So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
Embodiments of apparatus and methods for retrieving a downhole tool are provided. In one embodiment, a retrieval tool is configured to align itself with the downhole tool, such as a whipstock. The self alignment is achieved using contours in the retrieval tool to guide the retrieval tool into engagement with the downhole tool. The retrieval tool is guided as it translates along the downhole tool in response to an axial force, such as gravity, force transferred through the conveyance, or a wire line tractor. As such, alignment of the retrieval tool with respect to the downhole tool requires no rotational or hydraulic manipulation from the surface. Therefore, the retrieval tool may be conveyed into the wellbore on a flexible conveyance such as a wire line, a slick line, coiled tubing, co-rod, etc. Further, the retrieval tool may be conveyed on a conventional conveyance such as a drill pipe.
A retrieval tool 112 is shown in
In operation, a flexible conveyance 114 is coupled to the connector portion 302 of the retrieval tool 112. The retrieval tool 112 is run into the wellbore 100 by extending and lowering the conveyance 114 from the conveyance member 116. When the retrieval tool 112 is on a flexible conveyance such as a wireline, slickline, coiled tubing, or co-rod, the retrieval tool 112 may not be rotated into alignment from the surface. The retrieval tool 112 travels down the inner diameter of the tubular 102 with the lead end portion 304 downhole and the full diameter portion 404 up-hole. The full diameter portion 404 and the non-contoured side 306 have a diameter that is smaller than the inner diameter of the tubular 102. The full diameter portion 404 may also include centralizers (not shown) which are designed to allow the retrieval tool 112 to travel substantially in the center of the tubular 102 while allowing the retrieval tool 112 to have a decreased diameter. The retrieval tool 112 continues down the wellbore and eventually the angled tip 307 encounters the whipstock 104. The retrieval tool 112 may encounter the whipstock 104 in a position where the engagement member 118 is in rotational alignment with the profile 202 of the whipstock 104, or a position where the engagement member 118 is not in alignment with the profile 202. If the engagement member 118 and profile 202 are in alignment, the contoured side 402 of the retrieval tool 112 will travel along the concave surface 125 of the whipstock 104 until the engagement member 118 engages the profile 202. As the conveyance member 116 continues to unwind, slack will be placed in the conveyance 114 indicating that the retrieval tool 112 and the whipstock 104 are in the engagement position. The conveyance member 116 then lifts the conveyance 114 which in turn pulls the retrieval tool 112 and the whipstock 104 toward the surface.
In the situation where the engagement member 118 is not aligned with the profile 202 of the whipstock 104, the retrieval tool 112 is adapted to self align with the whipstock 104. The angled tip 307 encounters the upper end of the whipstock 104. In one embodiment, the angled tip 307 is designed to guide the lead end portion 304 of the retrieval tool 112 toward the concave surface 125 of the whipstock 104. With the lead end portion 304 adjacent the concave surface 125, the contoured side 402 of the retrieval tool 112 will rotate the retrieval tool 112 at least partially circumferentially as it travels along the concave surface 125. The rotation will continue until the engagement member 118 is aligned with profile 202 and the non-contoured side 306 is facing the inner diameter of the tubular 102 or the window 108. The conveyance member 116 will continue to lower the conveyance 114 allowing gravity to pull the retrieval tool 112 along the concave surface 125. The retrieval tool 112 travels down until the engagement member 118 engages the profile 202. The whipstock 104 and retrieval tool 112 are then removed from the wellbore 100 as described above.
