ACTIVE IN-SITU CONTROLLED PERMANENT DOWNHOLE DEVICE
This application claims the benefit under 35 U. S. C. § 119(e) to U.S. Patent Application Serial No. 12/415289, entitled, "Active In-Situ Controlled Permanent Downhole Device", filed on March 31, 2009. This application is hereby incorporated by reference in its entirety.
BACKGROUND
Field of the Invention
[0001] Embodiments of the present invention generally relate to downhole control of well systems, and more particularly to scalable systems of permanent downhole devices with active in-situ control.
Description of the Related Art
[0002] The following descriptions and examples are not admitted to be prior art by virtue of their inclusion in this section.
[0003] 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. However, in an era in which hydrocarbon resources are becoming more scarce and difficult to obtain, a premium is placed on the ability to maximize or optimize hydrocarbon production for each well in a field. One way to effectively manage a well is through the use of so called intelligent completions. Intelligent completions are completion assemblies that may be altered after run in to vary the settings of individual downhole devices. These types of completions are generally complex, expensive, and difficult to manage. For example, one difficulty in controlling a device is the time lag between an occurrence of an event resulting in a significant altering
of conditions downhole and the ability to detect the event and provide for a suitable adjustment to the appropriate downhole device.
SUMMARY
[0004] In accordance with one embodiment of the claimed invention, a controllable downhole device may include a telemetry module configured to communicate with a surface component and an energy module configured to at least power an actuator. In addition, the downhole device may further include a controller communicably coupled to the telemetry module and one or more sensors, and a controllable component coupled to the actuator. The controller may be configured to read a desired state from the surface component and compare the desired state to an actual state detected by the one or more sensors. The controller may then instruct the actuator to adjust the controllable component such that the actual state approaches the desired state.
[0005] In accordance with another embodiments of the claimed invention a method of completing a well may comprise installing a downhole device comprising a telemetry module, an energy module configured to at least power an actuator, a controller communicably coupled to the telemetry module and one or more sensors, and a controllable component coupled to the actuator. The method may further include providing a surface controller comprising a desired state input device configured to accept a desired state and then provide the desired state to the controller via the telemetry module. Another step may be inputting a desired state into the desired state input device. Measuring an actual state may be performed by the one or more sensors followed by the step of comparing the desired state with the actual state. Still another step may be instructing the actuator to adjust the controllable component such that the actual state is modified in a direction towards the desired state.
[0006] Other or alternative features will become apparent from the following description, from the drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying drawings illustrate only the various implementations described herein and are not meant to limit the scope of various technologies described herein. The drawings are as follows:
FIG. 1 is a cross-sectional schematic of a multi-lateral well system, in accordance with an embodiment of the invention;
FIG. 2 is a partial cross-sectional schematic of an active in-situ controlled downhole device, in accordance with an embodiment of the invention;
FIG. 3 is a flow chart of the surface and in-situ control systems, in accordance with an embodiment of the invention;
FIG. 4 is a flow chart of the surface and multi-lateral well control systems, in accordance with an embodiment of the invention; and
FIG. 5 is a flow chart of the surface and field control systems, in accordance with an embodiment of the invention.
DETAILED DESCRIPTION
[0008] In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible. In the specification and appended claims: the terms "connect", "connection",
"connected", "in connection with", "connecting", "couple", "coupled", "coupled with", and "coupling" are used to mean "in direct connection with" or "in connection with via another element"; and the term "set" is used to mean "one element" or "more than one element". As used herein, the terms "up" and "down", "upper" and "lower", "upwardly" and downwardly", "upstream" and "downstream"; "above" and "below"; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention.
[0009] Referring generally to FIG. 1, this drawing represents a schematic cross- section of a well system 100. The well system 100 may include a main bore 10 extending below a surface 14. The surface 14 may be a terrestrial or sub-sea surface. The main bore 10 may have some portions lined with casing 12. Lateral branches 20 and 30 may extend from the main bore 10. In this exemplary embodiment, lateral branches 20 and 30 are shown as primarily horizontal or deviated branches extending through various formations. For example, lateral branch 20 may extend through formations 22, 24, and 26, and lateral branch 30 may extend through formations 32, 34, and 36. Although multiple formations and multiple branches are shown, embodiments of the claimed invention may not be limited to this example. In some cases, embodiments may include single formation systems, single wellbore systems, and non-deviated systems in a variety of combinations and configurations. In addition, the lateral branches 20 and 30 are shown as being provided with substantially similar configurations. Other embodiments of a well system may include different configurations for each lateral branch.
[0010] In the interest of simplification, only lateral branch 20 will be described in detail with the understanding that the non-limiting concepts presented for lateral branch 20 may be included in other embodiments of single and multiple well bore systems as well as lateral branch 30. Within lateral branch 20, active in-situ controlled downhole devices 200 may be provided proximate to formations 22, 24, and 26 in order to individually control the flow from the formations, through the devices, and into the lateral bore 28. Three downhole devices 200 are shown in this example, but less than
three or more than three downhole devices 200 may be used. In addition, the downhole devices 200 may be identical to one another, or differ in terms of configuration and/or function. In order to simplify the description, the downhole device 200 will be detailed with respect to an inflow control device including a controllable component such as a controllable valve 210. Additionally, one or more packers 220 may be used to section the annulus surrounding the lateral branch 20. The lateral branch 20 is shown as being provided in an open hole configuration, but the lateral branch may be lined or cased and perforated, gravel packed, or implemented with expandable screens for example, depending upon the requirements of the particular branch and/or well.
[0011] As shown, the packers 220 may function to divide the lateral bore 20 into various sections with respect to formations 22, 24, and 26. Accordingly, each individual valve 210 of a respective downhole device 200 may be operated to adjust the inflow from each formation depending upon conditions in the lateral branch. For example, the valves 210 may be adjusted to balance inflow across all three formations 22, 24, and 26, or to shut off one or more formations 22, 24, and 26, in order to control water cut flowing into the lateral bore 28. The valves 210 may be provided in a variety of locations. For example, the first two downhole devices 200 have the valves 210 positioned to control inflow through the circumference of the downhole device 200, while the third downhole device 200 controls inflow through an open end of the lateral bore 28. The downhole devices 200 may be coupled together through the use of pipe sections 40 provided between the downhole devices 200. Alternatively, casing may be used to couple together the downhole devices 200.
[0012] Turning now to FIG. 2, this drawing illustrates a partial cross-sectional schematic of an embodiment of an active in- situ controlled downhole device 200 provided in an open hole wellbore 222. The downhole device 200 may comprise a packer 220, such as a swellable packer, mechanically set packer, or hydraulically set packer for example, configured to seal a portion of the wellbore 222. The wellbore may be segmented by a series of packers 220 (only one is shown in this illustrative
embodiment) so that the flow from each section of a well can be controlled individually. The downhole device 200 may be provided proximate to a formation 232 containing a desirable fluid such as hydrocarbon. Fluid from the formation 232 may fill the annulus 242 surrounding the downhole device 200 and may be constrained or directed to flow in a particular direction in part due to the sealing effects of the packer 220.
[0013] In some embodiments, fluid may enter into an interior bore 215 via a sand screen 230, as shown in this example. The passageway may continue through an opening in the side of the downhole device 200, while in other situations, the passageway may be through one end of the downhole device 200. After passing through the sand screen 230, the fluid inflow (from a formation to the production stream in this case) may be controlled by a controllable component such as a variable valve or choke 210, among other types of components. This embodiment of a choke 210 is shown as a sliding sleeve, although it should be recognized that many different types of controllable mechanisms may be used. The choke 210 may be operated between an opened and closed position in order to control the rate of fluid flowing into the interior bore 215 of the downhole device 200.
[0014] The adjustable choke 210 may in turn be coupled to an actuator 235. The actuator 235 may use any type of actuation method including, but not limited to, electric, hydraulic, electro-hydraulic, electro-mechanical, and other various combinations of actuation methods. The actuator 235 may be coupled to other components of an in-situ system 240 including, but not limited to, one or more sensors 250, controller modules 260, energy storage and/or conversion modules 270, and telemetry modules 280. The telemetry module 280 may be communicatively coupled to the surface via hydraulic, electric, or optical, cables or control lines, or combinations of the various types of communicatively coupling methods. In addition, some portion or all of the communicative coupling may be wireless, such as inductive coupling, receiver/transmitter systems, pressure or acoustic systems, or combinations of various forms of wireless coupling. The communication between the surface and the downhole
device 200 may include information signals, such as data and/or commands, and power or energy signals, or a combination of both.
[0015] A desirable state, for example a desired flow rate into the downhole device
200 to be permitted by the adjustable choke 210, may be set and resettable by an operator on the surface either at the well site or at a location remote from the well site. A setting corresponding to the desirable state may be sent to the in- situ controller module 260 via the telemetry module 280. Sensors 250 provided in the downhole device 200 may then detect the current state (e.g., the current flow rate through the downhole device 200) and provide the information to the controller module 260. In some cases, the controller module 260 may provide this information uphole to the operator on the surface for their information in real time. Either way, the controller module 260 may be configured with decision making protocol (e.g., control logic) to compare the current flow rate, as detected by the sensors 250, with the desired flow rate, as sent by the operator, and provide appropriate commands to the actuator 235 such that the position of the choke 210 may be modified to adjust the flow rate toward the desired amount. The sensors 250 may then update the change in flow rate, provide this differential to the controller module 260, and repeat the process until the desired flow rate is reached. In some embodiments, no further action may be required by the operator in order to reach the desired flow rate as the downhole device 200 may function in a relatively autonomous fashion after the initial setting of a desired state.
[0016] The various modules and devices in the downhole device 200 may be powered by the energy module 270. The energy module 270 may include energy storage devices such as batteries and super capacitors, for example, among other forms of energy storage. In addition, the energy module 270 may include energy conversion devices configured to convert vibration, flow, or optical energy into a form appropriate for powering the actuator 235 and other modules of the downhole device 200. However, in some embodiments the energy module 270 may be a transformer or other transmission
device able to directly couple electrical power provided by a cable to the various components and modules via the controller module 260.
[0017] Throughout the operation of reading the current state via the sensors 250 and adjusting the actuator 235 via the controller module 260, the downhole device 200 may be configured such that all control actions to optimize the flow rate are done in-situ and actively by the on-board controller module 260 and the rest of the components in the system, without any direction or interference from the operator aside from the initial setting of the desired state. Accordingly, the operator may be constantly informed about the current flow rate (or other desired state) and achieve the desired flow rate they initially set without further involvement. However, in some embodiments, the downhole device 200 may be configured to allow further changes by the operator as considered appropriate with regard to the well operations or sensor 250 readings.
[0018] Referring now to FIG. 3, this figure is flowchart used to illustrate an embodiment of a working principle of an active in-situ controlled downhole device (such as the downhole device 200 in FIG. 2 for example), along with exemplary embodiments of some of the identified components. The flowchart may comprise two primary components, a surface component 300 and an active in-situ controlled downhole device component 350. The surface component 300 may further comprise surface setting 302 (e.g., such as when the desired state was input at that surface in the previous example) and surface energy source 304. The downhole device component 350 may comprise a telemetry component 352, a controller component 354, an actuator component 356, a hardware component 358, a sensor component 360 and a downhole energy component 364.
[0019] As with the previous embodiment, a desired state may be input by an operator at the surface via the surface setting 302. In the case of a flow control device for example, the desirable state, or the key performance indicator (i.e., the control variable), may be flow rate, water cut, or any other parameter the operator may like to control. In addition, the controller component 354 may be configured to provide the operator with a
selection of several different modes in order to control one or multiple downhole variables depending on the desired optimization scheme. Embodiments of the claimed invention may not be limited to a single desired state setting.
[0020] The surface setting 302 may be provided to the controller component 354 via the telemetry component 352. The sensor component 360 may read the current state of the system 362 and provide this information to the controller component 354. The controller component 354 may then compare the current state of the system 362 with the surface setting 302 and instruct the actuator component 356 to adjust the hardware of the downhole device 358 accordingly. Adjusting the hardware of the downhole device 358 in turn affects the current state of the system 362 which is then detected by the sensor component 360 and provided to the controller component 354. The controller component 354 may then compare the current state of the system 362 with the surface setting 302 and provide another adjustment instruction to the actuator component 356. In addition, the controller component 354 may also provide the current state of the system 362 back to the operator for display via the telemetry component 352 and the surface component 300. The path taken by the information may be illustrated by a signal flow path 380 shown in solid lines in the flowchart.
[0021] The telemetry provided by the telemetry component 352 may be either wired, wireless, or some combination of wired and wireless telemetry. The wired telemetry may be electrical, hydraulic, mechanical, or any other method or combination of wired methods. The wireless telemetry may be electromagnetic, acoustic, or any other method or combination of wireless methods. The controller component 354 may be configured to compare the current state of the system 362 with the surface setting 302 and determine the degree to which the actuator component 356 should adjust or modify the hardware of the downhole device 358, if at all. The controller component 354 may be electronic, hydraulic, mechanical, or other type of circuitries containing imbedded control logic. The control logic may be proportional, integral, differential, adaptive, neuro- network, or any other type of control methodology, including combinations of the
identified methodologies, depending on the circumstances of the particular application. For example, in the case of an embodiment of a flow control device, an electronic controller component may compare the current flow rate with an initial setting (e.g., surface setting 302) and determine the appropriate response by a PID (proportional- integral-differential) control logic to achieve a desired flow rate via desired system dynamics.
[0022] The actuator component 356 may receive instructions from the controller component 354 to adjust the hardware of the downhole device 358 accordingly. The actuator component 356 may be electrical, hydraulic, mechanical, or any other type, as well as combinations of various types, of actuators. For example, in the case of a flow control device, the actuator component 356 may be an electrical motor driving a ball screw to either push or pull an adjustable choke in the flow control device. The hardware of the downhole device 358 may be a flow control valve, a safety valve, a formation isolation valve, or any other type of downhole device which requires actuations to modify a current state to a desirable final state. In some embodiments, the hardware of the downhole device 358 may be permanently located downhole.
[0023] The current state of the system 362 may include both internal and external parameters of the hardware of the downhole device 358. For example, in the case of a flow control device, the current state of the system 362 may be the position of the choke (internal to the device), flow rate and water cut through the choke (internal to the device), temperature and pressure of fluids located in the annulus (external to the device), or oil/water contact front (external to the device).
[0024] The sensor component 360 may measure the current state of the system, feed the measurements back to the controller component 354 to determine the proper instructions for the actuator component 356, and send the measurements back to the surface for display (via the telemetry component 352 and the surface component 300). The sensor component 360 may be any type of sensor or sensors depending upon the required parameters of the controller component 354. For example, in a flow control
embodiment, the sensor component 360 may be configured to monitor temperature, pressure, flow rate, flow type (water, oil, gas cut), or even perform deep reading measurements including electromagnetic, seismic, or joined electromagnetic seismic sensors to detect oil/water front movement, among others.
[0025] The downhole energy component 364 may provide power to the rest of the downhole components of the downhole device that may require energy to operate. Energy flows may be indicated by the energy flow path 390 represented by dashed lines between the various components of the system. The energy component 364 may be powered by the surface energy source 302, or the energy component 364 may be configured such that no energy is required from a surface energy source 302. In some embodiments, the downhole energy component 364 may comprise three major subcomponents, power generation/conversion, power storage, and power transmission. The power generation sub-component may harvest energy from the surrounding environment (e.g., flow, vibration, electrochemical potentials, or any other type of surrounding energy source), while the energy conversion may convert one type of energy from either uphole (i.e., the surface energy source 302) or in-situ downhole, to another type of energy downhole (e.g., from electrical energy uphole to hydraulic energy downhole). The power storage sub-component may be rechargeable batteries, capacitance banks, hydraulic accumulators, or any other type of energy storage device. The power transmission subcomponent may be either wired, wireless, or some combination of wired and wireless power transmission. The wire power transmission may be electrical, hydraulic, mechanical, optical, or any other type of wired power transmission. The wireless power transmission may be electromagnetic such as inductive coupling, acoustic, or any other method of wireless power transmission.
[0026] Referring generally to FIG. 4, this drawing illustrates a flowchart of an embodiment of the claimed invention. Active in-situ controlled devices may be used individually in one location or scaled up to a network of downhole devices in multiple locations in a well. In such a case, optimization of the system may be achieved either
locally or globally. As show in the figure, the flowchart may comprise two primary components, a surface component 400 and a well system 450. The surface component 400 may further comprise surface setting 410 (e.g., such as inputting a desired state as in the previous embodiment), a surface network controller component 420, and a current state of the well component 430. The well system 450 may comprise a first lateral branch 460 with three zones controlled by active in-situ controlled downhole devices 462, 462, and 466, and a second lateral branch 470 also with three zones controlled by active in-situ controlled downhole devices 472, 474, and 476. Although the first and second lateral zones 460 and 470 are both represented as comprising three zones, embodiments of the claimed invention may not be limited to this example. Each lateral branch 460, 470 may have the same or different numbers of zones along with the same or different numbers of active in-situ controlled downhole devices. In some cases, there may be branches with no active in-situ controlled downhole devices. The final configuration of any well system 450 will be dependent upon the specific characteristics of the surrounding well environment.
[0027] The well system 450 may be instrumented with a network of active in-situ controlled devices 462, 464, 466, 472, 474, and 476, linked to a network controller component 420. The network controller component 420 may be provided at a downhole location (not shown) or at a surface location such as the location of the surface component 400. The surface component 400 may be provided proximate to the actual well site or remote from the well site. The well site itself may be at a terrestrial location or may be submerged at a sub-sea location.
[0028] For local optimization (i.e., with regard to each lateral branch), an operator may independently set the desired state of each downhole device 462, 462, 466, 472, 474, and 476. In such a case, each zone could operate individually based upon the readings of the sensors associated with that particular zone. For example, in the case of flow control, operators may set the specific flow rate desired from downhole devices 462, 464, and 476, while setting the specific water cut desired from downhole devices 466, 472, and
474. Of course, in some embodiments, more than one desired parameter may be set for each downhole device. For example, the desired water cut may be set for each of the downhole devices 462, 462, 466, 472, 474, and 476, along with a desired flow rate. In such a case, one parameter may have to take precedence over the other, such that the flow rate may be desired as long as the water cut is kept below a maximum value.
[0029] With regard to global optimization, an operator may set the desired state of the well system 450, leaving the network controller component 420 to determine the desired parameters for each downhole device 462, 462, 466, 472, 474, and 476. The network controller component 420 may then function by communicating the one or more desired parameters necessary to achieve the desired state of the well system 450 with the individual downhole devices 462, 462, 466, 472, 474, and 476. For example, in the case of flow control, an operator may set the network controller component 420 to achieve a maximum total flow rate from the well system 450 within a certain upper limit of water cut. In some embodiments, each in-situ controller 260 (see FIG. 2) may be configured to communicate with other controllers 260 of the same or corresponding well systems 450. The in-situ controller 260 may be able to communicate either with or without the interaction of a surface network controller component 420. In such a case, each downhole device 462, 462, 466, 472, 474, and 476, may be able to coordinate their functions with the other downhole devices 462, 462, 466, 472, 474, and 476, of the well system 450. For example, downhole device 476 may be able to exchange information with downhole devices 462 and 464 to achieve a desired flow rate, while downhole device 466 may be able to exchange information with downhole devices 472, and 474 to maintain a desired water cut.
[0030] Turning now to FIG. 5, this drawing is a flowchart of an embodiment of the claimed invention. In this embodiment, a surface component 500 is communicably coupled to a field system 550. The surface component 500 may further include surface setting 510, a surface network controller component 520, and a current state of the field component 530. The field system 550 may comprise a first well 560, a second well 590,
and a third well 595, although embodiments of other fields may have fewer than three wells or more than three wells. Each well may comprise multiple branches and may include either vertical or deviated wellbores. Within each wellbore, multiple zones may exist and one or more active in-situ controlled devices may be associated with each zone. However, in some cases, there may be zones or wellbores in which no active in-situ controlled devices are present. As an illustrative example, the first well 560 may comprise a first lateral branch 570 and a second lateral branch 580. The first lateral branch 570 may include one or more downhole devices (e.g., three are shown 572, 574, and 576) while the second lateral branch 580 may also include one or more downhole devices (e.g., three are shown 582, 584, and 586).
[0031] The individual wells 560, 590, and 595 may be controlled locally or globally at a field system 550 level. For example, each well 560, 590, and 595 may be optimized for maximum flow rate independent of the other wells. However, in other cases, an operator may input a global desired flow rate for the field system 550. In some embodiments, the surface network controller component 520 may be configured to determine the individual desired flow rates for each of the individual wells 560, 590, and 595, for example, such as balancing the flow rates across each of the wells 560, 590, and 595, to provide for a more efficient production of a reservoir. In still other embodiments, the operator may be able to set desired parameters at a local or global (with respect to each well) level for each of the downhole devices 572, 574, 576, 582, 584, and 586.
[0032] While the invention has been disclosed with respect to a limited number of embodiments, those skilled in the art, having the benefit of this disclosure, will appreciate numerous modifications and variations there from. It is intended that the appended claims cover such modifications and variations as fall within the true spirit and scope of the invention.