Abstract:
A combined guide and automatic rod rotator device for a downhole sucker rod which is reciprocating axially. The sucker rod is connected with a swivel mechanism to allow rotational movement of the sucker rod. The combined guide and automatic rod rotator device includes a cylindrical body and at least two vanes extending radially from the cylindrical body, wherein the vanes are helically arranged on the body.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention is directed to a combined rod guide and rod rotator which may be used in downhole well applications.  
           [0003]    2. Prior Art  
           [0004]    Rod guides are used for stabilizing and centralizing sucker rods which are usually long, cylindrical rods used in downhole well applications. In one type of application, the sucker rod is reciprocated within a well bore or tubing string to pump oil or other fluids from a reservoir.  
           [0005]    The rod itself is usually attached at the surface to a pumping unit. The rod and attached rod guide or guides reciprocate axially upwardly and downwardly within the tubing string. Oil and other fluid passes upwardly through the gap between the rod and the tubing string to the surface. The rod is prevented from moving sideways or wobbling by the installation of periodic rod guides. The rod guides typically have a number of vanes, fins or blades which extend radially and centralize the rod within the cylindrical tubing. This prevents the rod from wearing or from other damage. Any wear will, thus, occur to the rod guide fins.  
           [0006]    The rod guides may be fabricated from various materials, such as synthetic materials which are oil-resistant and resistant to abrasion.  
           [0007]    In one known type of procedure, the cylindrical rod is manufactured initially and then the guides are affixed thereto by adhesive bonding.  
           [0008]    It is also desirable to prevent the vanes from wearing on the tubing string in a single location. Accordingly, in the past, there have been devices at or near the surface which will rotate the rod upon each reciprocal movement of the rod in the well. These known rod rotators are mechanically driven at the surface or are driven by the reciprocal axial movement of the rod.  
           [0009]    Also in the past, helically wound fins or vanes have been added or wrapped around a sucker rod such as shown in Bostic, U.S. Pat. No. 1,633,843, entitled “Snap-On Sucker Rod Guide”.  
           [0010]    It is desirable to provide a rod guide that will prevent sideways or wobbling movement and centralize the rod within the string. It is also desirable at the same time to provide a rod guide which will facilitate periodic rotation of the guide so that wear on the tubing string is evenly applied.  
           [0011]    It is also desirable to provide a rod guide that will be rotated by the resistance of fluid against the vanes of the rod guide, without requiring further mechanical action.  
         SUMMARY OF THE INVENTION  
         [0012]    The present invention is directed to a combined rod guide and automatic rod rotator device.  
           [0013]    In a typical well operation, a sucker rod extends from the surface downhole to a production area where fluid is located. The sucker rod will reciprocate in the well bore or tubing string and may be composed of a number of sections which are joined together by threaded couplings.  
           [0014]    One or more devices constructed in accordance with the present invention will be utilized in conjunction with the sucker rod in order to stabilize and centralize the sucker rod in the downhole well. A cylindrical body surrounds the circumference of the sucker rod. The cylindrical body is also coaxial with the sucker rod which passes through a cylindrical opening in the body. The combined rod guide and rod rotator device includes at least two opposed fins or vanes which extend radially from the cylindrical body. Each vane has a pair of substantially planar sidewalls that are parallel to each other. Each vane is helically arranged on the cylindrical body. In one embodiment, each vane travels and extends helically approximately 90° around the body. The hydraulic force of the fluid downhole will cause the device and the attached sucker rod to rotate.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0015]    [0015]FIG. 1 is a simplified diagram of one well arrangement utilizing the combined rod guide and rod rotator device of the present invention.  
         [0016]    [0016]FIG. 2 is an alternate arrangement of a well utilizing the combined rod guide and rod rotator device of the present invention.  
         [0017]    [0017]FIG. 3 is a simplified diagram of a further, alternate arrangement of a well utilizing the combined rod guide and rod rotator device of the present invention.  
         [0018]    [0018]FIG. 4 illustrates an end view and FIG. 5 illustrates a perspective view of a combined rod guide and rod rotator device having two extending vanes.  
