US3108637A

US3108637A - Packer retrieving tool

Info

Publication number: US3108637A
Application number: US784743A
Authority: US
Inventors: William T Lee; Dean W Osmun; James L Newman
Original assignee: Bowen Itco Inc
Current assignee: Bowen Itco Inc
Priority date: 1959-01-02
Filing date: 1959-01-02
Publication date: 1963-10-29
Anticipated expiration: 1980-10-29

Description

Oct. 29, 1963 w. T. LEE ETAL' PACKER RETRIEVING TOOL 2 Sheets-Sheet 1 Filed Jan. 2, 1959 James L. /Ve wman ATIO/PNEY Oct. 29, 1963 w. T. LEE ETAL 3,108,637

PACKER RETRIEVING TOOL Filed Jan. 2, 1959 2 Sheets-Sheet 2 w QM:

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z/ameJ Z. Newman INVENTORS ATTORNEY United States Patent 3,108,637 PACKER RETREVING TOOL William T. Lee, Dean W. Osmun, and James L. Newman, Houston, Tex assignors to Bowen-Itco, Inc., Houston, Tom, a corporation of Texas Filed Jan. 2, 1959, Ser. No. 784 ,74? 4 Claims. (Cl. 166-99) This invention relates to a packer retrieving device and more particularly to a tool for releasing and removing a packer from the interior of a well casing tubing, or the like.

In the production and operation of oil and gas wells, it is often necessary to pack off or seal the annulus between the well casing and tubing, or operating string, at some desired location for the punpose of withdrawing fiuid from the well at a predetermined depth or from a specific zone of the formation which the well penetrates. For this purpose it is customary to introduce into the casing, attached to the string of drill pipe, tubing, or production string, a packer assembly which is adapted to be anchored in the casing at the desired level by manipulation of such a string to seal oif the annulus. Such packer mechanism may also be introduced into the Well and set therein in some other conventional manner.

Well packer equipment of this kind is sometimes designed to be left in the well when the string is withdrawn, but frequently is constructed to be released and removed with the string. Under some conditions, such as Where it is desired to anchor the packer in the wells against both upward and downward movement, or in the event of sticking of the packer or failure of the releasing mechanism, it becomes impossible to release the packer, so that it is then necessary to drill or cutaway the anchoring mechanism in order to recover the packer.

In the releasing of stuck packers, it has been customary heretofore to make use of a milling tool or cutter of tuibular shape adapted to be lowered into the well attached to the lower end of an operating string and rotated in engagment with the anchoring mechanism or slips of the packer to mill away the slips and release the packer. Such tools may be provided with a central mandrel extending downwardly beyond the lower end of the cutter and which is shaped to be extended into the tubular inner support of the packer assembly to centralize and hold the cutter in a centered position in the well during the cutting operation.

One difficulty often encountered in the use of packer releasing apparatus of this kind is that upon the drilling away and releasing of the anchoring mechanism of the packer, the parts of the packer thus freed fall to the bottom of the well, making it necessary to carry out costly fishing operations to clear the well before further drilling or production operators can be resumed.

The present invention has for an important object the provision of packer retrieving apparatus for use in wells embodying means for releasing the packer by cutting away the anchoring slips of the packer assembly, and including means for holding the assembly against falling in the well and by which the packer assembly may be retrieved with the operating string.

Another object of the invention is to provide packer retrieving apparatus of the kind referred to having means for holding the parts of the packer assembly in assembled relation when the assembly has been released and whereby the assembly may be removed from the well in an assembled condition.

A further object of the invention is the provision of packer retrieving apparatus embodying cutter means adapted to be lowered into a well on an operating string and rotated therein to cut away the anchoring slips of a packer assembly to release the same, and including catch- 3 ,lh8,637 Patented Get. 29, 1%63 ice ing mechanism positioned to hold the packer assembly against falling in the well, and which may also be actuated to permit withdrawal of the mechanism from the well in the event that the packer assembly cannot be released.

