Abstract:
A casing cutting and recovery tool having a cutting assembly, an expansion assembly having one or more deforming members, and a recovery assembly is used to cut a window in wellbore casing, secure a removable segment of wellbore casing that was previously disposed within the window, and recover the removable segment of wellbore casing with the tool. One or more cutting assemblies provides one or more cuts in the wellbore casing. The deforming members of the expansion assembly then expand outwardly at least two portions of the wellbore casing shaped by the cut or cuts. The recovery assembly secures the removable segment of the wellbore casing to the tool so that the tool and the removable segment of wellbore casing can be recovered together from the wellbore.

Description:
BACKGROUND 
       [0001]    1. Field of Invention 
         [0002]    The invention is directed to a casing profiling, or cutting, and recovery systems for use in oil and gas wellbores and, in particular, to a downhole tool for cutting a section of wellbore casing and recovering the section from the wellbore. 
         [0003]    2. Description of Art 
         [0004]    In general, cutting “windows” or openings in oil and gas wellbore casing so that “offshoot,” “lateral,” or “branch” wellbores are well known in the art. Previously, the windows were cut using a whipstock or whipstock-packer assembly and a cutting or milling tool disposed on the end of a drill string. Cutting the windows using these milling tools usually results in jagged edged and irregularly shaped openings. As a result, if it is desired to close the window, sealing the irregularly shaped opening is extremely difficult, if not impossible. 
         [0005]    Additionally, cutting the windows using these prior milling tools resulted in various sized debris falling into or remain in the wellbore after being cut by the milling tools. As a result, these pieces had to be recovered using wellbore fluid or fishing tools, both of which requires the wellbore to be “off-line” or “down” during the recovery efforts. 
         [0006]    Accordingly, prior to the development of the present invention, there has been no downhole tool for cutting and recovering a section or segment of wellbore casing or method for forming an opening in casing in a well that: permits cutting the casing segment and removing the segment of wellbore casing from the wellbore in a single downhole trip; permits cutting a segment of wellbore casing with relatively smooth edges, thereby increasing the possibility that the window can be re-sealed; and decreases the amount of debris within the wellbore as a result of cutting the window. Therefore, the art has sought a downhole tool for cutting and recovering a section or segment of wellbore casing and a method for forming an opening in casing in a well that: permits cutting the casing segment and removing the segment of wellbore casing from the wellbore in a single downhole trip; permits cutting a segment of wellbore casing with relatively smooth edges, thereby increasing the possibility that the window can be re-sealed; and decreases the amount of debris within the wellbore as a result of cutting the window. 
       SUMMARY OF INVENTION 
       [0007]    Broadly, the disclosure is directed to a casing cutting and recovery tool having a cutting assembly, an expansion assembly having one or more deforming members, and a recovery assembly that preferably includes a magnet. The casing cutting and recovery tool is used to cut a window in wellbore casing, secure a removable section of wellbore casing that was previously disposed within the window, and recover the removable section of wellbore casing with the tool. One or more cutting assemblies provide primary cuts and secondary cuts in the wellbore casing. The expansion assembly expands outwardly two portions of the wellbore casing shaped by the primary cuts. The magnet secures the removable section of wellbore casing to the tool so that the tool and the removable section of wellbore casing can be recovered together from the wellbore. 
         [0008]    In one specific embodiment, the casing cutting and recovery tool comprises a housing having a housing bore. The housing bore has a piston chamber and piston operatively associated therein. The piston is operatively associated with the expansion assembly and the expansion assembly has at least two expansion members operatively associated therewith. The recovery assembly includes an actuating member, such as a motor or solenoid and a recovery assembly housing. The magnet is disposed on the outer wall surface of the recovery assembly. The recovery assembly housing is moveable radially outward and inward relative to the housing by the actuating member. 
         [0009]    The downhole tools for cutting and recovering a section or segment of wellbore casing and methods for forming an opening in casing in a well have the advantages of: permitting cutting the casing segment and removing the segment of wellbore casing from the wellbore in a single downhole trip; permitting cutting a segment of wellbore casing with relatively smooth edges, thereby increasing the possibility that the window can be re-sealed; and decreasing the amount of debris within the wellbore as a result of cutting the window. 
