Abstract:
An indicator comprising a band having a first radial dimension; one or more protectors having a greater radial dimension and disposed sufficiently proximate the band to substantially avoid wear of the band during running of the indicator and method.

Description:
BACKGROUND 
       [0001]    In subterranean drilling and completion arts there is commonly need to provide feedback to an operator of conditions downhole. For example, it is often helpful if not necessary to know when a string reaches a selected location for a number of reasons associated with downhole operations. One such situation is to determine when the string has reached a selected position downhole in order to begin another operation such as a liner expansion. Beginning a liner expansion too shallowly or too deep relative to the selected depth tends to produce results in the completion that are less desirable and may have to be corrected thereby costing money and time. 
         [0002]    Snap in and snap out collets have been used in connection with such operations and while they function generally well for their intended purpose, they are less than entirely reliable as it is possible for them to indicate at a point downhole that is not the intended point. 
         [0003]    As downhole operations become more and more precision driven and therefore precision sensitive, the art will well receive improved indicators having increased precision and confidence in operation. 
       SUMMARY 
       [0004]    An indicator including a band having a first radial dimension, one or more protectors having a greater radial dimension and disposed sufficiently proximate the band to substantially avoid wear of the band during running of the indicator. 
         [0005]    A method for indicating landing of an indicator at a selected location including running an indicator comprising a band having a first radial dimension, one or more protectors having a greater radial dimension and disposed sufficiently proximate the band to substantially avoid wear of the band during running of the indicator; observing change in weight on a string connected to the indicator. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0006]    Referring now to the drawings wherein like elements are numbered alike in the Figures: 
           [0007]      FIG. 1  is a perspective view of an indicator disclosed herein; 
           [0008]      FIG. 2  is an axial cross sectional view of the indicator illustrated in  FIG. 1  within a landing profile; 
           [0009]      FIG. 3  is an alternate embodiment of the indicator having a closed end. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    Referring to  FIG. 1 , an indicator  10  is illustrated. It is to be understood that the indicator will be run into a subterranean formation through a borehole in the formation on a “string”, the term being abundantly familiar to those of ordinary skill in the subterranean drilling and completion art. The specifically illustrated embodiment of indicator is configured as a collet but it is to be understood that the features of the indicator  10  responsible for its function can be employed with alternate carrier  12  configurations and hence the invention is not limited to a collet. The indicator requires an indicator band  14  that is proud of a base surface  16  of the carrier  12 . The indicator band  14  includes perimetrical edges  20  and  22  that are in one embodiment angled at about 70 degrees (in an axial direction of the tool, the angles best illustrated in the cross sectional view of  FIG. 2 ). In other embodiments different angles might be employed within an operative range. Angles of as little as about 30 degrees will still provide positive indication of landing while angles as great as about 80 degrees are still operative significant feedback to the operator and retrievability. 
         [0011]    In the particular embodiment of the  FIG. 1  illustration the carrier  12  as noted is a collet configuration where a tubular overall structure is perimetrically complete at one end  24  and perimetrically incomplete at an opposing end  26 . The incomplete end  26  may be configured with one or more kerfs  28  therein to provide the carrier  12  with flexibility in the radial direction. As illustrated in  FIG. 2 , the radial flexibility is employed inwardly while resilience is employed outwardly to facilitate engagement of the band  14  with the profile  18 . 
         [0012]    The band  14  is receivable in a profile groove  18  (see  FIG. 2 ) of a profile  30 , which reception will provide an indication that the carrier  12  has reached its intended landing site. The indication comes to the operator in the form of weight taken off the string from surface. Weight is taken off the string because once the indicator band has engaged the profile groove  18 , weight is taken up on the profile  30 . 
         [0013]    On at least one axial side of the band  14  is a protector  32 . In the illustrated embodiment there is also a protector  34 . It is to be understood that either or both may be used in particular embodiments. The one or more protectors that are used have for their purpose to prevent or substantially reduce contact of the band  14  with other structures with which it is not intended to come into contact. In one embodiment, the one or more protectors are about 20 thousandths of an inch larger radially than band  14 , while a range of about 20 to about 60 thousandths is operable. This difference in radial dimension avoids becoming an obstruction in the downhole environment but effectively protects the band  14  from wear so that reliable engagement with groove  18  is assured. In addition to the greater radial dimension of the protector(s)  32 ,  34 , their cross sectional shape is configured to enhance desired engagement while reducing the possibility of the indicator creating a false indication of arrival at the selected location. 
         [0014]    Each protector  32 ,  34  includes a low slope surface  36 ,  38  respectively. The surface  36 ,  38  is at an angle of about 15 degrees to about 30 degrees providing that the angle is always less than that of surfaces  20  and  22 . This configuration allows the protector to slide past obstructions in the downhole environment easily thereby avoiding false weight changes. Further, the surface  36 ,  38  will help move the string away from the obstruction further protecting the band  14  and increasing reliability of the indicator. It will be noted that in the illustrated embodiment, the surfaces  36 ,  38  are faced in two directions, one uphole and one downhole. This means that the benefits noted are available both during run in and pull out. 
         [0015]    In order for the indicator  10  to function as intended, the profile  30  must be internally configured to receive the band  14  and the protector(s)  32 ,  34 . Thereby, upon the indicator reaching the desired depth in the borehole, the band  14  and the protectors  32 ,  34  will automatically snap into engagement with the groove  18  and recesses  40  and  42  respectively. The edges  20  and  22  will seat on edges  44  and  46  respectively to provide the appropriate weight change and thereby indicate landing and also to hold the band  14  in engagement until a selected amount of overpull is applied to remove the indicator from the borehole. 
         [0016]    Referring to  FIG. 3 , the incomplete end  26  from the first described embodiment is left complete perimetrically with kerfs therefore starting axially inboard of both ends of the indicator. This is clearly shown in  FIG. 3  with the now closed end  50  illustrated. The closed end  50  may simply be an uncut portion of the original tubular or may be added to the configuration of  FIGS. 1 and 2 , if desired, by welding or other attachment procedure. In this embodiment, a higher spring force is achieved due to the greater support for the flexible portion of the indicator identified with bracket and numeral  52  in  FIG. 3 . 
         [0017]    While it has been noted above that a collet is not the only structure contemplated by the inventor it is further noted that the band and protectors could be disposed upon a radially extendible dog for example in a suitable housing with similar results. The band would still be protected from wear and a positive indication of landing would be assured. 
         [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.