Abstract:
The invention concerns a casing tool and a method for connecting casing tubulars using a top drive. The casing tool comprises a top cover that may be connected either releasably or non-releasably to the top drive and an elongated inner body that may be connected releasingly to the top cover. The inner body displays a longitudinally directed through-going channel, preferably with a gasket near one of its longitudinal ends, and comprises a first longitudinal part slideably arranged within the lop cover and a second longitudinal part that may be guided into a casing tubular. One or more radially displaceable clamps is connected to the lower part of the casing tool for engaging the inside wall of the casing tubular. The radial displacement of the clamps is achieved by use of radial displacement means.

Description:
TECHNICAL FIELD 
       [0001]    The present invention concerns a casing tool and a method for connecting casing tubulars using a top drive as disclosed in the introductory part of the main claims. More specifically the invention concerns at casing tool that may be releasably fixed to a top drive in a drilling derrick for interconnecting casing tubulars, i.e. casings inserted into drilling holes for hydrocarbon productions. 
       BACKGROUND AND PRIOR ART 
       [0002]    Particularly in oil and gas industry, sections of casing tubulars are being interconnected and inserted into a borehole to achieve the extended length of the borehole lining. To avoid that the interconnected casing string falls into the well while adding a new section, the slips of a spider located on the floor of the drilling platform are often used. The new section or stand of casing is then moved from a rack to the well centre above the spider. The treaded pin of the section of casing tubular to be connected is then located over the threaded box of the casing in the well and the connection is made up by rotation there between. An elevator is then connected to the top of the new section and the whole casing string is lifted slightly to enable the slips of the spider to be released. The whole casing string is then lowered until the top of the section is adjacent the spider whereupon the slips of the spider are re-applied, the elevator disconnected and the process repeated. 
         [0003]    It is well known to use a power tong or similar turning means to torque the connection up to a predetermined torque in order to make the connection. These turning means located on the platform, either on rails, or hung from a drilling derrick on a chain, constitute often large and complex machineries which require a considerable amount of space and maintenance. 
         [0004]    In the last decades use of top drive has been common in order to perform the interconnection of casing tubulars with sufficient torque strength. This type of operations requires the use of a dedicated tool that may connect to the top drive in one longitudinal end and may engage with the casing tubular at the other end so that the casing tubular can be rotated and lifted/lowered in to/out of the bore hole. An example of connecting tubular sections using a top drive and a corresponding casing tool is disclosed in publication WO 00/05483. This casing tool comprises a plurality of gripping elements that are radially displaceable by hydraulic or pneumatic fluid in order to drivingly engage the tubular section. This again permits a screw connection between the engaged tubular section and a further tubular section with the required torque. Another example of a top drive and a casing tool is found in publication WO 2006/116870 A1 disclosing a casing tool comprising a body assembly and a gripping assembly with a grip surface adapted to move from a retracted position to an engaged position to radially engage a work piece in response to relative axial displacement, the latter being activated by relative rotation within the tool. Further, publication U.S. Pat. No. 8,454,066 B2 discloses a tool for moving rigid spokes arranged in close fitting relation with spike guides on an annular body to allow for radial movements only between a retracted position and an engaged position. 
         [0005]    Common for the prior art casing tools of the type described above is the use of either hydraulic or pneumatic fluid or relative rotation within the tool, in order to initiate and complete the process of engaging the tool to the casing tubular. This increases the complexity of the tool, thus releasing important undesired aspects such as higher production cost and higher degree of maintenance. 
         [0006]    There is therefore a need to mitigate the disadvantages with the existing systems and to reduce the investments in extra equipment. 
         [0007]    It is thus an object of the present invention to present a solution providing an easier and more cost effective activation of the engagement between the tool and the casing tubular, and which also fulfills the requirements of robustness and reliability. Another object of the invention is to provide an engagement mechanism that may be easily released, both in normal operations and in case of certain mechanical malfunctioning. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention is set forth and characterized in the main claims, while the dependent claims describe other characteristics of the invention. 
