Patent Abstract:
A flow control apparatus ( 800 ) includes a tubular member ( 818 ) having a plurality of openings ( 820, 822, 824, 826 ) that allow fluid flow between an exterior and an interior flow path ( 828 ) of the tubular member ( 818 ) and a multi-stage flow restricting section ( 804 ) operably positioned in a fluid flow path between a fluid source disposed exteriorly of the tubular member ( 818 ) and the interior flow path ( 828 ). The flow restricting section ( 804 ) including a plurality of flow restricting devices ( 838, 844, 850 ) each operable to create a pressure drop. Actuatable devices ( 830, 832, 834, 836 ) operably associated with the openings ( 820, 822, 824, 826 ) are sequentially actuatable to allow fluid flow through the associated openings ( 820, 822, 824, 826 ), thereby sequentially reducing the pressure drop experienced by fluids flowing from the fluid source to the interior flow path ( 828 ).

Full Description:
TECHNICAL FIELD OF THE INVENTION 
     This invention relates, in general, to controlling the production of fluids from a well that traverses a hydrocarbon bearing subterranean formation and, in particular, to an apparatus for controlling the inflow of production fluids from the subterranean well that is adjustable over the life of the well. 
     BACKGROUND OF THE INVENTION 
     Without limiting the scope of the present invention, its background will be described with reference to producing fluid from a subterranean formation, as an example. 
     During the completion of a well that traverses a hydrocarbon bearing subterranean formation, production tubing and various equipment are installed in the well to enable safe and efficient production of the formation fluids. For example, to prevent the production of particulate material from an unconsolidated or loosely consolidated subterranean formation, certain completions include one or more sand control screens positioned proximate the desired production intervals. In other completions, to control the flow rate of production fluids into the production tubing, it is common practice to install one or more fluid flow control devices within the tubing string. 
     Recently, attempts have been made to utilize fluid flow control devices within completions requiring sand control. While certain benefits have been achieved through the use of such devices, many of these devices are complicated to operate and have suffered from poor reliability. In addition, it has been found that during the life of the well, as the formation depletes and reservoir pressure decreases, the flow control characteristics of many such fluid flow control devices may not remain suitable for achieving the desired production goals, particularly in long horizontal intervals. 
     Accordingly, need has arisen for a fluid flow control device for controlling the inflow of formation fluids in a completion requiring sand control. A need has also arisen for such a fluid flow control device that is reliable in a variety of flow conditions. Further, a need has arisen for such a fluid flow control device that can be used throughout the life of the well. 
     SUMMARY OF THE INVENTION 
     The present invention disclosed herein comprises a fluid flow control apparatus for controlling the inflow of formation fluids. The fluid flow control apparatus of the present invention is reliable in a variety of flow conditions. In addition, the fluid flow control apparatus of the present invention can be used throughout the life of the well and may be used in conjunction with a filter medium to serve as a sand control screen with flow control capabilities. 
     In one aspect, the present invention is directed to a sand control screen that is positionable within a wellbore. The sand control screen includes a base pipe having at least one opening that allows fluid flow between an exterior of the base pipe and an interior flow path of the base pipe. A filter medium is positioned exteriorly of the base pipe. An actuatable device is operably associated with the at least one opening. The actuatable device is operable to initially prevent fluid flow through the at least one opening and is actuatable to allow fluid flow through the at least one opening. In one embodiment, the actuatable device is a pressure actuated device that is actuated responsive to an increase in pressure to a predetermined level in the interior flow path. For example, the pressure actuated device may be a rupture disk. 
     In another aspect, the present invention is directed to a sand control screen that includes a base pipe having at least one opening that allows fluid flow between an exterior of the base pipe and an interior flow path of the base pipe. A filter medium is positioned exteriorly of the base pipe. A flow restricting device is disposed in a fluid flow path between the filter medium and the at least one opening. An actuatable device is operably associated with the at least one opening. In this embodiment, the flow restricting device is operable to create a pressure drop in fluids flowing therethrough. In addition, the actuatable device is operable to initially prevent fluid flow through the at least one opening and is actuatable to allow fluid flow through the at least one opening. 
     In yet another aspect, the present invention is directed to a sand control screen that includes a base pipe having at least one opening that allows fluid flow between an exterior of the base pipe and an interior flow path of the base pipe. A filter medium is positioned exteriorly of the base pipe. A one way valve is disposed in a fluid flow path between the filter medium and the at least one opening. An actuatable device is operably associated with the at least one opening. In this embodiment, the one way valve is operable to allow fluid flow in a downstream direction from the filter medium to the at least one opening and to prevent fluid flow in an upstream direction from the at least one opening to the filter medium. In addition, the actuatable device is operable to initially prevent fluid flow through the at least one opening and is actuatable to allow fluid flow through the at least one opening. 
     In a further aspect, the present invention is directed to a sand control screen that includes a base pipe having at least one opening that allows fluid flow between an exterior of the base pipe and an interior flow path of the base pipe. A filter medium is positioned exteriorly of the base pipe. A flow restricting device and a one way valve are disposed in a fluid flow path between the filter medium and the at least one opening. An actuatable device is operably associated with the at least one opening. In this embodiment, the flow restricting device is operable to create a pressure drop in fluids flowing therethrough, the one way valve is operable to allow fluid flow in a downstream direction from the filter medium to the at least one opening and prevent fluid flow in an upstream direction from the at least one opening to the filter medium and the actuatable device is operable to initially prevent fluid flow through the at least one opening and is actuatable to allow fluid flow through the at least one opening. Also in this embodiment, the flow restricting device may be upstream or downstream of the one way valve or the flow restricting device and the one way valve may be integrally formed. 
     In another aspect, the present invention is directed to a flow control apparatus for controlling the inflow of production fluids from a subterranean well. The flow control apparatus includes a tubular member having a plurality of openings that allow fluid flow between an exterior of the tubular member and an interior flow path of the tubular member. The flow control apparatus also includes a multi-stage flow restricting section that is operably positioned in a fluid flow path between a fluid source disposed exteriorly of the tubular member and the interior flow path. The flow restricting section includes a plurality of flow restricting devices each of which is operable to create a pressure drop and each of which is associated with one of the openings creating a plurality of flow paths between the fluid source and the interior flow path via the respective openings. Actuatable devices are operably associated with at least some of the openings. Each of the acutatable devices initially prevents fluid flow through the associated opening and is actuatable to allow fluid flow through the associated opening to sequentially reduce the pressure drop experienced by fluids flowing from the fluid source to the interior flow path. 
     In one embodiment of the fluid flow control apparatus, at least some of the flow restricting devices include one way valve capabilities to prevent fluid flow from the flow restricting section to the fluid source. In another embodiment, the fluid flow control apparatus includes a filter medium disposed exteriorly of the tubular member between the fluid source and the multi-stage flow restricting section. 
     In yet another aspect, the present invention is directed to a sand control screen that includes a base pipe having first and second openings that allow fluid flow between an exterior of the base pipe and an interior flow path of the base pipe. A filter medium and a flow restricting section are disposed exteriorly of the base pipe. The flow restricting section including first and second flow restricting devices that respectively create first and second pressure drops in fluids flowing therethrough. The first flow restricting device provides a first flow path between the filter medium and the interior flow path via the first opening. The first and second flow restricting devices provide a second flow path between the filter medium and the interior flow path via the second opening. An actuatable device is operably associated with the first opening. The actuatable device is operable to initially prevent fluid flow through the first opening and is actuatable to allow fluid flow through the first opening. In this manner, fluid flow through the flow restricting section is adjustable from the second flow path to the first flow path which reduces the pressure drop associated with fluid flow through the flow restricting section. 
     In one embodiment of the sand control screen, an actuatable device operably associated with the second opening initially prevents fluid flow through the second opening and is actuatable to allow fluid flow through the second opening. Additionally or alternatively, a one way valve may be associated with one or both of the flow restricting devices to prevent fluid flow from the flow restricting section to the filter medium. 
     In a further aspect, the present invention is directed to a sand control screen that includes a base pipe having first, second and third openings that allow fluid flow between an exterior of the base pipe and an interior flow path of the base pipe. A filter medium and a flow restricting section are disposed exteriorly of the base pipe. The flow restricting section including first, second and third flow restricting devices that respectively create first, second and third pressure drops in fluids flowing therethrough. The first flow restricting device provides a first flow path between the filter medium and the interior flow path via the first opening. The first and second flow restricting devices provide a second flow path between the filter medium and the interior flow path via the second opening. The first, second and third flow restricting devices provide a third flow path between the filter medium and the interior flow path via the third opening. First and second actuatable devices are operably associated with the first and second openings. The first and second actuatable devices are operable to initially prevent fluid flow through the first and second opening, respectively and are actuatable to allow fluid flow through the first and second openings, respectively. The second actuatable device may be a pressure actuated device that is actuated responsive to an increase in pressure to a first predetermined level in the interior flow path. The first actuatable device may also be a pressure actuated device that is actuated responsive to an increase in pressure to a second and higher predetermined level in the interior flow path. In this manner, fluid flow through the flow restricting section is adjustable from the third flow path to the second flow path and then to the first flow path, thereby progressively reducing the pressure drop associated with fluid flow through the flow restricting section. 
     In one embodiment, each of the flow restricting devices also has a one way valve associated therewith that prevents fluid flow from the flow restricting section to the filter medium. Also in this embodiment, the base pipe may include a fourth opening that allows fluid flow between the exterior of the base pipe and the interior flow path of the base pipe and provides a fourth flow path that bypasses the first, second and third flow restricting devices. In this configuration, an actuatable device is operably associated with the fourth opening that is operable to initially prevent fluid flow through the fourth opening and is actuatable to allow fluid flow through the fourth opening, thereby bypassing the first, second and third flow restricting devices. 
     In another aspect, the present invention is directed to a one way valve that includes a substantially tubular outer housing and a ball cage disposed within the outer housing. The ball cage has a substantially tubular member that defines an internal flow passageway. An annular flange extends radially outwardly from the tubular member and has a plurality of passageways extending longitudinally therethrough. An annular retainer flange extends radially outwardly from the tubular member. A plurality of longitudinally extending tracks disposed relative to an outer surface of the tubular member and extend between the annular flange and the annular retainer flange. A plurality of balls are disposed within an annular region defined by the outer housing, the outer surface of tubular member, the annular flange and the annular retainer flange. Each of the balls corresponds with one of the tracks such that the balls are allowed to travel longitudinally within the tracks but are prevented from traveling circumferentially within the annular region outside of the corresponding tracks. 
     In one configuration, the balls are remote from the passageways to allow fluid flow through the one way valve in a first direction. In another configuration, the balls seat relative to the passageways to prevent fluid flow through the one way valve in a second direction. 
     In one embodiment, each of the tracks has a substantially uniform circumferential width along its longitudinal length. In another embodiment, each of the tracks has a greater circumferential width proximate the annular retainer flange as compared to its circumferential width proximate the annular flange. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which: 
         FIG. 1  is a schematic illustration of a well system operating a plurality of fluid flow control devices according to the present invention; 
         FIG. 2  is side view partially in quarter section of a fluid flow control device according to the present invention; 
         FIG. 3  is side view partially in quarter section of a fluid flow control device according to the present invention; 
         FIG. 4  is side view partially in quarter section of a fluid flow control device according to the present invention; 
         FIG. 5  is side view partially in quarter section of a fluid flow control device according to the present invention; 
         FIG. 6  is side view partially in quarter section of a fluid flow control device according to the present invention; 
         FIG. 7  is side view partially in quarter section of a fluid flow control device according to the present invention; 
         FIG. 8  is side view partially in quarter section of a fluid flow control device according to the present invention; 
         FIG. 9  is side view partially in quarter section of a fluid flow control device according to the present invention; 
         FIGS. 10A-E  are cross sectional views of various embodiment of flow restricting devices for use in a fluid flow control device according to the present invention; 
         FIGS. 11A-F  are cross sectional views of various embodiments of one way valves for use in a fluid flow control device according to the present invention; 
         FIGS. 12A-C  are views of one embodiment of an annular one way valve having a plurality of flow paths therethrough that may be used in a fluid flow control device according to the present invention; and 
         FIGS. 13A-C  are views of another embodiment of an annular one way valve having a plurality of flow paths therethrough that may be used in a fluid flow control device according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention. 
     Referring initially to  FIG. 1 , therein is depicted a well system including a plurality of fluid flow control devices embodying principles of the present invention that is schematically illustrated and generally designated  10 . In the illustrated embodiment, a wellbore  12  extends through the various earth strata. Wellbore  12  has a substantially vertical section  14 , the upper portion of which has installed therein a casing string  16 . 
     Wellbore  12  also has a substantially horizontal section  18  that extends through a hydrocarbon bearing subterranean formation  20 . As illustrated, substantially horizontal section  18  of wellbore  12  is open hole. 
     Positioned within wellbore  12  and extending from the surface is a tubing string  22 . Tubing string  22  provides a conduit for formation fluids to travel from formation  20  to the surface. Positioned within tubing string  22  is a seal assembly  24  and a plurality of fluid flow control devices  26 . Through use of the fluid flow control devices  26  of the present invention, control over the flow rate and composition of the produced fluids is enabled. For example, by choking production from the entire producing interval, a more uniform production profile from the entire interval is achievable. Specifically, if production from formation  20  were allowed without downhole choking, a majority of the production into tubing string  22  would come from the portion of formation  20  near the heel of the well with little contribution from the portion of formation  20  near the toe of the well. This scenario can result in premature water encroachment as the desired fluids from the portion of formation  20  near the heel depletes. 
     By incorporating one or more fluid restricting devices in each fluid flow control device  26  of the present invention, a more uniform production profile along the entire length of substantially horizontal section  18  can be achieved. In addition, in those embodiments having more than one fluid restricting device in series within each fluid flow control device  26 , the uniform production profile can be maintained for the life of the well as the pressure drop associated with fluid flow control devices  26  can be adjusted over time. 
     In the illustrated embodiment, each of the fluid flow control devices  26  provides not only fluid flow control capability but also sand control capability. The sand control screen elements or filter media associated with fluid flow control devices  26  are designed to allow fluids to flow therethrough but prevent particulate matter of sufficient size from flowing therethrough. The exact design of the screen element associated with fluid flow control devices  26  is not critical to the present invention as long as it is suitably designed for the characteristics of the formation fluids and any treatment operations to be performed. For example, the sand control screen may utilize a nonperforated base pipe having a wire wrapped around a plurality of ribs positioned circumferentially around the base pipe that provide stand off between the base pipe and the wire wrap. Alternatively, a fluid-porous, particulate restricting, metal material such as a plurality of layers of a wire mesh that are sintered together to form a fluid porous wire mesh screen could be used as the filter medium. As illustrated, a protective outer shroud having a plurality of perforations therethrough may be positioned around the exterior of the filter medium. 
     Even though  FIG. 1  depicts the fluid flow control devices of the present invention in an open hole environment, it should be understood by those skilled in the art that the fluid flow control devices of the present invention are equally well suited for use in cased wells. Also, even though  FIG. 1  depicts a string of fluid flow control devices, it should be understood by those skilled in the art that the fluid flow control devices of the present invention are equally well suited for use in wells that are divided into a plurality of intervals using packers or other sealing devices between adjacent fluid flow control devices or groups of fluid flow control devices. 
     In addition, even though  FIG. 1  depicts the fluid flow control devices of the present invention in a horizontal section of the wellbore, it should be understood by those skilled in the art that the fluid flow control devices of the present invention are equally well suited for use in deviated or vertical wellbores. Accordingly, it should be understood by those skilled in the art that the use of directional terms such as above, below, upper, lower, upward, downward and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure. Further, even though  FIG. 1  depicts the fluid flow control devices of the present invention as including sand control screen elements, it should be understood by those skilled in the art that the fluid flow control devices of the present invention are equally well suited for use in completions that do not require sand control. 
     Referring next to  FIG. 2 , therein is depicted a fluid flow control device according to the present invention that is representatively illustrated and generally designated  100 . Fluid flow control device  100  may be suitably coupled to other similar fluid flow control devices, seal assemblies, production tubulars or other downhole tools to form a tubing string as described above. Fluid flow control device  100  includes a sand control screen section  102  and a flow restrictor section  104 . Sand control screen section  102  includes a suitable sand control screen element or filter medium, such as a wire wrap screen, a woven wire mesh screen or the like, designed to allow fluids to flow therethrough but prevent particulate matter of sufficient size from flowing therethrough. In the illustrated embodiment, a protective outer shroud  106  having a plurality of perforations  108  is positioned around the exterior of the filter medium. 
     Flow restrictor section  104  is configured in series with sand control screen section  102  such that production fluid must pass through sand control screen section  102  prior to entering flow restrictor section  104 . Flow restrictor section  104  includes an outer housing  110 . Outer housing  110  defines an annular chamber  112  with base pipe  118 . Base pipe  118  includes an opening  120  that allow fluid flow between the exterior of base pipe  118  and an interior flow path  122  within base pipe  118 . An actuatable device  124  is disposed within opening  120 . 
     In operation, fluid flow control device  100  is installed within the well with actuatable device  124  in its unactuated configuration. In this configuration, no fluid is able to flow through fluid flow control device  100 . In certain embodiments, actuatable device  124  may be a pressure actuated device that is actuated responsive to an increase in pressure to a predetermined level in interior flow path  122 . For example, actuatable device  124  may be a rupture or burst disk that provides for one-time-use. In this case, a membrane of the rupture disk is engineered to fail at a fixed pressure such that exposing the membrane to such a pressure opens a passageway through the rupture disk. Use of such a rupture disk enables a single opening event and does not allow for resealing. It should be noted, however, by those skilled in the art that other types of actuatable devices may alternatively be used, such devices including, but not limited to, valves, sliding sleeves, removable plugs and the like. In addition, other methods of actuating a device or otherwise establishing communication through the base pipe can be used including, but not limited to, hydraulic control systems, electrical actuators, punch tools and the like. Once actuatable device  124  has been actuated, fluid flow through opening  120  and therefore fluid flow control device  100  is allowed. Accordingly, fluid flow control device  100  may be operated from a no flow configuration to a flow enabled configuration by actuating actuatable device  124 . 
     Referring next to  FIG. 3 , therein is depicted a fluid flow control device according to the present invention that is representatively illustrated and generally designated  200 . Fluid flow control device  200  may be suitably coupled to other similar fluid flow control devices, seal assemblies, production tubulars or other downhole tools to form a tubing string as described above. Fluid flow control device  200  includes a sand control screen section  202  and a flow restrictor section  204 . Sand control screen section  202  includes a suitable sand control screen element or filter medium. In the illustrated embodiment, a protective outer shroud  206  having a plurality of perforations  208  is positioned around the exterior of the filter medium. 
     Flow restrictor section  204  is configured in series with sand control screen section  202  such that production fluid must pass through sand control screen section  202  prior to entering flow restrictor section  204 . Flow restrictor section  204  includes an outer housing  210 . Outer housing  210  defines an annular chamber  212  with base pipe  218 . Base pipe  218  includes an opening  220  that allows fluid flow between the exterior of base pipe  218  and an interior flow path  222  within base pipe  218 . An actuatable device  224  is disposed within opening  220 . A flow restricting device  226  is also disposed with annular chamber  212 . Flow restricting device  226  includes a flow passageway  228  that creates a pressure drop in fluids that pass therethrough. 
     In operation, fluid flow control device  200  is installed within the well with actuatable device  224  in its unactuated configuration. In this configuration, no fluid is able to flow through fluid flow control device  200 . Once actuatable device  224  has been actuated, fluid flow through opening  220  and therefore fluid flow control device  200  is allowed. In this embodiment, the fluid flowing from sand control screen section  202  to interior flow path  222  via opening  220  must pass through flow passageway  228  of flow restricting device  226 . Flow passageway  228  is engineered to create a desired pressure drop in the fluids passing therethrough which also controls the flow rate at a given reservoir pressure. As discussed above, when a string of fluid flow control devices  200  extends from the heel to the toe of the well, establishing a suitable pressure drop in all such fluid flow control devices  200  will help to equalize the production profile along the length of the interval. 
     Even though flow restricting device  226  has been depicted with a tubular flow passageway  228 , those skilled in the art with recognize that other types of flow restricting devices could alternative be used. For example, in addition to tubular flow passageways, as best seen in  FIG. 10C , other suitable flow restricting devices include orifice plates, as best seen in  FIG. 10A , nozzles, as best seen in  FIG. 10B , coiled tubulars, as best seen in  FIG. 10D , helical passageways, as best seen in  FIG. 10E  and the like may be used. 
     Referring next to  FIG. 4 , therein is depicted a fluid flow control device according to the present invention that is representatively illustrated and generally designated  300 . Fluid flow control device  300  may be suitably coupled to other similar fluid flow control devices, seal assemblies, production tubulars or other downhole tools to form a tubing string as described above. Fluid flow control device  300  includes a sand control screen section  302  and a flow restrictor section  304 . Sand control screen section  302  includes a suitable sand control screen element or filter medium. In the illustrated embodiment, a protective outer shroud  306  having a plurality of perforations  308  is positioned around the exterior of the filter medium. 
     Flow restrictor section  304  is configured in series with sand control screen section  302  such that production fluid must pass through sand control screen section  302  prior to entering flow restrictor section  304 . Flow restrictor section  304  includes an outer housing  310 . Outer housing  310  defines an annular chamber  312  with base pipe  318 . Base pipe  318  includes an opening  320  that allows fluid flow between the exterior of base pipe  318  and an interior flow path  322  within base pipe  318 . An actuatable device  324  is disposed within opening  320 . A one way valve is disposed with annular chamber  312 . One way valve  326  prevents fluid loss into the formation when pressure within interior flow path  322  exceeds that of the formation, for example when pressure is used to actuate actuatable device  324 . 
     In operation, fluid flow control device  300  is installed within the well with actuatable device  324  in its unactuated configuration. In this configuration, no fluid is able to flow through fluid flow control device  300 . Once actuatable device  324  has been actuated, fluid flow through opening  320  is allowed. In this embodiment, the fluid flow from interior flow path  322  to the formation is prevented by one way valve  326 . This prevents fluid loss when pressure is used to actuate similar actuatable devices in this or other fluid flow control devices. When the actuation pressure is released, fluid flow from the formation to interior flow path  322  through one way valve  326  is allowed. 
     As should be understood by those skilled in the art a variety of different one way valve configurations may be suitable used in the flow restrictor section of the fluid flow control devices of the present invention. For example, a spring biased annular sleeve, as best seen in  FIG. 11A , a spring biased ball and seat, as best seen in  FIG. 11B , a pivoting gate, as best seen in  FIG. 11C , a spring biased poppet and seat, as best seen in  FIG. 11D , a resilient member that radially flexes, as best seen in  FIG. 11E , a plurality of floating balls in an annular race and circumferentially spaced apart seats, as best seen in  FIG. 11F  and the like may be used. In addition, it should be understood by those skilled in the art that a one way valve could alternative be positioned in series with the actuatable device within the base pipe. 
     Referring next to  FIG. 5 , therein is depicted a fluid flow control device according to the present invention that is representatively illustrated and generally designated  400 . Fluid flow control device  400  may be suitably coupled to other similar fluid flow control devices, seal assemblies, production tubulars or other downhole tools to form a tubing string as described above. Fluid flow control device  400  includes a sand control screen section  402  and a flow restrictor section  404 . Sand control screen section  402  includes a suitable sand control screen element or filter medium. In the illustrated embodiment, a protective outer shroud  406  having a plurality of perforations  408  is positioned around the exterior of the filter medium. 
     Flow restrictor section  404  is configured in series with sand control screen section  402  such that production fluid must pass through sand control screen section  402  prior to entering flow restrictor section  404 . Flow restrictor section  404  includes an outer housing  410 . Outer housing  410  defines an annular chamber  412  with base pipe  418 . Base pipe  418  includes an opening  420  that allows fluid flow between the exterior of base pipe  418  and an interior flow path  422  within base pipe  418 . An actuatable device  424  is disposed within opening  420 . A flow restricting device  426  is disposed with annular chamber  412 . Flow restricting device  426  includes a flow passageway  428  that creates a pressure drop in fluids that pass therethrough. A one way valve  430  is disposed downstream of flow restricting device  426  within annular chamber  412 . One way valve  430  prevents fluid loss into the formation when pressure within interior flow path  422  exceeds that of the formation, for example when pressure is used to actuate actuatable device  424  and other similar devices. 
     In operation, fluid flow control device  400  is installed within the well with actuatable device  424  in its unactuated configuration. In this configuration, no fluid is able to flow through fluid flow control device  400 . Once actuatable device  424  has been actuated, fluid flow through opening  420  is allowed. In this embodiment, fluid loss from flow path  422  to the formation is prevented by one way valve  430 . Fluid production from the formation to interior flow path  422  via opening  420  is allowed. This fluid flow must pass through flow passageway  428  of flow restricting device  426  which is engineered to create a desired pressure drop in the fluids passing therethrough which also controls the flow rate therethrough at a given reservoir pressure. As discussed above, when a string of fluid flow control devices  400  extends from the heel to the toe of the well, establishing a suitable pressure drop in all of such fluid flow control devices  400  will help to equalize the production profile along the length of the interval. 
     Referring next to  FIG. 6 , therein is depicted a fluid flow control device according to the present invention that is representatively illustrated and generally designated  500 . Fluid flow control device  500  may be suitably coupled to other similar fluid flow control devices, seal assemblies, production tubulars or other downhole tools to form a tubing string as described above. Fluid flow control device  500  includes a sand control screen section  502  and a flow restrictor section  504 . Sand control screen section  502  includes a suitable sand control screen element or filter medium. In the illustrated embodiment, a protective outer shroud  506  having a plurality of perforations  508  is positioned around the exterior of the filter medium. 
     Flow restrictor section  504  is configured in series with sand control screen section  502  such that production fluid must pass through sand control screen section  502  prior to entering flow restrictor section  504 . Flow restrictor section  504  includes an outer housing  510 . Outer housing  510  defines an annular chamber  512  with base pipe  518 . Base pipe  518  includes an opening  520  that allows fluid flow between the exterior of base pipe  518  and an interior flow path  522  within base pipe  518 . An actuatable device  524  is disposed within opening  520 . A flow restricting device  526  is disposed with annular chamber  512 . Flow restricting device  526  includes a flow passageway  528  that creates a pressure drop in fluids that pass therethrough. A one way valve  530  is disposed upstream of flow restricting device  526  within annular chamber  512 . One way valve  530  prevents fluid loss into the formation when pressure within interior flow path  522  exceeds that of the formation, for example when pressure is used to actuate actuatable device  524  and other similar devices. 
     In operation, fluid flow control device  500  is installed within the well with actuatable device  524  in its unactuated configuration. In this configuration, no fluid is able to flow through fluid flow control device  500 . Once actuatable device  524  has been actuated, fluid flow through opening  520  is allowed. In this embodiment, fluid loss from flow path  522  to the formation is prevented by one way valve  530 . Fluid production from the formation to interior flow path  522  via opening  520  is allowed. This fluid flow must pass through flow passageway  528  of flow restricting device  526  which is engineered to create a desired pressure drop in the fluids passing therethrough which also controls the flow rate therethrough at a given reservoir pressure. As discussed above, when a string of fluid flow control devices  500  extends from the heel to the toe of the well, establishing a suitable pressure drop in all of such fluid flow control devices  500  will help to equalize the production profile along the length of the interval. 
     Referring next to  FIG. 7 , therein is depicted a fluid flow control device according to the present invention that is representatively illustrated and generally designated  600 . Fluid flow control device  600  may be suitably coupled to other similar fluid flow control devices, seal assemblies, production tubulars or other downhole tools to form a tubing string as described above. Fluid flow control device  600  includes a sand control screen section  602  and a flow restrictor section  604 . Sand control screen section  602  includes a suitable sand control screen element or filter medium. In the illustrated embodiment, a protective outer shroud  606  having a plurality of perforations  608  is positioned around the exterior of the filter medium. 
     Flow restrictor section  604  is configured in series with sand control screen section  602  such that production fluid must pass through sand control screen section  602  prior to entering flow restrictor section  604 . Flow restrictor section  604  includes an outer housing  610 . Outer housing  610  defines an annular chamber  612  with base pipe  618 . Base pipe  618  includes an opening  620  that allows fluid flow between the exterior of base pipe  618  and an interior flow path  622  within base pipe  618 . An actuatable device  624  is disposed within opening  620 . A flow restricting device  626  is disposed with annular chamber  612 . Flow restricting device  626  includes a flow passageway  628  that creates a pressure drop in fluids that pass therethrough. Flow restricting device  626  also includes an integral one way valve  630 . One way valve  630  prevents fluid loss into the formation when pressure within interior flow path  622  exceeds that of the formation, for example when pressure is used to actuate actuatable device  624  and other similar devices. 
     In operation, fluid flow control device  600  is installed within the well with actuatable device  624  in its unactuated configuration. In this configuration, no fluid is able to flow through fluid flow control device  600 . Once actuatable device  624  has been actuated, fluid flow through opening  620  is allowed. In this embodiment, fluid loss from flow path  622  to the formation is prevented by one way valve  630 . Fluid production from the formation to interior flow path  622  via opening  620  is allowed. This fluid flow must pass through flow passageway  628  of flow restricting device  626  which is engineered to create a desired pressure drop in the fluids passing therethrough which also controls the flow rate therethrough at a given reservoir pressure. As discussed above, when a string of fluid flow control devices  600  extends from the heel to the toe of the well, establishing a suitable pressure drop in all of such fluid flow control devices  600  will help to equalize the production profile along the length of the interval. 
     Referring next to  FIG. 8 , therein is depicted a fluid flow control device according to the present invention that is representatively illustrated and generally designated  700 . Fluid flow control device  700  may be suitably coupled to other similar fluid flow control devices, seal assemblies, production tubulars or other downhole tools to form a tubing string as described above. Fluid flow control device  700  includes a sand control screen section  702  and a flow restrictor section  704 . Sand control screen section  702  includes a suitable sand control screen element or filter medium. In the illustrated embodiment, a protective outer shroud  706  having a plurality of perforations  708  is positioned around the exterior of the filter medium. 
     Flow restrictor section  704  is configured in series with sand control screen section  702  such that production fluid must pass through sand control screen section  702  prior to entering flow restrictor section  704 . Flow restrictor section  704  includes an outer housing  710 . Outer housing  710  defines an annular chamber  712  with base pipe  718 . Base pipe  718  includes an opening  720  and an opening  722  that allow fluid flow between the exterior of base pipe  718  and an interior flow path  724  within base pipe  718 . An actuatable device  726  is disposed within opening  720  and an actuatable device  728  is disposed within opening  722 . A flow restricting device  730  is disposed with annular chamber  712 . Flow restricting device  730  includes a flow passageway  732  that creates a pressure drop in fluids that pass therethrough. In addition, a flow restricting device  734  is disposed with annular chamber  712 . Flow restricting device  734  includes a flow passageway  736  that creates a pressure drop in fluids that pass therethrough. 
     In certain operations, fluid flow control device  700  is installed within the well with actuatable devices  726  and  728  in their unactuated configurations. In this configuration, no fluid is able to flow through fluid flow control device  700 . Thereafter, actuatable device  726  may be actuated downhole to establish fluid communication therethrough. Alternatively, fluid flow control device  700  may be installed within the well with actuatable device  726  removed or otherwise disabled. In either installed configuration, once fluid flow through opening  720  is enabled, the fluid flowing from sand control screen section  702  to interior flow path  724  via opening  720  must pass through flow restricting device  734  and flow restricting device  730 . Each of flow restricting device  734  and flow restricting device  730  is engineered to create a desired pressure drop in the fluids passing therethrough, which also controls the flow rate therethrough at a given reservoir pressure. As discussed above, when a string of fluid flow control devices  700  extends from the heel to the toe of the well, establishing a suitable pressure drop in all of such fluid flow control devices  700  will help to equalize the production profile along the length of the interval. 
     As the reservoir becomes depleted and the reservoir pressure declines, the pressure drop created by flow restricting device  734  together with flow restricting device  730  may no longer be desirable. In the present embodiment, the pressure drop associated with fluid flow control device  700  can be adjusted to enhance the ultimate recovery from the reservoir. Specifically, when it is desired to reduced the pressure drop through fluid flow control device  700 , actuatable device  728  may be actuated downhole to establish fluid communication through opening  722 . In this configuration, the fluid flowing from sand control screen section  702  to interior flow path  724  now passes through flow restricting device  734  and opening  722  bypassing flow restricting device  730  and the pressure drop associated therewith. Accordingly, this embodiment allows for the reduction in the pressure drop experienced by fluids passing therethrough by establishing a fluid pathway that bypasses flow restricting device  730 . 
     Referring next to  FIG. 9 , therein is depicted a fluid flow control device according to the present invention that is representatively illustrated and generally designated  800 . Fluid flow control device  800  may be suitably coupled to other similar fluid flow control devices, seal assemblies, production tubulars or other downhole tools to form a tubing string as described above. Fluid flow control device  800  includes a sand control screen section  802  and a flow restrictor section  804 . Sand control screen section  802  includes a suitable sand control screen element or filter medium. In the illustrated embodiment, a protective outer shroud  806  having a plurality of perforations  808  is positioned around the exterior of the filter medium. 
     Flow restrictor section  804  is configured in series with sand control screen section  802  such that production fluid must pass through sand control screen section  802  prior to entering flow restrictor section  804 . Flow restrictor section  804  includes an outer housing  810 . Outer housing  810  defines an annular chamber  812  with base pipe  818 . Base pipe  818  includes a plurality of openings  820 ,  822 ,  824 ,  826  that allow fluid flow between the exterior of base pipe  818  and an interior flow path  828  within base pipe  818 . Each of opening  820 ,  822 ,  824 ,  826  has an actuatable device  830 ,  832 ,  834 ,  836  respectively disposed therein. A flow restricting device  838  is disposed with annular chamber  812 . Flow restricting device  838  includes a flow passageway  840  that creates a pressure drop in fluids that pass therethrough and an integral one way valve  842  that prevents fluid loss into the formation. In addition, a flow restricting device  844  is disposed with annular chamber  812 . Flow restricting device  844  includes a flow passageway  846  that creates a pressure drop in fluids that pass therethrough and an integral one way valve  848  that prevents fluid loss into the formation. Further, a flow restricting device  850  is disposed with annular chamber  812 . Flow restricting device  850  includes a flow passageway  852  that creates a pressure drop in fluids that pass therethrough and an integral one way valve  854  that prevents fluid loss into the formation. 
     In certain operations, fluid flow control device  800  is installed within the well with each of actuatable devices  830 ,  832 ,  834 ,  836  in their unactuated configuration. In this configuration, no fluid is able to flow through fluid flow control device  800 . Alternatively, fluid flow control device  800  may be installed within the well with actuatable device  830  removed or otherwise disabled. In either installed configuration, once fluid flow through opening  820  is enabled, the fluid flowing from sand control screen section  802  to interior flow path  828  via opening  820  must pass through each of flow restricting devices  838 ,  844 ,  850 , each of which is engineered to create a desired pressure drop in the fluids passing therethrough and control the flow rate therethrough at a given reservoir pressure. As discussed above, when a string of fluid flow control devices  800  extends from the heel to the toe of the well, establishing a suitable pressure drop in all of such fluid flow control devices  800  will help to equalize the production profile along the length of the interval. 
     As the reservoir becomes depleted and the reservoir pressure declines, the pressure drop created by flow restricting devices  838 ,  844 ,  850  may no longer be desirable. In the present embodiment, the pressure drop associated with fluid flow control device  800  can be adjusted. Specifically, when it is desired to reduced the pressure drop through fluid flow control device  800 , actuatable device  832  may be actuated downhole to establish fluid communication through opening  822 . This actuation may be achieved by pressuring up interior flow path  828  to a predetermined first level. During this pressuring up phase, fluid loss into the formation is prevented by one way valve  842 . 
     Once communication through opening  822  is established, the fluid flowing from sand control screen section  802  to interior flow path  828  now passes through flow restricting devices  844 ,  850  and opening  822  bypassing flow restricting device  838  and the pressure drop associated therewith. Accordingly, this embodiment allows for the reduction in the pressure drop experienced by fluids passing therethrough by establishing a fluid pathway that bypasses flow restricting device  838 . 
     As the reservoir becomes further depleted, the pressure drop created by flow restricting devices  844 ,  850  may no longer be desirable. In the present embodiment, the pressure drop associated with fluid flow control device  800  can be again adjusted. Specifically, when it is desired to reduced the pressure drop through fluid flow control device  800 , actuatable device  834  may be actuated downhole to establish fluid communication through opening  824 . This actuation may be achieved by pressuring up interior flow path  828  to a predetermined second level that is higher than the first level. During this pressuring up phase, fluid loss into the formation is prevented by one way valve  848 . 
     Once communication through opening  824  is established, the fluid flowing from sand control screen section  802  to interior flow path  828  now passes through flow restricting device  850  and opening  824  bypassing flow restricting devices  838 ,  844  and the pressure drops associated therewith. Accordingly, this embodiment allows for the reduction in the pressure drop experienced by fluids passing therethrough by establishing a fluid pathway that bypasses flow restricting devices  838 ,  844 . 
     As the reservoir becomes even further depleted, the pressure drop created by flow restricting device  850  may no longer be desirable. In the present embodiment, the pressure drop associated with fluid flow control device  800  can be further adjusted. Specifically, when it is desired to reduced the pressure drop through fluid flow control device  800 , actuatable device  836  may be actuated downhole to establish fluid communication through opening  826 . This actuation may be achieved by pressuring up interior flow path  828  to a predetermined third level that is higher than the second level. During this pressuring up phase, fluid loss into the formation is prevented by one way valve  854 . 
     Once communication through opening  826  is established, the fluid flowing from sand control screen section  802  to interior flow path  828  now passes through opening  826  bypassing all of the flow restricting devices and the pressure drops associated therewith. Accordingly, this embodiment allows for the progressive reduction in the pressure drop experienced by fluids passing therethrough by establishing fluid pathways that sequentially bypass additional ones of the flow restricting devices. 
     Referring now to  FIGS. 12A-C , therein are depicted various views of an annular one way valve having a plurality of flow paths therethrough that is generally designated  900 . Annular one way valve  900  may be used in any of the above described fluid flow control devices in conjunction with or as an alternative to any of the one way valves described above such as the one way valves depicted in  FIGS. 11A-F . Annular one way valve  900  include a ball cage  902  that is disposed within an outer housing  904  such as the outer housings of the fluid flow control devices described above. Ball cage  902  includes a substantially tubular member  906  that, along with other portions of the base pipe described above, defines an internal flow passageway  908 . Ball cage  902  includes a radially outwardly extending annular flange  910  having a plurality of passageways  912  extending longitudinally therethrough. As illustrated, there are eight passageways  912 , only some of which are visible in the various views. It should be understood by those skilled in the art that other numbers of passageways both greater than and less than eight could alternatively be used. 
     Formed within the outer surface of tubular member  906  are a plurality of longitudinally extending slots  914 . Each slot  914  circumferentially corresponds to one of the passageways  912 . Ball cage  902  includes a radially outwardly extending annular retainer flange  916  having a plurality of notches  918  formed therein. Each notch  918  circumferentially corresponds to one of the slots  914 . Together, corresponding notches  918  and slots  914  form tracks  920 . Disposed within each of the tracks  920  is a ball  922 . When ball cage  902  is disposed within housing  904  as depicted in  FIG. 12A , each ball  922  is retained within its corresponding track  920  such that the balls are allowed to travel longitudinally within annular region  924  but are prevented from traveling circumferentially within annular region  924  beyond the width of the corresponding track  920 . Accordingly, a corresponding one-to-one relationship is created between balls  922  and passageways  912 . 
     In operation, balls  922  move within tracks  920  in response to pressure difference between passageways  912  and annular passageway  926  that is selectively in fluid communication with internal flow passageway  908 . For example, fluid communication between annular passageway  926  and internal flow passageway  908  may be prevented in a manner similar to that described above with reference to actuatable devices disposed within openings of a base pipe, such as actuatable device  324  within opening  320  of base pipe  318 . Likewise, fluid communication between annular passageway  926  and internal flow passageway  908  may be allowed by actuating such an actuatable device. When annular passageway  926  is in fluid communication with internal flow passageway  908  and the pressure in internal flow passageway  908  is less than the pressure at passageways  912 , fluid flow through one way valve  900  from upstream of passageways  912  to internal flow passageway  908  is allowed as balls  922  are remote from passageways  912 . When annular passageway  926  is in fluid communication with internal flow passageway  908  and the pressure in internal flow passageway  908  is greater than the pressure at passageways  912 , fluid flow through one way valve  900  toward passageways  912  from internal flow passageway  908  is disallowed as balls  922  seat within passageways  912 . Accordingly, one way valve  900  provides reliable flow control by selective allowing and preventing fluid flow therethrough which, when used within one of the fluid flow control devices described above, prevents fluid loss into a formation from internal flow passageway  908  but allows production from the formation into internal flow passageway  908 . 
     Even though tracks  920  have been depicted as being formed by slots  914  within the outer surface of tubular member  906  and notches  918  in annular retainer flange  916 , it should be understood by those skilled in the art that tracks  920  can take other configurations, such configuration also being considered within the scope of the present invention. For example, radially outwardly extending longitudinal rails or other structures attached to the outer surface of tubular member  906  may be used to form tracks  920  above the outer surface of tubular member  906  such that corresponding balls  922  are prevented from traveling circumferentially within annular region  924  beyond the rails. 
     Referring now to  FIGS. 13A-C , therein are depicted various views of an annular one way valve having a plurality of flow paths therethrough that is generally designated  950 . Annular one way valve  950  may be used in any of the above described fluid flow control devices in conjunction with or as an alternative to any of the one way valves described above such as the one way valves depicted in  FIGS. 11A-F . Annular one way valve  950  include a ball cage  952  that is disposed within an outer housing  954  such as the outer housings of the fluid flow control devices described above. Ball cage  952  includes a substantially tubular member  956  that, along with other portions of the base pipe described above, defines an internal flow passageway  958 . Ball cage  952  includes a radially outwardly extending annular flange  960  having a plurality of passageways  962  extending longitudinally therethrough. As illustrated, there are eight passageways  962 , only some of which are visible in the various views. It should be understood by those skilled in the art that other numbers of passageways both greater than and less than eight could alternatively be used. 
     Formed within the outer surface of tubular member  956  are a plurality of longitudinally extending slots  964 . Each slot  964  circumferentially corresponds to one of the passageways  962 . Ball cage  952  includes a radially outwardly extending annular retainer flange  966  having a plurality of notches  968  formed therein. Each notch  968  circumferentially corresponds to one of the slots  964 . Together, corresponding notches  968  and slots  964  form tracks  970 . Disposed within each of the tracks  970  is a ball  972 . When ball cage  952  is disposed within housing  954  as depicted in  FIG. 13A , each ball  972  is retained within its corresponding track  970  such that the balls are allowed to travel longitudinally within annular region  974  but prevented from traveling circumferentially within annular region  974  beyond the width of the corresponding track  970 . Accordingly, a corresponding one-to-one relationship is created between balls  972  and passageways  962 . 
     In operation, balls  972  move within tracks  970  in response to pressure difference between passageways  962  and an annular passageway  976  that is selectively in fluid communication with internal flow passageway  958 . For example, fluid communication between annular passageway  976  and internal flow passageway  958  may be prevented in a manner similar to that described above with reference to actuatable devices disposed within openings of a base pipe, such as actuatable device  324  within opening  320  of base pipe  318 . Likewise, fluid communication between annular passageway  976  and internal flow passageway  958  may be allowed by actuating such an actuatable device. When annular passageway  976  is in fluid communication with internal flow passageway  958  and the pressure in internal flow passageway  958  is less than the pressure at passageways  962 , fluid flow through one way valve  950  from upstream of passageways  962  to internal flow passageway  958  is allowed as balls  972  are remote from passageways  962 . In this embodiment, tracks  970  allow balls  972  to move a limited circumferentially distance which reduces the flow restriction through one way valve  950  as compared to one way valve  900  described above as balls  972  are no longer in the direct flowpath of fluids flowing therethrough. Likewise, allowing such limited circumferentially travel of balls  972  within tracks  970  reduces erosion of balls  972  which could otherwise reduce the sealing capability of balls  972 . When annular passageway  976  is in fluid communication with internal flow passageway  958  and the pressure in internal flow passageway  958  is greater than the pressure at passageways  962 , fluid flow through one way valve  950  toward passageways  962  from internal flow passageway  958  is disallowed as balls  972  seat within passageways  962 . Accordingly, one way valve  950  provides reliable flow control by selective allowing and preventing fluid flow therethrough which, when used within one of the fluid flow control devices described above, prevents fluid loss into a formation from internal flow passageway  958  but allows production from the formation into internal flow passageway  958 . 
     Even though tracks  970  have been depicted as being formed by slots  964  within the outer surface of tubular member  956  and notches  968  in annular retainer flange  966 , it should be understood by those skilled in the art that tracks  970  can take other configurations, such configuration also being considered within the scope of the present invention. For example, radially outwardly extending longitudinal rails or other structures attached to the outer surface of tubular member  956  may be used to form tracks  970  above the outer surface of tubular member  956  such that corresponding balls  972  are prevented from traveling circumferentially within annular region  974  beyond the rails. 
     While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.

Technology Classification (CPC): 4