Abstract:
A multi-tasking downhole rod guide for centralizing a downhole pump rod production tubing within production tubing, while simultaneously reducing abrasion and deterioration of the production tubing and engendering auxiliary pump-boosting functions—with minimal energy consumption. The rod guide is configured with an elongate helix having a continuous trough-like channel through hydrocarbons flow upwardly under high pressure. As the pressurized hydrocarbons flow through a succession of plates at each equidistant helical level, the elongate helix rotates synchronously with the upwardly flowing hydrocarbons within the production tubing string. A multi-tasking downhole rod guide for centralizing downhole production tubing within a well casing, while simultaneously reducing abrasion and deterioration of the tubing and engendering auxiliary pump-boosting functions—with minimal energy consumption. The rod guide is configured with an elongate helix at each equidistant level which rotates in synchronization with the production string.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority based upon U.S. Provisional Application Ser. No. 61/471,196 filed Apr. 3, 2011. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to a downhole rod guide apparatus, and more particularly relates to an apparatus for performing a rod guide centralizer function downhole within a well bore, while simultaneously performing tubing-abrasion-reduction and auxiliary pump-boosting functions, with concomitant minimal energy consumption. 
       BACKGROUND OF THE INVENTION 
       [0003]    There have been developed several downhole rod guides for sustaining the centralized disposition of a pumping rod within a string of production tubing. It is well known that such conventional rod guides suffer from excessive wear and abrasion under the influence of upwardly streaming high-pressure hydrocarbons. Such hydrocarbon streams typically include abrasive solid materials such as sand and debris which drastically undermine rod guide life cycle particularly because these occluded materials are moving at high speed. In addition, these solids and other troublesome materials appreciated tend to inhibit the upwards hydrocarbon flow. 
         [0004]    These and other known deficiencies in the rod guide art have continued to render sustaining continuous flow of hydrocarbons from subsurface formations via downhole pumping systems upwardly to the well surface elusive to remedy, and unduly expensive in view of the necessity to frequently conduct rod guide maintenance because of inherently short life cycles and substantial consumption of energy to sustain demanding pumping requirements. Accordingly, these limitations and disadvantages of the prior art are overcome with the present invention, wherein improved means and techniques are provided which are especially useful for pumping hydrocarbons to the well surface with minimal prerequisite maintenance and without consuming substantial extra energy. 
       SUMMARY OF THE INVENTION 
       [0005]    Embodiments of the present invention afford a panoply of functions heretofore unknown in the downhole art. In particular, embodiments not only perform the well known rod guide centering function relied upon by practitioners in the art, wherein a string of interconnected rotating rods is centrally guided within production tubing, which, in turn, is circumscribed by well casing, but also simultaneously perform a plurality of supplemental functions crucial to efficient continuous lifting of hydrocarbons from a subsurface formation downhole to the well surface. 
         [0006]    As will be understood by those skilled in the art, such embodiments may be adapted to effectively achieve the hydrocarbon pumping purposes contemplated hereunder for many variations of hydrocarbon pumping protocols such as are achieved primarily via circular pumps, and including jack pumps, centrifugal pumps, etc.—with minimal additional energy being consumed. For instance, embodiments may be molded to accommodate a variety of formations and therein be readily adapted to suit both rotating and reciprocating downhole pumping applications. Embodiments would be screwably secured, or secured via like connection, to the pump rod at the well base—at the point of downhole hydrocarbon extraction—and with the production tubing locked into place in a manner well known in the art. Thus, rod guide embodiments of the present invention are integrated with and disposed concentrically of the axial pump rod in order to perform the rod-centralizing function in a manner heretofore unknown in the art. 
         [0007]    Embodiments of the multi-tasking rod guide taught herein preferably comprise an elongate helix, i.e., helical configuration, which, as clearly depicted in the drawings, incorporate a spiral configuration preferably nominally every 90°, but not limited to 90° , that continually rotates as hydrocarbons are urged upwardly from downhole, toward the well surface. It will be appreciated that this continual rotational action of upwardly-flowing hydrocarbons causes the helical structure contemplated by embodiments of the present invention to synchronously rotate along with the flowing hydrocarbons within production tubing and the like. It is estimated that, for every rotation of embodiments of the present invention, approximately a ½ inch lift is realized per 90° so that approximately 2 inches of hydrocarbon fluid are lifted for each rotation. 