         [0019]    [0019]FIG. 6 illustrates a perspective view and FIG. 7 illustrates an end view of a combined rod guide and rod rotator device having three extending vanes.  
         [0020]    [0020]FIG. 8 illustrates an end view and FIG. 9 illustrates a perspective view of a combined rod guide and rod rotator device constructed in accordance with the present invention having four extending vanes.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    The embodiments discussed herein are merely illustrative of specific manners in which to make and use the invention and are not to be interpreted as limiting the scope of the instant invention.  
         [0022]    While the invention has been described with a certain degree of particularity, it is to be noted that many modifications may be made in the details of the invention&#39;s construction and the arrangement of its components without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the embodiments set forth herein for purposes of exemplification.  
         [0023]    Referring to the drawings in detail, FIGS. 1, 2 and  3  illustrate alternate arrangements utilizing the combined guide and automatic rod rotator device  10  of the present invention.  
         [0024]    As seen in FIG. 1, a typical pumping jack unit  12  would be located at the surface. An engine or motor moves a beam  38 . A cable  14  attached to the beam reciprocates a polished rod  16  axially as shown in arrow  18 .  
         [0025]    Typical components in a well operation might include a stuffing box  20 , a lateral flow line  22 , a tubing head  24  and casing head  26 . Various alternatives and permutations of these arrangements are known.  
         [0026]    Movement of the polished rod  16  causes reciprocal axial movement of a sucker rod  30  downhole within a well bore or tubing string  32 . The sucker rod maybe composed of a number of sections which are joined together by threaded coupling  28 . The sucker rod  30  will extend from the surface downhole to a production area where fluid is located. The sucker rod  30  will reciprocate in the well bore or tubing string. The sucker rod will be powered or driven from the surface and will drive a downhole pump or other tool. Fluid in the production area will be brought to the surface in the space between the sucker rod  30  and the well bore or tubing string  32 .  
         [0027]    A bearing block  34  permits free rotational movement of the sucker rod  30  within the tubing string or well bore.  
         [0028]    As will be explained in detail, the reciprocal movement of the rod guide  10  through downhole fluid will cause the attached sucker rod to rotate radially.  
         [0029]    [0029]FIG. 2 illustrates an alternate arrangement utilizing the combined guide and automatic rod rotator device of the present invention. A typical pumping jack unit  40  would be located at the surface. A cable  42  reciprocates a polished rod  44  axially as shown by arrow  46 .  
         [0030]    Typical components in a well operation might include a stuffing box  48 , a lateral flow line  50 , a tubing head  52  and a casing head  54 . Movement of the polished rod  44  causes reciprocal axial movement of a sucker rod  56  downhole within a well bore or tubing string  58 . The sucker rod  56  may be composed of a number of sections joined together by couplings  62 .  
         [0031]    A rod rotator  60  rotates the sucker rod upon each axial passage of the rod. Various types of mechanical rod rotators are known. In one type of known rod rotator  60 , a rotating force is provided by a ratchet handle that is moved upward by movement of the rod and moves downward by gravity to cause rotation of the rod. The present invention could be used in conjunction with an existing rod rotator to encourage rotational movement.  
         [0032]    [0032]FIG. 3 illustrates a further alternate arrangement utilizing the combined guide and automatic rod rotator device  10  of the present invention.  
         [0033]    A typical pump jacking unit  70  would be located at the surface. A cable  72  reciprocates a polished rod  74  axially as shown by arrow  76 .  
         [0034]    Typical components in a well operation might include a stuffing box  78 , a lateral flow line  80 , a tubing head  82  and a casing head  84 .  
         [0035]    Movement of the polished rod  74  causes reciprocal axial movement of a sucker rod  86  downhole within a well bore or tubing string  88 . The sucker rod  86  is composed of a number of sections joined together by couplings  92 . One of the connections would be a swivel coupling  90  which permits free rotation of one section of the rod with another. In the embodiment shown in FIG. 3, the sucker rod below the swivel coupling  90  would be rotated by force of fluid on the guide  10  while the sucker rod above the coupling would not rotate.  
         [0036]    By use of swivel couplings and the present invention, it is possible to rotate only a portion of the length of the sucker rod.  
         [0037]    [0037]FIG. 4 is an end view and FIG. 5 is a perspective view of a first embodiment of a combined rod guide and rod rotator  10  constructed in accordance with the present invention.  
         [0038]    A cylindrical body  100  surrounds the circumference of the sucker rod  30 . The cylindrical body  100  is also coaxial with the sucker rod which passes through a cylindrical opening in the body  100 .  
         [0039]    The combined rod guide and rod rotator  10  also includes two opposed fins or vanes  102  and  104  which extend radially from the cylindrical body  100 . By way of example and not by way of limitation, the sucker rod may have a one inch diameter and the total diameter of the device is approximately 2.3 inches. The device may have a length of approximately 6 inches.  
         [0040]    The vanes each have a pair of substantially planar side walls that are parallel to each other.  
         [0041]    Each of the fins is oriented approximately 180° radially from each other. Each vane  102  and  104  is helically arranged on the cylindrical body  100 . In the embodiment shown, each vane travels and extends helically approximately 90° around the body. The vanes may be helically wound to a lesser or greater extent. Between the vanes, an exterior face may have a radiused configuration to mate with the interior of the tubing string or well bore.  
         [0042]    Additionally, each vane  102  and  104  tapers toward the ends of the cylindrical body. Accordingly, the device has a length slightly longer than the length of each of the vanes.  
         [0043]    [0043]FIG. 6 is a perspective view and FIG. 7 is an end view of the second embodiment of a combined rod guide and rod rotator  110  constructed in accordance with the present invention.  
         [0044]    A cylindrical body  112  surrounds the circumference of the sucker rod. The cylindrical body  112  is also coaxial with the sucker rod which passes through the cylindrical opening in the body. The combined rod guide  110  also includes three oppose fins or vanes  114 ,  116  and  118  which extend radially from the cylindrical body. The vanes each have a pair of substantially planar sidewalls that are parallel to each other. In the embodiment shown in FIGS. 6 and 7, each of the vanes are oriented approximately 120° radially from an adjoining vane. Each vane  114 ,  116  and  118  is helically arranged on the cylindrical body  110 . In the embodiment shown, each vane travels and extends helically approximately 90° around the body. The vanes maybe helically wound to a lesser or greater extent.  
         [0045]    [0045]FIG. 8 is an end view and FIG. 9 is a perspective view of a third embodiment of a combined rod guide and rod rotator  120  constructed in accordance with the present invention.  
         [0046]    A cylindrical body  122  surrounds the circumference of the sucker rod. The cylindrical body  122  is also coaxial with the sucker rod which passes through a cylindrical opening in the body. The combined rod guide and rod rotator also includes four opposed fins or vanes  124 ,  126 ,  128  and  130  which extend radially from the cylindrical body  122 . Each of the vanes has a pair of substantially planar sidewalls that are parallel to each other. Each of the vanes is oriented approximately 90° radially from each other. Each vane  124 ,  126 ,  128  and  130  is helically arranged on the cylindrical body  122 . Each vane travels and extends approximately 90° around the body.  
         [0047]    In each of the embodiments, the rotation will tend to equalize wear on the tubing or well string.  
         [0048]    In one method of construction, a sucker rod is placed within a mold having a cavity. The guide material is then poured into the mold where it cures and adheres around the sucker rod. Accordingly, the combined guide is adhesively bonded to the rod. The force indicated by arrow  36  in FIG. 1 will be brought to bear against each of the vanes. Accordingly, the force of the fluid will cause the device  10  and the attached rod to rotate.  
         [0049]    The vanes will be helically arranged in the direction so as to tighten any threaded connection at the coupling which joins the sections together. For example, if the section couplings have a right hand thread to tighten, the vanes will be arranged to rotate the rod in the same direction.  
         [0050]    Whereas, the present invention has been described in relation to the drawings attached hereto, it should be understood that other and further modifications, apart from those shown or suggested herein, may be made within the spirit and scope of this invention.