Patent Publication Number: US-9885212-B2

Title: Downhole oscillator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. provisional application Ser. No. 61/468,637 filed on Mar. 29, 2011, which is incorporated herein by reference as if reproduced in full below. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     FIELD OF THE DISCLOSURE 
     The disclosure relates, in general, to a downhole drilling apparatus. More specifically, the invention is directed to a downhole oscillator providing vibration or oscillation along at least a portion of the bottom hole assembly. 
     BACKGROUND 
     Those in the oil and gas field attempt to reduce harmful vibrations that occur during drilling operations. However, in some cases, the providing of purposeful oscillation or vibration to a bottom hole assembly is desired as it will work to reduce friction and improve the string to bit weight transfer. High friction can lead to high well tortuosity thereby limiting step-out and possibly negatively affecting productivity. By providing purposeful oscillation or vibration one can reduce drag thereby improving weight transfer to the bit. Further, tool face control may be improved by minimizing static friction. 
     This provision of oscillation or vibration may work to beneficially increase the penetration rate, extend drill bit life through the improved weight transfer and reduction of impact forces, and/or reducing the amount of drill pipe compression that would be required otherwise. Oscillation can be beneficial in any type of drilling operations, including, but not limited to, directional or horizontal drilling, and other applications such as fishing and milling. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     A downhole oscillator having an eccentric member is provided that creates oscillation of at least a part of the bottom hole assembly. An exemplary embodiment of the downhole oscillator includes an outer housing at least partially surrounding a motor and a functionally coupled eccentric member. The motor at least partially drives the rotation of the asymmetrical eccentric member thereby producing oscillations or vibrations along at least a portion of the downhole assembly. The motor&#39;s action is at least in part facilitated by expulsion of fluid from the drill string through the motor and onto the interior of the outer housing such that the force of the interaction between the motor and outer housing produces rotation in the motor. This rotation may be enhanced through expulsion of fluid from the eccentric member whereby the interaction of the expelled fluid therefrom interacts with the interior of the outer housing thereby providing rotation of the eccentric member. Different sized and weighted eccentric members may be utilized to produce the desired oscillating effect. 
     Alternatively, the fluid may be expelled from the motor and/or the eccentric member against the interior of the wellbore thereby providing the desired rotation. 
     A method of use may include providing an outer housing, a motor capable of producing rotational movement, and an asymmetrical eccentric member and functionally coupling same. Connecting the foregoing to a drill string. Activating the motor to produce vibration in at least a portion of the drill string. 
     Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially exploded view of an exemplary embodiment of the downhole oscillator. 
         FIG. 2  is a partially exploded view of an exemplary embodiment of the downhole oscillator showing select channels therein. 
         FIG. 3  is a perspective view of the motor and top sub. 
         FIG. 4  is a perspective view of the housing and the lower sub. 
         FIG. 5  is a perspective view of an exemplary embodiment of a fully assembled jet motor with an exemplary eccentric member attached thereto. 
         FIG. 5A  is a perspective view of an alternative embodiment of the eccentric member. 
         FIG. 5B  is a perspective view of an alternative embodiment of the eccentric member. 
         FIG. 6  is a perspective view of an alternative embodiment of the eccentric member. 
         FIG. 6A  is a perspective view of an alternative embodiment of the eccentric member. 
         FIG. 6B  is a perspective view of an alternative embodiment of the eccentric member. 
         FIG. 7  is a partial exploded view of an exemplary embodiment of the motor of  FIG. 5 . 
         FIG. 7A  is a partial exploded view of an alternative embodiment of the motor of  FIG. 5 . 
         FIG. 8A  is a cross-sectional view of the power shaft of an exemplary embodiment motor taken along plane  8 A in  FIG. 7 . 
         FIG. 8B  is an alternative embodiment of  FIG. 8A . 
         FIG. 9A  is a cross-sectional view of an exemplary embodiment of the eccentric member taken along line  9 A- 9 A in  FIG. 10 . 
         FIG. 9B  is a cross-sectional view of an alternative embodiment of the eccentric member. 
         FIG. 10  is a cross-sectional view of an exemplary embodiment of the motor taken along axis A-A of  FIG. 5 . 
