Abstract:
Disclosed herein relates to a single piece tubular member. The tubular member having a non-radially displaceable portion and a radially displaceable portion, the radially displaceable portion being movable to a position of similar radial displacement as that of the non-radially displaceable portion and a position of relatively large radial displacement in comparison to the non-radially displaceable portion. The tubular member also having at least one cutting arrangement disposed at the radially displaceable portion.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a divisional application of U.S. Ser. No. 11/671,181, filed Feb. 5, 2007, the contents of which are incorporated by reference herein in their entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     For a variety of reasons there are occasions when tubular structures such as casings and production tubing, for example, positioned downhole in wellbores need to be cut. Some examples are for removal of a damaged section of tubing or to provide a window for diagonal drilling. 
     Cutters have been developed that have rotating portions with knives that are pivoted radially outwardly to engage the inner surface of the tubular structure to perform a cut. Such cutters have a multitude of pivoting joints, cams and actuators that interact to rotate the knives between the noncutting and cutting configurations. The complexity of such cutters increases fabrication costs and potential failure modes. 
     Accordingly, the art is in need of less complex cutting tools. 
     BRIEF DESCRIPTION OF THE INVENTION 
     Disclosed herein relates to a single piece tubular member. The tubular member having a non-radially displaceable portion and a radially displaceable portion, the radially displaceable portion being movable to a position of similar radial displacement as that of the non-radially displaceable portion and a position of relatively large radial displacement in comparison to the non-radially displaceable portion. The tubular member also having at least one cutting arrangement disposed at the radially displaceable portion. 
     Further disclosed herein relates to a cutting tool. The cutting tool having a deformable tubular member having an inside surface and an outside surface and a plurality of lines of weakness thereat. At least one of the lines of weakness being positioned closer to one of the outside surface and the inside surface and at least one other of the plurality of lines of weakness being positioned closer to the other of the outside surface and the inside surface. The cutting tool also having at least one cutting element disposed at a portion of the tubular member most radially displaceable from an undeformed position of the tubular member. 
     Further disclosed herein relates to a method of cutting a downhole tubular. The method includes delivering a tubular cutting tool, with a plurality of lines of weakness thereon, to a downhole position within a downhole tubular that is to be cut, rotating the tubular cutting tool, and actuating the tubular cutting tool. The actuating causing a radially deformable portion of the tubular cutting tool to radially deform compared to an unactuated position of the tubular cutting tool. The actuating also causing a cutting element attached to the radially deformable portion to contact a downhole tubular to be cut. 
     Further disclosed herein relates to a method for making a cutting tool. The method includes configuring a deformable tubular member with a plurality of lines of weakness, with at least one of the plurality of lines of weakness disposed at each of an inside dimension and an outside dimension of the tubular member. The method also includes locating the plurality of lines of weakness relative to each other to facilitate deforming a portion of the tubular member to a greater radial dimension than the undeformed tubular member, and locating a cutting arrangement on the portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike: 
         FIG. 1  depicts a partial cross sectional view of a cutting tool disclosed herein in an unactuated configuration; 
         FIG. 2  depicts a partial cross sectional view of the cutting tool of  FIG. 1  in an actuated configuration; 
         FIG. 3  depicts a partial cross sectional view of the cutting tool of  FIG. 2  taken at arrows  3 - 3 ; 
         FIG. 4  depicts a partial cross sectional view of another embodiment of a cutting tool disclosed herein in an unactuated configuration; 
         FIG. 5  depicts a partial cross sectional view of the cutting tool of  FIG. 4  in an actuated configuration; and 
         FIG. 6  depicts a partial cross sectional view of the cutting tool of  FIG. 5  taken at arrows  6 - 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A detailed description of several embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures. 
     Referring to  FIGS. 1 and 2 , a partial cross sectional view of an embodiment of the cutting tool  10  is illustrated. The cutting tool  10  includes a tubular member  14  that has a radially displaceable portion  18  and a non-radially displaceable portion  20 . As illustrated in  FIG. 1  the radially displaceable portion  18  is in an unactuated configuration and as illustrated in  FIG. 2  the radially displaceable portion  18  is in an actuated configuration. In the actuated configuration the radially displaceable portion  18  forms two frustoconical sections  22  and  26 . The greatest radial deformation  30  of the tubular member  14  occurs where the two frustoconical sections  22  and  26  meet. Thus, an annular flow area  34  is defined by the greatest radial deformation  30  and an outside surface  38  of the non-radially displaceable portion  20 . At least one axial groove  42  in the outside surface  38  forms a first fluid passage through which fluid can flow between an uphole annular area  44  and a downhole annular area  46  when the radially displaceable portion  18  is in the actuated configuration. A second fluid passage  50  is formed through the center of the tubular member  14  defined by an inside surface  52  of the tubular member  14 . 