         [0009]    In particular, the invention concerns a casing tool for connecting casing tubulars using a top drive. The casing tool comprises a top cover that may be connected either releasably or non-releasably to the top drive and an elongated inner body that may be connected releasingly to the top cover. The inner body displays a longitudinally directed through-going channel, preferably with a gasket near one of its longitudinal ends, and comprises a first longitudinal part slideably arranged within the top cover and a second longitudinal part that may be guided into a casing tubular. 
         [0010]    The casing tool further comprises a first sleeve arranged concentric and axial displaceable along at least part of the inner body at an axial distance (d) from the top cover, force transferring means for transferring a first external axial force (F 1 ) exerted on the top cover in directed towards the casing tubular at least partly to the first sleeve, at least one clamp connected radially displaceable to the first sleeve for engaging the inside wall of the casing tubular and radial displacement means extending at least partly along the second longitudinal part of the inner body for imparting radial displacement of at least one of the at least one clamp during relative axial displacement of the first sleeve and the inner body. The first external axial force (F 1 ) is preferably exerted after an obstruction of axial displacement of the inner body relative to the casing tubular 
         [0011]    In a preferred embodiment the casing tool further comprising a first impact means configured to abut the end of the casing tubing during insertion therein, where an obstruction of the axial displacement of the inner body relative to the casing tubular is ensured by connecting the first impact means to the inner body via the force transferring means, for example when the at least one clamp is in an engaging position. The first impact means may comprise a first impact face situated between the end of the first sleeve facing the top cover and the radial displacement means. Furthermore, the first impact means may be connected by connection means to an outer enclosure radially enclosing at least the end of the first sleeve facing the top cover and the force inducing means. 
         [0012]    In another preferred embodiment the force transferring means comprises a second sleeve arranged adjacent to the end of the top cover facing the second longitudinal part and at least one locking means arranged in contact with the axial end of the first sleeve facing the top cover, wherein the force transferring means is configured so that an axial force on the second sleeve activates a mainly casing tubing directed axial displacement of the at least one locking means. 
         [0013]    The at least one locking means may comprise at least one pivot arm, where an axial force on the second sleeve causes a mainly outward oriented radial displacement of a first arm of the pivot arm and a mainly casing tubing directed axial force from the second arm of the pivot arm. The second arm may be either in direct or indirect contact with the first sleeve. The second sleeve may further comprise a third sleeve and an annular body connected to an axial end of the third sleeve facing the second longitudinal part and radially abutting a contact face of the first arm of at least one pivot arm, wherein the annular body comprises a radial projection configured to impose the outward directed radial displacement of the first arm during axial displacement of the second sleeve. 
         [0014]    Alternatively the at least one locking means may comprise at least one lockable wheel and a lower sleeve, wherein an axial force on the second sleeve causes a release of the at least one lockable wheel and a mainly casing tubing directed axial force from the lower sleeve. 
         [0015]    In another preferred embodiment the first sleeve comprises an inner tubing extending at least across the radial displacement means situated on the inner body and a flange or collar connected to the end of the inner tubing facing the top cover. The outer diameter of the flange is larger than the outer diameter of the inner tubing. 
         [0016]    In another preferred embodiment the first sleeve displays at least one clamp fitting recess, wherein each recess is configured to allow its corresponding clamp to be displaced in the radial direction only after assembly. 
         [0017]    In another preferred embodiment the radial displacement means comprises at least one first tapered face. Furthermore, the at least one of the at least one clamp may comprise at least one second tapered face facing the at least one first tapered face. 
         [0018]    In another preferred embodiment the axial end of the top cover facing the second longitudinal part and the axial end of the force transferring means facing the top cover, for example the axial end of the third sleeve, are configured as interacting cam bodies allowing interconnection by rotation. This interconnection may for example be obtained by exerting an external axial force (F) that causes the contact face of the first arm to supersede the radial projection. The interacting cam bodies are advantageously configured to allow a top cover directed axial displacement of the second sleeve when the interacting cam bodies are rotated into the interconnected state and a third external axial force (F 3 ) directed towards the casing tubing is exerted on the top cover. This axial displacement of the second sleeve causes the at least one clamp to release the radial force on the casing tubular set up by the radial displacement during engagement. For example, the displacement may cause the second sleeve to axially disconnect from the at least one pivot arm. 
         [0019]    In another preferred embodiment the casing tool further comprising at least one second sleeve connected release mechanism configured to allow a top cover directed axial displacement of the second sleeve. For example, the axial displacement may cause the second sleeve to disconnect from the at least one pivot arm. 
         [0020]    The invention also concerns a method using a casing tool in accordance with the above mentioned characteristics. The method comprising the following steps:
       inserting the second longitudinal part of the inner body a predetermined length into the casing tubular, the length being set by a first impact means connected to the inner body to hinder axial displacement of the inner body relative to the casing tubular and   exerting a first casing tubular directed external axial force (F 1 ) on the top cover causing equally directed axial displacements of the top cover, the first sleeve and the at least one clamp,   whereby engagement of the casing tool with the casing tubular is achieved by interaction with the radial displacement means imparting radial displacement of at least one of the at least one clamp during said axial displacements.       
 
         [0024]    In other to achieve an additional engagement of the at least one of the at least on clamp the method may further comprise the step:
       releasing the first casing tubular directed external axial force (F 1 ) on the top cover,   exerting a second external axial force (F 2 ) directed opposite to the first external axial force (F 1 ),       
 
         [0027]    thereby exerting a second external axial force directed tension on the inner body, creating an increase in the relative axial force between the dies and the inner body. 
         [0028]    To release the engagement between the casing tool and the casing tubular the following steps may be performed:
       exerting a third external axial force (F 3 ) on the top cover in direction of the casing tubular causing equally directed axial displacements,   rotating the top cover (either subsequent to the axial displacement or simultaneously), thereby achieving an interconnected assembly comprising the top cover, the second sleeve and the inner body and   raising the assembly, causing a top cover directed axial displacement of the first sleeve and the at least one clamp. The latter step releases the engagement of the clamp(s) by interaction with the radial displacement means.       
 
         [0032]    An alternative or additional way of releasing the engagement between the casing tool and the casing tubular is obtained by performing the following step:
       activating at least one second sleeve connected release mechanism causing a top cover directed axial displacement of the first sleeve and at least one of the at least one clamp, thereby releasing the engagement between the casing tool and the casing tubular through interaction with the radial displacement means.       
 
         [0034]    In the following description, numerous specific details are introduced to provide a thorough understanding of embodiments of the claimed tool and method. One skilled in the relevant art, however, will recognize that these embodiments can be practiced without one or more of the specific details, or with other components, systems, etc. In other instances, well-known structures or operations are not shown, or are not described in detail, to avoid obscuring aspects of the disclosed embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS: 
         [0035]      FIG. 1  is a perspective view of the casing tool in accordance with a first embodiment of the invention showing the tool in engaged position, 
           [0036]      FIG. 2  is a radial view of the casing tool in accordance with  FIG. 1  showing the engaged tool inserted into a casing tubular, 
           [0037]      FIG. 3  is a cross sectional view of the casing tool along section A-A of  FIG. 2 , 
           [0038]      FIG. 4  is a radial view of the casing tool in accordance with  FIG. 1  with the outer enclosure removed, 
           [0039]      FIG. 5  is a cross sectional view of the casing tool along section A-A of  FIG. 4 , 
           [0040]      FIG. 6  is a cross sectional view of the casing tool along section B-B of  FIG. 5 , 
           [0041]      FIG. 7  is a cross sectional view of the casing tool along section C-C of  FIG. 5 , 
           [0042]      FIG. 8  is a cross sectional view of the casing tool in accordance with the invention, showing the end of the tool inserted into the casing tubular, 
           [0043]      FIG. 9  is a schematic view showing the principals of converting axial displacement of the dies into radial displacement using tapered faces, wherein  FIG. 9( a )  is showing the initial engagement due to movement of the die and  FIG. 9( b )  is showing the additional engagement due to opposite directed tensioning of the inner body, 
