appreciable contact between the inside surface of the reverse bend in the liner and the bottom of the groove.

2. The method set forth in claim 1, wherein:

the bottom of the groove is disposed substantially parallel to the axis of the expander tool from its lower end upwardly for a majority of its length.

3. The method set forth in claim 1, wherein:

the reverse bend in said liner is preformed and positioned in relation to the groove in the expander device so that the inside surface of the reverse bend is spaced from the bottom of the groove at all times to prevent pushing of the metal of liner at the reverse bend during the forcing of the expander device downwardly in the liner.

4. The method set forth in claim 1, wherein:

the reverse bend portion of the liner is preformed and positioned at a lesser depth than the depth of the groove in the expander tool throughout a substantial portion of the length of the groove to thereby space the reverse bend portion of the liner away from the surface of the groove to minimize pushing of the metal of the liner outwardly as the expander device is forced downwardly relative to the liner.

5. The method set forth in claim 4, including:

by-passing fluid in the tubing or pipe upwardly through the expander device as the device is forced downwardly in the liner.