Pulling tool

Patent metadata

Field	Value
Publication number	US-9695658-B2
Application number	US-201214358761-A
Country	US
Kind code	B2
Filing date	Nov 29, 2012
Priority date	Nov 30, 2011
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A pulling tool for latching onto an object, such as a plug, downhole in a wellbore includes a base element extending in a longitudinal direction from a proximal end for being connected to a wireline tool to a distal end adapted to engage the object, and a latching mechanism encircling the base element and being movable in the longitudinal direction between a deactivated position and an activated position, having a piston sleeve, a key element for latching onto the downhole object, the key element being slidably received inside the piston sleeve and extending from an end of the piston sleeve towards the distal end of the base element, and a piston spring forcing the piston sleeve in the longitudinal direction towards the proximal end of the base element.

First claim

The invention claimed is:

1. A pulling tool for latching onto an object, downhole in a wellbore, the pulling tool comprising:
a base element extending in a longitudinal direction from a proximal end for being connected to a wireline tool to a distal end adapted to engage the object, and
a latching mechanism encircling the base element and being movable in the longitudinal direction between a deactivated position and an activated position, the latching mechanism comprising:
a piston sleeve,
a key element for latching onto the downhole object, the key element being slidably received inside the piston sleeve and extending from an end of the piston sleeve towards the distal end of the base element, and
a piston spring forcing the piston sleeve in the longitudinal direction towards the proximal end of the base element,

wherein the latching mechanism is adapted to latch onto the downhole object when being activated by supplying a hydraulic fluid via a fluid channel extending from the proximal end of the base element to an expandable piston chamber which is at least partly defined by the piston sleeve, whereby the piston sleeve is slidable in the longitudinal direction towards the distal end of the base element as the latching mechanism is brought from the deactivated position to the activated position, and the latching mechanism is adapted to be disengaged from the downhole object when the supply of hydraulic fluid is terminated, whereby the latching mechanism is brought from the activated position to the deactivated position by the piston spring forcing the piston sleeve in the longitudinal direction towards the proximal end of the base element.

2. A pulling tool according to claim 1 , wherein the key element comprises a plurality of arms flexible in a radial direction, the arms having protrusions at a distal end for engaging a recess of the downhole object.

3. A pulling tool according to claim 2 , wherein the base element is adapted to allow an inwards flexion of the arms when the latching mechanism is in the deactivated position.

4. A pulling tool according to claim 3 , wherein the key element is slidable in the longitudinal direction towards the proximal end of the base element as the latching mechanism is moved towards the deactivated position, and the base element is adapted to allow an inwards flexion of the arms when the key element is displaced towards the proximal end of the base element.

5. A pulling tool according to claim 1 , wherein the base element comprises a protruding flange adjacent the distal end for underpinning the plurality of arms of the key element when the latching mechanism is in the activated position, the flange preventing direct inwards radial movement.

6. A pulling tool according to claim 1 , wherein the base element further comprises a protrusion adjacent the distal end, thereby restricting longitudinal movement of the key element beyond the protrusion.

7. A pulling tool according to claim 1 , wherein the latching mechanism further comprises a key spring forcing the key element in the longitudinal direction towards the distal end of the base element.

8. A downhole retrieval system for pulling an object in a wellbore, comprising:
a pulling tool for latching onto an object downhole, and
a hydraulic system for supplying hydraulic fluid to the pulling tool,

wherein the pulling tool is a pulling tool according to claim 1 .

9. A downhole retrieval system according to claim 8 , further comprising:
a stroker tool for providing a force in an axial direction, comprising:
a hydraulic system driven by a motor,
a stroker cylinder, and
a hydraulic piston rod driven by the hydraulic system and movable in the axial direction in the stroker cylinder, the piston rod being connected with the pulling tool and the first mentioned hydraulic system.

10. A downhole retrieval system according to claim 8 , further comprising:
a stroker cylinder, and
a hydraulic piston rod movable in the axial direction in the stroker cylinder, wherein the pulling tool is mounted on the piston rod and the hydraulic system supplies hydraulic fluid to both the pulling tool and the stroker cylinder to drive the hydraulic piston rod in the axial direction and to the pulling tool.

11. A downhole retrieval system according to claim 8 , further comprising a driving unit for driving the entire retrieval system forward in inclining sections of a wellbore.

12. A method of connecting and disconnecting the retrieval system according to claim 8 to a downhole object, comprising:
activating the pulling tool by supplying a hydraulic fluid to the pulling tool whereby the latching mechanism is moved in the longitudinal direction,
latching the pulling tool onto the object,
providing a pulling force in the pulling tool,
terminating the supply of hydraulic fluid to the pulling tool, and
disengaging the pulling tool from the object.

13. A method according to claim 12 , wherein the latching the pulling tool onto the object comprises:
inserting the distal end of the pulling tool into the downhole object until the key element abuts the downhole object,
forcing the pulling tool further towards the downhole object, whereby the key element is forced towards the proximal end of the base element, thereby compressing the key spring, and the arms enter a position allowing inwards flexion, and
moving the pulling tool still further into the downhole object whereby the projections on the arms of the key element pass a fishing neck of the downhole object and enter the recess of the downhole object.

14. A pulling tool according to claim 1 , wherein the key element is slidable in the longitudinal direction towards the distal end of the base element as the latching mechanism is moved towards the activated position and the hydraulic fluid is supplied to the piston chamber.

15. A pulling tool according to claim 1 , wherein the key element is slidable either towards the distal end or towards the proximal end when in the activated position or the deactivated position.

16. A pulling tool according to claim 1 , wherein the proximal and distal ends of the base element are fixed relative to one another in the same position in both the activated and deactivated positions.

17. A pulling tool according to claim 1 , wherein the key element is detachable from the downhole object when the supply of hydraulic fluid is terminated and the latching mechanism is in the deactivated position.

18. A pulling tool according to claim 1 , wherein to disconnect the pulling tool from the downhole object, the supply of hydraulic fluid to the piston chamber is terminated, at which time the piston spring will force the piston sleeve and the key element towards the proximal end.

19. A pulling tool according to claim 1 , wherein the base element is movable further into the downhole object, when the tension on the pulling tool is released, to thereby allow the key element to radially move inward relative to the base element, whereby the key element and thus the pulling tool may be disconnected from the downhole object by pulling the pulling tool in an uphole direction.

20. A pulling tool for latching onto an object, downhole in a wellbore, the pulling tool comprising:
a base element extending in a longitudinal direction from a proximal end for being connected to a wireline tool to a distal end adapted to engage the object, and
a latching mechanism encircling the base element and being movable in the longitudinal direction between a deactivated position and an activated po

Assignees

• Welltec As

Inventors

• Hallundbæk Jørgen
• Evertsen Steffen
• Sommer Rasmus

Classifications

• E21B23/042 Primary

  using a single piston or multiple mechanically interconnected pistons · CPC title

• E21B31/20

  gripping internally, e.g. fishing spears · CPC title

• E21B31/12

  Grappling tools, e.g. tongs or grabs · CPC title

• E21B31/18

  gripping externally, e.g. overshot · CPC title

• E21B23/04 Primary

  operated by fluid means, e.g. actuated by explosion (E21B23/08 takes precedence) · CPC title