         [0010]    In one aspect, one or more of the foregoing advantages is achieved by an apparatus for forming an opening in casing in a well in which the apparatus comprises a cutting assembly for lowering into a casing of a well, the cutting assembly having at least one cutting member for Cutting at least one slot in the casing to define a segment for removal; a deforming member carried with the cutting assembly, the deforming member being selectively actuated from a surface of the well for deforming outward at least two portions of the casing adjacent the slot; and a recovery assembly carried with the cutting assembly for engaging and removing the segment from the casing. 
         [0011]    A further feature of the apparatus is that the cutting assembly may be disposed above the deforming member. Another feature of the apparatus is that the deforming member may be disposed above the recovery assembly. An additional feature of the apparatus is that the deforming member may comprise at least two rollers. Still another feature of the apparatus is that the apparatus may further comprise a secondary cutting assembly, wherein the cutting assembly and the secondary cutting assembly each include at least two linear charges. A further feature of the apparatus is that the recovery assembly may include a magnet and an actuating member for moving the magnet radially outward to engage and remove the segment from the casing. Another feature of the apparatus is that the deforming member may be operatively associated with a piston disposed within a piston chamber, a lower portion of the piston being operatively associated with a conically shaped deforming member housing. An additional feature of the apparatus is that the lower portion of the piston may include a conically shaped drive wedge, the drive wedge being slidingly engaged with the conically shaped deforming member housing. Still another feature of the apparatus is that the piston and drive wedge may include a bore, the bore having disposed therein a ball seat, a ball, and a ball release. A further feature of the apparatus is that the piston chamber may include hydraulic fluid. Another feature of the apparatus is that the piston chamber may further include a vent port. 
         [0012]    In another aspect, one or more of the foregoing advantages is achieved by an apparatus for forming an opening in casing in a well in which the apparatus comprises a cutting assembly for lowering into a casing of a well, the cutting assembly having at least one linear shaped charge for cutting at least one slot in the casing to define a segment for removal; a piston movable by high pressure against a wedge member to radially expand a deforming member carried with the cutting assembly, the deforming member being selectively actuated by the piston for deforming outward at least two portions of the casing adjacent the slot; and a recovery assembly carried with the cutting assembly for engaging and removing the segment from the casing, the recovery assembly having a radially moveable magnet. 
         [0013]    A further feature of the apparatus is that the piston and wedge member each may include a bore, the bore having disposed therein a ball seat, a ball, and a ball release. Another feature of the apparatus is that the piston may be disposed within a piston chamber having an upwardly biased spring and hydraulic fluid. An additional feature of the apparatus is that the piston chamber may further include a vent port. 
         [0014]    In an additional aspect, one or more of the foregoing advantages is achieved by a method of cutting and removing a segment of casing disposed in a well to form an opening in the casing in which the method comprises the steps of: (a) lowering a casing cutting tool into a bore of a casing; (b) cutting at least one slot in the casing with the casing cutting tool to define a segment of casing to be removed; (c) with the casing cutting tool, forcing outward at least two portions of the casing adjacent the slot, thereby freeing the segment from the casing; then (d) removing the segment, thereby leaving an opening in the casing. 
         [0015]    A further feature of the method is that the method may further comprise the step of: (e) raising the casing cutting tool with the segment of the casing from the bore of the casing. Another feature of the method is that step (c) may be performed by applying downward pressure on a piston disposed within casing cutting tool causing the piston to move downward, the downward movement of the piston causing at least two expansion members to move radially outward to engage each of the at least two portions of the casing adjacent the slots to force outward each of the at least two portions of the casing against the slot. An additional feature of the method is that the downward pressure may be created by fluid pumped into a bore within casing cutting tool, the bore being in fluid communication with the piston. Still another feature of the method is that step (d) may be performed by actuating an actuating member to move a magnet radially outward to engage the segment o the casing and withdraw the segment of casing into the bore of the casing. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0016]      FIG. 1  is a partial cross-sectional view of one specific embodiment of a casing cutting and recovery tool, or system, of the present invention shown in its run-in position. 
           [0017]      FIG. 2  is an elevational perspective view of the exterior of wellbore casing showing primary longitudinal and primary latitudinal cuts made in the wellbore casing by the casing cutting and recovery tool shown in  FIG. 1 . 
           [0018]      FIG. 3  is a cross-sectional view of the wellbore casing shown in  FIG. 2  taken along line  3 - 3 . 
           [0019]      FIG. 4  is an elevational view of the exterior of the wellbore casing of  FIGS. 2-3  showing the expanded casing portions formed by the casing cutting and recovery tool shown in  FIG. 1 . 
           [0020]      FIG. 5  is a cross-sectional view of the wellbore casing shown in  FIG. 4  taken along line  5 - 5 . 
           [0021]      FIG. 6  is an elevational view of the exterior of the wellbore casing of  FIGS. 2-5  showing secondary cuts made in the wellbore casing by the casing cutting and recovery tool shown in  FIG. 1 . 
           [0022]      FIG. 7  is a cross-sectional view of the wellbore casing shown in  FIG. 6 , taken along line  7 - 7 . 
           [0023]      FIG. 8  is cross-sectional view of the casing cutting and recovery tool shown in  FIG. 1  disposed within the wellbore casing shown in  FIGS. 2-7  showing the expanded casing portions formed by the casing cutting and recovery tool shown in  FIG. 1  and showing the section of the wellbore casing to be engaged by the recovery assembly of the casing cutting and recovery tool shown in  FIG. 1 . 
           [0024]      FIG. 9  is cross-sectional view of the casing cutting and recovery tool shown in  FIG. 1  disposed within the wellbore casing shown in  FIGS. 2-7  showing the section of the wellbore casing engaged by the recovery assembly of the casing cutting and recovery tool shown in  FIG. 1 . 
           [0025]      FIG. 10  is cross-sectional view of the casing cutting and recovery tool shown in  FIG. 1  disposed within the wellbore casing shown in  FIGS. 2-7  showing the section of the wellbore casing engaged and withdrawn into the bore of the wellbore casing by the recovery assembly of the casing cutting and recovery tool shown in  FIG. 1 . 
           [0026]      FIG. 11  is an elevational view of the exterior of the wellbore casing shown in  FIGS. 2-7  showing the window made in the wellbore casing by the casing cutting and recovery tool shown in  FIG. 1 . 
           [0027]      FIG. 12  is a cross-sectional view of the wellbore casing shown in  FIG. 11  taken along line  11 - 11 . 
       
    
    
       [0028]    While the invention will be described in connection with the preferred embodiments, it will be understood that it is not intended to limit the invention to that embodiment. On the contrary, it is intended to cover all alternatives, modifications, and equivalents, as may be included within the spirit and scope of the invention as defined by the appended claims. 
       DETAILED DESCRIPTION OF INVENTION 
       [0029]    Referring now to  FIGS. 1-12 , casing cutting and recovery tool  10 , or tool  10  or downhlole tool  10 , comprises upper end  12 , lower end  14  and housing  16 . Upper end  12  and lower end  14  both include threads  18  for securing tool  10  to a casing, drill pipe, tubing string, or wireline (not shown) or other downhole tools (not shown). Housing  16  includes housing bore  20  longitudinally disposed at least partially through housing  16  and outer wall surface  22 . 
         [0030]    Tool  10  includes at least one cutting assembly  21 . In the embodiment shown in  FIG. 1 , Cutting assembly  21  includes linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34  disposed along a radial arc of outer wall surface  22 . Linear charges are known in the art and may be obtained from Accurate Arms Company, Inc. located in McEwen, Tenn. Briefly, linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34  are shaped explosive devices having a substantially V or U cross-section. When detonated, the explosive force is expelled out of an opening along the top of the V or U cross-section so that the explosive force is directed in a desired direction. As shown in  FIG. 1 , linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34  are arranged in such a way that there is a left upper horizontal linear charge  24 , a left vertical linear charge  26 , a left lower horizontal linear charge  28 , a right upper horizontal linear charge  30 , a right vertical linear charge  32 , and a right lower horizontal linear charge  34 . It is to be understood, however, that a single linear charge may be shaped to have the same arrangement as shown in  FIG. 1 . Preferably, each linear charge  24 ,  26 ,  28 ,  30 ,  32 ,  34  is disposed along outer wall surface  22  such that the tops of each linear charge  24 ,  26 ,  28 ,  30 ,  32 ,  34  are flush with outer wall surface  22 . In other embodiments (not shown), cutting assembly  21  include devices for abrasive jetting, milling, electronic discharge machining, chemical jetting or erosion, flame cutting, broaching, scarring, wheel cutting, perforating, slotting, or other device, or using any method, known to persons skilled in the art. Further, linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34  do not have to provide straight cuts or parallel cuts. Instead, linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34  can be arranged to cut one or more arcuate shaped cuts, including circular shaped cuts. 
         [0031]    Housing  16  also includes piston chamber  36  disposed within housing  16 . In the embodiment shown in  FIG. 1 , piston chamber  36  is disposed below linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34 . Piston chamber  36  includes vent port  38  and piston  40  slidingly engaged within piston chamber  36 . In a preferred embodiment, hydraulic fluid is disposed within piston chamber  36  and vent port  38  includes a plug (not shown) for maintaining the hydraulic fluid within piston chamber  36  during run. The plug is easily dislodged from vent port  38  during operation of piston  40  (discussed in greater detail below). Piston  40  includes piston seals  42 , piston rod  43 , and piston bore  44  extending through piston rod  43  and piston  40 . Vent port  38  is always below piston seals  42 . Spring  46  acts to force piston  40  in the upward direction (arrow  47 ). In other words, piston  40  is upwardly biased. Piston rod  43  can also include fastener hole  48  through its side wall for receiving a fastener (not shown) such as a screw (not shown). 
         [0032]    The lower end of piston rod  43  is secured by a fastener (not shown) to drive wedge  50  by inserting the lower end of piston rod  43  into upper bore portion  52  of wedge bore  54  of drive wedge  50 . Alternatively, drive wedge  50  and piston rod  43  can be a single component. Wedge bore  54  includes lower bore portion  56  that has a smaller inner diameter compared to the inner diameter of upper bore portion  52 . 
         [0033]    Drive wedge  50  has a conical shape with the narrow end at the bottom of drive wedge  50 . The outer surface of drive wedge  50  is in sliding engagement with expansion assembly  60 . As illustrated in  FIG. 1 , expansion assembly  60  includes expansion assembly housing  62 . In one specific embodiment, the outer surface of drive wedge  50  has lands and grooves (not shown) and expansion assembly housing  62  has reciprocal lands and grooves (not shown) so that upward and downward movement of wedge driver  50  pushes or pulls expansion assembly housing  62  through the connecting lands and grooves. 
         [0034]    Expansion assembly housing  62  includes expansion assembly housing chamber  64  for receiving drive wedge  50 . Expansion assembly  60  also includes at least two expansion members shown in  FIG. 1  as expansion rollers  66 . In this arrangement, as drive wedge  50  moves downward, in the direction of arrow  51 , expansion assembly housing  62  is forced outward radially, in the direction of arrows  68 ,  69 , so that expansion rollers  66  engage the wellbore casing to bend or force “open” the wellbore casing as discussed in greater detail below. Ball seat  70  is disposed within wedge upper bore portion  52 . Ball seat  70  includes ball  72  that initially blocks the downward flow of fluid through piston bore  44 . As discussed in greater detail below, after piston  40  has been forced downward (arrow  51 ) to radially expand expansion rollers  66 , ball release  74  having stem  75  and head  76  engages ball  72  and forces ball  72  off of ball seat  70  so that fluid is permitted to flow downward through piston bore  44  and into expansion assembly housing chamber  64 . As a result, drive wedge  50  can be forced upward, in the direction of arrow  47 , so that each expansion rollers  66  can be retracted into housing  16  of tool  10  (discussed in greater detail below). In a preferred embodiment, head  76  is disposed within chamber  78  of housing  16  such that head  76  can move slightly within chamber  78 . 
         [0035]    Disposed below expansion assembly  60  is recovery assembly  80 . Recovery assembly  80  includes housing  82  that is operatively associated with a source of movement, i.e., an actuating member of device such as a motor or a solenoid  85  ( FIGS. 8-10 ). The outer surface of housing  82  includes magnet  84 . In this specific embodiment, outer surface of housing  82  also includes a second cutting assembly made up of upper horizontal linear charge  86  and lower horizontal linear charge  88 . Housing  82  is radially moveable relative to housing  16  by solenoid  85 . Although housing  82  is shown as being flush with outer wall surface  22  of housing  16 , it is to be understood that housing  82  may be slightly recessed within housing  16  during the period of time that recovery assembly  80  is not in use, i.e., during run-in of the tool  10  or during operation of Cutting assembly  21  or expansion assembly  60 . 
         [0036]    Referring now to  FIGS. 2-12 , in operation, tool  10  is lowered through wellbore casing  90  by a work string (not shown) to the desired location where a window is to be cut in wellbore casing  90 . Wellbore casing has casing bore  91  defined by inner casing wall surface  92  and casing outer wall surface  93 . Once properly located within wellbore casing  90 , linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34  are initiated using known devices and techniques, such as detonator and prima cord activated electronically from the surface of the well. In the embodiment shown in  FIGS. 2-12 , the explosive force from linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34  creates primary longitudinal cuts  95 ,  98  and primary horizontal cuts  94 ,  96 ,  97 ,  99  in wellbore casing  90  ( FIGS. 2-3 ). 
         [0037]    Thereafter, tool  100  is raised up in wellbore casing  90  until rollers  66  of expansion assembly  60  are disposed on the inner wall surface  92  of wellbore casing  90  parallel to primary longitudinal cuts  95 ,  98  and in between primary horizontal cuts  94 ,  96 ,  97 ,  99 . Referring to  FIG. 1 , fluid (not shown), such as wellbore fluid or hydraulic fluid, is then pumped down the work string and into housing bore  20  to actuate piston  40 . Once actuated, piston  40  is forced downward in the direction of arrow  51  causing drive wedge  50  to radially expand expansion assembly housing  62  and, thus, expansion rollers  66  outwards in the direction of arrows  68 ,  69 . In so doing, the plug is forced out of vent port  38  causing piston chamber  36  to be in fluid communication with the wellbore. Thus, the hydraulic fluid within piston chamber  36  is forced out of piston chamber  36  allowing piston  40  to move downward. Further, the pressure within piston chamber  36  is hydrostatic pressure. 
         [0038]    Piston  40  is forced downward until ball release  74  engages ball  72  and removes ball  72  from ball seat  70 . As a result, fluid being pumped down work string and housing bore  20  is permitted to flow through piston bore  44  and wedge bore  54  alongside ball release  74  and into expansion assembly housing chamber  64 . Fluid is continued to be pumped resulting in pressure equilibrium being established above and below piston  40 , i.e., within housing bore  20 , piston chamber  36 , and expansion assembly housing chamber  64 . Due to the equilibrium established in these spaces, expansion rollers  66  remain extended to contact inner wall surface  92  of wellbore casing  90  and force outward two portions of wellbore casing  90 , referred to herein as expanded casing portions  100 ,  102  ( FIG. 5 ). Tool  10  is then either raised or lowered as appropriate so that expansion rollers  66  move along the entire longitudinal length of primary longitudinal cuts  95 ,  98  in between primary horizontal cuts  94 ,  96 ,  97 ,  99 . As a result, longitudinal openings  101 ,  103  are formed in wellbore casing  90  ( FIGS. 4-5 ). 
         [0039]    After longitudinal openings  101 ,  103  are formed, expansion rollers  66  are retracted into housing  16  by decreasing or eliminating the pumping of fluid down housing bore  20  ( FIG. 1 ). The reduced or elimination of pumping pressure down housing bore  20  allows spring  46  to force piston  40  upward in the direction of arrow  47 . As piston  40  moves upwards in the direction of arrow  47 , fluid within expansion assembly chamber  64  flows upwards past ball seat  70 , through piston bore  44 , and through housing bore  20 . Also, wellbore fluid (not shown) flows into piston chamber  36  through vent port  38 . The flow of fluid flows upwards past ball seat  70 , through piston bore  44 , and through housing bore  20  and/or through vent port  38  can also assist in the movement of piston  40  upward. As piston  40  moves upwards (arrow  47 ), drive wedge  50  also moves upwardly causing expansion assembly housing  62  and, thus, expansion rollers  66  to retract into housing  16 . 
         [0040]    Tool  10  is then raised further up wellbore casing  90  until magnet assembly  80  is disposed between primary longitudinal cuts  95 ,  98  and in between primary horizontal cuts  94 ,  96 ,  97 ,  99 . A top cross-sectional view of the location of tool  10  at this stage of operation is shown in  FIG. 8 . Tool  10  may include verification tools to ensure that tool  10  is properly located and expanded casing portions  100 ,  102  are properly formed. The verification tools can include one or more video, acoustic, ultrasonic, or tactile system known in the art that can easily be adapted for these functions. If expanded casing portions  100 ,  102  are not in their correct position, tool  10  can be repositioned so that expansion assembly  60  can be re-engaged to expand expanded casing portions  100 ,  102 . 
         [0041]    The second cutting assembly, linear charges  86 ,  88  in  FIG. 1 , is initiated using known devices and techniques, such as prima cord activated electronically from the surface of the well. The explosive force from linear charges  86 ,  88  creates secondary horizontal cuts  112 ,  114  in wellbore casing  90  ( FIG. 6 ). In a preferred embodiment, motor or solenoid  85  radially moves magnet housing  82  outward in the direction of arrow  130  until magnet  84  and linear charges  86 ,  88  contact casing inner wall surface  92  ( FIG. 9 ). It is to be understood, however, that linear charges  86 ,  88  do not have to be in contact with inner wall surface  92 . It is also to be understood that magnet  84  does not have to be in contact with inner wall surface  92  at the time linear charges  86 ,  88  or activated. 
         [0042]    It is also to be understood that a second cutting assembly such as linear charges  86 ,  88  is not required. For example, in embodiments in which cutting assembly  21  is capable of abrasive jetting, milling, electronic discharge machining, chemical jetting or erosion, flame cutting, or wheel cutting, second cutting assembly is not needed because cutting assembly  21  can be used to make secondary horizontal cuts  112 ,  114 . Therefore, in these embodiments, a single cutting assembly  21  can be part of tool  10 . 
         [0043]    After secondary horizontal cuts  112 ,  114 , wellbore casing section  110  is now removable from the remainder of wellbore casing  90 . If magnet  84  is not already in contact with wellbore casing section  110 , magnet  84  is moved into contact with wellbore casing section  110  by motor/solenoid  85 . Motor/solenoid  85  may be activated through any device or method known in the art such as through electronic activation from the surface. 
         [0044]    Wellbore casing section  110 , secured by magnet  84  is then moved into wellbore casing bore  91  by moving motor/solenoid  85  in the direction of arrow  132 . Tool  10  and wellbore casing section  110  can then be raised up wellbore casing bore  91  by the work string, thereby leaving wellbore casing  90  with window  120  ( FIGS. 11-12 ). 
         [0045]    Tool  10  provides the advantages of creating a smooth walled window  120  in wellbore casing  90 . Thus, potential damage to other downhole tools, components and strings is lessened because window  120  includes few, if any, jagged cuts and sharp edges. Additionally, the possibility of being able to reseal window  120  is raised because there are less irregularly shaped spaces that need to be filled or covered. Further, tool  10  lessens the amount of debris that may be left in the wellbore or that needs to be recovered using recovery fluids or recovery tools. Moreover, tool  10  permits window  120  to be cut and removed using a single tool making a single downhole run. Thus, cost savings are achieved using tool  10 . 
         [0046]    Further, additional components, such as a measurement while drilling component, flow sub, J &amp; shear joint, bottom trip anchor, and/or whipstock may be secured to lower end  14  to facilitate placement or operation of tool  10  or to allow additional components, such as a whipstock, to be placed within wellbore as part of the operation of tool  10  during its single trip downhole. 
         [0047]    It is to be understood that the invention is not limited to the exact details of construction, operation, exact materials, or embodiments shown and described, as modifications and equivalents will be apparent to one skilled in the art. For example, piston  40  may be actuated using any method or device known to persons of ordinary skill in the art. Additionally, one or more linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34  may be disposed along outer wall surface  22  of housing  16  such that the outer surfaces of linear charges  24 ,  26 ,  28 ,  30 ,  32 ,  34  are either recessed into housing  16  or protrude outside of outer wall surface  22 . Further, upper horizontal linear charge  86  and lower horizontal linear charge  88  are not required to be disposed on outer surface of magnet housing  82 . In other words, upper horizontal linear charge  86  and lower horizontal linear charge  88  are not required to be moveable radially. Instead, upper horizontal linear charge  86  and lower horizontal linear charge  88  may be disposed on outer wall surface  22  of housing  16 . Moreover, the primary and secondary cuts may be formed using abrasive jetting, milling, electronic discharge machining, chemical jetting or erosion, flame cutting, perforating, slotting, broaching, scarring, wheel cutting, or using any other device or method known to persons skilled in the art. Further, a single cutting assembly may be included as part of tool  10  to provide all of the primary and secondary cuts. Additionally, the expansion members may be inflatable components shaped to correspond to expanded casing portions  100 ,  102  that can be inflated to force expanded casing portions  100 ,  102  outwardly. Alternatively, the expansion member may be swage having a ramp profile. Accordingly, the invention is therefore to be limited only by the scope of the appended claims.