     The greatest radial deformation  30  contacts an inner surface  60  of a tubular structure  62  that is to be cut by the cutting tool  10 . A cutting arrangement positioned at the greatest radial deformation  30  engages with and cuts through the tubular structure  62 . The cutting arrangement can include a hardened portion of the metal of which the tubular member  14  is made, which can include sharpened portions of the metal, for example. Alternately the cutting arrangement can include an insert  16  of another material into the tubular member  14 . A cutting arrangement insert  16  can be made of such materials as tungsten carbide or diamonds, for example, which can be used separately or in combination. 
     The radially displaceable portion  18  is reconfigurable between the unactuated configuration and the actuated configuration. In the unactuated configuration the frustoconical sections  22  and  26  are configured as cylindrical components having roughly the same inside dimension as the tubular member  14  in the uphole annular area  44  and a downhole annular area  46 . Reconfiguration from the unactuated to the actuated configuration is effected, in one embodiment, by the application of an axial compressive load on the tubular member  14 . Conversely, reconfiguration from the actuated to the unactuated configuration is effected by the application of an axial tensile load on the tubular member  14 . 
     Reconfigurability of the radially displaceable portion  18  between the actuated configuration and the unactuated configuration is due to the construction thereof. The radially displaceable portion  18  is formed from a section of the tubular member  14  that has three lines of weakness, specifically located both axially of the tubular member  14  and with respect to the inside surface  52  and the outside surface  38  of the tubular member  14 . In one embodiment, a first line of weakness  66  and a second line of weakness  70  are defined in this embodiment by diametrical grooves formed in the outside surface  38  of the tubular member  14 . A third line of weakness  74  is defined in this embodiment by a diametrical groove formed in the inside surface  52  of the tubular member  14 . The three lines of weakness  66 ,  70  and  74  each encourage local deformation of the tubular member  14  in a radial direction that tends to cause the groove to close. It will be appreciated that in embodiments where the line of weakness is defined by other than a groove, the radial direction of movement will be the same but since there is no groove, there is no “close of the groove”. Rather, in such an embodiment, the material that defines a line of weakness will flow or otherwise allow radial movement in the direction indicated. The three lines of weakness  66 ,  70  and  74  together encourage deformation of the tubular member  14  in a manner that creates a feature such as the radially displaceable portion  18 . The feature is created, then, upon the application of an axially directed mechanical compression of the tubular member  14  such that the radially displaceable portion  18  is actuated as the tubular member  14  is compressed to a shorter overall length. Other mechanisms can alternatively be employed to actuate the tubular member  14  between the unactuated relatively cylindrical configuration and the actuated configuration presenting the frustoconical sections  22  and  26 . For example, the tubular member  14  may be reconfigured to the actuated configuration by diametrically pressurizing the tubular member  14  about the inside surface  52  in the radially displaceable portion  18 . 
     Referring to  FIG. 3 , a cross sectional view of the cutting tool  10  of  FIG. 2  is shown taken at arrows  3 - 3 . The fluid passages between the cutting tool  10  and the inside surface  52 , of the tubular structure  60 , created by the axial grooves  42 , is illustrated. Although the axial grooves  42  are illustrated herein as V-shaped, it should be appreciated that alternate embodiments can have grooves of any shape. It should also be noted that in alternate embodiments the cutting tool  10  could be used to cut through any downhole tubular structure such as a casing  78  for example. 
