Patent Publication Number: US-11384621-B2

Title: Automatic flow control valve

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application No. 62/536,730 filed Jul. 25, 2017 entitled Automatic Flow Control Valve. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates generally to hydrocarbon well control, and in particular to a method and apparatus for controlling inflow within a zone of a subterranean formation during production. 
     2. Description of Related Art 
     In hydrocarbon production, it has become common to utilize directional or horizontal drilling to reach petroleum containing rocks, or formations, that are at a horizontal distance from the drilling location. Horizontal drilling is also commonly utilized to extend the wellbore along a horizontal or inclined formation or to span across multiple formations with a single wellbore. 
     In horizontal hydrocarbon wells, it is frequently desirable to select which zone of the wellbore is to be opened for production. One method of selecting a zone to be opened is to provide valves within each zone which may be selectably opened to provide access to the zone, as desired by the user. One conventionally type of valve which may be utilized in such situations is a sleeve valve having a plurality of ports therethrough which may be selectably covered or uncovered by sliding a sleeve within a pipe. 
     During production, a zone may, at times, have excess water in the production zone, which is undesirable within the well. When there is excess water in a zone, valves must be closed to limit water contamination. 
     One current difficulty with the sleeve valves is that although zones may be selectably opened or closed, additional tools and sensors may be required to determine the location of the water inflow such that the correct valve(s) may be closed. Additionally, such valves may require a tool to be run into the valve to mechanically open or close it. It may be time consuming to detect which valve(s) must be closed and then to run the tool into the valve(s) to mechanically close them. Furthermore, should conditions within a zone change over time such that subsequently the water therein is redistributed or eliminated, valves must be periodically opened and tested to determine if the zone can be returned to production. This is also a time consuming operation. 
     SUMMARY OF THE INVENTION 
     According to a first embodiment of the present invention there is disclosed an apparatus for controlling the flow of a fluid from a subterranean well zone to a pipe located within a bore in the well zone comprising an elongate tubular body having an interior passage and a valve passage extending between an exterior of the tubular body and the interior passage with a sliding sleeve adapted to selectably cover and uncover the valve passage. The apparatus further includes a chamber formed on one end of the sliding sleeve and having an elongate narrow passage extending thereto from the exterior of the tubular body, wherein a pressure drop of the fluid through the elongate narrow passage is adapted to move the sliding sleeve between a closed and an open position and a flow restrictor between the chamber and the interior passage of the tubular body wherein the flow restrictor has a pressure drop dependent only upon a flow rate of the fluid therethrough. 
     The chamber may include a spring therein biasing the sliding sleeve to the closed position. The elongate narrow passage may be formed as a spiral chamber within a wall of the tubular body between the interior passage and the exterior of the tubular body. The elongate narrow passage may be formed between threading of a first and second tubular bodies. The threading may be adjustable in length so as to be operable to adjust the pressure drop therethrough. 
     According to a further embodiment of the present invention there is disclosed a method for controlling the flow of a fluid through a valve within a subterranean well zone comprising producing a first pressure drop between an exterior of a valve body and a chamber therein through an elongate passage and creating a second pressure drop between the chamber and an interior of the valve body dependent only upon a flow rate through a flow restrictor. The method further comprises displacing a sleeve within the valve body when the pressure within the chamber is below a desired pressure and uncovering an opening between the exterior and the interior of the valve body. 
     Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In drawings which illustrate embodiments of the invention wherein similar characters of reference denote corresponding parts in each view, 
         FIG. 1  is a cross-sectional view of a wellbore having a plurality of automatic flow control valves according to the first embodiment of the invention. 
         FIG. 2  is a perspective view of one of the control valves of  FIG. 1 . 
         FIG. 3  is a perspective view of the control valve of  FIG. 2  with the outer casing removed. 
         FIG. 4  is a longitudinal cross-sectional view of the control valve of  FIG. 2  taken along the line  4 - 4  in the first extended position with the sleeve closed. 
