US3120871A

US3120871A - Retrieving tool

Info

Publication number: US3120871A
Application number: US657954A
Authority: US
Inventors: Cordova Samuel F De
Original assignee: Individual
Current assignee: Individual
Priority date: 1957-05-08
Filing date: 1957-05-08
Publication date: 1964-02-11
Anticipated expiration: 1981-02-11

Description

S. F. DE CORDOVA RETRIEVING TOOL Feb. 11, 1964 Filed May 8, 1957 INVENTOR. Jamue/ E 0 9 Cora 0 v0 BY gimp/J m ATTOFA/EKS United States Patent 3,129,371 RETREVING TOOL Samuel F. de (Iordova, R0. Box 4%, Jennings, La. Filed May is, 1957, Ser. No. 657,954 Claims. (Cl. 166-55) My invention relates to a retrieving tool, and more particularly, to a tool for retrieving from a well devices attached above the bottom of the well against longitudinal displacement.

In various operations designed to condition oil wells or the like for production, it is necessary to pack-oil the well at a given depth to prevent the flow of fluids thereby. Well packers have been designed with serrated slips or other means adapted to grip the internal wall of the casing to fix at a selected depth an expanda le packing element or similar device. Certain well packers, such as permanent or cementing packers, are designed to resist fluid pressures from either direction longitudinal of the Well and, as such, are designed to be locked against upward or downward movement therein. Consequently, once set, a packer cannot be raised or lowered by conventional means and should subsequent operations dee it desirable to remove the packer from the well, it has heretofore been necessary to mill away the entire well packer structure and then to retrieve the broken pieces which fall to the bottom of the well by conventional fishing devices of the magnetic or hydraulic type.

It is, therefore, an object of my invention to provide an apparatus for removing permanent or cementing packers or similar devices locked against axial movement with any well, While causing a minimum amount of damage thereto.

It is a further object of my invention to provide an apparatus for the removal or" set packers which apparatus substantially eliminate the necessity of fishing for broken particles of the packer.

It is a further object of my invention to provide a retrieving tool which permits the circulation of fluid therethrough while retrieving an object which plugs the well therebelow.

It is a further object of my invention to provide a tool retrieving apparatus which is economical to construct and simple and eflicient in operation.

My retrieving tool comprises a grappling device adapted to grip positively a portion of the lodged tool to pre vent it from falling to the bottom of the well when its attachment to the well casing is subsequently severed, and a cutting shoe to mill away at least those elements of the packer gripping the well casing against upward movement thereof. During the milling operation circulation of drilling fluid is unimpeded and milled chips and pieces of the packer are carried upwardly therewith to the surface. After the upper slips or well casing grippers are milled away, the retrieving tool is raised by means of the drill string to which it is attached whereby the grappling device pulls the packer upwardly to remove it from the well.

Other objects and novel features of the invention will become apparent from the following specification when viewed in connection with the accompanying drawings wherein:

FIG. 1 is a vertical section of the improved retrieving tool in condition for engagement with the fish; and

FIG. 2 is a vertical section of my improved retrieving tool preparatory to removal of the fish from the well.

Referring to the drawings, reference numeral 1 denotes a well casing within which is set a well packer 2 so as to resist displacement thereof in either axial direction. The particular manner in which such well packers are set is not particularly material to this invention, but for purposes of illustration I have shown a typical structural arrangement thereof. In this embodiment, the well packer 2 includes a central mandrel 3 having a sub 4 at the upper end adapted for engagement by external threads on a drill string, of the type shown at 5 below the packer, so that the packer can be raised, lowered or rotated therewith in a thread tightening direction. The lower portion of the mandrel 3 is enlarged radially to present an external shoulder 6 above which are slidably carried on the mandrel 3 lower slips 7 and engaging frusto-conical slip expanders 3. Slidable on the upper portion of mandrel 3 is a sleeve 9 on which is carried upper slips 1% engageable with upper slip expander wedges 11. An expandable packing element 12 is carried on the sleeve between the slip expanders 8 and 11. To set the packer at a selected depth within the well casing 1, the sleeve 9 is forced down along mandrel 3 to force upper slips 10' over its slip expander 11 to lock the packer against upward movement and then the mandrel 3 is raised to force the lower slip 7 upwardly over its expander 55 by means of shoulder 6 thus expanding the lower slips to grip the casing wall 1 against downward movement. During expansion of the lower slips 7 the upward thrust against the lower slip expander 8 forces it toward the upper expander 11 to compress axially the expansible packer element 12 and expand it radially to seal off the casing 1 against fluid flow. It is apparent that with the upper slips resisting any force that may tend to pull the well packer up through the casing and with the lower slips resisting downwmd movement, the well packer cannot conveniently be removed from the well by conventional surface-controlled means.