         [0008]    As will be hereinafter described, this helix structure is preferably configured to bias upward vertical hydrocarbon fluid movement more than horizontal hydrocarbon fluid movement. It will be understood that angular momentum is engendered and efficiently used to lift recovered hydrocarbons being driven by substantial upward pressure. An important aspect of embodiments hereof is that, in the course of achieving unprecedented efficient upward flow of hydrocarbon fluids, there is virtually no inhibiting influence manifest thereupon. Notwithstanding, of course, this paucity of inhibiting influences may be promoted by practitioners in the art invoking such commonly-applied devices as shim-stock, spacers, or otherwise adjusting string-connecting threads to facilitate a tight fit in rod guide embodiments for delivering optimum rotational efficiency contemplated hereunder. 
         [0009]    Heretofore unknown in the rod guide prior art, preferred embodiments of the present invention configured with a slip ring or the like at the well surface enable conventional pump-driven rotation to be supplemented by booster pumping action which is effectuated when the “horse” pulls upwardly and downwardly—manifest as conventional pump action—while causing the pump rod to rotate, thereby causing upwardly-directed pumping action emanating downhole. It should be evident that that this rotational movement of the helical structure taught herein effectively fosters continuous upward hydrocarbon flow, since the crucial downhole pumping function has been unexpectedly and significantly enhanced. Furthermore, it will also be seen that embodiments of the present invention have been preferably structured in order to inherently impart unique dislodging and scooping functions at the well bottom via a specially-configured bottom-level member, wherein the downhole hydrocarbon stream is urged to enter a trough-like member functioning as if it were a track or channel of the helical structure and then this hydrocarbon stream is pushed upwards inherently synchronized with rotation of the centralizing rod guide, i.e., the hydrocarbon stream is urged upwardly under the forceful influence of the instant multi-function rod guide. 
         [0010]    It has been found to be advantageous for embodiments of the present invention to be configured with a top-level member having a plurality of ball bearings or the like, preferably with four or six such ball bearings or the like, in order to facilitate fluid travel and flow mechanics as will hereinafter be described. It has also been found to be particularly effective, once the typical high-pressure hydrocarbon flow—as high as 4500 psi—reaches atop the production string, to include a spring-loaded retention member or the like to reduce counterproductive reverse flow upon the production string&#39;s upwardly-powered flow when pumping ceases. Embodiments should also preferably be structured with beveled edges or like structures to promote being seamlessly mated with the trough-like member taught herein. 
         [0011]    Thus, it will be appreciated that preferred embodiments have been configured to eliminate and to avoid potentially troublesome backflow of hydrocarbons which have been pumped from downhole to the well surface. Since hydrocarbon backflow has essentially inherently been prevented, conventional procedures such as flow-line re-priming and the like have been rendered unnecessary. Accordingly, application of preferred embodiments of the instant multi-purpose rod guide flow-lines have inherently become devoid of the presence of any air. 
         [0012]    Of course, as is well known by those skilled in the art, it is essential that any apparatus introduced into the production string sustain optimal hydrocarbon flow, i.e., avoid inhibiting upward flow of hydrocarbons. Accordingly, it has been found that helix configurations of the present invention should be in the range 90° to 180°, and preferably be in the range 110° to 130°, and more preferably be in the range 115° to 120°. 
         [0013]    It will also be seen that embodiments of the present invention should preferably overlap the production string inner wall at the top portion of the well. To achieve this inner wall-overlap, a suitable predetermined portion of the inner wall should be cut out for snugly accommodating therewithin the implicated portion of the instant multi-tasking rod guide. As an example, for producing wells having 4 inch inside diameter production tubing, ¼ inch thick, a 5 inch top piece would be appropriate. The walls could be situated as 4 ½ inches with ¼ inch indenture achieved by cutting ⅛ inch into each side, to effectuate the prerequisite contemplated overlap. For this illustration having a 4 inch length from the offset and a ¼ inch cut into the inner surface of the wall, the extra pump-boosting pressure on upward hydrocarbon flow may be shown by the formula: 
         [0000]      Volume for rotation=(π)×(4¼ inch)×(2 inches)   (1)
 
