Abstract:
A percussion apparatus and method of using the percussion apparatus. The apparatus may be used for delivering an impact to a tubular string. The apparatus comprises a cylindrical member having an internal bore containing an anvil and a first guide profile. The apparatus further includes a rotor disposed within the internal bore, and wherein the rotor member comprises a body having an outer circumference with a second guide profile thereon, and wherein the rotor contains a radial hammer face. In a first position, the second external guide profile of the rotor will engage with the first guide profile of the cylindrical member so that the radial hammer face can contact the anvil. In a second position, the second guide profile of the rotor will engage with the first guide profile of the cylindrical member so that the radial hammer face is separated from the anvil shoulder. Multiple rotors and multiple stators may be employed. The rotor may be operatively associated with a stator that directs flow into the rotor. The rotor may be comprised of a plurality of inclined blades. The percussion apparatus may be incorporated into a tubular string and used for multiple purposes within a well bore. For instance, a method of cementing a well with the percussion apparatus is disclosed.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates to a device and a method for delivering an impact or a force to a device. More particularly, but not by way of limitation, this invention relates to a percussion apparatus used with tubular members.  
           [0002]    Rotary bits are used to drill oil and gas well bores, as is very well understood by those of ordinary skill in the art. The monetary expenditures of drilling these wells, particularly in remote areas, can be a very significant investment. The daily rental rates for drilling rigs can range from a few thousands dollars to several hundreds of thousands of dollars. Therefore, operators have requested that the well bores be drilled quickly and efficiently.  
           [0003]    Prior art drill bits include, for instance, the tri-cone rotary bit. The tri-cone bit has been used successfully for many years. The rock will be crashed by the impact of the tri-cone buttons. Also, the PDC bit (polycrystalline diamond compact bit) has been used with favorable success. The PDC cutters do not crash, but will shear off the rock. Both bit types have their advantages, nevertheless tri-cone bits, utilizing the crashing action, are more universally useable. Therefore, attempts have been made to enhance the impact and hence the crashing action utilizing separate impact and/or jarring tools in order to drill wells or as an aid in drilling wells. However, those attempts have been largely case limited, non-economical, or unsuccessful.  
           [0004]    Therefore, there is a need for a device that can deliver an impact and a force to a drilling tool, like a bit. There is a further need for a percussion-impacting tool that can be placed within a work string that will aid in the drilling and remedial work of wells. Further an impacting tool is needed that will aid to move a work string. There is also a need for a percussion-impacting tool that can be placed inside a tubular, for cleaning out the tubular. There is an additional need for percussion-impacting tools that can support compacting actions for cementing casing and tubing in well bores and others. These, and many other needs, will be met by the following invention.  
         SUMMARY OF THE INVENTION  
         [0005]    A tool for delivering an impact and a force is disclosed. The tool comprises a cylindrical member having an internal bore, with the internal bore containing an anvil shoulder and a first guide profile. The tool further includes a first rotor disposed within the internal bore, and wherein the first rotor comprises a body having an outer circumference with a second guide profile thereon and an internal portion, and wherein the first rotor contains a radial hammer face. In a first position, the second external guide profile of the first rotor will engage with the first helical guide profile of the cylindrical member so that the radial hammer face can contact the anvil shoulder. In a second position, the second guide profile of the first rotor will engage with the first guide profile of the cylindrical member so that the radial hammer face is separated from the anvil shoulder.  
           [0006]    In one embodiment, the internal bore of the cylindrical member contains a third guide profile and a second anvil shoulder. The tool further comprises a second rotor disposed within the internal bore, and wherein the second rotor comprises a body having an outer circumference with a fourth guide profile thereon, and wherein the second rotor member contains a second radial hammer face.  
           [0007]    The fourth guide profile of the second rotor will engage with the third thread profile of the internal bore so that the second radial hammer face contacts the second anvil shoulder. The fourth guide profile of the second rotor will engage with the third guide profile of the internal bore so that the second radial hammer face is separated from the second anvil shoulder.  
           [0008]    In the preferred embodiment, the first rotor further comprises a plurality of blades. The blades are arranged so that a flow stream therethrough will cause a rotation of the rotor. The flow stream may be either in a liquid, or gaseous state, or a combination of both.  
           [0009]    The tool may further comprise a stator positioned within the internal bore, with the stator positioned to direct the flow stream to the first rotor. In the preferred embodiment, the stator comprises a cylindrical member having a plurality of blades disposed about a central core, and wherein the plurality of blades of the stator directs the flow stream to the first rotor so that the first rotor rotates.  
           [0010]    A method of delivering an impact and a force to a tool is also disclosed. The method includes providing a device for delivering an impact or force to the tool, the device comprising a member having an internal bore with a first guide profile; a rotor disposed within the internal bore, and wherein the rotor comprises a body having an outer circumference with a second guide profile thereon, and wherein the rotor contains a radial hammer face. The method further includes flowing a flow stream down the internal bore and then flowing the flow stream through the internal portion of the rotor. The flow stream may be in a liquidized or gaseous state, or a combination of both. The rotor is rotated by the flow stream flowing therethrough.  
           [0011]    Next, the first guide profile is engaged with the second guide profile so that the rotor travels in a direction opposite the flow of the flow stream. The rotor continues to rotate via the flow stream flowing therethrough. The first guide profile and the second guide profile engage so that the rotor travels in the same direction as the flow of the flow stream. When traveling in the same direction as the flow stream, the radial hammer face impacts against an anvil of the member having the internal bore. The radial hammer face of the rotor can also hit an anvil that is connected to any kind of tool like a bit when traveling in the same direction as the flow stream. Put another way, the rotor travels in an oscillating mode along the central axis of the member having the internal bore caused by the engagement between the first guide profile with the second guide profile.  
           [0012]    The method further comprises continuing to flow the flow stream down the internal bore and through the rotor which in turn rotates the rotor by flowing the flow stream therethrough. The first guide profile and the second guide profile are engaged so that the rotor travels in a direction opposite the flow of the flow stream. As the flow stream continues to be flown, the rotor continues to rotate which in turn continues to engage the first guide profile with the second guide profile so that the rotor travels in the same direction as the flow of the flow stream, and the radial hammer face will, in turn, impact against the anvil.  
           [0013]    In one of the preferred embodiments, the tubular member is connected to a drill bit member and the method further comprises drilling the well bore by percussion impacting of the radial hammer face against the anvil. In another of the preferred embodiments, the percussion sub is axially connected to a drill bit member. Alternatively, for example, the tubular member may be connected to an object stuck in a well, and the method further comprises jarring the object by percussion impacting of the radial hammer face against the anvil.  
           [0014]    In yet another embodiment, a tool for delivering an alternating force is dislcosed. The tool in this embodiment comprises a first member having an opening and first profile, with the first member having a first area thereon. A second member is disposed within the opening of the first member, with the second member containing a second profile, and a second area. The second member has a first position relative to the first member wherein the first profile cooperates with the second profile so that the second area contacts the first area. The second member has a second position relative to the first member wherein the first profile cooperates with the second profile so that the second area is separated from the first area. In one embodiment, the second member is a rotor, and wherein the rotor contains a plurality of blades disposed about a center core and wherein the plurality of blades turn in response to a flow stream flowing there through. Also, the first area may be an anvil shoulder, and the second area may be a hammer. In a preferred embodiment, the first member is a cylindrical member.  
           [0015]    In yet another preferred embodiment, a tool for vibrating a cement slurry within a well bore is disclosed. The well bore will have a concentric casing string therein. The tool includes a first member attached to a cementing shoe, the cementing shoe being disposed at an end of the casing string. The first member has an anvil and a first profile thereon. The tool further contains a rotor disposed within the first member, with the rotor having a second profile and a hammer, and wherein the rotor is disposed to receive the cement slurry pumped down an inner portion of the casing string. The first profile will cooperate with the second profile, in a first position, so that the hammer contacts the anvil. The first profile further cooperates with the second profile, in a second position, so that the hammer is separated from the anvil. This oscillating movement of the rotor vibrates the cement slurry. In one embodiment, the rotor contains a plurality of blades disposed about a center core and wherein the blades turn in responsive to the cement slurry flowing there through. A stator may be included in order to direct the cement slurry into the blades of the rotor. In the preferred embodiment, the first member is a cylindrical member attached to the casing string within the well bore. A shock module member may be included, with the shock module member being operatively associated with the rotor.  
           [0016]    The described percussion tool can be described more particularly, but not by way of limitation, as a percussion sub. An advantage of the presented percussion subs in drill strings will result in increase rates of drilling penetration. Another advantage is that the percussion sub may be used to free work strings that become stuck in a well. Still yet another advantage is that the percussion sub of the present invention can obtain very high vibration frequencies. For instance, frequencies of 20 Hz are possible.  
           [0017]    Another advantage is that numerous configurations of the percussion sub are possible within a work string. For example, the percussion sub can be used in a drill string as an addition to existing drilling equipment; or the percussion sub used as a stand alone tool; or the percussion sub can be placed in more than one position in the drill string; or the percussion sub can be combined in series with more than one percussion subs. The percussion sub can also be an integral member of any other apparatus connected to a work string in order to function as a percussion tool.  
           [0018]    Another advantage is that the percussion sub can also be used in a drill string with a rotary steerable assembly. Yet another advantage is that the percussion sub can be placed in a drill string having a motor or a turbine assembly. Still another advantage is that the percussion tool can be used to cement casing within a well bore.  
           [0019]    A feature of the present invention includes use of a turbine type of design that utilizes a plurality of rotator blades. The flow stream flows through the internal portion of the rotor, through the blades so that the rotor rotates. Another feature is the rotor will have disposed thereon a guide profile that cooperates with a reciprocal guide profile that allows for a raised and lowered position. In one embodiment, the guide profile is on the outer circumference of the rotor, while in another embodiment, the guide profile is contained on an internal portion.  
           [0020]    Another feature is that the flow through the internal bore of the percussion sub activates the percussion sub. The flow stream can be a liquid, a gas, a liquid stream with solids, a gas stream with solids, or a mixture of liquids, gas and solids. Still yet another feature is that the operator can control the frequency of the hammer striking the anvil by varying the pumping rate, by varying the guide profiles, by varying the number of rotors, or by varying the rotor arrangement. Yet another feature is that the operator can control the amount of impact of the hammer striking the anvil by varying the mud weight, by varying the guide profiles, by varying the blade design, or by varying the rotor weight. Still yet another feature is that the percussion sub will continue vibrating despite flow streams containing high solids contents.  