           [0044]      FIG. 10  is a radial view of the casing tool in accordance with a second embodiment of the invention showing the tool in engaged position, 
           [0045]      FIG. 11  is a cross sectional view of the casing tool along section A-A of  FIG. 10 , 
           [0046]      FIG. 12  is a cross sectional view of the casing tool along a section perpendicular to section A-A of  FIG. 10  relative to the tools axial axis and 
           [0047]      FIG. 13  is a cross section view of the casing tool along a section D-D of  FIG. 12 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0048]    In the following to different embodiments will be disclosed, where both embodiments are based on the following general concept (see for example  FIGS. 1-4  and  FIGS. 10-12 ): After inserting a tool  1  into the casing tubular  4 , 5  the dies  34  on the sleeve  8  engage the inner wall of the lower tubular  6 ″ by relative (non-rotational) axial displacements of the zigzag patterns  9 , 9 ′ in response to a downward directed axial force. The through-going fluid channel  27  and the rubber gasket  7  allows leak free circulation of fluid, rendering fluid flow into the casing tubular  4 , 5  possible. A subsequent upward directed force strengthens this die engagement. Release of the tool  1  from the casing  4 , 5  may be performed by a combination of axial force and rotational force. 
       First Embodiment 
       [0049]      FIG. 1  shows one embodiment of the casing tool  1  in a perspective view, while  FIGS. 2 and 3  show the same casing tool  1  as in  FIG. 1  in a radial view and a cross sectional view along section A-A, respectively, after completing an engaging insertion into a casing tubular  4 . In the following the terms upper and lower signify the orientation from and to the casing tubular  4 , respectively. Furthermore, the terms outward and inward signify the radial orientation from and to the center of the tool  1 , respectively. 
         [0050]    With reference to  FIGS. 2-7  the particular embodiment of the inventive tool  1  comprises the following main components:
       a top drive part  2  having upper threads in order to connect to a top drive (not shown),   an upper cam body  18  and a lower cam body  16 , which bodies  16 , 18  may be connected and disconnected by simple rotations clockwise and counterclockwise,   lower threads  29  for connecting the top drive part  2  and the upper cam body  18 ,   an inner tubular  6  comprising an upper tubular  6 ′ situated mainly within the top drive part  2  and the upper cam body  18  and a lower tubular  6 ″ situated mainly within the casing tubular  4  after complete engagement,   a through-going fluid channel  27  extending throughout the entire length of the inner body  6 ,   an upper impact piece  20  ( FIG. 5 ) connected to the upper tubular  6 ′ with a lock ring  21  and situated within an annular cavity formed by the top drive part  2 , the upper cam body  18  and the upper tubular  6 ′,   upper gear teeth  42  ( FIG. 6 ) surrounding the upper tubular  6 ′ and situated within a cavity formed by the top drive part  2  and the upper tubular  6 ′,   lower gear teeth  40  ( FIG. 7 ) surrounding the inner tubular  6  and situated within the lower cam body  16 ,   first cam springs  26  interconnecting the upper and lower cam bodies  18 , 16 ,   second cam springs  17  interconnecting the lower cam bodies  16  and the top drive part  2 ,   an annular spring  14 , 14 ′ having an outward oriented bulge or protrusion  14 ′,   a lower impact piece  10  configured to abut the threaded part  5  of the casing tubular  4 , 5  after insertion,   a plurality of pivot arms  12  comprising a long arm  12 ′, a short arm  12 ″ and a pivot point in form of a bolt  13  fixed to the lower impact piece  10 ,   a sleeve  8  having a flange  11  at its upper end and die recesses at its lower end,   flange springs  25  interconnecting the lower impact piece  10  and the flange  11 ,   an outer enclosure  3  fixed to the lower impact piece  10  by screws  24  and surrounding the above mentioned components up to the top drive part  2 ,   a plurality of dies  34  arranged within the die recesses, where each die  34  comprises an elastomeric contacting face  19  at its outward directed radial surface and a die zigzag pattern  9 ″ at its inward directed radial surface,   tubular zigzag pattern  9 ′ at the outer wall of the lower tubular  6 ″, wherein the tubular zigzag pattern  9 ′ and the die zigzag pattern  9 ″ form mirror patterns,   rubber gasket  7  arranged below the dies  34  ensuring a fluid tight seal between the inner wall of the casing tubular  4  and the lower tubular  6 ″,   tilting levers  35  connected at one end underneath the lower cam body  16  and at the other end to sheaves  31  via bolt connections  22  and   lever screws  23  situated in the sheaves  31 .       
 
         [0072]    The top components comprising the top drive part  2 , the upper cam body  18 , the upper impact piece  20 , the lock ring  21  and the upper gear teeth  42  form an assembly called a top cover  100 . Further, the mid components comprising lower cam body  16 , the lower gear teeth  40 , the annular spring  14 , 14 ′ and the pivot arms  12  form an assembly called a force transferring means  200 . 
         [0073]    Initially the tool  1  is lowered into the casing tubular  4 , 5  until its threaded part  5  abuts the lower impact piece  10 , the latter being fixed to the outer enclosure  3 . In this starting position the abutting impact piece  10  prevents any downward axial displacement of the inner tubular  6  since the bulge  14 ′ in the annular spring  14  is located above a contacting face  15  at the end of the long arm  12 ′ of each pivot arm  12 . Further, the end of the short arm  12 ″ below the pivot point bolt  13  is contacting the upper axial face of the sleeve&#39;s  8  flange  11 , the latters being arranged concentrically around the inner tubular  6 . In the lower half of the sleeve  8  there are arranged die recesses configured to allow only radial displacements of the dies  34  when installed. 
         [0074]    In this particular starting position exertion of axial forces on the tool  1  cause corresponding axial displacements of the top drive part  2 , the upper impact piece  20  and upper cam body  18 . In absence of any rotation the upper cam body  18  will impact the lower cam body  16  in an impact point  32  ( FIG. 4 ), causing an axial force to be exerted also on the lower cam body  16  and the connected annular spring  14 . If this latter force is sufficient to overcome the radial spring force exerted by the long arm  12 ′ on the annular spring  14 , the bulge  14 ′ will move the arm  12 ′ radially outwards. An axial pressure is thus imparted on the flange  11  by the short arm  12 ″ causing the sleeve  8  and the attached dies  34  to be axially displaced. Finally, the mirrored zigzag patterns  9 , 9 ′ on the dies  34  and the lower tubular  6 ″ force the dies  34  radially outwards. The desired clamping of the dies  34  onto the inner walls of the inner tubular  6  is thereby achieved. The lower gear teeth  40  ensure that the lower cam body  16  is only displaced in the axial direction. Flange springs  25  may be arranged between the flange  11  and the lower impact piece  10  in order to re-position the sleeve  8  and the flange  11  when the dies  34  are released from the inner tubular  6 . 
         [0075]    When the contacting surface  15  of the long arm  12 ′ has passed the center of the bulge  14 ′ the pivot arms  12  are in a locked position relative to the annular spring  14 , the lower cam body  16  and the inner tubular  6 . In absence of any rotation the upper cam body  18  and the top drive part  2  may in this pre-tensioning situation be lifted up until impact occurs between the upper cam body  18  and the upper impact piece  20 . Exertion of any further upwards directed force would thus be transferred to the lower tubular  6 ″, causing a larger axial force and thus an additional clamping/tensioning force onto the inner walls of the casing tubular  4  from the dies  34 . 
         [0076]    It is emphasized that both the initial clamping and the additional clamping are performed without any rotational movements of the tool  1 . 
         [0077]    Release of the tool  1  from the casing tubular  4  may be achieved by lowering the top drive part  2  and the upper cam body  18  applying a downward directed force, while enforcing a counterclockwise rotation. The latter rotation forms an interconnection between the upper cam body  18  and the lower cam body  16  in contrast to simple impact  32  in absence of rotation. During rotation upper cams  33  with upward directed inclined planes  37  at the lower part of the upper cam body  18  are meshing with corresponding inclined planes  37 ′ on the upper part of the lower cam body  16 , thereby lifting the latter axially upwards. Due to the axial displacement of the now interconnected bodies  16 , 18  the long pivot arm  12 ′ looses its grip with the annular spring  14 , thus releasing the tool  1  from the casing tubular  4 . Upper gear teeth  42  arranged between the top drive part  2  and the upper cam body  18  are configured to mesh with the top drive part  2  when impact  30  exists (or about to take place) between the upper cam body  18  and the upper impact piece  20 , i.e. when the top drive part  2  is in its upper position. Further, arrangement of the first cam springs  26  ensure that such an impact  30  prevails in the absence of downward directed axial force (F). The impact piece  20  may be fixed by a locking ring  21 . The second cam springs  17  ensure positioning of the top drive part  2  relative to the lower cam body  16 . 
         [0078]    To be able to release the tool  1  manually, e.g. in case of any loss of rotational freedom between the two cam bodies  16 , 18 , the tool  1  may be arranged with pivoting levers  35  connected underneath the lower cam body  16  in one end and sheaves/plates  31  fixed by bolts  34  at the other end. The plates  31  are fastened to the outer enclosure  3  by screws. To manually release the tool  1  dedicated release or lever screws  23  are inserted so that the pivoting levers  35  pivots around the bolts  34 , thereby pressing the lower arm radially inwards and the higher arm axially upwards. The lower cam body  16  experiences thus a corresponding axially displacement, thereby releasing the annular spring  14  from the pre-tensioning long arm  12 ′. The further mechanisms are identical to the regular release described above. 
         [0079]      FIG. 8  shows the axially displaceable sleeve  8 , the radially displaceable dies  34 , the engagement means  9 , 9 ′, 9 ″ and the rubber gasket  7  in further details. The displaced mirror configurations of the zigzag patterns constituting the engagement means is apparent. Due to the sliding action on each or some of the tapered surfaces any axial displacement of either the lower tubular  6 ″ or the sleeve  8  results in a radial displacement of the dies  34 . The same effect is achieved by any relative axial displacement between these two objects  6 ″. 8 . The principle of converting axial displacement of the dies  34  into radial displacement using tapered faces is better illustrated in  FIGS. 9( a ) and 9( b ) . For the sake of clarity only one tapered surface  9 ′ on the lower tubular  6 ″ and only one contacting tapered surface  9 ″ on the die  34  is shown. When the sleeve  8  is displaced downward (in direction towards the casing tubular), the tapered surface  9 ″ glides on the mirrored tapered surface  9 ′, thereby pressing the contacting layer  19  of the die  34  towards the inside wall of the casing tubular  4  (see  FIG. 9( a ) ). Likewise, when the inner tubular  6  experiences a force directed towards the top drive, the tapered surface  9 ′ glides on the tapered surface  9 ″, causing an equally directed pressing of the contacting layer  19  towards the inner wall of the casing tubular  4  (see  FIG. 9( b ) ). The situation shown in  FIGS. 9( a ) and ( b )  corresponds to the pre-tensioning force and the additional tensioning force described above. 
       Second Embodiment 
       [0080]      FIGS. 10-13  illustrate a second embodiment of the inventive casing tool  1 , where  FIG. 10  shows the casing tool inserted into a casing as viewed in a radial direction. Further,  FIGS. 11 and 12  shows a cross sectional view along a section A-A of  FIG. 10  and a cross sectional view along a section perpendicular to section A-A relative to the axial axis, respectively, and  FIG. 13  shows a cross sectional view along a section D-D of  FIG. 12 . 
         [0081]    The second embodiment of the inventive tool  1  comprises the following main components:
       a top drive part  2  having threads in order to connect to a top drive (not shown),   an upper cam body  18  and a lower cam body  16 , which bodies  16 , 18  may be connected and disconnected by simple rotations clockwise and counterclockwise,   an inner tubular  6  comprising an upper tubular  6 ′ situated mainly within the top drive part  2  and the upper cam body  18  and a lower tubular  6 ″ situated mainly within the casing tubular  4  after complete engagement,   a through-going fluid channel  27  extending throughout the entire length of the inner body  6 ,   an upper impact piece  20  connected to the upper tubular  6 ′ with a lock ring  21  and situated within an annular cavity formed by the top drive part  2 , the upper cam body  18  and the upper tubular  6 ′,   upper gear teeth  42  surrounding the upper tubular  6 ′ and situated within a cavity formed by the top drive part  2  and the upper tubular  6 ′,   lower gear teeth  40  (corresponding to  FIG. 7  of embodiment 1) surrounding the inner tubular  6  and situated within the lower cam body  16 ,   first cam springs  26  interconnecting the upper and lower cam bodies  18 , 16 ,   a mid sleeve  51  surrounding the inner tubular  6  and the lower cam body  16 ,   a lower impact piece  10  fixed by screws  59  to the mid sleeve  51  and configured to abut the threaded part  5  of the casing tubular  4 , 5  after insertion,   second cam springs  17  interconnecting the mid sleeve  51  and the top drive part  2 ,   releasable wheels  52  situated within recesses along the radial surface of the lower cam body  16 ,   triangular brackets  53  fixed to the releasable wheels,   a lower sleeve  54  surrounding the inner tubular  6  underneath the lower cam body  16 ,   elongated brackets  55  fixed to the triangular brackets  53  in a first longitudinal end and to the lower sleeve  54  in a second longitudinal end,   a sleeve  8  having a flange  11  at its upper end and die recesses at its lower end,   an inner tubular flange  56  radially extending from the inner tubular  6  between the lower cam body  16  and the flange  11 , wherein the inner tubular flange  56  is fixed to the mid sleeve  51  by screws  57 ,   lower sleeve springs  58  interconnecting the flange  11  and the lower sleeve  54 .   flange springs  25  interconnecting the lower impact piece  10  and the flange  11 ,   a plurality of dies  34  arranged within the die recesses, where each die  34  comprises an elastomeric contacting face  19  at its outward directed radial surface and a die zigzag pattern  9 ″ at its inward directed radial surface,   tubular zigzag pattern  9 ′ at the outer wall of the lower tubular  6 ″, wherein the tubular zigzag pattern  9 ′ and the die zigzag pattern  9 ″ form mirror patterns,   rubber gasket  7  arranged below the dies  34  ensuring a fluid tight seal between the inner wall of the casing tubular  4  and the lower tubular  6 ″, and   lever screws  23  having one end fixed with their screw head situated underneath the flange  11  and the other end arranged underneath the inner tubular flange  56 .       
 
         [0105]    As for the first embodiment the top components comprising the top drive part  2 , the upper cam body  18 , the upper impact piece  20 , the lock ring  21  and the upper gear teeth  42  form the assembly called the top cover  100 . Further, the mid components comprising lower cam body  16 , the lower gear teeth  40 , the mid sleeve  51 , the releasable wheels  52 , the triangular brackets  53 , the lower sleeve  54 , the elongated brackets  55 , the inner tubular flange  56  and the lower sleeve springs  56  form the assembly called the force transferring means  200 . 
