Patent Publication Number: US-10788054-B2

Title: Reverse flow jet pump

Description:
STATEMENTS REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT 
     Not Applicable. 
     REFERENCE TO A “SEQUENCE LISTING”, A TABLE, OR A COMPUTER PROGRAM 
     Not Applicable. 
     BACKGROUND 
     Technical Field 
     The subject matter generally relates to systems in the field of oil and gas operations wherein a jet pump having a nozzle, throat and diffuser operate through use of the Bernoulli principle. 
     U.S. Pat. Nos. and Publication Nos. 8,118,103; 1,604,644; 8,419,378; and 2,040,890 are incorporated herein by reference for all purposes in their respective entireties. Each and every patent, application and/or publication referenced within each respective referenced patent is also incorporated herein by reference for all purposes in its respective entirety. 
     BRIEF SUMMARY 
     A jet pump of a downhole tool in a wellbore, wherein the jet pump has a nozzle in fluid communication with a throat and wherein the throat is further in fluid communication with a diffuser, the jet pump further having a central channel located towards an uphole end of the downhole tool, wherein the central channel is configured to house a volume of power fluid; a first annular channel defined in the downhole tool, wherein the first annular channel is arranged around the nozzle and in fluid communication with the central channel; a volume of production fluid located towards a downhole end of the downhole tool; a second annular channel defined in the downhole tool configured to house the volume of production fluid; and a reverse channel in fluid connection with the second annular channel, wherein the reverse channel is in fluid communication with the nozzle. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The exemplary embodiments may be better understood, and numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. These drawings are used to illustrate only typical exemplary embodiments of this invention, and are not to be considered limiting of its scope, for the invention may admit to other equally effective exemplary embodiments. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated, in scale, or in schematic in the interest of clarity and conciseness. 
         FIG. 1  depicts a schematic sectional view of an exemplary embodiment of a jet pump of a downhole tool within a wellbore. 
         FIG. 2  depicts a perspective cross sectional view of an exemplary embodiment of a jet pump. 
         FIG. 3  depicts an enlarged view of the embodiment of  FIG. 2 . 
         FIG. 4  depicts an alternate perspective cross sectional view of the embodiment of  FIG. 2 . 
         FIG. 5  depicts an enlarged view of the nozzle region of the embodiment of  FIG. 4 . 
         FIG. 6  depicts a schematic sectional view in perspective of the volume of production fluid and the volume of power fluid in the nozzle and throat region. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT(S) 
     The description that follows includes exemplary apparatus, methods, techniques, and instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described exemplary embodiments may be practiced without these specific details. 
       FIG. 1  depicts a schematic view of a downhole tool  10  in a wellbore  12  having an exemplary embodiment of a jet pump  20 . As depicted in  FIG. 1 , the exemplary embodiment of the jet pump  20  is a liquid-liquid jet pump; optionally, the jet pump  20  may also function as a liquid-gas jet pump. The downhole tool  10  generally has an end  11  that is closer uphole to the surface of the wellbore  12  and, an end  13  that is more downhole in relation to the wellbore  12 . Although the wellbore  12  is depicted as a vertical wellbore, the wellbore  12  may also have other configurations; by way of example only, the wellbore  12  may be horizontal or substantially horizontal in shape, or curved. Further, the wellbore  12  may optionally be lined with a casing or tubular  16 . There may be an annulus  14  between the downhole tool  10  and the wellbore  12 , or between the downhole tool  10  and casing or tubular  16 . The downhole tool  10  may have a sealing element or packer  18  to sealingly engage against the inner wall  15  of the wellbore  12  or casing  16 . When the oilfield operations commence, the wellbore  12  may produce a volume of production fluid  30 . The downhole tool  10  may prevent the volume of production fluid  30  from entering a portion of the annulus  14  by activating the sealing element  18 . The annulus  14  may further be divided into a top annulus  14   a  and bottom annulus  14   b  when the sealing element  18  is engaged. 