         FIG. 5  is a longitudinal cross-sectional view of the middle portion of the control valve of  FIG. 2  taken along the line  4 - 4  in the second retracted position with the sleeve open. 
         FIG. 6  is a longitudinal cross-sectional view of the middle portion of the control valve of  FIG. 2  taken along the line  4 - 4  in the second retracted position with the sleeve open in a further embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a wellbore  10  is drilled into the ground  8  to a production zone  6  by known methods. The production zone  6  may contain a horizontally extending hydrocarbon bearing rock formation or may span a plurality of hydrocarbon bearing rock formations such that the wellbore  10  has a path designed to cross or intersect each formation. As illustrated in  FIG. 1 , the wellbore includes a vertical section  12  having a valve assembly or Christmas tree  14  at a top end thereof and a bottom or production section  16  which may be horizontal or angularly oriented relative to the horizontal located within the production zone  6 . After the wellbore  10  is drilled the production tubing  20  is of the hydrocarbon well is formed of a plurality of alternating liner or casing section  22  sections and in line valve bodies  24 . The valve bodies  24  are adapted to control fluid flow from the surrounding formation proximate to that valve body and may be located at predetermined locations to correspond to a desired production zone within the wellbore. In operation, between 2 and 100 valve bodies may be utilized within a wellbore although it will be appreciated that other quantities may be useful as well. 
     Turning now to  FIG. 2 , a perspective view of one valve body  24  is illustrated. The substantially elongate cylindrical valve body  24  extends between first and second ends  26  and  28 , respectively, having a central passage  30  therethrough. The first end  26  of the valve body is connected to adjacent liner or casing section  22  with an internal threading in the first end  26 . The second end  28  of the valve body is connected to an adjacent casing section with external threading around the second end  28 . Although the threading is described as internal in the first end  26  and external around the second end  28 , it will be appreciated that any threading configuration could be used, as well. 
     Referring to  FIGS. 3 and 4 , the valve body  24 , extending between first and second ends  26  and  28 , respectively, is comprised of a first end connector  32  proximate to the first end  26  with a flow restrictor  34  therein, an outer casing  36  (removed in  FIG. 3  for illustration purposes) enclosing a connecting cap  38 , a first inner sleeve  40 , a threaded sleeve  42 , a thread cooperating sleeve  44 , a spring seat  46 , a compression spring  48 , a shifting sleeve  50  and a second inner sleeve with second end connector  52  proximate to the second end  28 . As best seen on  FIG. 4 , a portion of the second inner sleeve with second end connector  52  is substantially enclosed in the outer casing  36 . 
     As best seen on  FIG. 2 , the elongate cylindrical outer casing  36  extends between first and second ends  70  and  72 , respectively. The outer casing  36  includes a plurality of first end ports  74  therethrough proximate to the first end  70 , and a plurality of second end ports  76  therethrough proximate to the second end  72 . The first and second end ports  74  and  76  extend from the exterior to the interior of the outer casing  36 . The first end ports  74  are sized to provide a fluid passage between the production section  16  and the first annular passage  62 , as will be described in more detail below. The second end ports  76  are sized to provide a fluid passage between the production section  16  and a second annular passage  78 , as will be described in more detail below. 