         [0000]    Practitioners in the art will recognize this relationship as corresponding to the volume of hydrocarbon liquid being lifted upon and through the helix structure of the present invention. 
         [0014]    If rotation of the production string were to cease, then it is contemplated that the helix configuration taught by the present invention would be sealed because of consequent plugging that would be inherently effectuated. 
         [0015]    Thus, it should be evident that important features of embodiments of the present invention are manifest as the elongate helical structure revolves each cycle through its heighth, thereby sustaining the centered position of the production rod, while simultaneously performing in-line booster pumping upon the upwards-flowing stream of hydrocarbons—in turn, urging the hydrocarbons upwardly through the trough-like channel path of the continuously rotating helix structure. 
         [0016]    It will also be seen that preferred embodiments of the present invention should be designed with a plurality of sharp edge members at the bottom of the helix in order to break up accumulations or clumps of high-viscosity tar balls and the like, akin to the action of a conventional paper-cutter. By avoiding or at least minimizing the adverse impact of high viscosity clumps of tar balls, embodiments of the present invention tend to optimize the upward flow of hydrocarbons as contemplated hereunder. 
         [0017]    It is accordingly an object of the present invention to provide a novel downhole rod guide that exceeds the capabilities and expectations of rod guides known in the art. 
         [0018]    It is also an object and advantage of the present invention that a multi-tasking rod guide is disclosed that not only handily performs the centering function known in the art, but also affords auxiliary pumping to supplement upwardly pumping of hydrocarbons from the well-bottom and inherently imparts less abrasion on the contact surfaces of production string and casing walls, respectively. 
         [0019]    It is also an object and advantage of the present invention that embodiments simultaneously perform a plurality of functions without substantially increasing the demand for consumption of energy. 
         [0020]    These and other objects of the present invention will become apparent from the following specifications and accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  depicts a frontal perspective view of a multi-tasking rod guide embodiment of the present invention, with half of the well casing removed. 
           [0022]      FIG. 2  depicts a cross-sectional view of the multi-tasking rod guide embodiment depicted in  FIG. 1 , and depicting a side view of the lower section thereof. 
           [0023]      FIG. 3  depicts a top view of the backflow preventer feature of the multi-tasking rod guide embodiment of the present invention depicted in  FIGS. 1 and 2 . 
           [0024]      FIG. 4  depicts a top view of the multi-tasking rod guide embodiment depicted in  FIG. 1 . 
           [0025]      FIG. 5  depicts a cross-sectional view of the multi-tasking rod guide embodiment depicted in  FIG. 2 , wherein the section is depicted along line  4 - 4 . 
           [0026]      FIG. 6  depicts a cross-sectional view of the multi-tasking rod guide embodiment depicted in  FIG. 2 , wherein the section is depicted along line  5 - 5 . 
           [0027]      FIG. 7  depicts a bottom view of the multi-tasking rod guide embodiment depicted in  FIGS. 1 and 2 . 
           [0028]      FIG. 8  depicts a frontal perspective view of a portion of the multi-tasking rod guide embodiment depicted in  FIG. 1 , featuring the backflow preventer contained in the top thereof. 
           [0029]      FIG. 9  depicts a frontal perspective view of a portion of the multi-tasking rod guide embodiment depicted in  FIG. 2 , featuring an intermediate plate member of its plurality of intermediate plate members. 
       
    
    
     DETAILED DESCRIPTION 
       [0030]    Reference is made herein to the figures in the accompanying drawings in which like numerals refer to like components. Table 1 enumerates the assigned numerals. 
         [0000]    
       
         
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 1 
               
             
             
               
                   
               
               
                 Rod Guide Component Listing 
               
             
          
           
               
                 # 
                 Component Name 
                 Structure/Function 
                 Remarks 
               
               
                   
               
             
          
           
               
                 2 
                 pump rod 
                 axial 
                   
               
               
                 5 
                 hydrocarbon stream 
                 flowing upward toward surface 
                 high-pressure stream 
               
               
                 10 
                 rod guide 
                   
                 multi-functional 
               
               
                 15 
                 overlap-portion 
                 overlaps casing internal wall per cut-out 
               
               
                 30 
                 helical portion 
                 elongate 
                 continuously rotating 
               
               
                 40 
                 trough-like channel 
                 manifest on each successive helical level 
               
               
                 45 
                 entry point at bottom 
                 entry into channel at bottom (lowest level) 
               
               
                 50 
                 bevel 
                 disposed on backside of helix 
                 avoid contacting tubing 
               
               
                 55 
                 plurality of detents 
                 limits movement of backflow preventer 
               
               
                 h 
                 inter-level height 
                 between each successive helical level 
               
               
                 60 
                 plurality of plates 
                 collection surface at each level 
               
               
                 65 
                 collection plate 
                 at each level 
                 except top level 
               
               
                 66 
                 plurality of pillars 
                 4 per level; strengthens each level 
               
               
                 68 
                 pillar 
                 at each level 
               
               
                 70 
                 top collection plate 
                 at top level only 
                 thicker for stability 
               
               
                 75 
                 opening 
                 90-120°; on back-flow preventer 
               
               
                 80 
                 back-flow preventer 
                 prevents reverse flow of hydrocarbons; preferably 
                 prefer minimum 6 sides 
               
               
                   
                   
                 6-8 sides, forms secure seal 
               
               
                 85 
                 plurality of rollers 
                 ball bearings 
               
               
                 100 
                 bottom scooping plate 
                 configured with sharp edges to dislodge viscous 
                 like snow shovel for cutting &amp; 
               
               
                   
                   
                 hydrocarbons on well bottom 
                 scooping tar balls, etc. 
               
               
                 120 
                 plurality of sharp edges 
                 breaking up clumps of high-viscosity tar balls, 
                 help optimize upward flow of 
               
               
                   
                   
                 etc., at well-bottom 
                 hydrocarbon 
               
               
                 155 
                 well surface 
               
               
                 200 
                 production tubing 
                 production string 
               
               
                 225 
                 interior walls 
               
               
                   
               
             
          
         
       
     
