Abstract:
A flow control valve assembly with a plunger continuously movable between closed, intermediate, and open positions. The plunger has an uphole side and a downhole side opposite the uphole side, and both uphole and downhole sides are exposed to the same hydrostatic pressure in the well, resulting in a flow control device that can be operated with minimal power consumption and still withstanding high pressure loads.

Description:
BACKGROUND 
       [0001]    Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation, referred to as a reservoir, by drilling a well that penetrates the hydrocarbon-bearing formation. Once a wellbore is drilled, various forms of well completion components may be installed in order to control and enhance the efficiency of producing the various fluids from the reservoir. One such component is a flow control valve used to control the amount of fluid permitted to flow upward through the completion to the surface. 
       SUMMARY 
       [0002]    Embodiments of the present disclosure are directed to a flow control valve assembly including a plunger containment member and a plunger operatively coupled to the plunger containment member such that moving the plunger toward an uphole side and toward a downhole side opposite the uphole side in the plunger containment member causes the flow control valve to selectively open and close in response to administration of force to the plunger. The uphole side of the plunger and the downhole side of the plunger are exposed to a hydrostatic pressure of substantially equal magnitude. The assembly also includes a first seal between the plunger and the plunger containment member on the uphole side and a second seal between the plunger and the plunger containment member on the downhole side. 
         [0003]    The assembly can also include a power module to provide power to move the plunger to selectively open and close the flow control valve. The first and second seals are able to withstand 1,200 psi and the power module is configured to operate with between 8-10 watts. 
         [0004]    Further embodiments of the present disclosure are directed to a method for operating a flow control device. The method includes providing a flow control valve in a well, the flow control valve having a plunger containment member, a plunger, and a fluid port. The plunger is configured to travel forward and backward in the plunger containment member to open and close the flow control valve. The plunger has a first side and a second side opposite the first side. Both the first and second sides are exposed to pressure in the well of substantially equal magnitude, and the fluid port is opened or closed by moving the plunger within the plunger containment member. The method also includes providing a first seal for the first side of the plunger and a second seal for the second side of the plunger. The first and second seals are configured to withstand up to 1,200 psi. The method further includes operating a power module to move the plunger in the plunger containment member, wherein the power module consumes no more than 10 watts of power. 
         [0005]    Still further embodiments of the present disclosure are directed to a flow control device for use in a downhole completion. The flow control device includes a central fluid bore configured to conduct fluid upward from the well, the central fluid bore having a fluid port in a wall of the bore, and a plurality of sand screens positioned outside the central bore and configured to filter fluid as the fluid passes through the sand screens. The device also includes an annular bore configured to receive fluid after passing through the sand screens. The annular bore is fluidly connected to the fluid port in the central fluid bore. There is also a plunger positioned in the annular bore and configured to selectively block fluid flow from the annular bore into the central bore. The plunger is selectively, continuously movable between a closed position, an intermediate position, and a fully open position, the plunger having a downhole side and an uphole side opposite the downhole side, wherein the uphole side and downhole sides are both exposed to substantially the same hydrostatic pressure in the well. The device also includes a seal assembly between the plunger and the uphole side. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0006]      FIG. 1  is an illustration of an example of a completion deployed in a lateral wellbore and combined with a multi-zone control system, according to an embodiment of the disclosure; 
           [0007]      FIG. 2  is a schematic illustration of an example of a multi-zone control system utilizing a control module combined with a plurality of flow control devices, according to an embodiment of the disclosure; 
           [0008]      FIG. 3  is a schematic illustration of another example of a multi-zone control system utilizing a control module combined with a plurality of flow control devices, according to an embodiment of the disclosure; 
           [0009]      FIG. 4  is a schematic illustration of an example of lateral completion arrangement for use with a multi-zone control system, according to an embodiment of the disclosure. 
           [0010]      FIG. 5  is a cross-sectional view of a plunger-type flow control valve assembly according to embodiments of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0011]    In the following description, numerous details are set forth to provide an understanding of the present disclosure. However, it will be understood by those skilled in the art that the embodiments of the present disclosure may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. 
         [0012]    In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. 
         [0013]    The present disclosure generally relates to an electrically controllable, multi-zone control system. The multi-zone control system may be used for controlling the inflow of fluids into a completion, e.g. a lateral completion, at a plurality of well zones. According to an embodiment, hydraulically actuated, flow control devices are distributed along the completion in the various well zones. Additionally, a control module is positioned between the flow control devices, e.g. in a middle region of the completion. For example, the control module may be positioned between well zones and operated downhole for controlling flow control devices uphole and downhole relative to the location of the control module. 
         [0014]    The control module is supplied with hydraulic actuating fluid from a source, such as a downhole hydraulic fluid source or a surface source. In operation, the control module is electrically controllable to enable selective distribution of the hydraulic actuating fluid to specific flow control devices, e.g. flow control devices in a specific well zone. The control module may be actuated via electric signals to provide controlled distribution of hydraulic actuating fluid under pressure to selected flow control devices. The hydraulic actuating fluid is used to shift the selected flow control devices to a desired open or closed flow position allowing or blocking flow from the surrounding well zone. 
         [0015]    Effectively, the control module serves as a multi-zone distribution hub. In some embodiments, the control module is supplied with hydraulic actuating fluid via a single hydraulic control line and a pump is used to place the actuating fluid under suitable pressure for actuating the flow control devices. An electric line may be routed downhole to the control module to provide electrical control signals to the control module. Based on those control signals, the control module is actuated to direct hydraulic actuating fluid through relatively short hydraulic lines to specific flow control devices. As a result, electrical signals supplied through, for example, a single electric line may be routed downhole and used to ultimately control operation of flow control devices in a plurality of well zones, e.g. 2-5 well zones. Use of the electric line enables and simplifies active surface control of fluid flow into the completion at a plurality of downhole well zones. The use of electrical control signals also enhances the ability to multi-drop such a system to various other well zones. 
         [0016]    Referring generally to  FIG. 1 , an embodiment of a well system  20  is illustrated. In this embodiment, well system  20  is deployed in a wellbore  22  having a lateral wellbore section  24 , e.g. a generally horizontal wellbore section. The well system  20  comprises a completion  26  deployed in wellbore  22 . In a variety of applications, completion  26  may be in the form of a lateral completion deployed in lateral wellbore section  24  along a plurality of well zones  28 . 
         [0017]    In some applications, the lateral completion  26  is a lower completion initially installed downhole and then coupled with an upper completion  30  (shown in dashed lines) via a connect-disconnect system  32 . An artificial lift system, e.g. an electric submersible pumping system, may be deployed as part of or in cooperation with the upper completion  30  to produce fluids received via lateral completion  26 . During a production operation, the lateral wellbore section  24  may be isolated via a packer  34 , such as a production packer, set against a surrounding casing  35 . 
         [0018]    Lateral completion  26  comprises an interior flow region or passage  36  which may be along the interior of a base pipe  38 . The lateral completion  26  also comprises a plurality of sand screens  40  disposed about the base pipe  38  and located in corresponding well zones  28 . Additionally, the lateral completion  26  comprises a plurality of flow control device systems  41 . Each flow control device system  41  may comprise a plurality of flow control devices  42  located in each well zone  28 , as further illustrated in  FIG. 2 . In a variety of applications, the lateral completion  26  is assembled by connecting sections which may be referred to as joints  43 . For example, sand screen assembly joints  43  may be sequentially joined and deployed along lateral wellbore  24 . 
         [0019]    Referring generally to  FIGS. 1 and 2 , the flow control devices  42  are uniquely controlled via a control module  44 . The control module  44  effectively enables control of fluid flow from an exterior of lateral completion  26  to an interior of lateral completion  26  at specifically selected well zones  28 . In a variety of applications, the control module  44  may be located between sand screens  40  and between well zones  28 , e.g. at a generally central or middle location with respect to the plurality of well zones  28 . In other words, the control module  44  may be positioned such that at least some of the flow control devices  42  are uphole and at least some of the flow control devices  42  are downhole relative to the location of the control module  44 . It should be noted uphole refers to the side of the module  44  toward the surface regardless of whether the lateral wellbore  24  is horizontal or inclined. The downhole side of control module  44  is the opposite side which is farther into the wellbore relative to the control module. The well zones  28  may be separated and isolated via isolation packers  46  which are deployed in an un-set state and then set against the surrounding open hole wellbore wall, as illustrated. 
         [0020]    To facilitate an initial gravel packing of lateral wellbore  24  after setting of the packers  46 , the completion  26  also may comprise a plurality of shunt tubes  48  which deliver the gravel packing slurry to sequential well zones  28 . The shunt tubes extending through sequential well zones  28  may be joined at a shunt tube isolation valve structure  50  having valves for controlling the flow of gravel slurry. The valves in valve structure  50  serve to further isolate adjacent well zones  28  when the valves are closed, e.g. closed after gravel packing. During a gravel packing operation, gravel packing slurry is delivered downhole by a service tool and then diverted from the inside diameter to the annulus surrounding completion  26  via a port closure sleeve  52 . The gravel slurry flows along the annulus and shunt tubes  48  to form a uniform gravel pack  54 . 
         [0021]    In an operational example, the gravel slurry begins packing from the heel of the well and as the gravel/sand settles the dehydration fluid travels along a drainage layer between the first sand screen  40  and a solid section of the base pipe  38 . The dehydration fluid travels along this fluid return path until reaching a first sliding sleeve  56  of a plurality of sliding sleeves. In some applications, some of the returning dehydration fluid also flows through the corresponding flow control device system  41 , thus reducing or removing the use of additional sliding sleeves  56 . The dehydration fluid then flows into interior  36  and back to the surface through the base pipe  38  and corresponding tubing. Upon completion of the heel zone, the gravel slurry pumping operation is continued and this process is repeated at subsequent well zones  28 , with the aid of shunt tubes  48 , until screen out pressure is reached and the pumps are stopped. 
         [0022]    Once the service tool is retrieved, the upper completion  30  is deployed downhole and engaged with the lower completion  26  to establish communication from the surface to the lower completion  26 . For example, electrical and/or hydraulic communication may be established through the connect-disconnect  32  which can be in the form of an electrically powered connect-disconnect system. Electrical power and electrical control signals may be provided to the control module  44  via an electric line  58  routed through the connect-disconnect  32 . The electric line  58  may be coupled with a control system  60 , e.g. a computer-based control system, located at the surface or at another suitable location. 
         [0023]    In some applications, hydraulic actuating fluid may be provided to control module  44  via a hydraulic line  62  to enable selective actuation of the flow control devices  42 . The hydraulic line  62  may similarly be routed through the connect-disconnect  32  and coupled with a hydraulic pump and control system  64  located at the surface or at another suitable location. In other embodiments, however, the hydraulic line  62  may be routed to control module  44  from a downhole fluid reservoir as described in greater detail below. 
         [0024]    It should be noted the electric line  58  may comprise a single or multiple conductive paths for carrying electrical power, control signals, and/or data signals, e.g. data signals from sensors or other downhole equipment. By way of example, the electric line  58  may be in the form of a single line having a plurality of conductors able to independently carry power and/or data signals between, for example, surface control  60  and control module  44 . Similarly, the hydraulic line  62  may comprise a single flow path or a plurality of flow paths for carrying hydraulic actuation fluid. 
         [0025]    Referring again to  FIG. 2 , a schematic illustration is provided of an embodiment of an overall multi-zone control system  66  in which the control module  44  is electrically controlled via electrical control line  58  and serves as a multi-zone distribution hub. In this embodiment, sequential well zones  28  are isolated via packers  46  and the control module  44  is located proximate a generally central well zone  28 . The control module  44  may comprise control electronics  68 , e.g. a controller, which receive electrical control signals via electric line  58 . The electronics  68  may comprise control and telemetry features, and it may be embodied in a printed circuit board or otherwise suitably configured in control module  44 . 
         [0026]    Based on the control signals received via electric line  58 , the controller  68  executes flow control according to the instructions carried by the control signals. For example, the controller  68  may be used to control operation of a hydraulic manifold  70  of control module  44 . As described in greater detail below, the hydraulic manifold  70  may comprise a variety of electrically controllable valves which are actuated according to instructions carried by the electrical control signals. The control module  44 /manifold  70  are thus selectively controlled to direct flows of actuating fluid to the appropriate flow control system  41  and corresponding control devices  42  via a corresponding hydraulic line or lines  72 . 
         [0027]    In some embodiments, each hydraulic line  72  is routed to a corresponding well zone  28  and controls the simultaneous opening or closing of the group of flow control devices  42  in that specific corresponding well zone  28 . For example, control instructions may be provided by control system  60  to controller  68  of control module  44  via appropriate electrical signals sent along electric line  58 . In response to those instructions, the control module  44  controls hydraulic manifold  70  to ensure a flow of hydraulic actuating fluid to the appropriate flow control devices  42  in a given well zone or zones  28 . Accordingly, if undesirable fluid, e.g. water or undesirable gas, begins to flow into the interior  36  of lateral completion  26  at a specific well zone  28 , the group of flow control devices  42  in that particular well zone  28  may be closed to block further inflow. 
         [0028]    Depending on the type of surrounding formation and equipment used to construct lower completion  26 , the number and length of well zones  28  may vary. By way of example, the well zones  28  may be approximately 1000 feet in length and control module  44  may be used to control 2-5 well zones  28 . However, the lengths of well zones  28  may range from a few feet to thousands of feet, and the length may be the same or dissimilar from one well zone  28  to the next. Accordingly, the number of flow control devices  42  placed in each well zone  28  also may vary according to the parameters of a given application. 
         [0029]    In the specific example illustrated, the overall multi-zone control system  66  employs control module  44  to control well fluid flow at five different well zones  28 . Sometimes the number of well zones  28  controlled by an individual control module  44  may be selected based on the number of control line feed throughs available at isolation packers  46 . For example, if the isolation packers  46  have three control line feed throughs, then the number of well zones  28  serviced by the control module  44  may be selected based on the ability to accommodate the single electrical line  58  and a pair of hydraulic lines  72 . If the number of feed throughs in isolation packers  46  is increased, however, the multi-drop to other well zones  28  can also be increased accordingly. Also, the electric line  58  may be routed to additional control modules  44  so as to enable further control over inflow of well fluids at additional well zones  28 . 
         [0030]    Referring generally to  FIG. 3 , another embodiment of multi-zone control system  66  is illustrated. In this example, the control module  44  is supplied with hydraulic actuating fluid from a downhole reservoir  74  which may be pressure compensated via one or more compensators  76 . For example, the downhole reservoir  74  may serve as a hydraulic fluid bank for storing hydraulic actuating fluid downhole in a closed loop while being reservoir pressure or tubing pressure compensated via compensators  76 . 
         [0031]    The downhole reservoir  74  supplies hydraulic actuating fluid to control module  44  via hydraulic line  62 . In the embodiment illustrated, control module  44  comprises a hydraulic pump  78  powered by a motor  80  which, in turn, may be coupled to electrical power via electric line  58 . In some embodiments, the hydraulic pump  78  and the motor  80  may be combined into a single component. In the illustrated example, the hydraulic manifold  70  works in cooperation with a plurality of electrically actuated valves  82 , e.g. solenoid operated valves, to control flow of hydraulic actuating fluid along hydraulic lines  72 . An additional electrically actuated valve  84  may be used to enable circulation of hydraulic actuating fluid back to reservoir  74  when the electrically actuated valves  82  are closed to flow. This allows hydraulic pump  78  to continually operate and to simply return the pumped actuating fluid back to reservoir  74  when the electrically actuated valves  82  are in the closed position. 
         [0032]    When the control module  44 , e.g. controller  68 , receives instructions to change the flow position of flow control devices  42  in a given well zone or zones  28 , the appropriate valves  82  are shifted electrically to the desired flow or no-flow position. In the embodiment illustrated, the electrically actuated valve  84  has been shifted to the closed or no-flow position and one of the electrically controlled valves  82  has been shifted to the open flow position to enable flow of actuating fluid to the corresponding flow control devices  42 . In the illustrated example, the valve  82  shifted to the open flow position has effectively directed actuating fluid under pressure to the flow control devices  42  in the middle well zone  28 , thus shifting those flow control devices  42  to the closed flow position. When flow control devices  42  in the middle well zone  28  are closed, well fluids are prevented from flowing from the exterior of completion  26  to interior  36  at that well zone. 
         [0033]    Depending on the application, flow control devices  42  may have a variety of configurations. By way of example, the flow control devices  42  may comprise plunger assemblies  86 , e.g. hydraulically actuated plungers  86 . In some applications, the plungers  86  are spring biased or otherwise biased to an open flow position allowing flow of fluids from an exterior to an interior of lateral completion  26 . When hydraulic actuating fluid is allowed to flow to specific hydraulically actuated plungers  86  via manifold  70 , those plungers  86  are forced against the spring bias and into corresponding seats  88  to block further flow of fluids therethrough. 
         [0034]    In some embodiments, individual electrically actuated valves  82  may be coupled with flow control devices  42  in more than one well zone  28 . In the embodiment illustrated in  FIG. 3 , for example, one of the electrically actuated valves  82  controls corresponding flow control devices  42  in two well zones  28  on the left or heel side of control module  44 . Another one of the electrically actuated valves  82  controls the remaining flow control devices  42  in those same two well zones  28 . Depending on the parameters of a given well, formation, well zone arrangement, equipment configuration, and/or other factors, various flow control arrangements may be selected. In the illustrated example, two of the electrically actuated valves  82  are actuated to the open flow position to close the corresponding groups of flow control devices  42  and to completely block flow in each of the heel side well zones  28 . 
         [0035]    A sensor system  90  also may be used to optimize control over fluid flow in each of the well zones  28 . By way of example, the sensor system  90  may comprise a plurality of sensors  92  positioned along completion  26  and/or at other suitable locations within well zones  28 . The sensors  92  may be in the form of pressure sensors, temperature sensors, or other sensors distributed throughout the well zones  28 . The sensor data, e.g. pressure and temperature data, may be sent along electric line  58  to at least one of the controller  68  or control system  60  for processing. The processed data provides information that can be used for controlling flow into completion  26  at each well zone  28 . For example, if the sensor data indicates the presence of water and/or gas, the flow control devices  42  for that well zone  28  may be closed to block further inflow of fluid. 
         [0036]    Depending on the reservoir and surrounding formation, the lateral completion  26  may be constructed in various lengths and configurations. In  FIG. 4 , a schematic illustration is provided in which the lateral completion  26  is structured with a plurality of screen assembly joints  43 , e.g. four screen assembly joints, on each side of a flow control device, e.g. flow control device  42 . Consequently, a given flow control device(s) is able to collect fluid flow from the drainage layer in both uphole and downhole directions. For example, a given flow control device  42  may collect fluid flow from four uphole screen joints  43  and from four downhole screen joints. In the illustrated example, twenty four screen assembly joints  43  are disposed between the illustrated pair of isolation packers  46 . Depending on the application, the number of joints  43  as well as a number of flow control devices  42  between isolation packers  46  may vary and may be selected based on, for example, zonal flow parameters. As described above, the inflow of well fluids is collected from the screens  40  and diverted along a drainage layer of the completion  26  to the flow control devices  42 , e.g. to the plunger assemblies  86 , to enable selective choking of production flow. 
         [0037]    The overall zonal flow control system  66  may be adapted to a variety of applications and may be used to provide a low-cost, active control of multiple well zones  28 , e.g. five well zones, from a single distribution hub/module  44 . With additional feed throughs in packers  46  and in shunt tube isolation valve structures  50 , additional well zones  28  may be controlled via module  44 . The control module  44  serves as a distribution hub which can be multi-dropped to provide flow control in a plurality of well zones based on control signals through the simple electric line  58 . In some applications, the hydraulic actuating fluid may be selectively diverted by the control module  44  to actuate other components in the lower completion  26 , e.g. packers, sliding sleeves, or zonal isolation valves. The flow control devices  42  also may comprise various types of plunger assemblies which facilitate return flow through the sand screen assembly joints  43 . 
         [0038]    Depending on parameters of a given application, the control module  44  may be constructed in a variety of configurations and may comprise various features. Examples of such features include the integral pump  78  and the motor  80  used for hydraulic power generation. The control module  44  also may incorporate or work in cooperation with a pressure compensation system, e.g. compensators  76 . In some applications, the control module may comprise or work in cooperation with an accumulator used for storing hydraulic energy. Additionally, electronics  68  may comprise various types of controllers and telemetry systems utilized for communication and for controlling the components of control module  44  and overall flow control system  66 . 
         [0039]    Other components of the overall well system and multi-zone flow control system  66  also may be adjusted according to the parameters of a given application. The electric line  58  may comprise separate lines for power and data or a combined power/data line. The control system  60  and electric line  58  may be used for carrying a variety of signals along a wholly hardwired electrical communication line or a partially wireless communication line. Such adjustments to the well system may be made according to equipment, environmental, and/or other considerations. 
         [0040]      FIG. 5  illustrates a plunger-type flow control valve assembly  100  according to embodiments of the present disclosure. Any of the flow control devices described herein can be this plunger type of flow control valve. The assembly  100  includes a pressure-balanced plunger  112  held within a plunger containment member  114  that is shaped and sized to house the plunger  112  within an interior region of the plunger containment member  114  such that the plunger  112  is permitted to move axially within the plunger containment member  114  as shown by arrow A. When the plunger  112  is in a closed position (as in  FIG. 5 ) with the plunger  112  toward the right, the valve assembly  100  is closed. The flow control valve assembly  100  includes a fluid port  116  through which production fluid is permitted to flow into a main bore  117  when the plunger  112  is moved to the left. 
         [0041]    The plunger  112  has a downhole side  118  and an uphole side  120 . In previous designs, the plunger  112  was exposed to pressure on the downhole side  180  which was counter balanced by a force applied to the plunger  112  to the uphole side  120  to maintain the plunger  120  in the desired position. Depending on the installation, the pressure and counter balancing forces were large. The flow control valve assembly  100  also includes a power module  124  (shown schematically) that provides power to move the plunger up and down to open and close the valve assembly  100 . The present disclosure is directed to embodiments in which the pressure is balanced between the uphole side  120  and downhole side  180 . 
         [0042]    The assembly  100  includes a series of seals  122  which will permit the pressure to be applied to the uphole side  120  without contaminating the fluid flow through the fluid port  116 . The uphole side  120  and downhole side  180  can both be in communication with hydrostatic pressure in the wellbore mitigating and even eliminating the need to force the plunger  112  toward the closed position. The forces required to move the plunger  112  from the closed position toward any intermediate position or a fully-open position are also very low. In some embodiments the required power is 10 watts or less. The power consumption is related to the flow rates and the pressure rating. For a lower pressure and flow rate configuration, the power can be as low as 5 watts. The balanced design allows for a greater amount of pressure to be held. In some embodiments, the pressure can be as high as 5,000 psi. The seals  122  can be made of a different material and configuration than the interface between the plunger  112  and the downhole side  118  of the plunger containment member  114 , resulting in a differential force urging the plunger  112  in either direction, depending on the characteristics of the seals. The balanced design results in this resultant force being no greater than 50 pound-feet. In some embodiments the force is as much as 100 pound-feet, or as little as 20 pound-feet. Such an installation in a complex multi-zonal well installation as shown in the present disclosure was previously difficult and required power quantities greater than what was easily available. 
         [0043]    Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.