Abstract:
An anchor system includes an anchoring device and at least one of a restriction indicator and a load isolation device in operable communication with the anchoring device and method.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 61/159,663 filed Mar. 12, 2009, the entire disclosure of which is incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    In industries concerned with actions taken within earth formations, it is often necessary to anchor tools needed for a plethora of possible operations. Anchors come in many different forms and constructions and each has its strengths and weaknesses and hence each type tends to be favored for a relatively specific class of applications. While existing anchors work well for their intended purpose and are generally reliable, the costs of operational inconsistencies in downhole applications are significant. The art is therefore consistently seeking and interested in alternative constructions that improve reliability. 
       SUMMARY 
       [0003]    An anchor system includes an anchoring device and at least one of a restriction indicator and a load isolation device in operable communication with the anchoring device. 
         [0004]    A method for setting of an anchoring system includes protecting an outer gage diameter of an anchoring device with a restriction indicator having a gage diameter greater than any gage diameter of the anchoring device; and configuring the restriction indicator to hold a selected amount of string weight in the event that the system contacts a restriction in a borehole in which the system is being run. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    Referring now to the drawings wherein like elements are numbered alike in the several Figures: 
           [0006]      FIG. 1  is a perspective view of an anchor system; 
           [0007]      FIG. 2  is a cross section view of the anchor illustrated in  FIG. 1  taken along section line  2 - 2 ; 
           [0008]      FIG. 3  is a schematic enlarged view of the area proximate the enlarged ends  58 ; 
           [0009]      FIG. 4  is a representation similar to that of  FIG. 2  with the system modified to set based upon landing at a preinstalled structure in a borehole; and 
           [0010]      FIG. 5  is a schematic illustration of a hydraulic embodiment of the system disclosed herein. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    Referring to  FIG. 1 , an anchor system  10  is illustrated in perspective view. A mid to uphole portion of the drawing, identified by bracket  12 , depicts an anchoring device that is commercially available from Baker Hughes Incorporated under Product Family H15054. Downhole of this portion (to the right in the Figure) is a new configuration providing significantly improved function to the H15054 product. The new configuration may include either or both of a restriction indicator  14  and a load isolation device  46 , which in one embodiment is a collet device and in other embodiments may be a spring, j-slot, shear ring, parting ring, body lock ring, burst disk or other release configuration capable of selectively permitting setting of the anchor. Each has a separate function and hence can be used independently with the related benefit to an anchor system using the same. Together, additional benefit is achieved. An embodiment that includes both the restriction indicator  14  and the load isolation device  46  is specifically illustrated. It is to be understood that either of these features could be deleted from the drawing such that the drawing illustrates the other configuration alone. 
         [0012]    Referring to  FIG. 2 , the restriction indicator  14  is to be configured to have a gage surface  20  that is of greater dimension than any other portion of the system  10 . It is to be appreciated that the surface  20  is also axially relatively short and the restriction indicator  14  further includes a frustoconical section  22 . These attributes of the restriction indicator  14  work together to ensure that the restriction indicator is the most likely component of the system  10  to experience contact at a restriction within the borehole in which the system  10  is run. The configuration also ensures that in the event that a contact occurs, it is relatively easy to dislodge the system because of the relatively narrow band of material at surface  20  that can be lodged. When the restriction indicator  14  is employed, a relatively small frictional interaction is usually all that needs to be overcome to release the system from a restriction. This is further discussed hereunder. 
         [0013]    Restriction indicator  14  presents a relatively small gage surface  20  that is exposed to and might encounter a restriction contact. In addition, because of the short axial length of the surface  20  and the configuration of the frustocone  22 , if a restriction is encountered, it is a relatively easy affair to pull the system  10  back uphole and out of the restriction. Further, the restriction indicator provides a warning signal to an operator in that the restriction indicator  14  is releasably affixed by a release member  26  to a lower cone  28  which itself is releasably affixed by a another release member  56  (shear screw(s), parting ring, body lock ring, collet, etc.) to a shear sleeve  30 . In one embodiment, the release member  26  is a shear ring, but it will be understood that other release members, such as shear screw(s), parting ring, body lock ring, collet, etc., could be substituted. The release member  26  provides a signal to an operator indicative of a restriction by holding some selected amount of weight and then releasing causing a slack off in weight on the derrick (not shown) at surface and then a return of the weight, or in other words a spike (except in the negative direction with respect to load). The amplitude of the signal is dictated by the release value of the release member  26  and can be adjusted during manufacture of the system  10 . 