         [0031]    Referring to  FIGS. 1-9 , there is depicted a preferred embodiment of the present invention corresponding to a multi-tasking rod guide apparatus  10  circumscribing and centralizing pump rod  2  as will be hereinafter described. 
         [0032]    Specifically referring now to  FIGS. 1 and 2 , there is depicted a frontal perspective view of the elongate continuous helical configuration  30  taught by the present invention and a corresponding frontal cross-sectional view thereof, respectively. In particular, the helix comprising helical portion  30  is elongated in a vertical orientation and comprises a continuous trough-like channel  40  disposed on each plate member  65  situated on each of a succession of helical levels of plurality of plate members  60 . As depicted therein, each level of plurality of levels  60  comprises plate member  65 . Thus, fluid hydrocarbon  5  is driven upwards via continuous trough or channel  40  and its implicated plurality of collection plates level members  60 , and is ultimately delivered to well surface  155  under high-pressure. 
         [0033]    As clearly shown in partial cut-away frontal view in  FIG. 1 , while helical member  30  comprises a plurality of levels  60  with each level  65  being virtually identical to the other, top-level collection plate member  70  and bottom level scooping plate member  100  are configured differently in order to afford specific functions as herein described. In particular, the angular disposition of plurality of plate members  60  and top-level collection plate member  70  are offset from 90° for enabling uninterrupted upward hydrocarbon flow through continuous channel  40 . Bottom-level plate member  100  is configured at a steeper angle adjacent the well bottom in order to enable snow-shovel-like combined dislodging and scooping actions to facilitate, first, urging separation of viscous hydrocarbons  5 , e.g., as tar balls and the like, from the well bottom and, second, urging entry of such dislodged and scooped viscous hydrocarbons into channel lowest level  45  and consequent upward travel thereof along the trough-like channel  40  manifest on each plate member  65  situated on each corresponding successive helical level member of plurality of level members  60 , as hydrocarbon  5  is driven to the well surface  155  under high-pressure. 
         [0034]    In order to enable this contemplated efficient scooping function, it has been found that offsets ranging from about 20° to 30° are preferred; it will be understood by practitioners skilled in the art that these preferred offsets correspond to angles of about 110° to 120° relative to the horizontal. Those conversant in the art will also note that the elongated helix located at the lower plate level of plurality of plates  60  is depicted in  FIG. 2  with a bevel  50  disposed on the rear of the helix. This bevel configuration tends to avoid striking the production tubing  200  in a flat disposition, thereby affording extra support thereto, and smoothly commencing continuous upward helical movement thereof as contemplated hereunder. 
         [0035]    Each successive level member  65  of this helical configuration should preferably be successively spaced apart equidistant in a vertical disposition with height “h” between each such level member being essentially identical to every other level-member height differential. For instance, in one application of instant multi-tasking rod guide  10 , each helix level member  65  has been designed to measure approximately h=2% inches. With each level of helix  65  configured to be angled upwards, there is formed a trough-like channel  40  that tends to guide the pressure-driven continuous flow of hydrocarbon fluid  5  upwardly as the helix of the helical portion  30  is caused to rotate synchronously with hydrocarbon  5  within concentrically situated interior wall  225  of production tubing  200 . Hydrocarbon fluid  5  ultimately reaches atop axial pumping rod  2  near well surface  155  and tends to be delivered via a squirting and spraying action thereof atop at helix level member  70 , which serves as a collection plate or the like. 
         [0036]    Thus, as clearly depicted in the partial cut-away views in each of  FIGS. 1 and 2 , top collection plate  70  contained at the upper level member of helix  30  is configured to be thicker than plurality of lower level members  60  of this helix structure. For the illustrative scenario hereinbefore referenced, having a preferred thickness of from about 1½ to 2 inches, top plate member  70  lends integrity atop production string  200  as high-pressure hydrocarbon stream  5  is thrust upon this uppermost plate member typically with a squirting action. 
         [0037]    Now referring to  FIGS. 1-3 ,  6 , and  8 , the backflow prevention aspect of the preferred embodiment is depicted. As will be appreciated by practitioners skilled in the art, backflow preventer  80  enables hydrocarbons  5  to continuously flow upwardly within production string  200  without being inhibited by contra-flowing hydrocarbons. In this preferred embodiment, reverse flow preventer  80  is structured in a hexagonal configuration with a plurality of rollers  85  or the like affixed on at least two of its sides in order to promote uninhibited rotational movement thereof and raising or lowering thereof as hydrocarbon flow conditions may dictate. 
         [0038]    It is also an aspect of the present invention that the fit of backflow preventer  80  should preferably be essentially flush with interior walls  225  of production tubing  200  or include bevels  50  to assure that there is inherently no backflow so long as power is being supplied to the downhole pump system. Thus, where hydrocarbon  5  enters top helix plate  70  by a squirting and spraying action thereonto, this backflow preventer  80  should preferably fit snugly so as to securely seal hydrocarbon fluid  5  collected upon top-level member  70 . 
