Patent Publication Number: US-3874720-A

Title: Device for fishing from a borehole an elongated member, such as a drill string

Description:
United States Patent Reynard et al.  
 [ Apr. 1,1975  
 Institut Francais Du Petrole, Des Carburants Et Luhrifiants,, Rueil-Malmaison, France [22] Filed: July 26, 1972 [2]] Appl. No.: 275,165  
 [73] Assignee:  
 [30] Foreign Application Priority Data July 30, 1971 France 71.28182 [52] U.S. Cl 294/8626, 294/86/12 [51] Int. Cl ..E21b 31/02 [58] Field of Search 294/86.l, 86.12, 86.14,  
 294/8615, 86.17, 86.24, 86 CG, 86.26, 86.32; 24/123 F [56] References Cited UNITED STATES PATENTS 2,434,358 1/1948 Frank 174/84 S X 12/1957 Bundy ..294/86.12 3,697,114 10/1972 Chatard ..294/86.1  
 Primary Examiner-Evon C. Blunk Assistant Examiner-James L. Rowland Attorney, Agent, or FirmCraig &amp; Antonelli [57] ABSTRACT An arrangement for fishing an elongated member such as a drill pipe from a borehole which includes at least one upper tubular element, at least one lower tubular element, and an intermediary tubular element covered by a sock-like element adapted to be constricted on the elongated member to be fished from the borehole. The sock-like element is anchored at its ends respectively on the upper tubular element and on the lower tubular element. The intermediary tubular element is connected to the upper element through first releasable connection means and to the lower tubular element through second releasable connection means.  
 15 Claims, 14 Drawing Figures MENTED 1 SHEET 1 OF 7 FIGJ I &#39;AIENTED APR 1 I975 SHEET 3 BF 7 PATENTEU APR 1 9 5 SHEET 5 0F 7 FIG.5A  
 PATENTED 1 9 FIG.BA  
 FIG.6  
 DEVICE FOR FISHING FROM A BOREHOLE AN ELONGATEI) MEMBER, SUCH AS A DRILL STRING The present invention relates to a device for fishing from a well an elongated member such as a drill string, by the constriction of a sheath or sock-like member on the upper portion of the elongated member, resulting from the application of a traction force to said socklike member.  
  Devices for fishing an elongated member jammed in a borehole are already available, these prior devices comprising in combination a handling stem having one end adapted to be introduced into the well, a member extending said handling stem at said end thereof, this extending member being integral with said handling stem, at sock-like member constituted by a netting of metal wires, cables or strands, placed within said extending member, the ends of said sock-like member being respectively secured to said extending member and to said handling stem, said sock-like member being adapted to cap the elongated member, means for disengaging said extending member from said handling stem, and means for constricting said sock-like member on this elongated member, thereby gripping this elongated member by relative axial displacement of the extending member and of said handling stem.  
  These prior devices have proved to be particularly efficient in practice.  
  However in the case where such a device is used for fishing in a borehole a section of a flexible pipe, it is necessary at first to carry out, at the upper end of said pipe section, difficult and time consuming operations, so that the metal armourings included in the flexible pipe structure do not move away from the axis of this pipe and thus allow the introduction of the pipe into the sock-like member. Such preliminary operations are particularly difficult to carry out because the flexible pipe bears against the borehole walls, forming an helix which impedes the lowering of the fishing device down to its working position. Moreover this device requires the use of hydraulic fluid pressure means to operate and constriet the sock-like member.  
  The main object of the invention is accordingly to provide a device whereby the above-indicated drawbacks are avoided, and more particularly a device which is easy to operate, even for fishing at flexible pipe including helical armourings which moreover does not require the use of pressurized hydraulic fluid in the well and permits an easy anchoring or fastening of the lower end of the sock-like member to the elongated member to be fished, thereby permitting a better constriction of this sock-like member on said elongated member.  
  This and other objects are achieved, according to the invention, with a device for fishing in a borehole an elongated member, such as a drill pipe, comprising in combination:  
 a. at least one upper tubular element,  
 b. at least one lower tubular element,  
 c. an intermediary tubular element covered by a sock-like element adapted to be constricted on the elongated member to be fished and anchored at its ends respectively on said upper tubular element and onsaid lower tubular element, said intermediary element being connected to said upper element through first releasable connecting means and to said lower element through second releasable connecting means.  
  A non-[imitative embodiment of the invention will be described hereinunder with reference to the accompanying drawings wherein:  
  FIGS. I and IA respectively illustrate the upper and lower parts of the device,  
  FIGS. 2, 2A; 3, 3A; 4, 4A; 5, 5A; 6, 6A and 7, 7A, show the successive steps of operation of the device for fishing a section of drill pipe from a borehole.  
  FIGS. I and IA respectively illustrate the upper and lower part of a fishing device according to the invention, designated as a whole by reference numeral 1 and maintained vertically by means of a handling stem 2 connected to the ground surface. This device comprises a locking head 3 provided with three pawls or catches, upper interconnected tubular elements and a lower tubular element 6 extended downwardly by a shoe 7.  
  An intermediary tubular element 8, connecting the upper tubular element 5 and the lower tubular element 6, is covered by a sheath or sock-like member 9, anchored at its ends in the tubular elements 5 and 6, respectively.  
  The intermediary tubular element 8 is held in position by means of balls which penetrate an annular groove 11 provided in the upper tubular element 5, these balls being held in position by a locking ring 12, provided with an annular groove on its external wall and with an inner shoulder 30 on its internal wall. The ring I2 is maintained in its lowermost position, for which the groove 32 is not at the level of the balls 10. through a spring 13 which bears on a shoulder of the ring 12 and on the lower end of the head 14 of the intermediary tubular element 8, this head being made integral with the latter, for example through a threading. The intermediary tubular element 8 is internally provided at its upper part with pawls or catches blocked through the locking ring 12.  
  The lower tubular element 6 is made integral with the intermediary tubular element 8 through shear pins 16.  
  Positioned against the internal wall of the shoe 7 and held in position through the tubular cover 17 are pawls or catches I9 and gripping jaws 20.  
  The tubular cover 17 is locked at the lower part of the tubular element 6 through shear pins 18.  
 This device is operated as follows:  
  Within the borehole 2] is placed a drill column 22, consituted for example by a flexible drill pipe, which has been broken.  
  After the depth at which the pipe is broken has been ascertained, the drill pipe 22 is cut through a suitable device, which may be of any known type, in order to facilitate the following operating steps.  
  The depth at which the failure has occurred being known, the fishing device 1 is lowered by means of the handling stem 2, down to a level above the level at which the pipe has been cut (for example, a distance of, say, one meter is left between the shoe 7 and the pipe 22) and the position of the fishing device I is fixed.  
  The fishing device being in a fixed position, there is then lowered, through the axial bore of this device (FIGS. 2 and 2A), a tool for the centering and placing in a line, indicated as a whole by reference numeral 23 and suspended from a handling stem 24, the assembly being made integral for example through a threading.  
 The tool 23 isconstituted by four parts a lower part formed by an expansible tool 25, provided with jaws which can be moved away radially from one another by hydraulic control, an intermediary tube 26, a centering body 27 whereon are placed pawls or catches 28 and which is provided with an annular groove 29 and a head 27a connected to the centering body 27 through shear pins 35 (FIG. 6).  
  The expansible tool 25 is introduced into the drill pipe 22; a pressurized fluid is supplied to the expansible tool 25 through the handling stem 24, the centering head 27a, the centering body 27 and the intermediary tube 26.  
  The jaws of the tool 25, when moving away from one another, grip the internal wall of the drill pipe 22.  
  The fluid pressure inside the expansible tool 25 being maintained, a pull is exerted (FIGS. 3 and 3A) on the tool 23, through the handling stem 24, so as to place the helically twisted flexible drill pipe 22, which was bearing against the borehole wall in a substantially vertical position substantially along the borehole axis.  
  The drill pull is maintained, so as to keep the pipe 22 vertical and the hydraulic pressure in the tool 25 is also maintained.  