       FIGS. 2-5  depict various cross section views of an exemplary embodiment of the jet pump  20 . The jet pump  20  includes a nozzle or inner nozzle  22  which is in fluid communication with a throat  24 . The inner nozzle  22  may have an inner diameter of  54 . Although in fluid communication with the throat  24  in the exemplary embodiments depicted in  FIGS. 2-5 , the tip  21  of nozzle  22  is not physically connected to the throat  24  (as seen in the enlarged cross section depicted in  FIG. 5 ). The throat  24  is further fluidly connected to a diffuser  26  at the end opposite to the nozzle  22 . The throat  24  has an inner wall or surface  25 , and the diffuser  26  may also have an inner wall or surface  27 . The jet pump  20  includes a central channel  42  which houses a volume of power fluid  40 . The jet pump  20  may also possess one or more ports  46  which allow fluid flow from the central channel  42  to a first annularly arranged channel or annular channel or external nozzle  44  which surrounds the internal nozzle  22  (as can be seen in the enlarged view of  FIG. 5 ). The external nozzle  44  may have a flow diameter  56  (i.e. a diametrical range between an inner and outer diameter of the annular channel/external nozzle  44  defining a gap). The flow diameter  56  of the external nozzle  44  is greater than the inner diameter  54  of the internal nozzle  22 . The flow diameter  56  of external nozzle or annular channel  44  progressively narrows (or external nozzle  44  decreases in flow area) from entrance end to exit end, whilst the flow diameter  56  of the external nozzle  44  remains greater in size than the inner diameter  54  of the internal nozzle  22  from the entrance end to the exit end. Further, the first annular channel  44  may be contiguous with the inner wall  25  of the throat  24 . 
     The jet pump  20  may also include in an exemplary embodiment a second annularly arranged or annular channel  32  which is connected to the supply or volume of production fluid  30  by production fluid duct(s)  33 . In one exemplary embodiment, the diffuser  26  of the jet pump  20  may be defined within and distinct from the second annular channel  32 . The second annular channel  32  may connect to a reverse channel  34 , which may be a bore angled, by way of example only, at less than or equal to ninety (90) degrees in relation to the second annular channel  32 , or at any other angle which may allow the flow from the reverse channel  34  into the nozzle  22  or a feed end of the nozzle  22 . The reverse channel  34  is in fluid communication with the center of the nozzle  22 . Further, the reverse channel  34  does not intersect the first annular channel  44  or the ports  46 . 
     Referring back to  FIG. 1 , the volume of production fluid  30  and the volume of power fluid  40  may be commingled in the throat  24  and diffuser  26  to become a volume of a commingled fluid  50 . Further, as can be seen in  FIG. 1 , in an exemplary embodiment the diffuser  26  may also have one or more outlet orifices  29   a  in fluid communication with a commingled annulus  29   b  which is in fluid communication with channel(s)  28  which guide, direct, or transport the flow of the volume of commingled fluid  50  to the top annulus  14   a . Channel  28  in the exemplary embodiment shown is radial and generally functions to bridge or redirect flow of the commingled fluid from a downhole direction to an uphole direction. Outlet orifices  29   a  bypass or do not intersect production fluid duct(s)  33  and annular channel  32 . The commingled annulus  29   b  has greater inner and outer diameters than that of the annular channel  32 . 
     When operating the jet pump  20 , the packer or sealing element  18  is activated or energized to engage with the inner wall  15  of the wellbore  12  or tubular  16 , thus dividing the annulus  14  into a top portion annulus  14   a  above the packer  18  and a bottom portion annulus  14   b  below the packer  18 . 
     The oilfield operator may then supply, provide or pump the volume of power fluid  40  into the central channel  42  of the jet pump  20 . The power fluid  40  may then flow into the first annular channel  44  through ports  46 , and the first annular channel  44  progressively narrows creating an annular jet of power fluid  40  flow. The power fluid  40  then moves or jets into an uphole end of the throat  24 . The volume of power fluid  40  enters or jets into the throat  24  as an annular flow or stream of power fluid  40  which is adjacent to and coats or overlaps the inner wall  25  of the throat  24  providing a buffer zone between production fluid  30  and the inner wall  25 . 
     The wellbore  12  has a supply of production fluid.  30  within the wellbore  12  and towards the bottom annulus  14   b  and downhole end  13  of the downhole tool  10 . The volume of production fluid  30  may travel from the bottom annulus  14   b  of the wellbore  12  (or casing  16 ) into the downhole end  13  of the downhole tool  10 . The volume of production fluid  30  may next flow into the production fluid duct(s)  33  and then the second annular channel  32  and through the reverse channel  34  to the nozzle  22 . The production fluid  30  is entrained (via. Bernoulli principle/Venturi effect by the power fluid jetting through and out a progressively narrowing annular channel  44  into a region of greater area/volume) as a stream, or flow through the nozzle  22  and then into an uphole end of the throat  24 , where the production fluid  30  flows into the middle of the annular stream of power fluid  40 . The volume of power fluid  40  surrounds or buffers the production fluid  30  from contacting the inner wall  25  of the throat  24 . Thus, any or many cavitation bubbles entrained in the production fluid or formed in or between the interfaces of fluids  30 ,  40  may implode within, or be absorbed by the volume or zone of buffering power fluid  40  and the cavitation bubbles will not contact or are buffered from contacting or harming the inner wall  25  of the throat  24 , thus protecting said inner wall  25 . Cavitation bubbles, if contacted with the inner wall  25  or inner wall  27 , may erode and damage the throat  24  and/or diffuser  26 , respectively. The power fluid  40  and production fluid  30  may also initiate comingling at an interface between the respective fluids, whilst buffering of the production fluid  30  by the power fluid  40 , in the throat  24  of the jet pump  20  and may then flow together further comingling in the diffuser  26 . 