         [0039]    Based upon conditions prevalent in the downhole art, those skilled in the art will appreciate that it should generally be advantageous to provide the helical structure of the present invention with sides of ¾ to 1 inch width in order to achieve contemplated structural stability prerequisite for minimizing or even eliminating lateral movement thereof. In addition, it will also be understood that the clearance range of embodiments of the present invention are relatively small because of the extremely high pressures manifest during contemplated pumping of hydrocarbon towards the well surface. Indeed, based upon observations and experience in the art, a clearance as small as 0.01 inch may be too large and thus may be inadequate to be compatible with the protocol hereindescribed. 
         [0040]    Accordingly, preferred embodiments of the present invention should have a clearance range of only 0.001 to 0.005 inch to effectively perform as hereindescribed. That is, affording a tight fit between the exterior of rod guide embodiments of the present invention and production tubing interior surfaces is crucial to the successful heretofore unrealized efficient upward flow of hydrocarbon fluid. In conjunction with the stable structures taught hereunder, such close tolerances prevent lateral shimmy effects or slipping of rod guide  10  annularly disposed between pump rod  2  and production tubing  200 , thereby wholly avoiding consequent damage to production tubing attributable to scoring by grit and like foreign solid matter situated in situ with hydrocarbon  5  streaming upwardly to the well surface at high speeds and under high pressures. 
         [0041]    Based upon conditions prevalent in the downhole art, it is generally advantageous to provide the helical structure of the present invention with sides of ¾ to 1 inch width in order to achieve contemplated structural stability for minimizing or even eliminating lateral movement. It will also be readily appreciated by practitioners familiar with adverse viscosity conditions in Venezuela and similar exigent environments, wherein tar and likewise viscous materials are unavoidably present, that, as depicted in  FIGS. 1 and 2 , bottom-level member  100  comprises plurality of specially-configured members  120  having sharp rib-like and blade-like members for inherently simultaneously cutting into and dislodging viscous, semi-solid and liquid hydrocarbons, thereby promoting upward flow thereof—under the influence of downhole pumping known in the art—but reinforced by the auxiliary pumping action taught by the present invention. 
         [0042]    Moreover, it will be appreciated that, in such environments of extreme viscosity, embodiments of the present invention may optionally include any of several well known heating protocols to overcome pumping limitations. For instance, in one embodiment of the present invention, an electric heating member may be incorporated thereinto in order to further augment its extraordinary pumping capability. That is, based upon the novel helical structure taught herein, embodiments thereof may be invoked to supplement conventional pumping action and normal pump capabilities by tending to boost upward hydrocarbon fluid flow through its helical trough-like structure. It will be readily appreciated that this supplemental pumping aspect of the present invention continuously urges upward channel-flow of hydrocarbon until the top-level collection plate member has been reached and, ultimately, until the well surface has been reached shortly thereafter. It will also be understood that other environmental pumping limitations may be attributable to variation in temperature of downhole hydrocarbon so that a plethora of alternating hot spots and cold spots may be overcome by providing heat thereto, particularly at and/or near the well-bottom. 
         [0043]    It will be understood that embodiments hereof have been structured to afford sufficient vertical support attributable to its inherent stability. Referring now to  FIGS. 1-2 , and  8 - 9 , each pillar member  68  of plurality of pillar members  66  is disposed between each successive level member  65  of plurality of level members  60  to afford strength to the helical structure contemplated herein. Another aspect of this innate stability is the top-level plate structure which includes the hereinbefore described backflow preventer. More particularly, the opening  75  of this backflow preventer  80  is preferably 90° to 120° which corresponds to about ⅓ of 360°. Preferably constructed from solid metal or like strong and solid material, the backflow preventer acts like an immovable weight when it is caused to essentially drop into a 90° to 120° “hole”  75  if and when rotation abruptly ceases. 
         [0044]    Ergo, it will be readily seen that backflow preventer  80  plugs the implicated 90°-120° hole  75 , thereby preventing undesirable hydrocarbon backflow. It should be appreciated that the presence of a plurality of ball bearings on plurality of rollers  85  enable backflow preventer  80  to readily adapt as hydrocarbon fluid conditions vary, by appropriately sliding upwardly and downwardly to sustain optimal flow of hydrocarbon to the well surface. To further assure stable operation of embodiments of the present invention, a plurality of structural detent members  55  is disposed above the backflow preventer  80  to limit and control the extent of its upward movement. Embodiments of the backflow preventer may be configured with 8 sides instead of 6 sides especially to accommodate asynchronous rotation, thereby tending to effectively prevent hydrocarbon backflow under a diversity of demanding conditions. 
         [0045]    Those skilled in the art will appreciate that the present invention seals off the high-pressures that are engendered downhole and that drive hydrocarbons to the well surface, and, in so doing, inherently restricts direct pressure from being imposed upon vertical side wall by deflecting direct pressure thereupon. There is no bleed-over manifest on the sides thereof, shielding the sides from astronomically high pressures from the surface. 
         [0046]    Other variations and modifications will, of course, become apparent from a consideration of the structures and techniques hereinbefore described and depicted. Accordingly, it should be clearly understood that the present invention is not intended to be limited by the particular features and structures hereinbefore described and depicted in the accompanying drawings, but that the present invention is to be measured by the scope of the appended claims herein.