  The assembly being in a fixed position, it is now possible to lower (FIGS. 4 and 4A) the fishing device 1 around the drill pipe 22. The top of this drill pipe 22 penetrates the shoe 7, then comes into abutment at 36 inside the tubular cover 17; the pins 18 are sheared under the weight of the fishing device 1 resting at 36 on the drill pipe 22 which is kept in the vertical position by the tubular element 24. The tubular cover 17 is then released and thus releases firstly the gripping jaws 20, then the pawls or cathces 19 which come into abutment against pipe 22.  
  As it will appear from the following description, these grippingjaws 20 and these pawls or catches 19 will help in raising the drill pipe 22.  
  The fishing device moves further downwardly until (FIG. 4) the pawls or catches 28 come into abutment against the internal shoulder 30 of the locking ring 12 and this ring comes into abutment against a shoulder of the head 14 of the intermediary tubular element 8. In this upper position the ring 12 releases the pawls or catches 15 which come into the groove 29 of the centering body 27. The annular groove 32 is then in a position of disengagement from the intermediary tubular element 8 which was previously made integral with the tubular element 5 through the balls 10. The downward displacement of the fishing device 1 is then stopped.  
  The hydraulic pressure in the expansible tool 25 is decreased.  
  The collapsing of the drill pipe 22 is prevented by the pawls l9 and the gripping jaws 20. Through the handling stem 24 (FIG. 5) a pull is effected on the tool designated as a whole by reference numeral 23.  
  The locking balls 10 are expelled from the annular groove 11 into the annular groove 32, thus disconnecting the intermediary tubular element 8 from the upper tubular element 5. Under the tractive force exerted by the handling stem 24 on the intermediary tubular element 8, the shearing pins 16 are sheared, thus disconnecting the intermediary tubular element 8 from the lower tubular element 6. The intermediary tubular element 8, by moving away from the lower element 6, progressively withdraws the sheath or sock 9, as it can be seen at the upper part of FIG. 5A.  
  Having fully withdrawn the sock 9, the intermediary tubular clement (FIGS. 6 and 6A) comes into engagement with the locking head 3, on the pawls or cathces 33 which are now inserted in the annular groove 34, provided for this purpose in the head 14 of the tubular element 8. I  
  Through column 24 is exerted (FIG. 7 and 7A) a last pull on the tool 23. The centering head 270 being integral with the centering body 27 through pins 35 (FIG. 6), the latter are sheared, the centering head 27a and the tubular element 24 are raised to the ground surface to facilitate the final operation. The tool 23 remains suspended through pawls or catches 15.  
  The last step consists in applying a pull to the upper part of the fishing device 1, through the handling stem 2, so as to produce a constriction (FIG. 7A) on the drill pipe 22 of the sock 9 anchored at its ends on the tubular elements 5 and 6.  
  The pawls or catches l9 and the gripping jaws 20 provide for the fixation in position of-the lower element 7 on the flexible pipe during the raising of the whole assembly, thus preventing any relative sliding of the drill column relative to the lower part of the sock anchored in the lower element 7, which provides for an efficient constriction of the sock on the drill pipe wall.  
 As it appears from the foregoing, in the case where&#39; a fluid flows in the borehole it is not necessary to discontinue such fluid flow.  
  Moreover, when the drill column to be fished is rigid, it will be possible, without departing from the scope of the present invention, to omit the centering tool 23, if the upper part of the drill column permits a good operation of the fishing device.  
  Obviously, it will be advantageous in such a case to provide the lower end of the fishing device with a tool or crown for reboring the borehole, in order to facilitate the operations for placing the fishing device around the rigid drill column.  
 What we claim is:  
  l. A device for fishing an elongated member such as a drill pipe from a borehole, comprising in combination:  
 at least one upper tubular element,  
 at least one lower tubular element,  
 a sock-like element adapted to be constricted on the elongated member to be fished from the borehole, said sock-like member being anchored at its respective ends on said upper tubular element and on said lower tubular element, an intermediary tubular element disposed between said upper tubular element and said lower tubular element, a first releasable connecting means for releasably connecting a first end of said intermediary element to said upper tubular element, and a second releasable connecting means for releasably connecting a second end of said intermediary element to said lower tubular element, said intermediary element forming an inner lining for said sock-like member substantially between said first and second ends of said intermediary tubular element, said inner lining being of a greater diameter than the diameter of the elongated member to be fished from the borehole.  
  2. A device according to claim 1, wherein a handling stem is provided having at its lower end a tool for centering and placing in line said elongated element and wherein said upper tubular element, said intermediary element and said lower tubular element are freely slidable downwardly along said handling stem to cap the upper part of said elongated member, and wherein said centering tool includes means for uncoupling said first releasable connecting means, means for raising said intermediary element upon raising said handling stem and means for releasing said second releasable connecting means, thereby permitting constriction of the sock-like member directly on said elongated member as a result of a pull applied to said upper tubular element, and wherein said upper tubular element includes at its upper end, means for suspending said intermediary tubular element in a raised position.  
  3. A device according to claim 2, wherein said tool for centering and placing in line said elongated member comprises at its lower end a hydraulically controlled device adapted to grip said elongated element.  
  4. A device according to claim 2, wherein means for disconnecting said centering tool from said handling stem are provided, and means for suspending said intermediary tubular element from the head of said upper tubular element, and wherein means are provided on said intermediary tubular element for holding said centering tool after said tool is disconnected said handling stem.  
  5. A device according to claim 1, wherein said upper tubular element is provided with a recess in an internal wall thereof, and a locking ring with a releasing recess is provided, and wherein said first releasable connecting means consists of at least one locking element which is housed in the upper part of the intermediary tubular element and is inserted into said recess provided in said upper tubular clement, said locking element being held in place by an external wall of said locking ring and wherein a resilient means is provided for normally maintaining said releasing recess at a level which is distinct from that of said locking element.  
  6. A device according to claim 5. wherein said means for uncoupling said first releasable connecting means and for raising said intermediary tubular element comprises at least one pawl cooperating with an internal shoulder of said locking ring.  
  7. A device according to claim 1, wherein said lower tubular element comprises means for anchoring said lower tubular element into said elongated member, said anchoring means being covered by a tubular cover which is slidable upwardly to release said anchoring elcments.  
  8. A device according to claim 7, wherein said tubular cover is made integral with the lower tubular element through at least one shearing pin.  
  9. A device for withdrawingan elongated member from a borehole comprising: at least one upper tubular member; at least one lower tubular member; a socklike means disposed between and attached to said upper and lower tubular members for constricting on the elongated member; at least one additional tubular member disposedbetween said upper and lower tubular members within said sock-like means, said additional tubular member constituting an inner lining for said sock-like member and having a diameter greater than that of the elongated member to be withdrawn from the borehole.  
  10. A device according to claim 9, wherein means are provided for centering and alining the elongated element in the borehole and wherein said upper tubular member, said lower tubular member and said additional tubular member are freely slidable along said last-mentioned means.  
  11. A device for withdrawing an elongated member from a bore hole comprising: at least one upper tubular member; at least one lower tubular member; a socklike means disposed between and attached to said upper and lower tubular members for constricting on the elongated members: at least one additional tubular member disposed between said upper and lower tubular members within said sock-like means, said additional tubular member constituting an inner lining for said sock-like member and having a diameter greater than that of the elongated member to be withdrawn from the bore hole; means for centering and aligning the elongated element in the bore hole, said upper tubular member, said lower tubular member and said additional tubular member being freely slidable along said last-mentioned means; means for releasably connecting a first end of said additional tubular member from said upper tubular member; and an additional means for releasably connecting said additional tubular element from said lower tubular element.  
  12. A device according to claim 11, wherein said means for centering and alining the elongated element includes a means for uncoupling said means for releasably securing a first end of said additional tubular element, means for releasing said additional releasable connecting means, and means for raising said intermediary element upon raising of said means for centering and alining.  
  13. A device according to claim 12, wherein said means for centering and alining further includes a hydraulically controlled means for gripping said elongated element.  
  14. A device according to claim 13, wherein means are provided for anchoring said lower tubular member to the elongated member.  
  15. A device according to claim 14, wherein said means for centering and alining include a handling stem and a centering tool and wherein means are provided for disconnecting said centering tool from said handling stem.