Abstract:
A perimetrically acting collet includes a body and at least one mating profile opening in the body. A plurality of resilient members located adjacent one side of the at least one mating profile opening and a profiled body is biased perimetrically by the plurality of resilient members.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of an earlier filing date from U.S. Provisional Application Ser. No. 60/572,918 filed May 20, 2004, the entire disclosure of which is incorporated herein by reference. 

   BACKGROUND 
   In the hydrocarbon exploration and recovery arts, a collet is a well known and and well used tool. Traditionally, collets have been configured to locate and/or lock and/or position tools in a borehole. These tools are invaluable with respect to confidence about an ongoing operation whether the purpose of the specific collet is locating, locking or positioning. As downhole tools become more complex however, with zones and seals ubiquitously positioned, and restrictions in the casing becoming more problematic, and with advanced tools (considered necessary to enhance production) needing to be run through the tubing, collets have in some instances been identified as a source of consternation. Further, because collets operate on a radial deflection principal (inward or outward) and because in general collets run in tubing operate on a deflection inward/bias outward principal, the collet fingers necessarily scrape the inside dimension of the tubing in which they are run. This creates little wear on the inside of a blank tube but can be deleterious to seals exposed at that inside dimension. Moreover, because modern downhole systems often include many profiles therein, whether intended as profiles or simply defacto profiles, conventional collets can become stuck. Therefore well operators must expend time and effort tracking the potential snags downhole before employing a conventional collet. 
   SUMMARY 
   Disclosed herein is a perimetrically acting collet which includes a body and at least one lug opening in the body. At least one resilient member is located adjacent the at least one lug opening and a profile in the body is biased perimetrically by the at least one resilient member. 
   Further disclosed herein is a collet having at least one profile therein, the profile acting perimetrically of a cross-sectional shape of the collet. 
   Yet further disclosed herein is a method for engaging a mating profile. The method includes approaching the mating profile with a perimetrically acting collet, perimetrically deflecting the collet and perimetrically engaging the mating profile. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Referring now to the drawings wherein like elements are numbered alike in the several Figures: 
       FIG. 1  is an elevation view of a circumferential collet as described herein; and 
       FIG. 2  is an elevation view of the collet of  FIG. 1  engaged with a lug; 
       FIG. 3  is a perspective view of a collet with an orientation profile thereon; and 
       FIG. 4  is a view of an alternate selective collet embodiment. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1 , a circumferentially operating collet  10  is illustrated. As illustrated the device is circumferentially operating because it is circular in cross-section. It is to be noted however that this disclosure is directed to a peripherally acting collet because it is contemplated that specific embodiments may not be circular in cross-section. The collet as discussed herein does not act radially i.e., there is substantially no radial force (no more than incidental) in the engagement of the profile (discussed hereunder) but rather the force occurs around the perimeter of whatever cross-sectional shape the collet has. Collet  10  is, in the illustrated embodiment, of a tubular configuration. It is to be appreciated that collet  10  could be constructed from solid material or from material having one or more longitudinal openings that may or may not include an axial opening. In the event a solid material is employed, it would be machined to provide for the functional features that are described hereunder relative to the tubular embodiment shown. 
   Referring again to  FIG. 1 , collet  10  includes a body  11  having an engagement profile  12  which may comprise one or more teeth (as illustrated) or may comprise any profile capable of engagement with another structure. The structure (discussed below) may or may not have a complementary profile thereon but it will have a profile that is receptive of engagement profile  12 . Profile  12  extends along a peripheral region of collet  10 . The peripheral region may be proximate the exterior surface  14  of collet  10  or may occur somewhat radially inwardly thereof. Profile  12  is positioned such that it is resilient for engagement operations. In the illustrated embodiment, profile  12  extends from the outer surface  14  of collet  10  to an inside surface  16  of collet  10 , that surface defining the tubular lumen of the tool. 
   Resiliency is effected in different, sometimes cumulative ways depending upon the construction of the collet  10 . In the illustrated embodiment, the tube is closed at least in one of uphole and downhole of the mating profile opening  40  so that little resiliency is available in the body of the collet. In selective embodiments, discussed hereunder, some resiliency may also be available in the body of the collet since it will in cross-section be “C” shaped. In the embodiment illustrated in  FIG. 1 , resiliency is effected by removal of material from collet  10  “behind” the profile  12 . Such material removal is illustrated in  FIG. 1  as openings  18 ,  20 ,  22 ,  24  and  26 . It will be noted that openings  18  and  20 ,  22  and  24  are respectively aligned and separated by a peripheral bridge  28 ,  30  extending between resilient members  32 ,  34  and  36  (again, respectively). In the illustrated embodiment, bridges  28 ,  30  are located directly “behind” profile  12 . It will be appreciated that more bridges could be employed between resilient members and then could be alternately located between the resilient members. Bridges  28 ,  30  function to join resilient members to affect the character of the resilience afforded by the configuration. Character of resiliency is also affected by the number, radial thickness and perimetral width of each resilient member. Therefore, the degree of total resilience desired for the collet  10  is adjustable during manufacture by selecting inter alia, parameters for the resilient members and the number of resilient members. 
   Profile  12  must be at least on one side of mating profile opening  40  and some embodiments will have profiles  12  on both sides of mating profile opening  40 . In embodiments having profiles on both sides, the profiles may be identical or may be different, as desired for a particular application. 
   The mating profile opening  40  may be configured in a range of arc degrees of opening. The number of degrees selected will affect the size of a mating profile  42  ( FIG. 2 ) that will engage therewith and affects the designed in resilience that is possible. As the opening grows in number of degrees past 90 degrees, a practical limit will be reached regarding resiliency available therefore reducing snap-out force to something below useful. In one embodiment (illustrated) an angle of arc of about 60 degrees is employed. 
   Another feature of the collet  10  is that it may be employed as an orientation mechanism as well as a snap in/snap out engagement device. This is accomplished by adding a helical profile  48  to the downhole end  50  of collet  10  (see  FIG. 3 ). The helical profile  48  will cooperate with mating profile, in this case a lug  42  to orient the collet  10  and any tool connected thereto. A lug  42  having a pointed leading end  54  as shown is of benefit for an orientation operation since it enhances the action of following the helical profile  48 , end  54  also provides for a positive stop of the tool when the end  54  reaches an end  56  of lug opening  40 . 
   In an alternate embodiment of collet  10 , illustrated in  FIG. 4 , the collet  110  is configured as a selective device which has the capability of passing over non-conforming mating profiles. In order to pass over such non-conforming mating profiles there must not be end  56  ( FIG. 1 ) which would otherwise act as a positive stop, preventing the collet  110  from passing over. In the selective collet embodiment, provision is made in the profile to provide a positive stop if desired. One such positive stop profile is illustrated in  FIG. 4  as  112 , a no-go shoulder selective profile. 
   Because collet  110  includes a lug opening  140  that extends the length thereof embodiments which exist in tubular form will benefit from being fixed to other tools thereby lending additional structural support. This is illustrated schematically in  FIG. 4  where the collet  110  is shown mounted to a structural support  114  which may be another tool or simply a support mode for collet  110 . In more solid embodiments however, there is no need to affix the collet  110  to another tool for support reasons. 
   While preferred 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.