My retrieving tool 259 comprises a mandrel or main tubular body 21 threaded or otherwise adapted at its upper end 22 for attachment to a string of tubing (not shown). At the lower open end of the body 21 is secured a milling shoe 23 for a purpose to be hereinafter described. Within the body at the central portion thereof is an internal shoulder 24. If desired, the tubular body may be formed in two sections, as shown, and threaded together at 25 for ease of construction and assembly. Supported within the tubular body 21 is a pilot or a grapple rod 26 having a flange or other radial extension 27 at its upper end adapted to be supported on the internal shoulder 24 in the tubular body, as shown in FIG. 1. Both the grapple rod 26 and the integral flange 27 are sufficiently small in size as to render the grapple rod 26 freely slidable within the tubular body 21 above the lower limits dictated by flange Z7 and shoulder 24. Along the shank of grapple rod 26 immediately below the flange 27 are carried axial keys 28 receivable in keyways 29 cut into the internal shoulder 24. Consequently, with the flange 27 at rest on shoulder 24 with the keys so engaged, rotation of the tubular body 21 will produce concomitant. rotation of grapple rod 26. Additionally, in order to prevent initially any sliding movement of grapple rod 26 within tubular body 21 I provide shear pins 39 securing it thereto as for example at the flange 27. At the lower end of rod 26 is a grapple 31 here illustrated as an externally threaded member adapted to engage positively the sub 4 at the upper end of the packer 2 for which purpose the rod 26 is of suflicient length that grapple 31 extends below the milling shoe 23 enough so that even when the grapple has fully gripped the packer there is clearance between the milling shoe 23 and the top 9 of the packer.

I do not intend that the structure of my device be limited to the specific form of grapple shown. It will become apparent that any form of attaching means effected by the rotation of grapple rod 26 imparted through its keyed attachment with the tubular body 21, such as a J-slot attachment, a bayonet slot or the like will satisfy the requirements of my retrieving tool. It is further apparent that my invention is not limited to the specific fiange and shoulder means 27 and 24 shown to support the grapple rod within the tubular body. The radial extension 27 at the top of rod as need not be completely annular but may be segmental in which case it could itself be adapted to be received and supported in slots cut partially through shoulder 24 to provide the rotary coupling. Other means and devices may be substituted but the significant feature is the provision of a member to suspend the grapple rod below the lower open end of the tubular body to prevent it from falling therethrough together with means for imparting through the tubular body 21 to the grapple rod 26 a particular motion requisite to effect attachment to the fish lodged within the well casing 1.

Preferably, a fluid passage 32 is provided through the grapple rod 26 so that, if necessary or desirable, a jet of fluid may be directed against the upper end of the lodged fish to wash away any mud or the like that may otherwise impede connection of the grapple with the fish.

When full connection between the grapple rod 26 and the fish 2 is established the clearance between the lower end of milling shoe 23 and the upper end 9 of packer should be such that subsequent downward movement of the tubular body will not only shear the pins 30 but will move shoulder 24 free of the keys 28 whereby further rotation of tubular body 21 will not affect the grapple rod 26. Such further rotation causes milling shoe 23 to begin cutting away the sleeve 9 and other portions of the well packer surrounding the mandrel 3 until the upper slips it) are cut away or otherwise inactivated as shown in FIG. 2. Thereafter, the tubing string may again be raised to raise the tubular body 21 lifting shoulder 24 into engagement with its flange 27 and thereby raising grapple rod 26 with the freed packer from the well.

During the milling operation, I provide for circulation of drilling fluid around flange 27 and down through the open end of tubular body 21 to carry chips upwardly around the tubular body 21 to the surface. To facilitate flow of drilling fluid grooves 33 may be cut tluough upper flange 27.