         [0014]    Referring now to the load isolation device  46 , this feature provides the function of ensuring that the anchor system  10  sets only at a selected location such as the bottom of a borehole in which the anchor is to be used or at a landing profile (discussed hereunder as alternative embodiment) intended to cause the actuation. It ensures this by presenting a significantly lesser gage diameter than other components of the system  10 . This helps in the function of the system  10  in that it predisposes the actuation of the system  10  at the selected location such as the bottom of the borehole or at a landing profile, as is intended. Because the collet is of significantly smaller gage diameter, the likelihood of being actuated by a restriction is consequently smaller. The collet  46  is releasably secured by a collet release member  48  (shear screw(s), parting ring, body lock ring, collet, etc) to the shear sleeve  30  to prevent actuations caused merely by drag of the collet  46  along borehole structures during running. It is to be appreciated that in one embodiment the collet  46  extends downhole (to the right in the drawing) of the shear sleeve  30  by enough distance to allow the collet actuation shoulder  50  to make contact with and actuate a lower cone actuation shoulder  52 . Upon contact of the collet with the bottom of the hole (not shown), in the embodiment of  FIGS. 1 and 2 , load is built upon the collet release member  48  until a selected value of the release member is reached and surpassed. At that point the load isolation device  46  will move in an uphole direction relative to the rest of the system  10 . In fact, the load isolation device  46  has simply stopped moving downhole while the rest of the system  10  continues moving downhole. The load isolation device  46  moves closer to the lower cone  28  until actuation shoulder  50  on the load isolation device  46  makes contact with the actuation shoulder  52  of the lower cone  28 . In this position, the shear sleeve  30  is still extending for a lesser distance downhole than that of the load isolation device  46  thereby allowing the load isolation device  46  to provide a load to lower cone  28  and effectuate setting of the system  10 . 
         [0015]    Collet fingers  54  function to help prevent unintended actuation through the restriction indicator  14 , pursuant to a restriction, by transferring from the lower cone  28  to the shear sleeve  30  the load occasioned by contact between shoulder  32  and shoulder  34 , which is otherwise resisted only by setting release member  56 . The fingers  54  include enlarged ends  58  to interact with the shear sleeve  30  at groove  62  and lower cone  28  through undercut  60  therein, in which the ends  58  are positioned. In this configuration, unintended actuation due to the system encountering a restriction with restriction indicator  14  requires release of the release member  26 , movement of the restriction indicator  14  to load shoulders  32  and  34 . At this point, however, the load being transferred between load shoulders  32  and  34  will be transmitted axially along the lower cone, and will then load into the enlarged ends  58  of the collet fingers (through load shoulder B). The enlarged ends  58  of the collet fingers will then be placed into compression against load shoulder A. While this load is applied, the setting of the anchor  10  is prevented (see  FIG. 3 ). Thus the probability of achieving the intended setting is enhanced. 
         [0016]    In another embodiment, illustrated in  FIG. 4 , a system  110  is configured to actuate based upon landing in a preinstalled structure  164 . Structure  164  may be for example a tubular of some kind that has been previously placed in the borehole and is in some way held in place, perhaps by an anchoring system of some kind. The structure is configured at an uphole end thereof to interact selectively with a load isolation device  146 . This removes the requirement of the previously described embodiment that the load isolation device  46  extend downhole of the shear sleeve  30 . In the illustrated embodiment of  FIG. 4 , the shear sleeve  130  extends downhole of the load isolation device  146  and thereby offers additional protection thereto with regard to unintentionally engaging the load isolation device  146 , shearing the release member  148 , and setting the system  110  while running downhole. The structure  164  is configured to receive the shear sleeve  130  thereby aligning the system  110  in the borehole. After the shear sleeve  130  is received in the structure  164 , actuation end  166  will come into loaded contact with collet end  168  and cause actuation of the system  110  similarly to that described above for the embodiment of  FIGS. 1-3 . It will be understood that in one embodiment as shown, the ends  166  and  168  are profiled complementarily to one another. This profile may be angled as shown or orthogonal, or the surface may have another shape that aids in orientation of the system  110 , for example. 
         [0017]    Referring now to  FIG. 5 , another alternate embodiment of the system  210  is illustrated. In this embodiment the system  210  is actuated hydraulically and requires no set down weight on bottom or any structure. This embodiment may be located anywhere in the borehole that is desired. The system  210  includes a bottom sub  270  that replaces the shear sleeve  30  and  130  of the previous embodiments. The bottom sub  270  includes a hydraulic pathway  272  therein that feeds a port  274 . Hydraulic pressure is provided to this port  274  by string pressure that may be applied from the surface or other remote location. It is also possible for the system  210  to carry its own pressure source which may be in the form of a selectively openable chamber, a pump, etc. for example. Upon pressurization of the port  274 , fluid pressure within a hydraulic chamber  276 , defined in part by the collet  246  and in part by the sub  270 , is contained therein by seals  278 , which may be for example, o-rings. The increasing pressure in hydraulic chamber  276  ultimately will cause release of the release member  248  thereby facilitating movement of the collet  246  toward lower cone  28 . This movement is analogous to the movement of the load isolation device  46  in the first described embodiment and causes similar consequent actions of the system  210 . 
         [0018]    While one or more embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation.