Setting and retrieval mechanism

Abstract

A method for retrieving a downhole tool comprises moving a setting and retrieval sleeve 16 to position an engagement member release region 34 of the setting and retrieval sleeve to allow disengagement

Description

13 06 25 BACKGROUND

[0001] In the resource recovery industry tools are run into a borehole and set there fore various purposes. Some of these tools are permanently set but some are intended to be retrievable. Retrievable tools include apparatus to relieve tension on one or another of the components of a particular tool so that trapped energy in the tool from the setting process can be released, thereby facilitating the retrieval. While in the art there are retrieval mechanisms that work for the purpose, there are also difficulties related to access to the apparatus to relieve tension due to other tools being in the way or debris collecting on the tool obscuring retrieval apparatus. The art will benefit from additional retrieval mechanisms that provide reliability. SUMMARY

[0002] According to an aspect of the present invention, there is provided a method for retrieving a downhole tool as claimed in claim 1. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

[0004] Figure 1 is a cross section view of a tool have a retrieval mechanism as disclosed herein prior to setting of the tool;

[0005] Figure 2 is the mechanism in the set position;

[0006] Figure 3 is the mechanism in the release position;

[0007] Figure 3a is an enlarged portion of Figure 3 to elucidate details;

[0008] Figure 4 is the mechanism in the retrieve position;

[0009] Figure 5 is an alternate embodiment in a set position;

[0010] Figure 6 is the alternate embodiment of Figure 5 in the release position; and 13 06 25

[0011] Figure 7 is a well system including a tool with the release mechanism therein. DETAILED DESCRIPTION

[0012] A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

[0013] Referring to Figures 1-4, a first embodiment of a setting and retrieval mechanism 10 is illustrated. In Figure 1, the mechanism 10 is in a run in condition. The mechanism includes a mandrel 12 having wickers 14 thereon. A setting and retrieval sleeve 16 is disposed radially outwardly of the mandrel 12 and slidable thereon. The sleeve 16 is operably connected to an actuator sleeve 18 that allows input from the actuator sleeve 18 in the form of pushing downhole or pulling uphole to impart the same motion on the setting and retrieval sleeve 16. In an embodiment, this occurs through a thread 20. Adjacent the setting and retrieval sleeve 16 are a body lock ring 22, having wickers 24 at an inside surface thereof and wickers 26 at an outside surface thereof. Also adjacent the sleeve 16 is an engagement member 28, having inside surface wickers 30 engageable with outside surface wickers 26 of body lock ring 22. The setting and retrieval sleeve 16 defines an engagement member support region 32 and an engagement member release region 34. The sleeve 16 also includes a retrieval hook 36. Finally illustrated is a tool interface 38 that transmits both a compressive load to the tool during setting and a tensile load to the tool during retrieval.

[0014] Referring to Figure 2, the setting and retrieval mechanism 10 is in the set position. It should be noted that the setting and retrieval sleeve 16 has shifted relative to the mandrel 12. A load from uphole is transmitted through sleeve 18 into sleeve 16 and then through shoulder 40 of sleeve 16 into uphole end 42 of engagement member 28, through member 28 to downhole end 44 into surface 46 of tool interface 38. All of these components move in the downhole direction together. The body lock ring (BLR) 22 is engaged with engagement member 28 as well, so the body lock ring 22 2 13 06 25 also moves downhole relative to the mandrel 12. BLR 22 is segmented or a C-ring or similar so that it may ratchet along the wickers 14 of the mandrel 12 as it moves in the downhole direction (right of figure). The wickers 24 and wickers 14 are profiled to allow relative movement only of the BLR 22 moving downhole relative to the mandrel 12. Wickers 24 and 14 when engaged with each other prevent movement in the opposite direction. Accordingly, with the mechanism 10 in the position shown in Figure 2, energy imparted to the attached tool (not shown) through the sleeve 18 is held there indefinitely unless another action from uphole is taken.