In operation of the device my retrieving tool is lowered into the casing until the lower end of the tool Zll engages the upper end of the packer 2 lodged within the casing 1. Since the tubular body is guided against appreciable radial movement by virtue of its limited clearance within the casing 2 and since the grapple rod 26 is centrally disposed within the tubular body 21 by the shear pins 30 and the key attachment Z8, 29, the rod will be guided into the centrally disposed internally threaded sub 4 of the packer. Thereafter, the retrieving tool body 21 is rotated to rotate the grapple rod 26 and thread the attaching member 31 onto the sub 4 of the packer. After the connection with the well packer is established, the drill string and, hence, the tubular body 21 are driven downwardly to fracture the shear pins 36 and to slide the keyway 29 free of the keys 28 to render the tubular body rotatable on the grapple rod 26. Thereafter rotation of tubular body 21 will cause the milling shoe 23 to cut away the outer sleeve 9 and the upper slips with the tubular body 21 rotating and sliding down over grapple rod 26. Obviously, the width of the milling shoe must be such that it Will not sever the fish from the grappling means, and in the structure illustrated the mandrel 3 and sub 4 are left substantially intact. The mill 2.3 is centralized within the casing 2 by its limited radial clearance of the mill 23 relative to the casing 1 preventing any wandering thereof that would otherwise cause unnecessary damage to the mandrel such as would disrupt the connection with the grapple rod 26. After the milling shoe has cut away or inactivated the upper slip assembly, the expansible sleeve offers no appreciable resistance to the lower slip expander 8 and, therefore, it is substantially ineffective to resist movei ment of the packer and to wedge the lower slips 7 outward. Consequently, the tubing string may be raised until the shoulder 24 again engages the flange 27 to lift the grapple rod 26 and the packer from the well.

Throughout the milling operation, drilling fiuid may be circulated around the grapple rod 26 and out through the lower end of the milling shoe 2? to carry chips and pieces milled from the packer upward around the outside of the tubular body and tubing string to the surface. With the expansible element preventing passage of said chips downward to the bottom of the casing, there is no necessity to lower a magnet or other fishing device to extract such pieces from the well.

While a specific embodiment of my invention has been shown and described, many variations in structure within the scope of my invention defined by the following claims are possible and contemplated. There is no intention, therefore, of limitation to the exact details shown and described.

Having described my invention, I claim:

1. Apparatus for retrieving a fish from a well casing, said fish being secured against upward movement above the bottom of said well casing by holding means attaching said fish to the wall of said well casing, said apparatus comprising a tubular body open at the low-er end thereof, a grapple rod within said body, support means extending radially from the upper portion of said grapple rod, stop means within said tubular body engageable with said support means to suspend said grapple rod in an active position with the lower end thereof extending below said lower end of the body, coupling means connecting said grapple rod while in said active position to said body for rotation therewith, attachng means on the lower end of said grapple rod for attaching said rod to said fish upon engagement therewith and rotation relative thereto, said coupling means being releasable when said grapple rod is attached to said fish to permit downward movement of said body relative to said grapple rod into engagement with said fish, and a cutting member on the lower open end of said body adapted to sever said holding means after engagement therewith.

2 Apparatus for retrieving a fish from a well casing, said fish being secured to the wall of said well casing above the bottom thereof, said apparatus comprising a tubular body open at the lower end thereof, a grapple rod within said body, radial extensions near the upper end of said grapple rod, stop means within said body engaging wtih said radial extensions to support said grapple rod with the lower end thereof extending below said open lower end, coupling means engageable only when said radial extensions are engaged by said stop means to connect said grapple rod for rotation with said body, means interconnecting said grapple rod and said body to prevent relative sliding movement therebetween, attaching means on the lower end of said grapple rod for attaching said rod to said fish upon engagement therewith and rotation relative thereto, said interconnectin means being releasable when said grapple rod is attached to said fish to render said body slidable over said grapple rod for downward movement into engagement with said fish, and a cutting member on the lower open end of said body.

3. An apparatus for retrieving a fish from a well easing, said fish being supported above the bottom of the well casing by holding means firmly attaching said fish to the wall of said we 1 casing, said apparatus comprising,

(a) a tubular body open at the lower end thereof,

(b) a grapple rod movable longitudinally within said body,

(c) attaching means on the lower end of said grapple rod for attaching said rod to said fish upon engagernent therewith and rotation relative thereto,

(d) coupling means locking said body and said grapple rod against relative longitudinal m vement and for rotation together whereby said attaching means on said grapple rod may be engaged with said fish,

(2) said coupling means being releasable when said grapple rod is attached to said fish and upon downward movement of said body relative to said grapple rod to render said body longitudinally movable and rotatable relative to said grapple rod.