           [0021]    Yet another feature is that the only moving part is the rotor with blades therein. Another feature is the novel guide profiles. The cooperating guide profiles are highly dependable and results in a minimum of moving components. Still another feature is the percussion tool can be placed in a casing string with a cementing shoe and the percussion tool is used to cement the casing string within the well bore. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0022]    [0022]FIG. 1A is a top view of the rotor of the present invention.  
         [0023]    [0023]FIG. 1B is a cross-sectional view of the rotor from FIG. 1A taken along line A-A.  
         [0024]    [0024]FIG. 1C is a circumference view of the rotor seen in FIG. 1A.  
         [0025]    [0025]FIG. 2A is a top view of the sleeve of the present invention.  
         [0026]    [0026]FIG. 2B is a cross-sectional view of the sleeve from FIG. 2A taken along line A-A.  
         [0027]    [0027]FIG. 2C is a circumference view of the sleeve seen in FIG. 2A.  
         [0028]    [0028]FIG. 3A is a top view of the stator of the present invention.  
         [0029]    [0029]FIG. 3B is a cross-sectional view of the stator from FIG. 3A taken along line A-A.  
         [0030]    [0030]FIG. 4A is a cross-sectional view of the percussion bottom sub of the present invention.  
         [0031]    [0031]FIG. 4B is a top view of the percussion bottom sub.  
         [0032]    [0032]FIG. 5 is a cross-sectional view of the percussion top sub of the present invention.  
         [0033]    [0033]FIG. 6A is a partial cross-sectional view of the preferred assembled percussion sub shown in the raised position.  
         [0034]    [0034]FIG. 6B is a partial cross-sectional view of the preferred assembled percussion sub of FIG. 6A shown in the lowered position.  
         [0035]    [0035]FIG. 7A is a schematic illustration of a percussion sub embodiment having a rotor with external guide and an anvil.  
         [0036]    [0036]FIG. 7B is a schematic illustration of a laid out helical profile.  
         [0037]    [0037]FIG. 8 is a schematic illustration of another percussion sub embodiment having a rotor with internal guide and an anvil.  
         [0038]    [0038]FIG. 9 is a schematic illustration of another percussion sub embodiment having a rotor with external guide, a stator and an anvil.  
         [0039]    [0039]FIG. 10 is a schematic illustration of another percussion sub embodiment having multiple rotors with external guides, stators and anvils.  
         [0040]    [0040]FIG. 11 is a schematic illustration of another percussion sub embodiment having multiple rotors, stators, and anvils, whereby some stator function as anvils.  
         [0041]    [0041]FIG. 12 is a schematic illustration of another percussion sub embodiment having multiple rotors with more than one external guide and multiple stators functioning as anvils, whereby all the rotors are interconnected.  
         [0042]    [0042]FIG. 13 is a schematic illustration of another percussion sub embodiment having multiple rotors with one external guide and multiple stators functioning as anvils, whereby all the rotors are connected to each other.  
         [0043]    [0043]FIG. 14 is a schematic illustration of another percussion sub embodiment having multiple rotors, multiple stators, with an axial moveable bit attached thereto.  
         [0044]    [0044]FIG. 15A depicts a schematic illustration of the circumference view of the rotor engaging the sleeve in a raised position.  
         [0045]    [0045]FIG. 15B depicts the rotor and sleeve of FIG. 14A in a lowered position.  
         [0046]    [0046]FIG. 16 is a schematic illustration of the percussion sub positioned within a drill sting.  
         [0047]    [0047]FIG. 17A is schematic illustration of a prior art cementing technique.  
         [0048]    [0048]FIG. 17B is a schematic illustration of another preferred percussion sub embodiment. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0049]    Referring to FIG. 1A, a top view of the rotor  2  of the present invention will now be described. The rotor  2  comprises a generally cylindrical member having an outer wall  4  that extends radially inward to the internal portion  5 ; the rotor  2  contains a plurality of blades within the internal portion  5  (seen in FIG. 1B). Returning to FIG. 1A, the blades  6 ,  8 ,  10 ,  12 ,  14 ,  16 ,  18 ,  20  emanate from a center core  22 . The blades  6 - 20  are disposed with a certain angle or pitch, as will be fully set out later in the application.  
         [0050]    In FIG. 1B, a cross-sectional view of the rotor  2  from FIG. 1A taken along line A-A will now be described. It should be noted that like numbers appearing in the various figures refer to like components. As illustrated in FIG. 1B, the internal portion  5  has the center core  22 , with the center core  22  having extending therefrom the blade  14  extending to the outer wall  4 . The blade is attached at one end to the center core  22  and at the other end to the outer wall  4 . The center core  22  extends to the hammer radial face  23 . The rotor  2  has a first radial surface  24  that is essentially flat and a second radial surface  26 . The blade  14  has an angle of inclination of 45 degrees in the embodiment shown. It should be noted that the number of blades and the actual angle of inclination may vary. In other words, it may be that a greater number of blades in some applications are required, while in some instances, a lesser number of blades is required. Additionally, while an angle of inclination of 45 degrees is shown (denoted by the numeral  21 ), it should be understood that the angle may vary from zero (0) degrees to ninety (90) degrees. The rotor  2  is of similar construction to rotors of a turbine design that is commercially available from Smith International Inc. and Neyrfor Inc. under the name of Turbodrill.  
         [0051]    Referring now to FIG. 1C, a circumference view of the rotor  2  seen in FIG. 1A will now be described. In particular, FIG. 1C depicts the circumference view of the outer wall  4 . The outer wall  4  has the first flat radial surface  24  and the second surface  26 . FIG. 1C depicts that the second radial surface  26  is a jagged saw tooth profile  27  which begins at the surface  28  which then slopes generally downward, as denoted by the numeral  30  which in turn concludes at curved surface  32 , with the curved surface  32  having a radius of 0.125 inches in the preferred embodiment. The curved surface  32  extends to the vertically extending surface  34  which in turn extends to the second surface  36 . The second surface  36  will again extend to the generally downward sloped surface  38  and wherein the sloped surface  38  concludes at the curved surface  40 , with the curved surface  40  having a radius of 0.125 inches in the preferred embodiment.  
         [0052]    Reference is now made to FIG. 2A which is a top view of the sleeve  44  of the present invention. The sleeve  44  is a generally cylindrical member that contains an outer wall  46  and an inner surface  48 . FIG. 2B is a cross-sectional view of the sleeve  44  from FIG. 2A taken along line A-A. The sleeve  44  has a top surface profile, seen generally at  50 , and a bottom surface, seen generally at  52 . The top surface  50  is an essentially matching jagged saw-tooth profile  50  with the second surface  26  of the rotor  2 . Referring now to FIG. 2C, the circumference view of the sleeve  44 , and in particular the outer wall  46 , seen in FIGS. 2A and 2B will now be described. The second surface  50  is a jagged saw-tooth profile  50  which begins at the surface  54  which then slopes generally downward, as denoted by the numeral  56  which in turn concludes at curved surface  58 , with the curved surface  58  having a radius of 0.125 inches in the preferred embodiment. The curved surface  58  extends to the vertically extending surface  60  which in turn extends to the second surface  62 . The second surface  62  will again extend to the generally downward sloped surface  64  and wherein the sloped surface  64  concludes at the curved surface  66 , with the curved surface  66  having a radius of 0.125 inches in the preferred embodiment.  
         [0053]    A stator  70  is seen in a top view in FIG. 3A. The stator  70  is generally cylindrical and contains an outer wall  72  that in turn extends to an inner diameter surface  74 . The stator  70  has disposed therein a plurality of blades, namely blades  76 ,  78 ,  80 ,  82 ,  84 ,  86 ,  88 ,  90 . The stator blades will be attached at one end to the inner diameter surface  74  and at the other end to the center core  92 . The stator blades will be disposed at an angle of inclination that will be more fully explained with reference to FIG. 3B.  
         [0054]    Referring now to FIG. 3B is a cross-sectional view of the stator  70  from FIG. 3A taken along line A-A. Stator  70  has a first end  91   a  and second end  91   b . The blade  84  as an example is shown sloping downward at an angle of inclination of 45 degrees. The other blades ( 76 ,  78 ,  80 ,  82 ,  86 ,  88 ,  90 ) will slope downward in a similar fashion at an angle of inclination of 45 degrees. As noted earlier, the actual angle of inclination can be varied. The stator is designed to direct the flow stream to the rotor as will be more fully explained later in the application. As noted earlier, the flow stream may be a liquid or a gas, or a mixture of both. The flow stream may also contain solids.  
         [0055]    Referring now to FIG. 4A, a cross-sectional view of the percussion bottom sub  100  of the present invention will now be described. The bottom sub  100  comprises a generally cylindrical body having a first thread surface  102  that extends to a second outer surface  104  which in turn extends to the second thread surface  105 . Extending radially inward, the bottom sub  100  contains a first inner surface  106  that leads to center passage means  108 . The center passage means  108  contains a plurality of openings, including the opening  110 , which will have placed therein a nut and bolt which will serve as an anvil for an embodiment, as will be more fully explained later in the application. The center passage means  108  also contains openings spaced about the opening  110 , with these openings being generally aligned with the rotor  2  thereby providing an output path for the flow stream; in FIG. 4A, openings  112  and  114  are shown disposed through the center passage means  108 .  
         [0056]    In FIG. 4B, a top view of the percussion bottom sub  100  will now be described. The opening  112  and the opening  114  is shown, along with the other openings  116 ,  118 ,  120 . The center  110  will have placed therein a nut and bolt for the anvil, which is not shown in this view.  
         [0057]    Referring now to FIG. 5, a cross-sectional view of the percussion top sub  124  of the present invention will now be described. The percussion top sub  124  is a generally cylindrical member that includes an outer surface  126  which extends to an internal bore  128 . The internal bore  128  contains an internal thread  130  that in turn extends to a shoulder  132 . The shoulder  132  extends to the internal thread means  134 . The percussion top sub  124  and percussion bottom sub  100  are threadedly connected.  