[0015] Referring to Figure 3, the alluded to action from uphole has been taken and the mechanism 10 is illustrated immediately after that action was taken. Specifically, the action taken is a tensile load placed upon the sleeve 18, which pulls the sleeve 16 in the uphole direction sliding engagement member support region 32 out of alignment with the engagement member 28 and instead aligning the engagement member release region 34 with the engagement member 28. With this alignment, there is a radial space for the engagement member 28 to be driven into. Ratcheting the engagement member 28 over the BLR 22 allows the BLR 22 to stay in the set position while allowing the rest of the mechanism to be retrieved thereby removing the energy held in the attached downhole tool. Specifically, the wickers 14 on the mandrel 12 are engaged at a particular location along wickers 14 with the BLR 22 in the set position. This does not change when the tool is retrieved. Rather, the release of the engagement member 28 from the BLR 22 is what allows components to move. Reference is now made to Figure 3a, which is an enlarged view of the circumscribed area 3a-3a in Figure 3. This view makes what happens during retrieval easier to understand. Specifically, as noted, the wickers 24 of BLR 22 remain engaged with the wickers 14 on the mandrel 12 in the as set position. Because the sleeve 16 has moved however, which unaligns engagement member support region 32 with the engagement member 28 and instead aligns engagement member release region 34 with the engagement member 28, that member is free to be displaced radially outwardly and ratchet across the fixed position BLR 22. The engagement member 28 may be segmented or may be a C-ring or similar so that radially outward expansion is possible. It should also be noted that the wickers 26 on the BLR 22 and the wickers 13 06 25 30 on the engagement member 28 are angled such that the radially outward displacement of the engagement member 28 with relative axial movement between the engagement member 28 and BLR 22 is enabled. It will be appreciated that the wickers 24 and 26 of the BLR 22 are angled in the same direction but the movements appear in the opposite direction. This is because the first movement of the BLR 22 relative to the mandrel 12 is to the right in the Figure (BLR 22 moves to right while Mandrel 12 is stationary, for example) and the movement of the sleeve 16 is to the left (BLR 22 is stationary and sleeve 16 moves to left, for example). The apparent direction of ratcheting movement being opposite is actually a function of which component is moving relative to which component. In an embodiment, the angle is 60 degrees or less measured from a longitudinal axis of the BLR 22. Because of the ability of the engagement member 28 ratcheting over the BLR, the energy that was held within the mechanism to set the downhole tool is released. Further movement to complete with retrieval operation is illustrated in Figure 4.

[0016] In an alternate embodiment, illustrated in Figures 5 and 6, like parts have been numbered with 100 series equivalent numerals for clarity. In this embodiment, the required stroke of the mechanism 110 is reduced by replacing the two independent regions 32 and 34 with longitudinally shorter and interspersed regions 132 and 134. In other aspects this embodiment is the same as the forgoing embodiment. Viewing Figures 5 and 6 together will provide the understanding. When the mechanism is in the set position of Figure 5, the regions 132 interact with merlons 140 and when it is in the retrieve position the regions 132 interact with the crenels 142. This embodiment significantly reduces the required stroke to unsupport the engagement member 128 and allow retrieval of the downhole tool. In other respects, the teachings associated with the embodiment of Figures 1-4 apply to the embodiment of Figures 5-6.

[0017] If a threshold tensile load is desired prior to retrieval, a release member 48 such as a shear screw may be placed anywhere the sleeve 16 and the tool interface 38 overlap. One location is shown in Figure 1 with an illustration of a shear screw. 13 06 25

[0018] Finally, a well system 150 is schematically illustrated in Figure 7. The system 150 comprises a borehole 152 in a subsurface formation 154. A string 156 is disposed in the borehole and a retrieval mechanism 10, 110 is disposed with the string 156.

[0019] The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “about”, “substantially” and “generally” are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” and / or “substantially” and / or “generally” can include a range of ± 8% or 5%, or 2% of a given value.

[0020] The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and / or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anticorrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

[0021] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. 13 06 25

Claims

13 06 251. A method for retrieving a downhole tool comprising:moving a setting and retrieval sleeve (16) to position an engagement member release region of the setting and retrieval sleeve (16) to allow disengagement of an engagement member (28, 128) with a body lock ring (22, 122);placing a tensile force on the setting and retrieval sleeve (16);disengaging the engagement member (28, 128) from the body lock ring (22, 122) under the impetus of the tensile force on the setting and retrieval sleeve (16); andreleasing captured energy in the downhole tool by the disengaging and the tensile force on the setting and retrieval sleeve (16), wherein a retrieval hook (36) is on the setting and retrieval sleeve (16).

2. The method as claimed in claim 1 wherein the moving of the setting and retrieval sleeve (16) is pulling from an uphole location (42).

3. The method as claimed in claim 1 or 2 wherein the disengaging includes driving the engagement member (28, 128) away from the body lock ring (22, 122) with wickers (14).

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