     As seen on  FIGS. 1 and 4 , the first end connector  32  is connected to an adjacent liner or casing section  22  with internal threading in the first end  26 . As best seen on  FIGS. 4 and 5 , the second end of the first end connector  32  is connected to the first end  70  of the outer casing  36  with a threaded connection and a plurality of set screws  54  radially therearound, although it may be appreciated that other connection methods may be useful, as well. The first end of the first inner sleeve  40  abuts an annular shoulder  56  on the interior of the first end connector  32 , and is sized to be sealably engaged thereon. The connecting cap  38  engages on the second end of the first end connector  32  and sealably abuts an annular shoulder  58  therearound. As illustrated in  FIG. 5 , the connecting cap  38  is spaced apart from the first end connector  32  and first inner sleeve  40  so as to form a continuous annular passage therethrough. An aperture  60  extends axially from a void or fourth annular chamber  82 , as will be more fully described below, between the first end connector  32  and the connecting cap  38  to permit fluid flow from such void to the interior of the first end connector  32 . A flow restrictor  34 , as is commonly known, is sized to fit within the aperture  60 , providing a fluid passage  62  therethrough, as will be described in more detail below. The flow restrictor may be a standard flow restrictor, as is commonly known, or the flow restrictor may be selected to provide a constant pressure drop therethrough which is dependent only upon the flow rate of the fluid and independent of the viscosity of such fluid. In such a manner, the pressure drop through the flow restrictor will be unaffected by whether there is water or oil flowing therethrough. Examples of such devices may include such as, by way of non-limiting example, a Lee Vico Jet, relief valve or sharp edged orifice. 
     The first end  70  of the outer casing  36  engages upon the second end of the first end connector  32 , as described above. The second inner sleeve with second end connector  52  extends between first and second ends,  68  and  28 , respectively. The connecting cap  38  includes a cylindrical extension  64  sized to extend around the first end of the second inner sleeve with second end connector  52 . Proximate to the first end  68 , the outer diameter of the second inner sleeve with second end connector  52  has an outer diameter smaller than an inner diameter of the outer casing  36  to form a first annular chamber  80  therebetween. As set out above, the connecting cap  38  is spaced around the second inner sleeve with second end connector  52  at the first end  68  to form the fourth annular chamber  82  therebetween. 
     Within the first annular chamber  80  a threaded sleeve  42  and thread cooperating sleeve  44  are engaged upon each other and sealed to the outer casing  36  and second inner sleeve with second end connector  52  and separate the space therebetween into the first annular chamber  80  and a second annular chamber  86 . As illustrated an enlarged portion  84  of the threaded cooperating sleeve  44  engages upon the inner surface of the outer casing with a recessed portion proximate to a second end thereof. External threading  96  extends from an outer surface of the threaded sleeve  42  to engage upon an inner surface of the cooperating threaded sleeve  44  and form a spiral passage  98  therebetween. Proximate to the second end of the thread cooperating sleeve  44 , a plurality of ports  88  radially extend therethrough into the spiral passage  98 . The inner surface of the thread cooperating sleeve  44  includes a cooperating internal threading to match the external threading  96  thereby limiting the length of the spiral passage  98 . The threaded sleeve  42  and the thread cooperating sleeve  44  may be rotated relative to each other to adjust the length of the spiral passage  98 . It will also be appreciated that the threaded sleeve  42  and the thread cooperating sleeve  44  may be locked relative to each other by set screws or the like to fix such location. 
     As illustrated in  FIG. 5 , a cylindrical extension  100  at the second end of the threaded sleeve  42  extends to and abuts the spring seat  46 . It may be appreciated that while the spring seat  46  and threaded sleeve  42  are illustrated as two separate parts in the current embodiment of the invention, they could be co-formed. 
     The inner diameter of the spring seat  46  is sized to fit the outer diameter of the second inner sleeve with second end connector  52 . The outer diameter of the spring seat  46  is sized relative to the inner diameter of the outer casing  36  to allow an annular passage therebetween, connecting the second annular chamber  86  with a third annular chamber  104  formed between the spring seat  46  and a shifting sleeve  50  as will be more fully described below. A compression spring  48  is located within the third annular chamber  104  and extends between the spring seat  46  and the first end of the shifting sleeve  50  the purpose of which will be more fully described below. The outer diameter of the spring  48  is sized to match the outer diameter of the spring seat  46 .  FIG. 4  illustrates the compression spring  48  in the extended position with the shifting sleeve  50  in the first extended position;  FIG. 5  illustrates the compression spring  48  in the retracted position, with the shifting sleeve  50  in the second retracted position. 
     Referring to  FIGS. 4 and 5 , the outer surface of the first inner sleeve  40  is sealed to the second inner sleeve with second end connector  52  at a ridge  106  forming an end to the fourth annular chamber  82 . A plurality of ports  108  extend between the outer and inner surfaces of the second inner sleeve with second end connector  52 , fluidly connecting the third annular chamber  104  with the fourth annular chamber  82 . 
     As illustrated in  FIGS. 4 and 5 , the valve body  24  includes a shifting sleeve  50  slidably located between the outer casing  36  and the second inner sleeve with second end connector  52  within a fifth annular cavity  120  formed between the second inner sleeve with second end connector  52  and the outer casing  36 . The shifting sleeve  50  extends between first and second ends  110  and  112 , respectively, and includes an annular wall  114  sealably engaged to each of the outer casing  36  and the second inner sleeve with second end connector  52  through the use of seals  116  and  118  or the like as are commonly known. When in the first extended position with the sleeve closed, as illustrated in  FIG. 4 , the second end  112  of the shifting sleeve  50  abuts an annular wall  122  on the exterior of the second inner sleeve with second end connector  52 , and covers a plurality of ports  124 , extending through the second inner sleeve with second end connector  52  and distributed radially therearound. When in the second retracted position with the sleeve open, as illustrated in  FIG. 5 , the plurality of ports  124  are exposed, forming a fluid passage  78  allowing fluidic communication between the production section  16 , the fifth annular cavity  120  and the central passage  30 . 
     An optional annular filter  130 , as illustrated in  FIG. 6 , may be contained within the fifth annular cavity  120 , extending between first and second ends,  132  and  134 , respectively, and includes an annular wall  136  sealably engaged to the outer casing  36  through the use of a seal  138  or the like as are commonly known. The optional annular filter  130  may axially span the plurality of second end ports  76 , with the second end  132  of the annular filter  130  abutting an annular wall  140  on the exterior of the second inner sleeve with second end connector  52 . The annular filter  130  is connected to the second inner sleeve with second end connector  52  proximate to the annular wall  140  with threading and a plurality of set screws  142  radially therearound, although it may be appreciated that other connection methods may be useful, as well. When in the second retracted position with the sleeve open, as illustrated in  FIG. 6 , the plurality of ports  124  are exposed, forming a fluid passage  78  allowing fluidic communication between the production section  16  and the fifth annular cavity  120 , through the annular filter  130  and into the central passage  30 . The annular filter  130  may be formed using any type of filter medium as is commonly known. The annular filter  130  may limit the influx of sand or other contaminants from the production section  16  to the central passage  30 , while permitting fluid flow therethrough. 
     In a further embodiment of the invention, as illustrated in  FIG. 6 , the shifting sleeve  50  may include a second set of seals  150  and  152  or the like, as are commonly known, proximate to the first end  110 , with the seals  116  and  118  proximate to the annular wall  114 . The seals  152  and  116  engage upon the outer casing  36  while the seals  154  and  118  engage upon the second inner sleeve with second end connector  52 . The shifting sleeve  50  may include a recessed portion  154  forming an annular cavity  156  between the seals  150 ,  152  and  116 ,  118 . A plurality of ports  158  extend through the shifting sleeve  50  at the recessed portion  154  and are distributed radially therearound. A plurality of ports  160  extend through the second inner sleeve with second end connector  52  proximate to the recessed portion  154  of the shifting sleeve  50  and are distributed radially therearound. The ports  158  and  160  permit fluid flow between the annular cavity  156  and the central passage  30 , the purpose of which will be set out in more detail below. 
     Turning to  FIGS. 4 and 5 , when in operation, fluid follows from the production section  16  through the first annular passage  62  to the central passage  30  through a series of ports and cavities. From the production section  16 , the fluid passes through the plurality of first end ports  74  into the first annular chamber  80 . The fluid continues from the first annular chamber  80 , passing through the spiral passage  98 , to the plurality of ports  88  through to the second and third annular chambers  86  and  104 . Pressure loss through the spiral passage due to viscous effects is proportional to the length over which a fluid travels and the internal diameter of the fluid passage; the spiral passage  98  has an extended length proportional to the circumference of the threaded sleeve  42  and the number of threads throughout the threading  96 , and a small diameter defined by the thread profile. As a result, fluids with a higher viscosity such as oil will experience a higher pressure drop through the spiral passage  98  than fluids with a lower viscosity, such that the fluid pressure within the second and third annular chambers  86  and  104  will be lower than it was when it entered the valve body  24  from the production section  16 . Fluids with a lower viscosity, such as water or gas, will not experience the same pressure drop, and therefore when water passes through the spiral passage  98  the resulting pressure in the second and third annular chambers  86  and  104  will be higher than it would be for higher viscosity fluids. 
     From the third annular chamber  104  the fluid passes through the plurality of ports  108  to the fourth annular chamber  82 . From the fourth annular chamber  82 , the fluid passes through the flow restrictor  34 , providing fluid communication between the first annular passage  62  and the central passage  30 . As the pressure drop through the flow restrictor can be independent of the viscosity of the fluid, the pressure drop within the second and third annular chambers  86  and  104  is dependent only upon the length of the spiral passage  98  and the fluid viscosity. Therefore, a lower pressure will be formed therein when oil is flowing therethrough and higher therein when water or gas is flowing therethrough. 
     Referring to  FIG. 4 , fluid from the production section  16  enters the fifth annular cavity  120  through the plurality of ports  76  at the same pressure as within the production section  16 . If the pressure difference between the fifth annular cavity  120  and the third annular cavity  104  is low, such as when water enters the valve body  24 , the shifting sleeve will remain in the first extended position with the sleeve closed. 
     Now turning to  FIG. 5 , when a higher viscosity fluid, such as petroleum, enters the valve body  24  through the ports  74  and  76 , the pressure in the third annular chamber  104  will be lower than the pressure in the fifth annular chamber  120 , as previously described. When the pressure differential between the two annular chambers  104  and  120  is sufficient to overcome the spring force in the compression spring  48 , the shifting sleeve  50  will be drawn towards the spring seat  46 , exposing the ports  124 , allowing fluidic communication between the second annular passage  78  and the central passage  30 . 
     As described above, when the production section  16  contains a low viscosity fluid, such as water, a small volume of water may enter the valve body  24  through the first annular passage  62 . When the production section  16  contains a higher viscosity fluid, such as petroleum, a large volume of petroleum may enter the valve body  24  through both the first annular passage  62  and through the second annular passage  78 . The shifting sleeve  50  is automatically controlled by the viscosity of the fluid in the production section  16 , such when there is water entering the valve body  24 , the shifting sleeve  50  will close and significantly reduce the volume of water introduced into the production tubing  20 . As the valve body  24  is automatic depending on the fluid viscosity, additional testing and shifting tools are not required to determine where water or petroleum is entering the system. 
     In a further embodiment of the invention, as illustrated in  FIG. 6  and outlined above, the annular cavity  156  is in fluidic communication with the central passage  30 , with minimal pressure differential therebetween. When a lower viscosity fluid has shifted the shifting sleeve  50  as described above, should either of the seals  150  or  152  fail, permitting fluidic communication between the annular cavity  156  and the third annular chamber  104 , the third annular chamber  104  would be pressurized such that the pressure differential between the third annular chamber  104  and the annular cavity  156  is minimal, and therefore insufficient to overcome the spring force in the compression spring  48 , automatically returning the shifting sleeve  50  to the closed position, as illustrated in  FIG. 4 , closing the plurality of ports  124 . During failure of either seal  150  or  152 , there is fluidic communication between the third annular chamber  104  and the annular cavity  156 , and through the plurality of ports  160  into the central passage  30 . As the production zone  16  is fluidically connected to the third annular chamber  104  as set out above, the valve fails to an open position such that fluid from the production zone  16  is permitted to enter the valve body  24 . 
     While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.