         [0106]    Initially the tool  1  is lowered into the casing tubular  4 , 5  until its threaded part  5  abuts the lower impact piece  10 . In this starting position the abutting impact piece  10  prevents any downward axial displacement of the inner tubular  6  since the impact piece  10  is coupled to the inner tubular  6  by the screws  57  and also to the lower cam body by the locked wheels  52 . Exertion of axial forces on the tool  1  in direction of the casing tubular  4 , 5  cause corresponding axial displacements of the top drive part  2 , the upper impact piece  20  and upper cam body  18 . In absence of any rotation the upper cam body  18  will impact the lower cam body  16  in an impact area  32 , causing an axial force to be exerted also on the latter  16 . The force will release the wheel  52  which again causes the lower end of the lower cam body to impart downward directed pressure on the inner tubular flange  56 . Further, the inner tubular flange  56  abuts the lower sleeve  54 , creating the axial pressure on the flange  11  and thus the zigzag pattern induced radial displacement of the dies  34 . The flange springs  25  and the lower sleeve springs  56  arranged between the flange  11  and the lower impact piece  10  and between the flange  11  and the lower sleeve  54 , respectively, ensure re-positioning of the sleeve  8  and the flange  11  when the dies  34  are released from the inner tubular  6  (see below). 
         [0107]    In absence of any rotation the upper cam body  18  and the top drive part  2  may in this pre-tensioning situation be lifted up until impact occurs between the upper cam body  18  and the upper impact piece  20 . Exertion of any further upwards directed force would thus be transferred to the lower tubular  6 , causing a larger axial force and thus an additional clamping force onto the inner walls of the casing tubular  4  from the dies  34  in the same way as for the first embodiment. 
         [0108]    Note that both the initial pre-tensioning clamping and the additional clamping are performed without any rotational movements of the tool  1 . 
         [0109]    Release of the tool  1  from the casing tubular  4  may be achieved by lowering the top drive part  2  and the upper cam body  18  applying a downward directed force, and subsequently enforcing a counterclockwise (or alternatively clockwise) rotation. The latter rotation forms an interconnection between the upper cam body  18  and the lower cam body  16  in contrast to simple impact  32  in absence of rotation. During rotation upper cams  33  with upward directed inclined planes  37  at the lower part of the upper cam body  18  are meshing with corresponding inclined planes  37 ′ on the upper part of the lower cam body  16 , thereby lifting the latter axially upwards (see  FIG. 4 ). Due to the axial displacement of the now interconnected bodies  16 , 18  and the locking of the wheels  52  inside their respective recesses on the lower cam body  16 , the component constituting the force transferring means  200  releases the pressure on the flange  11  causing a further spring induced  25 , 58  release of the dies  34  from the casing tubular  4 , 5 . Upper gear teeth  42  may be arranged between the top drive part  2  and the upper cam body  18  that are configured to mesh with the top drive part  2  when impact  30  exists (or about to take place) between the upper cam body  18  and the upper impact piece  20  (see  FIG. 5 ), i.e. when the top drive part  2  is in its upper position. Further, arrangement of the first cam springs  26  ensure that such an impact  30  prevails in the absence of downward directed axial force (F). 
         [0110]    The second cam springs  17  ensure positioning of the top drive part  2  relative to the lower cam body  16 . 
         [0111]    To be able to release the tool  1  manually, e.g. in case of any loss of rotational freedom between the two cam bodies  16 , 18 , the tool  1  may be arranged with dedicated release screws  23  fastened underneath the flange  11 , going through dedicated holes in the lower sleeve  54 . By inserting suitable tools into aligned passages  60  into the lower impact access is gained to the release screws  23 . A Clockwise directed turns of these screws  23  cause the screw ends to abut underneath the inner tubular flange  56 , which again causes an upwards movement of the component constituting the force transferring means  200  and the inner tubing  6 . The further mechanisms are identical to the regular release described above. 
         [0112]    In the preceding description, various aspects of the apparatus according to the invention have been described with reference to the illustrative embodiment. For purposes of explanation, specific numbers, systems and configurations were set forth in order to provide a thorough understanding of the apparatus and its workings. However, this description is not intended to be construed in a limiting sense. Various modifications and variations of the illustrative embodiment, as well as other embodiments of the apparatus, which are apparent to persons skilled in the art to which the disclosed subject matter pertains, are deemed to lie within the scope of the present invention.