Another object of the invention is to provide packer retrieving apparatus including a central mandrel adapted to be attached to the lower end of an operating string in position to be extended through a packer assembly in a well and a cutter carried by the string for rotation therewith, the apparatus also embodying means carried on the mandrel in position for engagement with the packer assembly to hold the assembly against downward movement in the well when released and which is operable by rotation of the mandrel in the same direction as the direction of rotation of the cutter to place the apparatus in condition to be withdrawn from the assembly to leave the assembly in the well.

The above and other important objects and advantages of the invention may best be understood from the following detailed description, constituting a specification of the same, when considered in conjunction with the annexed drawings, wherein- FIGURE 1 is a fragmentary, vertical, central, crosssectional, somewhat diagrammatic view, on a reduced scale, illustrating the invention and showing the retrieving device inserted through a packer assembly in a well tubing or casing preparatory to the carrying out of a packer releasing operation;

FIGURE 2 is a side elevational view, partly in crosssection, showing details of construction and the arrangement of the parts of the retrieving tool in its retracted or inactive condition and with the resilient fingers locking the mandrel against rotation;

FIGURE 3 is a view similar to that of FIGURE 2 showing the tool of the invention in its catching or expanded condition and with the resilient fingers in a released non-locking position;

FIGURE 4 is a cross-sectional view, on an enlarged scale, taken along the line 44 of FIGURE 3, looking in the direction indicated by the arrows; and

FIGURE 5 is a cross-sectional view, on an enlarged scale, taken along the line 5-5 of FIGURE 3.

Referring now to the drawings in greater detail, the invention is illustrated herein in connection with its use in the retrieving of packer assemblies from oil wells having a well casing or tubing, such as that shown at T in FIG- URE 1, in which a packer assembly P of conventional design is anchored, as by means of upper and lower slip mechanisms S and S. Packer mechanism of this type is commonly introduced into the casing or tubing attached to a tubular production string and anchored at the desired location by manipulation of the string. Such packer mechanism is provided with a central tubular mandrel or body B, and when anchored is usually left in the well upon removal of the production string.

In the event that it is desired to remove the packer assembly from the 'well, it is customary to release the assembly by milling away the anchoring slips S and S by the use of tubular cutting tools of appropriate design lowered into the well on an operating string. The releasing of packer mechanism in this manner is, however, attended by the danger that the assembly, or some of its parts may fall in the Well and become stuck at some lower level therein or come to rest at the bottom of the well, necessitating expensive and time consuming fishing operations in order to recover the parts before further drilling or other operation of the well can be accomplished. It is for the purpose of preventing the falling of the packer assembly or its parts when released that the present invention has been designed.

In the present illustration the invention comprises an inner tubular mandrel, stinger, or inner part 10, which is externally threaded at its upper end portion for attachment to the lower end of the lowermost section 12 of a tubular operating string of pipe, generally designated 14, and provided at its lower end with an externally enlarged guide and actuator portion 16.

An outer generally tubular part or support member 18 is mounted on the inner part or mandrel it in surrounding relation thereto and for limited longitudinal and rotational movement relative to the inner part. This outer part 1% may conveniently be formed of upper and lower sections 29 and 22 threadably connected together as indicated at 24, the upper section being provided with an internal coarse square or buttress thread 26, which is threadably engageable with a similar external thread 28 on the inner part, to impart limited relative longitudinal movement to the parts upon relative rotation of the parts. The inner part is also provided with an insert 36, positioned in an external longitudinal recess 32 and which extends outwardly beyond the recess, in position for engagement with an inwardly extending stop element 34 to limit left hand rotation of the mandrel in the outer part. The stop member 3% may be removably secured to the inner part, as by means of screws 36, or the like.

At its upper end, the upper section 2:) is formed with an externally reduced portion 38, which fits into a lower end recess 49 in a fitting 4 2, whose upper end portion is internally threaded for connection with the lower external portion 44 of the lowermost section 12 of the operating string, whereby substantial clearance, as best seen at 46 in FIGURE 4, is provided between the external surface of the portion 33 and the inner wall of the recess to allow the outer part to rotate relative to the fitting.