If the retrieval tool 112 encounters the whipstock 104 at substantially a 180° angle from the engagement position, the retrieval tool 112 is designed so that the engagement member 118 will not engage the window 108. In the event that the lead end portion 304 of the retrieval tool 112 directly encounters the uppermost end of the whipstock 104, the full diameter portion 404, or the centralizers maintain the retrieval tool 112 in a position substantially in line with the tubular 102. The full diameter portion 404 or the centralizers may have an outer diameter which substantially matches the inner diameter of the tubular 102. The outer diameter will keep the retrieval tool 112 substantially in line with the bore of the tubular 102. Thus, the retrieval tool 112 will not rotate to a position in which the engagement member 118 may engage the window 108. In this position, the retrieval tool 112 may reach a depth at which further downward movement is prohibited due to the geometry and the angle of the whipstock 104 at the uppermost end. If the retrieval tool 112 and the whipstock's 104 geometrical juxtaposition prevent further downward movement of the retrieval tool 112, the retrieval tool 112 may then be raised clear of the whipstock 104. This will allow the retrieval tool 112 to freely rotate. The retrieval tool 112 is then lowered until it is in the engagement position as described above.
In an alternative embodiment, a tractor, not shown, may be used in conjunction with the flexible conveyance 114 to axially propel downhole tools such as the whipstock 104 or the retrieval tool 112. The tractor and retrieval tool 112 may be run to a position adjacent the whipstock 104. The tractor may then move the retrieval tool 112 along the whipstock 104. The retrieval tool 112 will self align to the engagement position as described above. Once in the engagement position the tractor may assist in raising the retrieval tool 112, thereby lifting the whipstock 104 and freeing it from the tubular 102.
In another alternative embodiment, the retrieval tool 112 is used with in a deviated or horizontal well including extended reach horizontal wells. In the horizontal well gravity does not assist the alignment of the retrieval tool 112. Therefore, a force must be applied to the retrieval tool 112 during the alignment process. The force may be provided by any suitable method of providing a force including, but not limited to, a tractor, a drill pipe, a co-rod or a coiled tubing. The force will align the retrieval tool 112 in the same manner as described above. Further, the full diameter portion 404 may maintain the retrieval tool 112 in a central position in the horizontal well.
In another embodiment, the downhole tool, such as a whipstock or re-entry guide, is adapted to guide a lug, run down on a flexible conveyance, into a slot on the downhole tool. The lug would follow a guide path on the downhole tool until it is in a position to allow the conveyance to lift the downhole tool out of the wellbore.
After the whipstock is removed from the wellbore a re-entry guide may be set on the setting tool 106, shown in
In operation, the re-entry guide 602 may be removed from the wellbore 100 using the lug 604 on a flexible conveyance 114. The lug 604 travels down the wellbore 100 and enters the entry portion 608 of the re-entry guide 602. The lug 604 follows the slot 606 and down the ramp 616 until the lug 604 is in the lower slot 614. Once in the lower slot 614, tension may be applied to the flexible conveyance 114 and the lug 604 will ride up into the upper portion of the upper slot 612 as shown in
In another embodiment, a series of slots 706 may be incorporated into a downhole tool 702, as shown in
The downhole tool 702 may be set into and/or removed from the wellbore 100 in much the same manner as the re-entry guide 602. To set the downhole tool 702, the lug 704 is located in one of the upper notches 714 while the flexible conveyance 114 lowers the downhole tool 702 into the wellbore 100. The downhole tool is then set. The tension is taken out of the flexible conveyance 114, and the lug is allowed to fall onto the ramp 710C, as shown, and into the lower notch 712. Once in the lower notch 712, tension is reapplied to the flexible conveyance 114, and the lug 704 is lifted until it hits ramp 710D. The ramp 710D guides the lug 704 towards the exit slot 708, thereby releasing the flexible conveyance 114 from the downhole tool 702. To retrieve the downhole tool 702, the flexible conveyance 114 with the lug 704 is run into the wellbore 100. The lug 704 will enter entry slot 708 and travel down the slot 708 until encountering ramp 710A. The ramp 710A maneuvers the lug toward the lower notch 712. Tension is then applied to the flexible conveyance 114, and the lug 704 moves up and hits ramp 710B which maneuvers the lug 704 into the upper notch 714. The downhole tool 702 may then be removed from the wellbore 100.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
This application claims benefit of U.S. Provisional Patent Application No. 60/821,624, filed on Aug. 7, 2006, which application is incorporated herein by reference in its entirety.
Number | Date | Country | |
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60821624 | Aug 2006 | US |