BACKGROUND OF THE DISCLOSURE

1 . Field of the Disclosure

[0001] The disclosure relates generally to systems and methods for selective control of fluid flow between a wellbore tubular such as a production string and a subterranean formation.

2. Description of the Related Art

[0002] Hydrocarbons such as oil and gas are recovered from a subterranean formation using a wellbore drilled into the formation. Such wells are typically completed by placing a casing along the wellbore length and perforating the casing adjacent each such production zone to extract the formation fluids (such as hydrocarbons) into the wellbore. Fluid from each production zone entering the wellbore is drawn into a tubing that runs to the surface. It is desirable to have substantially even drainage along the production zone. Uneven drainage may result in undesirable conditions such as an invasive gas cone and/or water cone. In the instance of an oil-producing well, for example, a gas cone may cause an in-flow of gas into the wellbore that could significantly reduce oil production. In like fashion, a water cone may cause an in-flow of water into the oil production flow that reduces the amount and quality of the produced oil. Accordingly, it may be desired to provide controlled drainage across a production zone and / or the ability to selectively close off or reduce in-flow within production zones experiencing an undesirable influx of water and/or gas. Additionally, it may be desired to inject a fluid into the formation in order to enhance production rates or drainage patterns.

[0003] The present disclosure addresses these and other needs of the prior art. SUMMARY OF THE DISCLOSURE

[0004] In aspects, the present disclosure provides an apparatus for controlling a flow of a fluid between a wellbore tubular and a formation. The apparatus may include a flow control device having a flow space formed therein; and a flow control element positioned in the flow space. The flow control element may be configured to flex between a first radial position and a second radial position in response to a change in a pressure differential along the flow space.

[0005] In aspects, the present disclosure also provides a method for controlling a flow of a fluid between a wellbore tubular and a formation. The method may include controlling fluid flow in a flow control device along the wellbore tubular by using a flow control element configured to flex between a first radial position and a second radial position in response to a change in a pressure differential in the flow control device.

[0006] In still further aspects, the present disclosure also provides a system for controlling a flow of a fluid between a wellbore tubular and a formation. The system may include a plurality of flow control devices positioned along the wellbore tubular, wherein each flow control device has a flow space formed therein; and a flow control element positioned in each flow space, each flow control element being configured to flex between a first radial position and a second radial position in response to a change in a pressure differential along the flow space.

[0007] It should be understood that examples of the more important features of the disclosure have been summarized rather broadly in order that detailed description thereof that follows may be better understood, and in order that the contributions to the art may be appreciated. There are, of course, additional features of the disclosure that will be described hereinafter and which will form the subject of the claims appended hereto. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The advantages and further aspects of the disclosure will be readily appreciated by those of ordinary skill in the art as the same becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings in which like reference characters designate like or similar elements throughout the several figures of the drawing and wherein:

Fig. 1 is a schematic elevation view of an exemplary multi-zonal wellbore and production assembly which incorporates an in-flow control system in accordance with one embodiment of the present disclosure;

Fig. 2 is a schematic elevation view of an exemplary open hole production assembly which incorporates an in-flow control system in accordance with one embodiment of the present disclosure;

Fig. 3 is a schematic cross-sectional view of an exemplary production control device made in accordance with one embodiment of the present disclosure;

Fig. 4 is a schematic elevation view of exemplary flow control element made in accordance with one embodiment of the present disclosure; and

Fig. 5 is a schematic elevation view of other exemplary flow control elements made in accordance with one embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0009] The present disclosure relates to devices and methods for controlling a flow of fluid in a well. The present disclosure is susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present disclosure with the understanding that the present disclosure is to be considered an exemplification of the principles of the disclosure and is not intended to limit the disclosure to that illustrated and described herein.

[00010] Referring initially to Fig. 1 , there is shown an exemplary wellbore 10 that has been drilled through the earth 12 and into a pair of formations 14, 16 from which it is desired to produce hydrocarbons. The wellbore 10 is cased by metal casing, as is known in the art, and a number of perforations 18 penetrate and extend into the formations 14, 16 so that production fluids may flow from the formations 14, 16 into the wellbore 10. The wellbore 10 has a deviated, or substantially horizontal leg 19. The wellbore 10 has a late-stage production assembly, generally indicated at 20, disposed therein by a tubing string 22 that extends downwardly from a wellhead 24 at the surface 26 of the wellbore 10. The production assembly 20 defines an internal axial flowbore 28 along its length. An annulus 30 is defined between the production assembly 20 and the wellbore casing. The production assembly 20 has a deviated, generally horizontal portion 32 that extends along the deviated leg 19 of the wellbore 10. Production devices 34 are positioned at selected points along the production assembly 20. Optionally, each production device 34 is isolated within the wellbore 10 by a pair of packer devices 36. Although only two production devices 34 are shown in Fig. 1 , there may, in fact, be a large number of such production devices arranged in serial fashion along the horizontal portion 32.

[00011] Each production device 34 features a production control device 38 that is used to govern one or more aspects of a flow of one or more fluids into the production assembly 20. As used herein, the term "fluid" or "fluids" includes liquids, gases, hydrocarbons, multi-phase fluids, mixtures of two of more fluids, water, brine, engineered fluids such as drilling mud, fluids injected from the surface such as water, and naturally occurring fluids such as oil and gas. Additionally, references to water should be construed to also include water- based fluids; e.g., brine or salt water. In accordance with embodiments of the present disclosure, the production control device 38 may have a number of alternative constructions that ensure selective operation and controlled fluid flow therethrough.

[00012] Fig. 2 illustrates an exemplary open hole wellbore arrangement 11 wherein the production devices of the present disclosure may be used. Construction and operation of the open hole wellbore 11 is similar in most respects to the wellbore 10 described previously. However, the wellbore arrangement 11 has an uncased borehole that is directly open to the formations 14, 16. Production fluids, therefore, flow directly from the formations 14, 16, and into the annulus 30 that is defined between the production assembly 21 and the wall of the wellbore 11. There are no perforations, and open hole packers 36 may be used to isolate the production control devices 38. The nature of the production control device is such that the fluid flow is directed from the formation 16 directly to the nearest production device 34, hence resulting in a balanced flow. In some instances, packers maybe omitted from the open hole completion.

[00013] Referring now to Fig. 3, there is shown one embodiment of a production control device 100 for controlling the flow of fluids from a reservoir into a production string, or "in-flow" and/or the control of flow from the production string into the reservoir, or "injection." The control devices 100 can be distributed along a section of a production well to provide fluid control and/or injection at multiple locations. Exemplary production control devices are discussed herein below.

[00014] In one embodiment, the production control device 100 includes a paniculate control device 110 for reducing the amount and size of particulates entrained in the fluids and a flow control device 120 that controls one or more flow parameters or characteristics relating to fluid flow between an annulus 30 and a flow bore 52 of the production string 20 (Fig. 1 ). Exemplary flow parameters or characteristics include but are not limited to, flow direction, flow rate, pressure differential, degree of laminar flow or turbulent flow, etc. The paniculate control device 110 can include a membrane that is fluid permeable but impermeable by particulates. Illustrative devices may include, but are not limited to, a wire wrap, sintered beads, sand screens and associated gravel packs, etc. In one arrangement, a wire mesh 112 may be wrapped around an unperforated base pipe 114.

[00015] In embodiments, the flow control device 120 is positioned axially adjacent to the paniculate control device 100 and may include a housing 122 configured to receive a flow control element 124. The housing 122 may be formed as tubular member having an annular flow space 126 that is shaped to receive the flow control element 124. The flow space 126 may provide a path for fluid communication between the annulus 30 of the wellbore 10 (Fig. 1) and the flow bore 52 of the production assembly 20. A flow path 132 may direct flow from the particulate control device 110 to the flow control device 120. In one arrangement, the fluid may flow substantially axially through the particulate control device 112, the flow path 132, and the flow control device 120.

[00016] Referring now to Figs. 3 and 4, in embodiments, the flow control element 124 may be configured to provide a specified local flow rate under one or more given conditions (e.g., flow rate, fluid viscosity, etc.). The flow control element 124 may vary the cross-sectional flow area in the flow space 126 to vary a pressure differential applied the flow control element 124. In one arrangement, an increase in flow rate may increase a pressure differential applied to the flow control element 124. In response, the flow control element 124 may reduce the cross-sectional flow area, which reduces the flow rate. Thus, in a somewhat closed-loop fashion, the flow rate along the flow control device 120 may be limited to a desired range or particular value. Thus, in one aspect, the flow control element 124 may be considered as self-adjusting relative to fluid flow rates.

[00017] In one embodiment, the flow control element 124 may be formed as body having a base or sleeve portion 140 and a movable portion 142. The slθθve portion 140 may be shaped to seat on a base pipe 134 or other suitable support structure.

[00018] In one arrangement, the movable portion 142 may be an annular rib or fin that projects radially into a gap 144 separating an interior surface of the housing from an exterior surface of the sleeve portion 140. The fin 142 may be formed partially or wholly of a flexible or pliable material that allows the fin 142 to flex between a first diameter and a second larger diameter. This flexure may cause the gap 144 to change in size between a first flow space 146 and a second smaller flow space 148. This change in size causes a corresponding change in the cross-sectional flow area available to the flowing fluid. The fin 142 may be configured to flex in response to a pressure differential caused by a flowing fluid 150. That is, the fin 142 may flex, expand or spread radially outward in response to a change in a pressure applied on the surfaces facing the flowing fluid, i.e., upstream surfaces 152. In some embodiments, the flexure may be graduated or proportionate. For instances, the fin 142 flexes to gradually reduce the gap 144 as the applied pressure differential increases. In other embodiments, the fin 142 may be calibrated to flex after a predetermined threshold pressure differential value has been reached. Also, the fin 142 may be configured to either remain permanently in the radially expanded shape or revert to a radially smaller shape. That is, the fin 142 may exhibit plastic and / or elastic deformation. Any material having an elastic modulus sufficient to allow the fin 142 to flex in response to an applied pressure may be used. Illustrative materials may include, but are not limited to, metals, elastomers and polymers.

[00019] It should be understood that the flow control device 120 is susceptible to a variety of configurations. Referring now to Fig. 5, in some embodiments, a flow control element 160 may include a fin 162 coupled to a biasing member 164. The biasing member 164 may be formed of a material capable of applying a biasing force, such as spring steel. The biasing member 164 may be constructed to urge the fin 162 into a radially retracted shape or position. In other embodiments, the biasing member 164 may be embedded in the fin 162. During operation, some or all of the pressure applied to the fin 162 may be transferred to the biasing member 164. As the biasing force is overcome, the fin 162 may move, e.g., pivot or expand to a radially enlarged shape. Also, in embodiments, two or more flow control elements may be serially positioned as shown. Such an arrangement may provide operationally redundancy in that a failure of one flow control element will bring a back-up flow control element into operation. Also, such an arrangement may utilize flow control elements that each are activated or responsive to different pressure differentials. For instance, a flow control 160 may be responsive to a large pressure differential / flow rate, the flow control device 170 is responsive to a medium pressure differential / flow rate, and the flow control device 172 is responsive to a low pressure differential / flow rate.

[00020] The teachings of the present disclosure are not limited to only production operations. For instance, referring to Fig. 5, embodiments of the present disclosure may be utilized to regulate injection operations. In injection operations, fluid from the surface or some other location may be pumped via a flow control device 100 into a formation. For such operations, a flow control element 170 may be positioned to be responsive to a fluid 176 flowing from a flow bore 52 into a production control device 100. In an injection mode of operation, a particular section or location in a formation is selected or targeted to be infused or treated with a fluid. The flow control elements 170 may configured as needed to obtain a desired injection pattern, .e.g., substantially equalized flow of the injected fluid into the formation over a length of a wellbore.

[00021] Referring generally to Figs. 1-5, in one mode of deployment, the reservoirs 14 and 16 may be characterized via suitable testing and known reservoir engineering techniques to estimate or establish desirable fluid flux or drainage patterns. The desired pattern(s) may be obtained by suitably adjusting the flow control devices 120 to provide a specified flow rate. The desired flow rate may be the same or different for each of the flow control devices 120 positioned along the production assembly 20. Because the pressure may vary for each of the hydrocarbon producing zones, the modulus of elasticity or biasing for each of the flow control elements may be individually varied as needed. That is, the behavior or response of the flow control elements may be tuned to the pressure and / or other parameter relating to a producing zone. Prior to insertion into the wellbore 10, formation evaluation information, such as formation pressure, temperature, fluid composition, wellbore geometry and the like, may be used to estimate a desired flow rate for each flow control device 120. The flow control elements 124 for each device may be selected based on such estimations and underlying analyses.

[00022] During a production mode of operation, fluid from the formation 14, 16 flows into the particulate control device 110 and then axially through the passage 132 into the flow control device 120. As the fluid flows through the flow control devices 120, the fluid flowing through the gap 144 of each flow device 120 generates a pressure differential that applies a pressure to the flow control elements 124 of each of the flow control devices 120. Generally speaking, the flow rate of the flowing fluid varies directly with the applied pressures. In response to the applied pressures, which may be the same or different, the flow control elements 124 flex in a predetermined manner to self-regulate in-f low from the production zones. For instance, highly productive zones may have relatively high flow rates that cause the flow control elements 124 to flex to minimize their respective gaps 144. The flow control elements 124 for the less productive zones, however, may exhibit little flexure due to the lower flow rates and therefore maintain their respective gaps 144 in a relatively large size.

[00023] It should be understood that Figs. 1 and 2 are intended to be merely illustrative of the production systems in which the teachings of the present disclosure may be applied. For example, in certain production systems, the wellbores 10, 11 may utilize only a casing or liner to convey production fluids to the surface. The teachings of the present disclosure may be applied to control the flow into those and other wellbore tubulars.

[00024] In aspects, the present disclosure provides an apparatus for controlling a flow of a fluid between a wellbore tubular and a formation. The apparatus may include a flow control device having a flow space formed therein; and a flow control element positioned in flow space. The flow control elθment may bθ configured to flex between a first radial position and a second radial position to in response to a change in a pressure differential along the flow space. In some embodiments, the flow space may be defined a least partially by an inner surface of the flow control device such that a radial flexure of the flow control element varies a space between the inner surface and the flow control element. Also, the flow control element may be configured to reduce a space between the inner surface and the flow control element as fluid flow increases in the space. In some arrangements, the flow control element may include a sleeve element and a movable portion projecting radially outward from the sleeve element. In embodiment, the movable portion is an annular member. Also, the flow control element may be formed at least partially of one of: (i) elastomer, (ii) polymer, and (iii) a metal. In variants, a biasing element may apply a biasing force to the flow control element. For instance, the biasing element may urge the flow control element to a radially retracted shape.

[00025] In still further aspects, the present disclosure also provides a system for controlling a flow of a fluid between a wellbore tubular and a formation. The system may include a plurality of flow control devices positioned along the wellbore tubular, wherein each flow control device has a flow space formed therein; and a flow control element positioned in each flow space, each flow control element being configured to flex between a first radial position and a second radial position in response to a change in a pressure differential along the flow space. In some applications, each flow control element is configured to provide a predetermined drainage pattern from the formation. The predetermined drainage pattern may be a substantially even drainage of fluids from at least a portion of the formation. Also, each flow control element may be configured to provide a predetermined fluid injection pattern for the wellbore tubular. In such applications, the fluid injection pattern is a substantially even injection of fluid into at least a portion of the formation.

[00026] For the sake of clarity and brevity, descriptions of most threaded connections between tubular elements, elastomeric seals, such as o-rings, and other well-understood techniques are omitted in the above description. Further, terms such as "valve" are used in their broadest meaning and are not limited to any particular type or configuration. The foregoing description is directed to particular embodiments of the present disclosure for the purpose of illustration and explanation. It will be apparent, however, to one skilled in the art that many modifications and changes to the embodiment set forth above are possible without departing from the scope of the disclosure.