Abstract:
A wellhead capable of steering fluid flow to minimize contact with equipment in the wellbore comprises a central bore and a plurality of side bores coupled to injection ports. The plurality of side bores comprise a rifled internal surface having a circular or helical configuration into which fluids can be injected. The side bores intersect with the central bore at a mixing chamber, which also comprises a rifled internal surface. By injecting fluids into the wellbore through these ports, the operator can create a vortex utilizing the full capacity of the wellhead while minimizing contact with any wireline equipment.

Description:
PRIORITY STATEMENT 
       [0001]    This is a non-provisional application claiming priority to U.S. Provisional Application No. 62/295,955, filed Feb. 16, 2016 and entitled “Wellhead Mixing Device.” The contents of this provisional application are incorporated herein by reference. 
     
    
     FIELD OF THE APPLICATION 
       [0002]    The application relates generally to a wellhead for introducing and promoting a circular or helical fluid flow to fluid introduced through various injection ports. 
       BACKGROUND 
       [0003]    Often, fluids injected into a wellbore may be reactive, corrosive, or otherwise damaging to wireline equipment. Alternatively, operations may necessitate wireline equipment being withdrawn simultaneously to the injection of fluid into the wellbore, which would mean the wireline equipment would face increased resistance in the form of counter-directional fluid flow. In both instances, creating a circular or helical fluid flow therefore minimizes the impact of these fluids on the equipment. 
         [0004]    Prior art wellheads, such as U.S. Pat. No. 6,575,247 to Tolman and U.S. Pat. No. 7,478,673 to Boyd, have attempted to introduce this flow pattern through use of angled injection ports and funneled mixing chambers to create a drain vortex. However, both of these methods reduce the overall capacity of the wellhead for fluid flow. 
         [0005]    A need therefore exists for a wellhead which can create a circular or helical fluid flow for larger amounts of fluid, for instance, as used in fracking-type operations. Embodiments disclosed in the present application meet this need. 
     
    
     
       DRAWINGS 
         [0006]      FIG. 1A  depicts a perspective view of an embodiment of the wellhead. 
           [0007]      FIG. 1B  depicts a top (plan) view of an embodiment of the wellhead. 
           [0008]      FIG. 1C  depicts a front view of an embodiment of the wellhead. 
           [0009]      FIG. 1D  depicts a side view of an embodiment of the wellhead. 
           [0010]      FIG. 2A  depicts a cross-sectional front view of an embodiment of the wellhead. 
           [0011]      FIG. 2B  depicts a cross-sectional side view of an embodiment of the wellhead. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0012]    Before describing selected embodiments of the present disclosure in detail, it is to be understood that the present invention is not limited to the particular embodiments described herein. The disclosure and description herein is illustrative and explanatory of one or more presently preferred embodiments and variations thereof, and it will be appreciated by those skilled in the art that various changes in the design, organization, order of operation, means of operation, equipment structures and location, methodology, and use of mechanical equivalents may be made without departing from the spirit of the invention. 
         [0013]    As well, it should be understood that the drawings are intended to illustrate and plainly disclose presently preferred embodiments to one of skill in the art, but are not intended to be manufacturing level drawings or renditions of final products and may include simplified conceptual views as desired for easier and quicker understanding or explanation. As well, the relative size and arrangement of the components may differ from that shown and still operate within the spirit of the invention. 
         [0014]    Moreover, it will be understood that various directions such as “upper,” “lower,” “bottom,” “top,” “left,” “right,” and so forth are made only with respect to explanation in conjunction with the drawings, and that the components may be oriented differently, for instance, during transportation and manufacturing as well as operation. Because many varying and different embodiments may be made within the scope of the concepts herein taught, and because many modifications may be made in the embodiments described herein, it is to be understood that the details herein are to be interpreted as illustrative and non-limiting. 