The upper section 20 also carries friction elements 48 which may take the form of leaf springs, secured to the upper section at their lower ends, as by means of screws 50, and whose upper end portions 54!- extend upwardly into the recess 40 between the external surface of the portion 38 and the internal Wall of the recess so that when one or more of such end portions 54 extends into one or more of such recesses 40 the sleeve 20 is locked to the mandrel to prevent relative rotation (FIG. 2). Suitable means, such as the coil spring 56, is positioned about the inner part whose upper end bears against the lower end of the lowermost section 12 of the operating string and whose lower end is seated on the upper end of the upper section of the outer part to yieldingly hold the outer part against upward movement relative to the inner part.

The lower section 22 of the outer part is longitudinally slotted to provide downwardly extending flexible packer supporting fingers or catch means 58, whose lower end portions are internally and externally thickened, as indicated at 60, to provide abutment portions positioned for engagement with the actuator portion 16 of the inner part to expand the fingers upon downward movement of the outer part relative to the inner part to the position illustrated in FIGURE 3. The actuator portion 16 of the inner part is formed with an upwardly facing annular shoulder 62, positioned for engagement with the end faces of the enlarged lower end portions 65 of the fingers to limit downward movement of the outer part relative to the inner part, and above the shoulder 62, the actuator portion, is formed with an upwardly and inwardly tapering external face 64, positioned to be engaged by the inner bevelled faces 66 of the enlarged lower end portions of the fingers to expand the fingers radially outwardly upon downward movement of the outer part relative to the inner part. As its lower end, the lower end enlargement 16 of the inner part may have an external, bevelled, guide face 68. The internally and externally thickened lower end portions 60 of the fingers 58 are also provided with upper and lower external

bevelled faces

70 and 72, for a purpose to be hereinafter pointed out.

In making use of the retriever mechanism constructed and arranged as described above, the device is connected to the lower end of the lowermost section 12 of the operating string, as illustrated in FIGURES 2 and 3, the parts being normally in the positions illustrated in FIGURE 3, and the upper end of the section 12 is threadably connected to the next section of the string above as by means of coupling element 74, having an externally threaded lower end portion 76 to which the upper end of the tubular cutter or milling tool 78 is connected in surrounding relation to the section 12 and which tool is provided with lower end cutting teeth 80 positioned for engagement with the anchoring mechanism S, S of the packer assembly to mill away the anchoring mechanism and release the packer assembly upon rotation of the milling tool in engagement therewith. With the retrieving mechanism thus assembled and connected to the operating string, the retriever mechanism is lowered in the well to extend the inner and outer parts of the retriever mechanism downwardly through the tubular body B of the packer assembly, so that the section 12 of the operating string may be extended through the body to permit the milling tool 78 to be engaged with the anchoring mechanism of the packer assembly to mill away the upper anchoring mechanism S upon rotation of the operating string.

During the lowering of the retriever mechanism with the fingers 58 in expanded positions, as illustrated in FIGURE 3, the lower external bevelled faces 72 of the fingers will engage the upper end of the body B and the inner part will be moved downwardly relative to the outer part against the resistence of the spring 56, permitting the inner bevelled faces 66 of the fingers to move upwardly and inwardly along the tapering face 64 of the actuator to permit the fingers to be contracted radially inwardly, as illustrated in FIGURE 2, to allow the mechanism to pass through the body. When the mechanism is lowered sufficiently so that the leaf springs 48 enter the bore of the body B, they are retracted from their locking position (FIG. 2) to their non-locking position (FIG. 3) and stay in such non-locking position until the fingers 43 pass below the body B at which time they return to the locking position of FIG. 2. As soon as the retriever mechanism has passed downwarly through the body, the spring 56 will cause the outer part to again move downwardly relative to the inner part to the catching position illustrated in FIGURE 3 (but with the spring 48 in the locked position of FIG. 2) to re-expand the fingers into positions for engagement with the lower end of the body B to hold the packer assembly against downward movement in the well when the anchoring mechanism of the assembly has been released.