(1) stop means on said body engageable by a portion of said grapple rod to prevent said grapple rod from sliding out of said open lower end, and

(g) a cutting member on the lower open end of said body adapted to sever said holding means after engagement therewith.

4. Apparatus for retrieving from a well casing a fish including a central portion and a gripping means on the outside thereof locking said central portion to the wall of the well casing against upward displacement thereof, said apparatus comprising,

(a) a tubular body having an open lower end,

(1)) a grapple rod slidable within said tubular body,

() radially extending shoulder means on said grapple rod,

((1) stop means on said body to engage said shoulder means and thereby limit downward sliding movement of said grapple rod relative to said body,

(6) coupling means locking said body and said grapple rod against relative movement only when said shoulder means and said stop means are engaged,

(f) attaching means on the lower end of said grapple rod for attaching said grapple rod to said central portion upon rotation of said body and grapple rod,

(g) said coupling means including shear pin means which is releasable when said grapple rod is attached to said central portion whereby said body may then move longitudinally and rotatably relative to said grapple rod, and

(h) cutting means on the lower end of said body for severing said gripping means after engagement therewith and upon continued rotation and longitudinal movement of said body relative to said grapple rod.

in a well bore, said apparatus comprising,

(a) a tubular body having an open lower end,

(b) a grapple rod within said tubular body,

(0) coupling means normally coupling said grapple rod to said tubular body coaxial therewith with the lower end of said grapple rod extending below the lower end of said tubular body,

(d) said body being longitudinally movable and rotatable relative to said grapple rod when said coupling means are released,

(e) a radially extending shoulder on said grapple rod,

(7) a stop member on said body engageable with said shoulder to prevent said grapple rod from passing through the open lower end of said tubular body,

g) attaching means on the lower end of said grapple rod for attaching said grapple rod to said fish upon rotation of said body and said grapple rod,

(11) said coupling means including shear pin means which is releasable when said grapple rod is attached to said central portion whereby said body may then move longitudinally and rotatably relative to said grapple rod, and

(1') cutting means on the lower end of said tubular body for severing said fish upon continued rotation and longitudinal movement of said body relative to said grapple rod.

References Cited in the file of this patent UNITED STATES PATENTS 2,261,564 Robichaux et a1 Nov. 4, 1941 2,481,637 Yancey Sept. 13, 1949 2,762,438 Naylor Sept. 11, 1956 2,804,148 Schremp et al Aug. 27, 1957 2,804,151 Le Bus Aug. 27, 1957 2,832,423 Hall Apr. 29, 1958

Claims

1. APPARATUS FOR RETRIEVING A FISH FROM A WELL CASING, SAID FISH BEING SECURED AGAINST UPWARD MOVEMENT ABOVE THE BOTTOM OF SAID WELL CASING BY HOLDING MEANS ATTACHING SAID FISH TO THE WALL OF SAID WELL CASING, SAID APPARATUS COMPRISING A TUBULAR BODY OPEN AT THE LOWER END THEREOF, A GRAPPLE ROD WITHIN SAID BODY, SUPPORT MEANS EXTENDING RADIALLY FROM THE UPPER PORTION OF SAID GRAPPLE ROD, STOP MEANS WITHIN SAID TUBULAR BODY ENGAGEABLE WITH SAID SUPPORT MEANS TO SUSPEND SAID GRAPPLE ROD IN AN ACTIVE POSITION WITH THE LOWER END THEREOF EXTENDING BELOW SAID LOWER END OF THE BODY, COUPLING MEANS CONNECTING SAID GRAPPLE ROD WHILE IN SAID ACTIVE POSITION TO SAID BODY FOR ROTATION THEREWITH, ATTACHING MEANS ON THE LOWER END OF SAID GRAPPLE ROD FOR ATTACHING SAID ROD TO SAID FISH UPON ENGAGEMENT THEREWITH AND ROTATION RELATIVE THERETO, SAID COUPLING MEANS BEING RELEASABLE WHEN SAID GRAPPLE ROD IS ATTACHED TO SAID FISH TO PERMIT DOWNWARD MOVEMENT OF SAID BODY RELATIVE TO SAID GRAPPLE ROD INTO ENGAGEMENT WITH SAID BODY ADAPTED TO SEVER SAID HOLDING MEANS AFTER ENGAGEMENT THEREWITH.