         [0015]    Embodiments of the present invention include an apparatus and methods for utilizing a wellhead having both a central bore, which can be suitable for wireline equipment operations, and a plurality of rifled internal bores with peripheral injection ports, which can be suitable for injecting fluid into the central bore. Significantly, the rifled internal bores can comprise a rifled internal surface that is designed to create circular or helical fluid flow for fluids being injected into the wellbore. 
         [0016]    As shown in the Figures, the wellhead features a mixing chamber that can be located beneath the peripheral injection ports, which can comprise the rifled internal surface that is designed to maintain the circular or helical fluid flow, while also blending the fluids from the plurality of peripheral injection ports. The mixing chamber can be located above and fluidly connected to the wellbore. 
         [0017]    Turning now to  FIG. 1A , the Figure depicts an external perspective view of an embodiment of the wellhead  10 , featuring a central bore  12  that can be fastened with a flange  14 , which, as shown, features a plurality of attachment points  16  for fastening the flange  14  to the top surface  18  of the wellhead  10 . In other embodiments, the flange  14  can be attached to the wellhead  10  by any number or any type of attachments (e.g., fasteners). The central bore  12  and the flange  14  are shown in this embodiment with a generic tubular  11  through which wireline operations can be conducted and various mechanical tools passed. 
         [0018]    The wellhead  10 , as shown in  FIG. 1A , can include two primary angled surfaces  20   a ,  20   b  and two secondary angled surfaces  30   a,    30   b  (shown in  FIG. 1B ). Each of these angled surfaces  20   a,    20   b,    30   a,    30   b  can comprise a flange  24   a,    24   b,    34   a,    34   b  (shown in  FIG. 1B ), wherein each flange can comprise a plurality of attachment points for securing a respective peripheral injection port  22   a,    22   b,    32   a,    32   b.  In the depicted embodiment, primary peripheral injection ports  22   a,    22   b  are shown as substantially larger than secondary peripheral injection ports  32   a,    32   b.  However, it can be appreciated by those of skill in the art that this is only one possible configuration of the wellhead, and alternative embodiments may comprise four equally spaced and sized injection ports, or injection ports of four varying sizes, as required by the job. 
         [0019]      FIGS. 1B, 1C, and 1D  depict an external top view, front view, and side view, respectively, of the embodiment depicted in  FIG. 1A . Attention is drawn to the embodiment shown in  FIG. 1B  that clearly depicts all four flanges  24   a,    24   b,    32   a,  and  32   b,  and a plurality of attachment points, which can be used for securing each flange to a respective angled surface  20   a ,  20   b,    30   a,    30   b.  In addition and as shown in  FIG. 1B , the plurality of attachment points for each of the four flanges  24   a,    24   b,    32   a,  and  32   b  can be used for securing a respective peripheral injection port  22   a,    22   b,    32   a,    32   b.  Attention is also drawn to  FIGS. 1C and 1D  which show the depicted embodiment having approximately 50% smaller depth than width, although as with  FIG. 1A , it can be appreciated that these dimensions will vary according to the requirements of the injection port configuration of each particular wellhead  10 .  FIGS. 1C and 1D  depict front and side views, respectively, of the wellhead  10  embodiment of  FIG. 1A .  FIG. 1C  shows flanges  24   a,    24   b,  and  34   a  comprising attachment points for securing respective peripheral injection ports  22   a,    22   b,  and  32   a.    FIG. 1D  shows flanges  24   a,    34   a  and  34   b  comprising attachment points for securing respective peripheral injection ports  22   a,    32   a  and  32   b.    FIGS. 1C and 1D  also depict the central bore  12  of the wellhead  10 , which can be fastened by a flange  14 , and the embodiment shown in these Figures includes a generic tubular  11  through which wireline operations can be conducted and various tools can be passed. 