         FIG. 11  is a cross-sectional view of an alternative embodiment of the motor. 
     
    
    
     DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Referring to  FIGS. 1 and 2 , an exemplary embodiment of a downhole oscillator  5  is shown which generally comprises a motor  10 , an eccentric member  20 , and an outer housing  25 . 
     As used herein, the term “upper” will refer to the direction of the top sub  150  that connects to a drill string or tubing (not shown). As used herein, the term “lower” will refer to the direction of the lower sub  100 . However, it will be understood that these terms are simply for ease of reference and have no bearing on the actual use of the invention. 
     A cylindrical, elongated outer housing  25  at least partially surrounds the motor  10 . The outer housing  25  may be used to connect the motor  10 , and its functionally coupled eccentric member  20 , to a drill string (not shown). The outer housing  25  may also at least partially surround the eccentric member  20 . 
     The outer housing  25  is functionally connectable at its string connection end  190  to a drill string, though the connection may not be direct. For example, in the exemplary embodiment shown, the outer housing  25  is connected to a top sub  150  at its string connection end  190 . The top sub  150  may then be functionally coupled to the drill string or tubing and a fluid source (not shown). 
     In the exemplary embodiment shown, the top sub  150  is generally cylindrical with a fluid passage  198  extending therethrough. Fluid passage  198  is generally aligned with axis A-A. The top sub  150  has an upper drill string connection end  188 , a lower motor connection end  194 , and a lower housing connection end  196 . The connection ends  188 ,  194 ,  196  may employ any known or later discovered method of connection, including, but not limited to, threaded connections. The top sub  150  contains at least one dump port  155  proximate the downhole oscillator  5 . The dump ports  155  may be disposed intermediate the lower motor connection end  194  and the lower housing connection end  196  of the top sub  150 . The dump ports  155  are in fluid communication with the fluid passage  198  of the top sub  150 , and thereby are in fluid communication with the fluid source. 
     Referring to  FIG. 3 , top sub  150  connects to jet motor  10  via lower motor connection end  194 . Jet motor  10  is rotably disposed within outer housing  25 . The outer housing  25  connects to the top sub  150  at its connection end  190 . When connected, at least a portion, if not all, of the dump ports  155  are disposed within the housing  25 . Further, at least a portion, if not all, of the motor  10  is disposed within the housing  25 . The motor  10  is functionally coupled to the top sub  150  thereby allowing at least some of the fluid, which may be pressurized as needed, to flow from the top sub  150  and into the motor  10 . 
     In operation, fluid, having a desired pressure, is pumped to the downhole oscillator  5 . When the lower motor connection end  194  of the top sub  150  is functionally connected to the motor  10 , some of the fluid that will pass through the fluid passage  198  of the top sub  150  will enter into the motor  10  therefrom. This fluid will power the motor  10  thereby producing the oscillations or vibrations. A housing annulus  200  is defined as the space between the interior surface  202  of the housing  25  and the exterior surface  204  of the motor  10  when the housing  25  and motor  10  are functionally coupled. At least some of the fluid will flow into the housing annulus  200  through the dump ports  155 , thereby bypassing the interior of the motor  10  on its way towards the bottom hole assembly. 
     The outer housing  25  is functionally connectable, either directly or indirectly, at its lower connection end  195  to a drill bit, bottom hole assembly, or other downhole component. This connection may be facilitated through the use of a lower sub  100  to connect the downhole oscillator  5  to the desired downhole component (not shown). Through direct connection of the outer housing  25  to the bottom hole assembly, and/or other downhole component, with or without the use of a lower sub  100 , the eccentric member  20  may be functionally coupled to the drill string while being allowed freedom of movement in order to effect the desired oscillation or vibration of same. 
     Referring to  FIG. 4 , outer housing  25  lower connection end  195  may be connected directly to lower sub  100 . 
     Referring to  FIGS. 5B and 6B , the eccentric member  20  of the exemplary embodiment is a generally asymmetrical member with a closed end  18  and an open connection end  24 . The eccentric member  20  is asymmetrical in that at least a portion of the eccentric member  20  has a larger surface area  181  than another portion of the eccentric member  180  extending axially therefrom thereby resulting in greater weight along the enlarged portion  180  of the eccentric member  20  in relation to the remaining portion  181 . The eccentric member  20  of the depicted exemplary embodiment is generally cylindrical; however, any shaped eccentric member  20  may be used wherein the shape and size of the eccentric member  20  varies from that shown in the exemplary embodiment herein so long as same fulfills the purpose of providing an eccentric member  20  with uneven weight distribution in order to produce vibration and/or oscillation in the downhole tool while in operation. 
     In an alternative embodiment shown in  FIGS. 5, 5A, and 6 , the enlarged portion  180  of the eccentric member  20  further contains a protrusion  182  extending therefrom. The protrusion  182  aids to add more weight to the enlarged portion  180  in order to further offset the eccentric member  20 . Additional or varying sized and/or weighted members  180 ,  182  may be utilized to produce the desired frequency of vibration when in operation. In operation, the eccentric members  20  may be changed out or reconfigured in order to produce the desired result. In an alternative embodiment, the protrusion  182  is weighted as needed to produce the desired oscillation/vibration. Further, multiple eccentric members  20  having varying protrusion  182  and enlarged portion  180  sizes and weights may be provided. 
     Referring to  FIGS. 5 and 7 , a channel  22  extends inwardly of the eccentric member  20  from its connection end  24 . In an exemplary embodiment, threading is provided on the interior surface of the eccentric member  20  proximate the connection end  24  for threaded connection to the threaded lower connector  23  of the power shaft assembly  36 . Threaded connection of eccentric member  20  and power shaft assembly  36  allows for eccentric member  20  to be removed and replaced with another eccentric member  20  of another size and weight to produce the desired oscillation and vibration. While a threaded connection is shown, it is understood that any type of functional coupling may be employed to affect the stated purpose. 
     In the exemplary embodiment shown in  FIGS. 5, 5B, and 6 , one or more rotation nozzles  26  are disposed in the cylinder wall  27  of the eccentric member  20 . In an exemplary embodiment depicted in  FIGS. 9A and 9B , at least two rotation nozzles  26  are provided. Rotation nozzles  26  are in fluid communication with the interior channel  22  of the eccentric member  20  which in turn is in fluid communication with the fluid source. The rotation nozzles  26  extend from the interior channel  22  out to the exterior surface  184  of the eccentric member  20 . This coupling allows fluid to flow from the channel  22  to the exterior of the eccentric member  20 . In the exemplary embodiment shown, fluid enters the channel  22  of the eccentric member  20  from the interior of the motor  10 , which in turn enters the motor  10  from the drill string. 
     Referring to  FIG. 9A , an exemplary embodiment of the nozzles  26  of the eccentric member  20  each have an axis N extending therethrough. Axis N extends radially with respect to the longitudinally extending axis AA, as shown in  FIGS. 5 and 7 , to allow radial fluid expulsion from the nozzle  26 . This fluid expulsion from the nozzles  26  may strike the interior  202  of the outer housing  25  thereby providing rotational thrust in a desired direction. 
     Alternatively, at least one rotation nozzle  26  may extend radially in an oblique or aslant manner, axis N′, thereby expelling fluid, when in operation, at an angle against a surface that is proximate thereto. The angling of the rotation nozzle  26 , and the interaction of the expelled fluid therefrom with a proximate surface thereto, will generate rotation of the eccentric member  20 . Examples of surfaces that are proximate the rotation nozzle  26  are the interior surface  202  of the housing  25 , the interior surface  34  of the control sleeve  12 , and the interior of the wellbore (not shown). 
     Described another way, the radially extending angle N′ of the rotation nozzles  26  may be angled with respect to a plane passing parallel to and along the longitudinal axis AA at the interior opening  29 , at the cylinder wall  27 , of the nozzle  26 . Wherein the angle N′ is acute in relation to the plane. In an exemplary embodiment, the plane intersects the nozzle axis N at the interior opening  29 . 
     Referring to  FIG. 9B , in an alternative embodiment, one or more rotation nozzles  26  may extend with their axis N oriented, at least partially, back toward the connecting end  24  of the eccentric member  20 . 
     Described another way, one or more rotation nozzles  26  may extend angularly with respect to a plane passing perpendicular to the longitudinal extension of axis AA. In other words, the angle N of the nozzles  26  may extend along the axis AA wherein the angle is acute in the direction of the eccentric member&#39;s  20  connecting end  24  and obtuse with respect to the direction of its closed end  18 . Alternatively, the nozzles  26  may be oriented in the reverse, wherein the angle N is acute in the direction of the closed end  18  of the eccentric member  20  and obtuse with respect to its open connecting end  24 . 
     Referring to  FIGS. 6A and 6B , in an alternative embodiment, the eccentric member  20  does not have rotation nozzles  26  nor a channel  22  and the rotation of the eccentric member  20  is driven solely by the motor  10 . In this embodiment, the connecting end  24  simply connects the eccentric member  20  to the motor  10  in order to provide the necessary rotation. 
     A motor  10  is provided for functional coupling with the eccentric member  20 . The motor  10  serves as a conduit for the pressurized fluid to the rotation nozzles  26  of the eccentric member  20  when the eccentric member  20  is the force pushing the rotation of the member  20 . The motor  10  may also serve as the sole or additional driving force of the eccentric member  20 . 
     Referring to  FIG. 5 , the exterior of the depicted exemplary embodiment of the motor  10  generally comprises a control sleeve  12  and upper subassembly  16  having a common central longitudinal axis AA. 
     Referring to  FIGS. 5 and 7 , the control sleeve  12  is generally composed of an elongated cylindrical barrel body, with a control sleeve channel  17  passing therethrough. The control sleeve channel  17  is oriented along axis AA. The control sleeve  12  is provided with a connecting assembly  19  at its upper end  32  for functional connection to the lower end  42  of the upper subassembly  16 . This functional connection may be a threaded connection as shown or any other known or later discovered attachment method. The upper subassembly  16  is provided with a connecting assembly  82  at its end  80  to allow connection to a drill string or tubing (not shown), directly or indirectly. As shown in  FIG. 3 , in an exemplary embodiment, upper subassembly  16  is connectable to top sub  150  lower motor connection end  194 . Threaded connections, as depicted, are commonly practiced. Accordingly, the control sleeve  12 , after installation on a drill string or tubing, is in a fixed position in relation to the drill string or tubing. 
     The power shaft assembly  36  includes the power shaft  30 , a lower radial bearing  46 , a thrust bushing  48 , an upper radial bearing  44 , a retainer  38  and an upper thrust bushing  70 . 
     The power shaft  30  comprises a hollow cylindrical structure having an internal channel  66  aligned with axis AA. The internal channel  66  allows fluid communication from a drill string or tube (not shown) to the channel  22  of the eccentric member  20 . 
     The power shaft  30  is constructed and sized to rotate within the control sleeve  12  with the lower radial bearing  46  and upper radial bearing  44  providing radial support. As the eccentric member  20  is fixedly attached to the power shaft  30 , the power shaft  30  at least partially drives the rotation of the eccentric member  20  thereby causing rotation of the power shaft  30  and the eccentric member  20  together in relation to the control sleeve  12  and the outer housing  25 . In an alternative embodiment, eccentric member  20  contains at least one rotation nozzle  26 , thereby providing at least a portion of the driving power. The power shaft  30  is at least partially surrounded by the control sleeve  12 . 
     The thrust bushing  48  extends intermediate the lower radial bearing  46  and the upper radial bearing  44 . 
     A retainer nut  38  is provided on the power shaft  30  intermediate the upper radial bearing  44  and the upper end  60  of the power shaft  30 . The retainer nut  38  is provided with an internal connection assembly  39  to functionally attach the retainer  38  to the corresponding connection assembly  81  provided on the power shaft  30 . A purpose of the functional connection between the retainer  38  and the power shaft  30  is to retain the radial bearings  44  and  46  and the thrust bushing  48  intermediate the retainer nut  38  and a shoulder  69  on the power shaft  30  and a shoulder  68  on the control sleeve  12 , as seen in  FIGS. 10 and 11 . 
     The power shaft  30 , control sleeve  12 , shoulder  68  of the control sleeve  12 , and the end  56  of the lower radial bearing  46  define a blind annular space  55 . The blind annular space  55  is intermediate the exterior surface  33  of the power shaft  30  and the inner surface  34  of the control sleeve  12 . The blind annular space  55  having an upper end  45  defined by the end  56  of the lower radial bearing  46  and the shoulder  68  of the control sleeve  12 . An annular opening  54  of the annular space  55  is defined intermediate the control sleeve  12  and the power shaft  30 . 
     In an alternative embodiment, an annular seal (not shown) may be provided at the end  56  of the lower radial bearing  46  to define the upper end  45  of the annular space  55 . 
     At least one drive nozzle  52  extends through the wall  31  of the power shaft  30 . In an exemplary embodiment, at least two drive nozzles  52  are provided and are radially spaced within the wall  31  of the power shaft  30 . The drive nozzles  52  are in fluid communication with the internal channel  66  of the power shaft  30 . 
     The drive nozzles  52  are located intermediate the annular opening  54  of the annular space  55  and the upper end  45  of the annular space  55 . The drive nozzles  52  allow fluid to flow from the internal channel  66  of the power shaft  30  to the annular space  55 . 
     The drive nozzles  52  each have an axis D therethrough, as seen in  FIGS. 8A and 8B . Referring to  FIG. 8B , axis D of the drive nozzle  52  is angled radially to allow fluid expulsion from the nozzles  52 . This fluid expulsion acting on the interior of the outer housing  25 , or other area proximate the nozzle  52 , provides rotational thrust in a desired direction. In addition, the radially extending angle D′ of the drive nozzle  52  may be angled obliquely or aslantingly thereby expelling the fluid therefrom, in operation, at an angle further encouraging rotation of the power shaft  30  and in turn rotating the eccentric member  20 . 
     Stated another way, the radially extending angle D′ of the drive nozzle  52  may be angled with respect to a plane P passing parallel to and along the longitudinal axis AA at the interior opening  57 . The radial angle D′ of the drive nozzle&#39;s  52  axis D in relation to the plane P is acute. In an exemplary embodiment, the plane P intersects axis D at the interior opening  57 . 
     In an alternative embodiment, axis D may extend backward toward the upper subassembly  16  of the motor  10 . Stated differently, axis D may be oriented angularly with respect to axis AA, as depicted in  FIG. 8A , wherein the angle is acute in the direction of the power shaft&#39;s  30  upper end  60  and obtuse with respect to the direction of its threaded lower connector  23 . Accordingly, the drive nozzles  52  are oriented rearward in relation to the power shaft  30 . 
     In the exemplary embodiments shown, the rotation nozzles  26  and drive nozzles  52  are depicted. In an alternative embodiment, not shown, ports, or openings, may be provided without nozzles to achieve the desired result. The principles taught in this disclosure apply with ports and/or openings used in lieu of rotation nozzles  26  and/or drive nozzles  52 . 
     Referring to  FIG. 7A , in an alternative embodiment, power shaft  30  is not equipped with drive nozzles  52 . In this embodiment, rotation nozzle  26  of the eccentric member  20  drives jet motor  10 . 
     Referring to  FIG. 10 , the inner surface  34  of the control sleeve  12  is spaced from the exterior surface  33  of the power shaft  30 . The resultant space therebetween defines gap  49 . In operation, fluid is forced through the internal channel  66  and is expelled through at least one drive nozzle  52 . Upon said expulsion the fluid impacts the inner surface  34 . The radial angle D′ of the drive nozzles  52  force the fluid to exit the nozzles  52  at a radial angle thereby providing, and/or enhancing the, rotational force when the fluid impacts the inner surface  34  resulting in the rotation of the power shaft  30  and, through functional coupling, the rotation of the eccentric member  20 . 
     In an exemplary embodiment, the gap  49  is in the range of 0.0381 cm to 0.0762 cm (0.015″ to 0.030″) for a motor  10  having a nominal diameter in the range of 3.175 cm to 4.445 cm (1.25″ to 1.75″). In an exemplary embodiment, the gap  49  is in the range of 0.508 cm to 0.635 cm (0.20″ to 0.25″) for a motor  10  having a nominal diameter in the range of 10.4775 cm to 12.065 cm (4.125″ to 4.75″). Generally, the gap  49  is effective in a range of ratios of gap  49  to nominal diameter of the control sleeve  12  (gap:sleeve diameter) as follows: 1:125 to 1:17. Depending on various application requirements, including the fluid used, nozzle size, pressure and other factors, ratios outside the foregoing range may be provided and even preferred. 
     Referring to  FIGS. 7 and 10 , the upper subassembly  16  comprises a generally hollow cylindrical body  61  having a connecting assembly  82  for functional coupling to a drill string or tubing (not shown) at its upper end  80 . In an exemplary embodiment, connecting assembly  82  of upper subassembly  16  functionally couples with lower housing connection end  196  of top sub  150 . Further, the upper subassembly  16  has a connecting assembly  83  at its lower end  42  for connecting the subassembly  16  to the motor  10  via its control sleeve  12  at the control sleeve&#39;s connecting assembly  19 . The upper subassembly  16  includes an interior channel  72  that is aligned with top sub  150  fluid passage  198  and axis AA. 
     An injection tube  96  is provided in upper subassembly  16 . The injection tube  96  includes an elongated tube  40  and a tube head  41 . The tube head  41  has a larger diameter than the tube  40 . A tube retaining nut  86  is provided to retain the tube head  41  between the retaining nut  86  and a shoulder  87  provided in upper subassembly  16 . The retaining nut  86 , tube head  41  and tube  40  define a continuous tube channel  95  aligned with axis AA. The retaining nut  86  has a connecting assembly  84  for functional connection to connecting assembly  83  provided in upper subassembly  16 . 
     In an exemplary embodiment, the injection tube  96  is retained in position by the retaining nut  86  and the shoulder  87  of upper subassembly  16 . The injection tube  96  is free to rotate about axis AA independent of the rotation of the power shaft  30  and upper subassembly  16 . 
     The upper subassembly  16  is provided with a cylindrical inset  88  at its lower end  42 . A thrust bushing  70  is at least partially disposed within the cylindrical inset  88  and provides a bearing surface intermediate the upper subassembly  16  and power shaft assembly  36 . The thrust bushing  70  additionally encloses and provides radial support for the tube  40 . 
     In an exemplary embodiment, the tube  40  extends past the lower end  42  of the upper subassembly  16  and into the channel  66  of the power shaft  30 . 
     The interior surface  71  of the thrust bushing  70  is sized and constructed to encircle the exterior surface  43  of the tube  40  but to allow rotation between the surfaces. The thrust bushing  70  further contains a flange  74  extending radially outward from the center of the bushing  70 . The flange  74  is received between the lower end  42  of the upper subassembly  16  and the upper end  60  of the power shaft  30 . The thrust bushing  70  includes a cylindrical inset  78  to receive a segment of the power shaft  30  at the upper end  60  of the power shaft  30 . The cylindrical inset  78  may be sized and constructed to slideably receive end  60  of power shaft  30 . 
     The diameter of the outer surface  43  of the tube  40  is preferably only slightly smaller than the diameter of the power shaft&#39;s channel  66  thereby allowing the tube  40  to be slideably received in the channel  66 . 
     In an exemplary embodiment, the injection tube  96  is at least partially composed of a tube wall  40  having a width and design such that the wall  40  will expand slightly when an appropriate operating pressure is moved through the tube channel  95 , interior to the wall  40 . Such slight expansion may create a seal between the exterior surface  43  of the tube wall  40  and the interior surface  93  of the power shaft  30 , wherein said interior surface  93  defines channel  66 . 
     In an exemplary embodiment, the tube wall  40  is provided with a slight flare proximate its lower end  64  to enhance sealing of the tube wall  40  against the interior surface  93 . A preferred flare angle is up to five degrees outwardly from the tube wall  40  segment that is not flared. 
     In summary, the power shaft assembly  36  is fixedly attached to the eccentric member  20 . The power shaft assembly  36  is rotatable within the control sleeve  12 . A blind annular space  55  is defined between the power shaft  30  and the control sleeve  12  for at least partial fluid expulsion. 
     In an alternative embodiment, the motor does not have the control sleeve  12 . In this embodiment, the fluid is expelled from the drive nozzles  52  directly against the interior surface  202  of the housing  25 . Alternatively, the fluid may be expelled from the drive nozzles  52  directly against the interior surface of the wellbore. 
     A purpose of the motor  10  is to provide a conduit for the fluid to enter the eccentric member thereby allowing rotation thereof through expulsion of fluid therethrough. A purpose of the motor  10  is to provide rotation, either alone or in addition to any rotative force produced by the eccentric member  20 , to the eccentric member  20  to create the desired vibration and/or oscillations in the bottom hole assembly. 
     In operation, the downhole oscillator  5  is formed whereby the motor  10  is functionally coupled to the eccentric member  20 . The motor  10  and the eccentric member  20  may be disposed, at least partially, within the outer housing  25 . The oscillator  5  is functionally coupled to a drill string or tube by way of the top sub  150 . A fluid (not shown), which may be drilling fluid or a gas, is introduced into the drill string or tube at a determined pressure. Pressure is applied to the fluid forcing the fluid through the channels  198 ,  72 ,  95 ,  66  and  22 . The fluid is forced through the drive nozzles  52  and, if present, the rotation nozzles  26  and is expelled against at least a portion of the outer housing  25  or control sleeve  12 . If no nozzles are utilized fluid will be expelled through the openings in the power shaft  30  wall  31  and, if present, the openings in the cylinder wall  27  of the eccentric member  20 . The pressure from the fluid in the channels  66  and  22  is greater than the ambient downhole pressure. Differential pressure at the rotation nozzles  26  and/or the drive nozzles  52 , or openings if nozzles are not utilized, create rotational torque on the eccentric member  20  and the power shaft  30 . 
     The proximity of the inner surface  34  of the control sleeve  12  or outer housing  25  provides a surface that is stationary relative to the power shaft  30 . The expansive force of the fluid escaping the drive nozzles  52  and/or rotation nozzles  26  and impinging the surface  34  of control sleeve  12  may enhance the rotational torque on the power shaft  30 . 
     The gap  49  may be determined to provide desired reactive force of fluid expelled through the drive nozzles  52  at the inner surface  34 . In addition, the force of the drilling fluid may be manipulated in order to control the thrust of the drilling fluid through the drive nozzles  52  and rotation nozzles  26 , if present, against the control sleeve  12  inner surface  34  and/or the interior surface of the outer housing  25  thereby controlling the rotation of the power shaft  30  and the eccentric member  20 . 
     As the drive nozzles  52  may be located intermediate the opening  54  of the annular space  55  and the upper end  45 , fluid forced out of drive nozzles  52  may be forced out of the opening  54 , thereby continually washing the annular spaces  55 ,  200  and preventing accumulation of debris therein. 
       FIG. 11  depicts an alternative exemplary embodiment wherein four drive nozzles  52  are located on the power shaft  30  in order to increase the amount of fluid expelled through the drive nozzles  52 . The drive nozzles  52  are depicted as symmetrically situated opposing pairs with respect to each other. However, the drive nozzles  52  may also be situated asymmetrically or in any combination of the two. 
     In an exemplary embodiment, an appropriate gas, such as nitrogen, may be utilized as the fluid medium. The construction of the present invention, particularly the construction of the injection tube wall  40  with expansion capability upon application of appropriate fluid pressure in the tube channel  95  together with the fit of exterior surface  43  of the tube wall  40  and the interior surface  93  of the power shaft  30  may allow the creation of an effective seal even though the fluid is a gas. 
     The exemplary embodiment providing a flared lower end  64  of the tube wall  40  provides an effective seal at the interior surface  93  as internal fluid pressure is applied at the open end of the lower end  64  of the tube wall  40 . 
     A method of use includes providing a downhole oscillator  5 . The downhole oscillator  5  may comprise providing a motor  10 , which may be capable of producing rotational movement, and/or one or more eccentric members  20 , wherein some may be capable of producing rotational movement and wherein same may be of varying sizes and weights. This step may further include providing an outer housing  25  at least partially surrounding the motor  10  and eccentric member  10 . In the exemplary embodiments shown, the outer housing  25  fully encloses the motor  10  and eccentric member  20  and connects to a top sub  150  and a lower sub  100  thereby remaining stationary in relation to the eccentric member and/or at least a portion of the motor  10 . Further, the motor  10  may contain a power shaft  30  having at least one opening or drive nozzle  52  in the shaft wall  31 . 
     Selecting an appropriate eccentric member  20  to provide the desired or requested oscillations and/or vibrations. This step may require selecting different eccentric members  20  depending on changing conditions downhole or changing requirements. 
     Manipulating the eccentric member  20  by adding or removing varying sizes, types, or shaped protrusions  182  to manipulate the weight and/or size of the eccentric member  20  as desired. The manipulating step may also include the utilization of different materials on the eccentric member, such as the use of cobalt for the protrusion  182  or steel or iron or some other material. 
     Functionally coupling the motor  10  to an eccentric member  20 . The coupling step may include coupling the motor  10  via its power shaft  30  to the selected eccentric member  20 . This coupling may be removable. Functionally coupling the eccentric member  20  to a drill string to produce the desired or requested oscillations (whereby when used in this specification the terms oscillations and vibrations are interchangeable). 
     Assembling the downhole oscillator  5  whereby desired. 
     Connecting the downhole oscillator  5  to the drill string, either directly or indirectly. 
     Lowering the eccentric member  20  and/or downhole oscillator  5  downhole. Introducing fluid to the drill string thereby powering the eccentric member  20 . Running the downhole oscillator  5  to produce oscillations to the bottom hole assembly. 
     Removing the downhole oscillator  5  from the wellbore. Switching out the eccentric member for another or otherwise manipulating the eccentric member  5  such that a different hertz will be produced once it is lowered back into the wellbore and operated. 
     A method of use may also include introducing a fluid or gas, collectively referred to as a fluid, under pressure to the downhole oscillator  5 . At least a portion of the fluid being introduced, under pressure, to the interior of the motor  10 . This fluid being used to power the motor  10  through the drive nozzles  52 , power the eccentric member  20  through the rotation nozzles  26 , and/or both. The fluid may travel through the dump ports  155  of the top sub  150  and travel along the interior  202  of the housing  25  thereby bypassing the motor  10  and the eccentric member  20  and proceeding downhole for use further down the string. The fluid that is used to power the motor  10  and/or the eccentric member  20  escapes the downhole oscillator  5  and will travel down the string to be used elsewhere. 
     Alternatively, a method of use may include further providing a power shaft  30 , the power shaft  30  having an upper end  80  and a lower end  81  and is functionally attached to an eccentric member  20  at the lower end  23 . The eccentric member  20  having a cylinder wall  27  and a longitudinal axis AA, with at least one eccentric member rotation nozzle  26 , having an opening axis N and an interior opening  29 , in the cylinder wall  27 . A method of use may also include an introducing step comprising introducing a fluid or gas under pressure to the rotatable power shaft  30  such that the fluid or gas is forced through the at least one rotation nozzle  26 . 
     Additionally, a method of use may include a combination of the two aforementioned methods, wherein a providing step comprises providing a power shaft  30  with at least one drive nozzle  52  and an eccentric member  10  with at least one rotation nozzle  26 . Method of use may also include an introducing step comprising introducing a fluid or gas under pressure to the rotatable power shaft  30  such that the fluid or gas is forced through the at least one drive nozzle  52  and the at least one rotation nozzle  26 . 
     In the aforementioned methods, the fluid may be a gas. The gas may be nitrogen. 
     The downhole oscillator  5  may provide vibrations of twenty-four to thirty-five Hz within the outer diameter of at least a portion of the bottom hole assembly; though other frequencies may be produced as desired. This degree of frequency may reduce the friction of the bottom hole assembly thereby improving the string to bit weight transfer when used with coiled tubing. Further, by providing vibrations to the bottom hole assembly, the rate of penetration may be improved. 
     The downhole oscillator  5  may allow up to one hundred twenty gallons of fluid per minute to flow therethrough. 
     The downhole oscillator  5  may be used with coiled tubing. 
     The depicted exemplary embodiments may be altered in a number of ways while retaining the inventive aspect, including ways not specifically disclosed herein. 
     Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of the words, for example “comprising” and “comprises”, means “including but not limited to”, and is not intended to (and does not) exclude other moieties, additives, components, integers or steps. 
     Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise. 
     Features and characteristics described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. 
     All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. In other words, the method steps have not been provided for in any particular sequential order and may be rearranged as needed or desired, with some steps repeated sequentially or at other times, during use. 
     Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features. 
     The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.