     Referring to  FIGS. 4 and 5 , an alternate exemplary embodiment of the cutting tool  110  is illustrated. The cutting tool  110  includes a tubular member  114  and a radially displaceable portion  118 . The radially displaceable portion  118  includes a plurality of extension members  120  attached thereto. As illustrated in  FIG. 4  the radially displaceable portion  118  is in an unactuated configuration and as illustrated in  FIG. 5  the radially displaceable portion  118  is in an actuated configuration. In the actuated configuration the radially displaceable portion  118  forms two frustoconical sections  122  and  126 . The extension members  120  are fixedly attached to the first frustoconical section  122  at a first portion  128 . A second portion  129  of the extension members  120  is positioned radially outwardly of the second frustoconical section  126  but is not attached to the second frustoconical section  126 . As such when the radially displaceable portion  118  is actuated the extension members  120  remain substantially parallel to the first frustoconical section  122  causing the second portion  129  of the extension members  120  to extend radially outwardly of the outermost portion of the frustoconical members  122 ,  126 . As such the greatest radial deformation  130  of the cutting tool  110  occurs at an end  132  of each of the extension members  120 . Control of the relationship of the greatest radial deformation  130  to the radial dimension of the end  132  in the unactuated configuration is completely controllable by setting the lengths of the second portions  129 . An annular flow area  134  is defined by the greatest radial deformation  130  and an outside surface  138  of a non-radially displaceable portion  140 . At least one axial space  142  between adjacent extension members  120  forms a first fluid passage through which fluid can flow between an uphole annular area  144  and a downhole annular area  146  when the centralizer  110  is in the actuated configuration. A second fluid passage  150  is formed through the center of the tubular member  114  defined by the inside surface  162  in the outside surface  138  forms a first fluid passage through which fluid can flow between an uphole annular area  144  and a downhole annular area  146  when the radially displaceable portion  118  is in the actuated configuration. A second fluid passage  150  is formed through the center of the tubular member  114  defined by an inside surface  152  of the tubular member  114 . 
     The greatest radial deformation  130  contacts an inner surface  60  of a tubular structure  62  that is to be cut by the cutting tool  110 . A cutting arrangement positioned at the greatest radial deformation  130  of the extension members  120  engages with and cuts through the tubular structure  62 . The cutting arrangement can include a hardened portion of the metal from which the extension members  120  are made. Alternately the cutting arrangement can include an insert of another material into the extension members  120 . A cutting arrangement insert can be made of such materials as tungsten carbide or diamonds, for example, which can be used separately or in combination. 
     The radially displaceable portion  118  is reconfigurable between the unactuated configuration and the actuated configuration. In the unactuated configuration the frustoconical sections  122  and  126  are configured as cylindrical components having roughly the same inside dimension as the tubular member  114  in the uphole annular area  144  and a downhole annular area  146 . Reconfiguration from the unactuated to the actuated configuration is effected, in one embodiment, by the application of an axial compressive load on the tubular member  114 . Conversely, reconfiguration from the actuated to the unactuated configuration is effected by the application of an axial tensile load on the tubular member  114 . 
     Reconfigurability of the radially displaceable portion  118  between the actuated configuration and the unactuated configuration is due to the construction thereof. The radially displaceable portion  118  is formed from a section of the tubular member  114  that has three lines of weakness, specifically located both axially of the tubular member  114  and with respect to the inside surface  152  and the outside surface  138  of the tubular member  114 . In one embodiment, a first line of weakness  166  and a second line of weakness  170  are defined in this embodiment by diametrical grooves formed in the outside surface  138  of the tubular member  114 . A third line of weakness  174  is defined in this embodiment by a diametrical groove formed in the inside surface  152  of the tubular member  114 . The three lines of weakness  166 ,  170  and  174  each encourage local deformation of the tubular member  114  in a radial direction that tends to cause the groove to close. It will be appreciated that in embodiments where the line of weakness is defined by other than a groove, the radial direction of movement will be the same but since there is no groove, there is no “close of the groove”. Rather, in such an embodiment, the material that defines a line of weakness will flow or otherwise allow radial movement in the direction indicated. The three lines of weakness  166 ,  170  and  174  together encourage deformation of the tubular member  114  in a manner that creates a feature such as the radially displaceable portion  118 . The feature is created, then, upon the application of an axially directed mechanical compression of the tubular member  114  such that the radially displaceable portion  118  is actuated as the tubular member  114  is compressed to a shorter overall length. Other mechanisms can alternatively be employed to actuate the tubular member  114  between the unactuated relatively cylindrical configuration and the actuated configuration presenting the frustoconical sections  122  and  126 . For example, the tubular member may be reconfigured to the actuated configuration by diametrically pressurizing the tubular member  114  about the inside surface  152  in the radially displaceable portion  118 . 
     Referring to  FIG. 6 , a cross sectional view of the cutting tool  110  of  FIG. 5  is shown taken at arrows  6 - 6 . The fluid passages between the cutting tool  110  and the inside surface  60 , of the tubular structure  62 , created by the axial spaces  142  between the extension members  120 , is illustrated. Although the extension members  120  depicted herein are rectangular prisms, it should be noted that alternate embodiments could have extension members of any shape. It should also be noted that in alternate embodiments the cutting tool  110  could be used to cut through any downhole tubular structure such as a casing  78  for example. 
     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.