         [0020]    Turning now to  FIGS. 2A and 2B , a detailed cross-section of the embodiment as depicted in front view  1 C and side view  1 D, respectively, is presented in further detail.  FIG. 2A  depicts the primary peripheral injection ports  22   a  and  22   b  in fluid communication with internal bores  25   a,    25   b.  Attention is drawn to the rifled internal bores  25   a,    25   b,  depicted here as a spiral rib pattern which protrudes slightly outward (i.e. creating a groove) within the space of rifled internal bores  25   a,    25   b.  It should be noted that any method of creating a rifled spiral pattern is within the scope of this embodiment; the spiral pattern may be a concave groove machined into the bore, or a convex protrusion created by a spiral insert attached to the bore surface (or alternatively, an insert may define a concave groove). 
         [0021]    When fluid is injected through either of the primary peripheral injection ports  22   a ,  22   b,  the rifled internal bores  25   a,    25   b  can introduce a centrifugal force into the fluid flow, thus causing the fluid to flow in a circular or helical pattern as it descends through the rifled internal bores  25   a,    25   b  into a mixing chamber  40  at exit orifices  26   a,    26   b.  The mixing chamber  40 , as shown in  FIG. 2A , can comprise a rifled internal bore  45 . 
         [0022]      FIG. 2B  depicts a similar arrangement for the secondary peripheral injection ports  32   a,    32   b,  which are shown in fluid communication with internal bores  35   a,    35   b,  having a similar rifled groove pattern to internal bores  25   a,    25   b.  Similar to  FIG. 2A , the rifled internal bores  35   a ,  35   b  can introduce a centrifugal force into the fluid flow, thus causing the fluid to flow in a circular or helical pattern as it descends through the rifled internal bores  35   a,    35   b,  and also leading to the mixing chamber  40  through respective exit orifices  36   a,    36   b.  While the rifled internal bores  25   a,    25   b  are shown, in  FIG. 2A , having similar dimensions to the central bore  12  of wellhead  10  and matched to the primary peripheral injection ports  22   a  and  22   b,  the rifled internal bores  35   a,    35   b,  in  FIG. 2B , as shown having smaller dimensions to match the secondary peripheral injection ports  32   a,    32   b.    
         [0023]    As with the ports, it can be appreciated that alternate embodiments of the invention may comprise any combination of rifled internal bores, including bores of equal size, or bores having four different sizes. Additionally, it can also be appreciated that some embodiments of the invention may feature un-rifled bore(s), as already known in the art, alongside rifled bores to give operators the option of not utilizing the circular or helical flow pattern introduced by the rifling. 
         [0024]    Mixing chamber  40 , as depicted in  FIGS. 2A and 2B , is a component of the wellhead  10  located internal to the surfaces and beneath central bore  12 . Mixing chamber  40  is depicted here as substantially uniform with central bore  12 ; this confers several advantages including the ability to insert wellbore tools requiring (or preferring) a constant internal diameter, and also simplifies the control of fluid flow through the wellhead  10 . 
         [0025]    Mixing chamber  40  is demarcated by a number of exit orifices  26   a,    26   b,    36   a,    36   b  leading from rifled internal bores  25   a,    25   b,    35   a,    35   b,  respectively, as described above. Mixing chamber  40  can also feature a rifled internal bore  45 , which can act to continue the circular or helical flow pattern of the fluid as it descends into the wellbore (not shown), beneath wellbore  10  and continuous with the central bore  12 . 
         [0026]    In an embodiment, the wellhead  10  is utilized to allow the mixing of fluid (gas or liquid) in the mixing chamber  40  via injection ports  22   a,    22   b,    32   a,    32   b  at the same time as conducting wireline work (including slick-line, braided-line, or electric-line wireline) or remedial work with pipes (coil tubing or jointed pipe). These mixes may include one or more of cement, chemicals, powder, ash, beads, pellets, freshwater, seawater, or brine. 
         [0027]    Various embodiments, usable within the scope of the present disclosure, have been described with emphasis and these embodiments can be practiced separately or in various combinations thereof. In addition, it should be understood that within the scope of the appended claims, the present invention can be practiced other than as specifically described herein.