         [0058]    [0058]FIG. 6A is the preferred embodiment of the assembled percussion sub  136  seen in a partial cross-section in the raised position. The internal thread means  134  will threadedly engage with the thread surface  102  thereby connecting the percussion top sub  124  and the percussion bottom sub  100 . Thus, the stator  70  has its first end  91   a  abutting the shoulder  132 . It should be noted that in some of the embodiments herein disclosed, the stator  70  itself is an optional component, as will be more fully explained later in the application. The stator  70  in turn is adjacent the rotor  2 . The stator  70  will direct the flow stream into the rotor  2 . The rotor  2  is positioned so that the jagged saw-tooth guide profile  27  (as seen in FIG. 1B) will be adjacent the sleeve  44 , and in particular, the jagged saw-tooth guide profile  50  (as seen in FIG. 2C) wherein the cooperation of the profiles will result in the percussion effect of the present invention. The bolt  138  is seen disposed within the opening  110 . The bolt  138  will serve as the anvil. Since the rotor  2  will be rotating during a flow down the bore  128  of the sub  136  and the internal portion  5  of the rotor  2 , the jagged saw-tooth guide profile  27  (as seen in FIG. 1B) of the rotor with the complementary jagged saw-tooth profile  50  (as seen in FIG. 2C) of the sleeve will cause the rotor to raise then lower and strike with the hammer radial face the bolt  138 , serving as anvil, which in turn transmits the impact to the percussion sub  136 . The direction of flow of the fluid stream is denoted by the arrow  11  in FIG. 6A.  
         [0059]    The frequency of the impact can be effected by several factors including the rate of pumping through the percussion sub  136 . Other factors include the specific design of the profile, like the number ofjagged saw-teeth. It should be understood that the percussion sub may be mounted in conjunction with a bit, or in work strings that contain other types of bottom hole assemblies. For instance, the percussion sub could be included on a fishing work string to aid in providing a jarring action when so desired by the operator. In the case wherein the percussion sub  136  is connected to a bit, the bit will be subjected to the impact.  
         [0060]    The sleeve  44  is fixedly connected to the percussion bottom sub  100  by conventional means such as welding or thread means or can be formed integrally thereon.  
         [0061]    [0061]FIG. 6A depicts the assembly while the rotor  2  has been raised due to the interaction of the jagged profile of the rotor  2  against the jagged guide profile of the sleeve  44 . The rotor  2  moves reverse to the direction of the flow of the flow stream when moving in the rotary motion. FIG. 6B depicts the assembly in FIG. 6A while the rotor  2  has been lowered in order to strike the sleeve, with the lowering being due to the interaction of the jagged guide profile of the rotor  2  against the jagged profile of the sleeve  44 . In particular, the hammer radial face  23  of the rotor  2  contacts the bolt  138 . As seen in FIG. 6B, the rotor  2  moves in the same direction of the flow of the flow stream when moving in a linear motion.  
         [0062]    Referring now to FIG. 7A, a schematic illustration of a percussion sub  170  embodiment having a rotor  172  with external guide profile  174  and an anvil  176  will now be described. In this embodiment, the rotor  172  will be rotated by the flow of a flow stream down the inner bore  178 . The sub  170  will be situated within a work string, as previously discussed. Thus, as the rotor  172  is rotated, the external guide profile  174  will cooperate with an inner guide profile  180  located on the inner body of the sub  170 . In accordance with the teachings of the present invention, as the rotor  172  turns, the cooperation of the external profile  174  and the internal profile  176  will cause a raising of the rotor  172  and in turn a lowering of rotor  172  which results in a striking of the hammer (rotor  172 ) against the anvil  176 . It should be noted that the external guide profile and internal guide profiles herein described will be similar to the jagged saw-tooth guide profile previously discussed in that the profiles provide a guide for cooperative engagement of the rotor to rotate as well as to raise and lower. The profiles for FIGS. 7A through 13 have a helical type of profile. The helical profile may take the form of a thread profile due to the curved nature of the profile about a cylindrical surface. FIG. 7B depicts a laid out the helical profile.  
         [0063]    In FIG. 8, a schematic illustration of another percussion sub  182  embodiment having a rotor  184  with internal guide profile  186  and an anvil  188  will now be described. The anvil  188  is either formed on the sub  182  or affixed to the sub by conventional means such as threads, welding, press fitting and other means. The anvil has a center section  190  that extends therefrom, with the center section  190  containing a guide profile  192 . In this embodiment, the rotor  184  will be rotated by the flow of the flow stream down the inner bore  194 . The sub  182  will be situated within a work string, as previously discussed. Thus, as the rotor  184  is rotated, the internal guide profile  186  will cooperate with the guide profile  192  located on the center section  190  of the anvil  188 . In accordance with the teachings of the present invention, as the rotor  184  turns, the cooperation of the guide profile  192  and the guide profile  186  will cause a raising of the rotor  184  and in turn a lowering of rotor  184  which results in a striking of the hammer (i.e. rotor  184 ) against the anvil  188 .  
         [0064]    In FIG. 9, a schematic illustration of another percussion sub  196  embodiment having a rotor  198  with external guide  200 , a stator  202  and an anvil  204  is shown. In the embodiment of FIG. 9, the stator  202  will direct the flow of the flow stream through the inner bore  206 . The flow will cause the rotor  198  to rotate wherein the external guide  200 , which is formed on the rotor  198 , will cooperate with the internal guide  200 , which is formed on the wall of the percussion sub  196 . Hence, the rotor  198  will raise then lower thereby causing the hammer effect as previously described.  
         [0065]    In FIG. 10, a schematic illustration of another percussion sub  208  embodiment having multiple rotors with external guides, stators and anvils will now be described. More particularly, the stator  210   a  directs flow of the flow stream to the rotor  212   a . The anvil  214   a  is connected to the percussion sub  208 . The rotor  212   a  has an external guide profile  216   a  that will cooperate with the internal guide profile  218   a  which in turn will raise the rotor  212   a , then lower the rotor  212   a  thereby striking the anvil  214   a.    
         [0066]    Mounted in tandem is stator  210   b  which receives the flow and then directs flow to the rotor  212   b . The anvil  214   b  is connected to the percussion sub  208 . The rotor  212   b  has an external guide profile  216   b  that will cooperate with the internal guide profile  218   b  which in turn will raise the rotor  212   b , then lower the rotor  212   b  thereby striking the anvil  214   b.    
         [0067]    [0067]FIG. 11 is a schematic illustration of another percussion sub  220  embodiment having multiple rotors and stators and wherein the stators function as anvils. As seen in FIG. 11, a stator  222   a  directs flow of the flow stream to the rotor  224   a  and wherein the rotor  224   a  has an external guide profile  226   a  that will cooperate with an internal guide profile  228   a  formed on the internal portion of the percussion sub  220 . Thus, the rotor  224   a  will be rotated which in turn causes the raising and then lowering of the rotor  224   a  thereby striking the stator  222   b . Note that the stator  222   b  acts as an anvil for the rotor  224   a.    
         [0068]    In the embodiment of FIG. 11, the second stator  222   b  directs flow to the second rotor  224   b  and wherein the rotor  224   b  has an external guide profile  226   b  that will cooperate with an internal guide profile  228   b  formed on the internal portion of the percussion sub  220 . Thus, the rotor  224   b  will be rotated which in turn causes the raising and then lowering of the rotor  224   b  thereby striking the stator  222   c , wherein the stator  222   c  serves as an anvil. Additionally, stator  222   c  directs flow to the rotor  224   c  and wherein the rotor  224   c  has an external guide profile  226   c  that will cooperate with an internal guide profile  228   c  formed on the internal portion of the percussion sub  220 . Thus, the rotor  224   c  will be rotated which in turn causes the raising and then lowering of the rotor  224   c  thereby striking the anvil  230 .  
         [0069]    Referring now to FIG. 12, a schematic illustration of another percussion sub  231  embodiment having multiple rotors and stators and anvils wherein the rotors are contacting each other, therefore, allowing for all rotors to oscillate in the same direction and frequency. The percussion sub  231  contains an anvil  232  that is connected to the sub  231  and has a center section  223  extending through the inner bore  234  of the sub  231 . The anvil  232  has ports  236  for the passage of the flow through the inner bore  234  and through the rotors and stators. The percussion sub  231  includes a rotor  238   a  that is disposed about the center section  233 . The rotor  238   a  has an external guide profile  240   a  that will engage within an internal guide profile  242   a  for cooperation as previously described. A stator  244   a  will direct flow of the flow stream to the rotor  238   a  which in turn will cause rotor  238   a  to rotate.  
         [0070]    The rotor  238   a  is fixedly attached, such as by thread means, splines or couplings, via a shaft  246   a  to the rotor  238   b . The shafts  246   a  consist of interconnecting pieces, with the interconnection being protruding teeth that cooperate with reciprocal grooves. The shafts  246   a  and  246   b  can also be interconnected via other means such as thread means.  
         [0071]    The stator  244   b  directs the flow to the rotor  238   b . The rotor  238   b  has an external guide profile  240   b  that cooperates with the internal guide profile  242   b . In this embodiment, the raising and lowering of the rotor  238   b  will strike the stator  244   a ; hence, stator  244   a  acts as an anvil. The rotor  238   b  is fixedly attached, such as by thread means, via a shaft  246   b  to the rotor  238   c . The stator  244   c  directs the flow to the rotor  238   c . The rotor  238   c  has an external guide profile  240   c  that cooperates with the internal guide profile  242   c . In this embodiment, the raising and lowering of the rotor  238   c  will strike the stator  244   b . In operation, the rotors  238   a ,  238   b ,  238   c  will rotate in phase and rise and lower in phase, since they are connected.  
         [0072]    [0072]FIG. 13 is a schematic illustration of another percussion sub  250  embodiment having multiple rotors, and stators. The percussion sub  250  is similar to the percussion sub  230  of FIG. 12 except that there is only a single external guide profile  252  that cooperates with and engages into the internal guide profile  254 . The other components found in FIG. 13 are similar to those found in FIG. 12, and similar numerals refer to like components. Thus, as flow of the flow stream is directed down the bore  234 , external guide profile&#39;s  252  engagement with the internal guide profile  254  will cause all of the rotors to rise, then fall striking the corresponding stators.  
         [0073]    With reference to FIG. 14, a schematic illustration of another percussion sub  260  embodiment having multiple rotors, stators, with a bit attached thereto will now be described. The embodiment of FIG. 14 also illustrates an interconnection means for interconnecting the rotors. Additionally, in the embodiment of FIG. 14, the bit that is connected to the tubular string is axial moveable relative to the tubular string. More specifically, the bit  264  is axially attached by conventional spline means with the top of the bit serving as an anvil  266 . The splines, schematically illustrated at  268 , are provided for allowing axial movement of the bit  264  relative to the tubular member  269  of sub  260  in oscillating movement, thereby allowing the incremental axial extension of the bit into the formation face. Please note that the tubular member  269  will be connected to a work string such as a drill string. The spline means consist of a series of projections on a bit shaft that fit into slots on the corresponding tubular  269 , enabling both to rotate together while allowing axial lateral movement, as is well understood by those of ordinary skill in the art.  
         [0074]    At the top portion of the rotor  270  is the projection  272 . A first stator  274  is provided so that the flow stream is directed to the rotor  270 , as previously described. The stator  274  has a bore  276  disposed there through. The second rotor  278  is disposed within the sub  260 , and wherein the rotor  278  contains a stem  280  disposed through bore  276 . The stem  280  contains a groove  282 , and wherein the groove  282  will cooperate with the projection  272 . The groove  282  and projection  272  are the interconnection means for interconnecting the rotors for rotational movement and are similar to a tongue in groove arrangement.  
         [0075]    At the top portion of the rotor  278  is the projection  284 . A second stator  286  is provided so that the flow stream is directed to the rotor  278 , as previously described. The stator  286  has a bore  288  disposed there through.  
         [0076]    The third rotor  290  is disposed within the sub  260 , and wherein the rotor  290  contains a stem  292  disposed through bore  288 . The stem  292  contains a groove  294 , and wherein the groove  294  will cooperate with the projection  284 . The groove  294  and projection  284  are the interconnection means. At the top portion of the rotor  290  is the projection  296 . A third stator  298  is provided so that the flow stream is directed to the rotor  290 , as previously described. The stator  298  has a bore  300  disposed there through.  
         [0077]    The fourth rotor  302  is disposed within the sub  260 , and wherein the rotor  302  contains a stem  304  disposed through the bore  300 . The stem  304  contains a groove  306 , and wherein the groove  306  will cooperate with the projection  296 . The groove  306  and projection  296  are the interconnection means. A fourth stator  308  is provided, and wherein the stator  308  directs the flow stream to the fourth rotor  302 . Due to the interconnection of the rotors  270 ,  278 ,  290 ,  302 , the rotors will rotate together as flow is directed therethrough. Thus, the rotors  270 ,  278 ,  290 ,  302  rise and fall (oscillate) in unison thereby providing the impact to the bit. In the embodiment shown in FIG. 14, the bit is actually impacted twice in a single cycle: first, by the rotors hitting the bit; second, by the falling work string, with the increment of downward movement of the work string being dependent upon the amount of hole created by the bit due to the first impact. The first rotor  270  has a guide profile  380  that is placed at the low side of the rotor  270 . The tubular member  269  of the sub  260  has an opposing guide profile  382  located on the inner body of the sub  170 . Hence, all interconnected rotors  270 ,  278 ,  290 ,  302  need only one pair of guide profiles ( 380 ,  382 ) to guide all rotors.  
         [0078]    Referring to FIG. 15A, the schematic illustration depicts the circumference view of the rotor  2  engaging the sleeve  44  in a raised position since the jagged saw-tooth guide profiles are not engaged. The surface  36  of the rotor  4  is contacting the surface  62  of the sleeve  44 . Notice the gap between the slope surface  30  of the rotor  4  and the slope surface  64  of the sleeve  44 . Flow will occur through the internal portion  5  of the rotor  2 , as previously described. The rotor  2  moves reverse to the direction of the flow of the flow stream when moving in rotary motion. FIG. 15B depicts the rotor  2  and sleeve  44  of FIG. 15A in a lowered position since the jagged saw-tooth guide profiles are engaged. Hence, the surface  36  of the rotor  2  has been allowed to clear surface  62  of the sleeve  44  thereby lowering rotor  4 . The slope surface  30  of the rotor  2  is now next to the sloped surface  64  of the sleeve  44 . The rotor  2  moves in the same direction of the flow of the flow stream when moving in linear motion.  
         [0079]    [0079]FIG. 16 is a schematic illustration of the percussion sub positioned within a drill sting  332  having a bit  334 . As can be seen, the percussion subs  136   a ,  136   b ,  136   c  can be placed in more than one position in the drill string  332 . Additionally, the percussion subs  136   a,b,c  can be used with a motor turbine tool  336  in the drilling of a well bore  338 . The percussion sub of the present invention can also be used with other tools, such as rotary steerable tools. In fact, the present apparatus may be added to most work strings any time a percussion effect is needed. It should be noted that the percussion sub of the present invention can be utilized as a component of different systems wherein a percussion and/or hammer effect is required. The percussion sub can be used in any surface or subsurface tool string, to clean out tubulars, as an impact hammer, as a vibration tool, as a cementing tool, as a compacting tool, etc.  
         [0080]    In yet another embodiment disclosed with the teachings of this invention, FIG. 17A depicts a schematic representation of the prior art technique used for cementing a casing string within a well bore. As those of ordinary skill in the art will appreciate, a well bore  400  is drilled. A casing string  402  is placed within the well bore  400 . The bore hole wall of the well bore  400  has an exposed formation face. A cementing shoe  404  is contained on the end of casing  402 . A cementing shoe  404  is commercially available from Halliburton Energy Services under the name Cementing Shoe or Casing Shoe, and is usually constructed of a drillable material such as aluminum.  
         [0081]    Cement is generally pumped down the inner portion of the casing  402 . The cement slurry in the casing is designated by the number  406 , and is schematically shown. The cement is pumped down casing  402  in the direction of flow arrow  408 , through the cement shoe  404 , and out into the annulus area  410 .  
         [0082]    As those of ordinary skill in the art will recognize, the drilling fluid, denoted by the number  412 , was already in place within the inner diameter of the casing  402  and the annulus area  410  before placement of the cement. The cement within the annulus area  410  is denoted by the numeral  420 . Therefore, as the cement is pumped down the inner portion of the casing  402 , and up annulus  410 , the drilling fluid  412  will be displaced, as is readily understood by those of ordinary skill in the art. The pumping of the cement continues until all of the cement has been pumped down the inner portion of casing  402 , and the annulus area  410  is completely filled with cement. The cement then is allowed to harden, thereby fixing the casing string  402  within the well bore  400 .  
         [0083]    Referring now to FIG. 17B, the cementing technique shown in FIG. 17A now contains a percussion tool, such as seen in FIGS. 6A and 6B and denoted as  136 . The percussion tool  136  is placed above the cementing shoe  404  in casing  402 . A shock module  440  is positioned between the percussion tool  136  and the casing  402 . The shock module  440  has build-in compression and tension systems like spring means  442   a  or arrangements of similar means. The spring means  442   a  can be a tension type of coil spring having a first end abutting shoulder  442   b  and a second end abutting shoulder  442   c . In one embodiment, the shock module  440  is threadedly connected to the percussion tool  136  at one end, and at the other end, the shock module  440  is connected to casing  402  via splined means.  
         [0084]    The shock module  440  lets the percussion tool  136  and the cementing shoe  404  concurrently move in an axial direction up and an axial direction down the well bore  400  relative to the casing  402 , hence, ensuring the axial vibration (shown by arrow  444 ) of the percussion tool  136 . In an embodiment not shown, the shock module  440  can be an integrated member of the percussion tool  136  itself As seen in FIG. 17B, the disclosed shock module  440  enhances the effect and the efficiency of the desired invention; however, the inclusion of the shock module  440  is not necessary to practice the invention herein disclosed.  
         [0085]    As cement is pumped in the flow direction of  408  down the inner diameter of casing  402 , the cement will be flowed through the percussion tool  136 . The pumping of the cement slurry will cause the percussion tool  136  to vibrate in an oscillating manner  444 , as previously described. The cement slurry will be subjected to the rotor blades of percussion tool  136 . Additionally, the rotor of the percussion tool  136  will travel in a first longitudinal direction, followed by a second longitudinal direction, all as previously described. The cement slurry exiting the percussion tool  136  will enter the cement shoe  404 . The slurry will then exit the cement shoe  404  and will travel into the annulus area  410 , displacing the drilling fluid  412 .  
         [0086]    In the prior art pumping of cement (such as seen in FIG. 17A), as the cement is pumped downhole, it is subjected to a static movement (pure static pressure). As those of ordinary skill in the art will recognize, problems occur due to imperfectly sealed formation-casing interfaces. Thus, remedial works, such as squeeze jobs, must be performed in order to insure a proper placement of cement in the annulus area, as well as to insure proper bonding of the cement to the outer diameter of the casing.  
         [0087]    As per the teachings of this new invention, the percussion tool  136  is placed above the cementing shoe  404  and the cement slurry can be pumped through the rotor and stator blades as other drilling slurries. Part of the hydraulic horsepower of the cement flow, which is being pumped, will be transformed into mechanical horsepower in the sense that the cement slurry becomes a vibrating mass column in the well bore. This vibration of the slurry reduces the friction between the cement particles itself, between the cement particles and the formation, and between the cement particles and the casing. This is a dynamic phase which is accomplished because of the percussion tool  136 , and differs from the prior art static movement of the cement slurry. This dynamic phase allows the cement slurry to flow more easily into formation voids, pore cracks, fissures, etc.  
         [0088]    Additionally, because the percussion tool  136  is vibrating the cement column, the cement particles have better settling. This will trigger fewer voids (porosity) in the annulus, therefore providing a much better sealing effect between cement particles, which in turn allows for better sealing effect between casing and formation, and casing and cement. Another advantage is that, since there is less porosity, there is higher density, which amounts to a better seal in the porous space of a formation. Additionally, with the teachings of the embodiment of FIG. 17B, there is reduced friction, hence less pressure column, therefore allowing for a higher cement column behind the casing with an equal amount of applied static pressure. For instance, see the cement column in FIG. 17A denoted by the numeral  414 , and the cement column denoted by the numeral  416  in FIG. 17B. Hence, because of the reduced friction, the same amount of pumping pressure will allow for a higher displacement shown as the difference between the distance of line  446   b  of FIG. 17B and line  446   a  of FIG. 17A into the annular area  410 . To put it another way, single line static pressure (cement pumps from the surface) will push the cement higher into the annulus behind the casing due to less pressure resistance when use of the percussion tool  136  is included. The difference of cement column height in the annulus  410  can also be explained with an enhanced efficiency of dynamic pressurized fluid in comparison with static pressurized fluids.  
         [0089]    Actually, twice the percussion tool  136  and the shock module  440  will actuate the cement column. First, the rotor of the percussion tool  136  will vibrate the cement column itself The cement column starts to pulsate. Second, the percussion tool  136  and cementing shoe  404  oscillate due to the axial movement enabled by the shock module  440 , thus they by themselves as a whole will activate the cement slurry once more.  
         [0090]    Although the present invention has been described in terms of specific embodiments, it is anticipated that alterations and modifications thereof will no doubt become apparent to those skilled in the art. It is therefore intended that the following claims be interpreted as covering all such alterations and modifications as fall within the true spirit and scope of the invention.