After the completion of the milling operation to release the upper anchoring mechanism S of the packer assembly, the lower anchoring mechanism S may be released by upward movement of the body B with the operating string, and the packer assembly may be withdrawn from the well with the operating string, the faces of the lower end enlargements 60 of the fingers 58 being engageable with the lower end of the packer assembly to cause the packer assembly to move upwardly with the string.

In the event that it should be impossible to release the packer assembly, or the packer assembly should become stuck in the well after having been released, and it should be desired to withdraw the retriever mechanism, then the retriever mechanism may be moved upwardly into the body B to engage the friction elements 48 with the internal wall of the body, whereupon the operating string may be rotated to rotate the inner part relative to the outer part, to engage the

threads

26 and 28, to cause the outer part to move upwardly relative to the inner part against the resistance of the spring 5-6, to move the fingers 58 upwardly relative to the actuator portion of the inner part, to allow the fingers to move radially inwardly to their retracted positions, whereupon the retriever mechanism may be withdrawn upwardly through the body B and recovered with the operating string leaving the packer assembly in the well.

When the outer part has been moved upwardly on the mandrel, by rotation of the mandrel relative to the outer part, as described above, the fingers 58 will be out of catching position, and if it should then be desired to reinsert the retriever mechanism through the packer assembly, this may be done by lowering the operating string to move the retriever mechanism into the body B until the friction elements 48 are in engagement with the internal surface of the body, whereupon the mandrel may again be rotated while the outer part is held stationary to move the actuator 64 into engagement with the fingers 58 to expand the fingers to catching positions, after which the mandrel may be moved downwardly through the body B to again engage the cutter 7 8 with the anchoring mechanism to continue the milling away of the anchoring mechanism, should this be necessary.

It will be noted that the external thread 28 of the mandrel is not quite in engagement with the internal thread 26 of the outer part or cage when the lower ends of the fingers 58 are shouldered on the shoulder 62 of the mandrel, as shown in FIGURE 3, and the key or stop member 30 is positioned to limit the rotation of the mandrel to the right in and relative to the outer part 18 to prevent the threads from binding, so that the parts are prevented from becoming stuck in catching position and are always in condition to be moved to retracted or releasing position by relative rotation of the parts with the friction elements 48 in engagement with the internal wall of the body B.

For satisfactory functioning of the apparatus, it is necessary that the coil spring 56 be of suflicient strength to move the outer part into catching position, as seen in FIGURE 3 against the frictional resistance of the elements 48 when the latter are in contact with the inner wall of the body B, while at the same time the friction elements 48 must exert suflicient force against the inner wall of the body Bto hold the outer part against rotation to permit the mandrel to be rotated to move the outer part to releasing position against the resistance of the coil spring.

It will thus be seen that the invention constructed and operated in the manner described above provides a retrieving tool which is of rugged construction; which may be used to recover a packer assembly from a well tubular casing; which is effective to prevent accidental loss of the parts of the packer assembly when released, and which may be recovered intact in the event that the packer assembly cannot be recovered with the tool from the well.

The invention is disclosed herein in connection with a certain specific embodiment of the same, but it will be understood that this is intended by way of example only, and that numerous changes can be made in the construction and arrangement of the various parts, within the spirit of the invention and the scope of the appended claims.

Having thus clearly shown and described the invention, what is claimed as new and desired to secure by Letters Patent is:

1. Apparatus for retrieving from a well a packer assembly having a central opening therethrough, comprismg:

(a) a tubular mandrel adapted to be connected at one end to a tubular operating string for lowering in a well to extend the mandrel through said opening;

() an internally threaded sleeve surrounding and movably mounted on the mandrel for longitudinal movement thereon;

(c) flexible catch fingers connected to said sleeve for lateral flexing movement toward and away from the mandrel;

(d) expander means connected to the mandrel for coaction with said catch fingers in a longitudinal catching position to flex said fingers away from the mandrel to position said fingers for engagement with the lower end of said assembly to support the assembly against downward movement relative to the mandrel;

(e) yieldable means positioned for coaction with the mandrel and sleeve to yieldingly urge said sleeve toward said catching position;

(1) said fingers being extended for engagement with the upper end of said assembly when in said catching position to resist downward movement of the sleeve and to retract said fingers for passing same downwardly with said mandrel through said opening;

(g) and release means for releasing said catch fingers from said catching position to a retracted position;

(h) said release means including:

\(1) friction elements on said sleeve and urged radially outwardly for engagement with the wall of said central opening;

(2) external threads on said mandrel threaded in engagement with said internal threads on said sleeve;

(3) the convolutions of said external threads being spaced longitudinally a greater distance than the width of the internal threads on said sleeve to enable said sleeve to move longitudinally without rotation to the extent of such spacing.

2. Apparatus for retrieving from a well a packer assembly having a central opening therethrough, comprismg:

(a) a tubular mandrel having a portion with external threads thereon and adapted to be connected at one end to a tubular operating string for lowering in a "well to extend the mandrel through said opening;

([2) an internally threaded sleeve surrounding said mandrel in threaded engagement with said external threads and having the threads on the mandrel and the sleeve longitudinally spaced with respect to each other for longitudinal movement thereon;

(d) expander means connected to the mandrel for coaction with said catch fingers in a longitudinal catching position to flex said fingers away :from the mandrel to position said fingers for engagement with the lower end of said assembly to support the assembly against downward movement relative to the mandrel;

(f) said fingers being extended for engagement with the upper end of said assembly when in said catching position to resist downward movement of the sleeve and to retract said fingers for passing same downwardly with said mandrel through said opening; and

(g) releasable lock means on said sleeve and connected for locking said sleeve to said mandrel for preventing relative rotation between said sleeve and said mandrel when said fingers are in the catching position to prevent inadvertent releasing of said fingers from the catching position.

3. Apparatus for retrieving from a well a packer assembly having a central opening therethrough, comprismg:

(a) a tubular mandrel having a portion with external threads thereon and adapted to be connected at one end to a tubular operating string for lowering in a well to extend the mandrel through said opening;

(b) an internally threaded sleeve surrounding said mandrel in threaded engagement with said external threads and having the threads on the mandrel and the sleeve longitudinally spaced with respect to each other for longitudinal movement thereon;

(d) expander means connected to the mandrel :for coaction with said catch fingers in a longitudinal catching position to flex said fingers away from the man drel to position said fingers for engagement with the lower end of said assembly to support the assembly against downward movement relative to the mandrel;

g) friction elements having their [lower portions connected to said sleeve but having their upper portions free to move radially inwardly and outwardly; and

(/1) a locking sleeve connected to said mandrel and having a recess therein for receiving the upper end of at least one of said friction elements when extended outwardly for thereby locking said threaded sleeve to said mandrel for preventing relative rotation therebetween but releasable from such locking position by an inward movement of said friction element.

4. Apparatus for retrieving from a well a packer assembly having a central opening therethrough, comprising:

(b) an internally threaded sleeve surrounding said mandrel in threaded engagement with said external threads and having the thread on the mandrel and the sleeve longitudinal spaced with respect to each other for longitudinal movement thereon;

(a') expander means connected to the mandrel for coaction with said catch fingers in a longitudinal catching position to flex said fingers away from the mandrel to position said fingers for engagement with the lower end of said assembly to support the assembly against downward movement relative to the mandrel;

g) and release means for releasing said catch fingers from said catching position to a retracted position;

(It) said release means including:

(1) friction elements on said sleeve and urged radially outwardly for engagement with the wall of said central opening;

(3) the convolutions of said external threads eing spaced longitudinally a greater distance than the width of the internal threads on said sleeve to enable said sleeve to move longitudinally without rotation to the extent of such spacing;

(i) said friction elements having their upper ends movable inwardly and outwardly;

(j) a locking sleeve connected to said mandrel and having a recess therein for receiving the upper end of at least one of said friction elements when extended outwardly for thereby locking said threaded sleeve to said mandrel for preventing relative rotation therebetween but releasable from such locking position by an inward movement of said friction element.

References Cited in the file of this patent UNITED STATES PATENTS 688,543 Petit Dec. 10, 1901 1,715,481 Ventresca June 4, 1929 1,765,864 Corey June 24, 1930 2,067,885 Brown Jan. 19, 1937 2,106,235 Brown Jan. 25, 1938 2,149,417 Brown Mar. 7, 1939 2,449,841 Claypool et a1 Sept. 21, 1948 2,481,637 Yancey Sept. 13, 1949 2,487,456 Lowrey Nov. 8, 1949 2,577,605 Clayton Dec. 4, 1951 2,657,907 Cochran et al. Nov. 3, 1953 2,683,492 Baker July 13, 1954 2,804,148 Schrempt et al. Aug. 27, 1957 2,882,015 Beck Apr. 14, 1959 2,904,114 Webb et al. Sept. 15, 1959 3,005,493 Crowe et al. Oct. 24, 1961

Claims

1. APPARATUS FOR RETRIEVING FROM A WELL A PACKER ASSEMBLY HAVING A CENTRAL OPENING THERETHROUGH, COMPRISING: (A) A TUBULAR MANDREL ADAPTED TO BE CONNECTED AT ONE END TO A TUBULAR OPERATING STRING FOR LOWERING IN A WELL TO EXTEND THE MANDREL THROUGH SAID OPENING; (B) AN INTERNALLY THREADED SLEEVE SURROUNDING AND MOVABLY MOUNTED ON THE MANDREL FOR LONGITUDINAL MOVEMENT THEREON; (C) FLEXIBLE CATCH FINGERS CONNECTED TO SAID SLEEVE FOR LATERAL FLEXING MOVEMENT TOWARD AND AWAY FROM THE MANDREL; (D) EXPANDER MEANS CONNECTED TO THE MANDREL FOR COACTION WITH SAID CATCH FINGERS IN A LONGITUDINAL CATCHING POSITION TO FLEX SAID FINGERS AWAY FROM THE MANDREL TO POSITION SAID FINGERS FOR ENGAGEMENT WITH THE LOWER END OF SAID ASSEMBLY TO SUPPORT THE ASSEMBLY AGAINST DOWNWARD MOVEMENT RELATIVE TO THE MANDREL; (E) YIELDABLE MEANS POSITIONED FOR COACTION WITH THE MANDREL AND SLEEVE TO YIELDINGLY URGE SAID SLEEVE TOWARD SAID CATCHING POSITION; (F) SAID FINGERS BEING EXTENDED FOR ENGAGEMENT WITH THE UPPER END OF SAID ASSEMBLY WHEN IN SAID CATCHING POSITION TO RESIST DOWNWARD MOVEMENT OF THE SLEEVE AND TO RETRACT SAID FINGERS FOR PASSING SAME DOWNWARDLY WITH SAID MANDREL THROUGH SAID OPENING; (G) AND RELEASE MEANS FOR RELEASING SAID CATCH FINGERS FROM SAID CATCHING POSITION TO A RETRACTED POSITION; (H) SAID RELEASE MEANS INCLUDING: (1) FRICTION ELEMENTS ON SIAD SLEEVE AND URGED RADIALLY OUTWARDLY FOR ENGAGEMENT WITH THE WALL OF SAID CENTRAL OPENING; (2) EXTERNAL THREADS ON SAID MANDREL THREADED IN ENGAGEMENT WITH SAID INTERNAL THREADS ON SAID SLEEVE; (3) THE CONVOLUTIONS OF SAID EXTERNAL THREADS BEING SPACED LONGITUDINALLY A GREATER DISTANCE THAN THE WIDTH OF THE INTERNAL THREADS ON SAID SLEEVE TO ENABLE SAID SLEEVE TO MOVE LONGITUDINALLY WITHOUT ROTATION TO THE EXTENT OF SUCH SPACING.