     Although the power fluid  40  and production fluid  30  may begin comingling in the throat  24  to form a volume of commingled fluid  50 , a distinct layer or buffer of power fluid  40  may still persist in at least a portion of or overlapping the inner wall  27  of the diffuser  26 , such that the diffuser  26  may also be protected from cavitation bubbles with a buffer of power fluid  40 . The volume of production fluid  30  and volume of power fluid  40  may continue to commingle in the diffuser. Thereafter, the volume of commingled fluid  50  may leave the diffuser  26  through one or more outlet orifices  29   a  (to bypass production fluid duct(s)  33 ) flowing next to commingled annulus  29   b  and then to channel(s)  28  for exiting the diffuser  26 . These outlet orifices  29   a , commingled annulus  29   b  and channel(s)  28  allow fluid communication from the diffuser  26  to the annulus  14  (or upper annulus  14   a ) whilst redirecting flow from the downhole direction as after leaving the channel(s)  28 , the commingled fluid  50  travels, moves or is transported uphole in the annulus  14   a  to the surface of the wellbore  12  where the commingled fluid  50  can be retrieved by the oilfield operator. 
       FIG. 6  depicts a schematic view of the volume of production fluid  30  and the volume or buffer of power fluid  40  in contact in the nozzle  22 ,  44  and throat  24  region. The surface area(s) or region(s) of contact  52  (defined generally as a cylindrical and/or frusto-conical shaped surface area or region) respectively between the two fluids  30 ,  40  as depicted in  FIG. 6  may have different geometries in alternative exemplary embodiments. For example, the surface area(s) of contact  52  may extend much farther into the throat  24  in alternative exemplary embodiments than is depicted in  FIG. 6 , or the two fluids  30 ,  40  may contact immediately after leaving the tip  21  of the nozzle  22 . It is to be appreciated that even if portions of the fluids  30 ,  40  begin to mix into a volume of commingled fluid  50  in the throat  24 , that a residual buffer of power fluid  40  may persist well into the throat  25  or diffuser  26  by laying adjacent to the inner walls  25 ,  27  (see  FIG. 4 ), respectively. 
     By way of example only, the surface areas of contact  52  may further be characterized as an initial surface area of contact  52   a  and a variable surface area of contact  52   b . The initial surface area of contact  52   a  between the two volumes fluids  30 ,  40  may occur at or proximate an inner wall  58  of the flow diameter  56  of the external nozzle  44  (at a first position where the volume of production fluid  30  exits the tip  21  of the internal nozzle  22 , at an inner diameter  54  of the internal nozzle  22 ). The variable surface area of contact  52   b  between the two volumes of fluids  30 ,  40  is a second downstream position  52   b  (relative to the first position  52   a ) which may occur at some variable distance within the throat  24  or diffuser  26 . The resultant surface area(s) of contact  52  between the jetted volume of power fluid  40  after exiting the exterior annular passage (or the external nozzle)  44  (especially if at, proximate or nearer the first position/initial surface area of contact  52   a ) and the volume of production fluid stream  30 , is relatively larger or greater than the surface area of contact between the two fluids in conventional prior art jet pumps (where the jet core is in the center and production fluid flows around of the jet core). 
     Advantage(s) resulting from the foregoing is that since the surface area of contact  52  between the volumes of power fluid  40  and produced/production fluid  30  is considerably or relatively larger in the present jet pump  20 , the momentum transfer between the two volumetric streams of fluids  30 ,  40  can be more effective than in conventional prior art jet pump configurations (which may only have an efficiency on the order of 30-35%), and increasing the surface area of contact  52  (i.e. increasing the surface area that the volume of power fluid  40  and the volume of produced fluid  30  are in contact directly relates to increasing the efficiency in jet pump  20 ). 
     While the exemplary embodiments are described with reference to various implementations and exploitations, it will be understood that these exemplary embodiments are illustrative and that the scope of the inventive subject matter is not limited to them. Many variations, modifications, additions and improvements are possible. For example, although the exemplary embodiments have been depicted and described with various “annular” channels (for example, annular channels  32 ,  44  and  29   b ), it is to be appreciated that these channels may not necessarily be annular in shape, but may be of any orientation to allow and arrange for the flow of the production fluid and power fluid as described. As an additional example, although central channel  42  is depicted and described as a central axial throughbore of the downhole tool  10 , it is to be appreciated that the supply of the volume of power fluid  40  may reach the annular channel  44  through other flow path geometries. 
     Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter.