Flow control system for use in an underground well

Abstract

A flow control system for use in controlling the flow of a fluid composition in an underground well is disclosed. The flow control system comprises a flow chamber with an inlet and an outlet oriented such that the fluid composition flows within the chamber, forming a vortex at least at the outlet. The flow control system further comprises at least one flow control structure formed and positioned within the flow chamber so that a circular flow velocity is reduced and the vortex is eliminated or substantially reduced.

Description

Title of the invention: Flow control system for use in an underground well. CONTEXT

[0001] This disclosure generally relates to the equipment used and the operations carried out in conjunction with an underground well and, in an example described below, more particularly provides a constant flow in an underground well regardless of the properties of the production or injection fluids.

[0002] In a hydrocarbon injection well, it is often advantageous to be able to regulate the flow of fluids from a wellbore to a terrestrial formation. Similarly, in an oil / fluid production well, it is often advantageous to be able to regulate the flow of fluids from the terrestrial formation to the wellbore.

[0003] Such regulation may have several objectives, including the prevention of water or gas conning, the minimization of sand production, the minimization of water and / or gas production, the maximization of oil and / or gas production, the balancing of production between areas, the reduction of pressure drop across the well, the reduction of erosion, etc.

[0004] It will be appreciated that progress in the art of providing a constant flow of fluid in a well would be desirable in the circumstances mentioned above, and that such progress would also be advantageous in a wide variety of other circumstances. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Embodiments of the flow control system are described with reference to the following figures. Identical or sequentially similar numbers are used in all figures to refer to similar elements and components. The elements shown in the figures are not necessarily drawn to scale. Some elements of the embodiments may be shown at an exaggerated scale or in a more schematic form, and certain details of the elements may be omitted for the sake of clarity and conciseness.

[0006] [Fig-1] is a schematic partial cross-sectional view of a well system which can incorporate the principles of this disclosure.

[0007] [Fig.2] is a schematic cross-sectional view at enlarged scale of a well screen and a flow control system that can be used in the well system of [Fig.1].

[0008] [Fig.3] is a schematic plan view of a flow chamber configuration of a flow control system having a single inlet and a single outlet.

[0009] [Fig.4] is a schematic plan view of another chamber configuration flow of a flow control system having a single inlet, a single outlet and a flow control structure.

[0010] [Fig.5] is a schematic plan view of a flow chamber configuration of a flow control system having multiple inlets and a single outlet.

[0011] [Fig.6] is a schematic plan view of a flow chamber configuration of a flow control system having multiple inlets, a single outlet and a plurality of flow control structures.

[0012] [Fig.7] is a schematic cross-sectional view of the flow chamber of the [Fig.4] taken along line 7-7 of [Fig.4].

[0013] [Fig.8] is a schematic cross-sectional view of the flow chamber of [Fig.6] taken along line 8-8 of [Fig.6].

[0014] [Fig.9] is a schematic cross-sectional view of another flow chamber including a flow control structure projecting from the opposite side of the flow chamber cavity.

[0015] [Fig. 10] is a schematic cross-sectional view of another flow chamber comprising several flow control structures projecting from the opposite side of the flow chamber cavity. DETAILED DESCRIPTION

[0016] [Fig. 1] representatively illustrates a well system 10 that can incorporate the principles of this disclosure. As shown in [Fig. 1], a borehole 12 has a generally vertical uncased section 14 extending downwards from the casing 16, as well as a generally horizontal uncased section 18 extending through a terrestrial formation 20.

[0017] A casing column 22 (such as a production casing column) is installed in the borehole 12. Several well screens 24, flow control systems 25 and sealing gaskets 26 are interconnected in the casing column 22.

[0018] The sealing gaskets 26 seal a ring 28 formed radially between the casing column 22 and the borehole section 18. In this way, fluids 30 can be produced from several intervals or zones of the formation 20 via isolated portions of the ring 28 between adjacent pairs of sealing gaskets 26.

[0019] Between each adjacent pair of sealing gaskets 26, a well screen 24 and a flow control system 25 are interconnected in the casing column 22. The well screen 24 filters the fluids 30 flowing into the casing column 22 from the ring 28. The flow control system 25 controls the flow of the fluids 30 in the casing column 22, regardless of the characteristics of the fluids.

[0020] At this point, it should be noted that the well system 10 is illustrated in the drawings and described herein as a simple example of a wide variety of well systems in which the principles of this disclosure may be used. It should be clearly understood that the principles of this disclosure are not at all limited to any of the details of the well system 10, or its components, shown in the drawings or described herein.

[0021] For example, it is not necessary, in accordance with the principles of this disclosure, for the borehole 12 to include a generally vertical borehole section 14 or a generally horizontal borehole section 18. It is not necessary for the fluids 30 to be produced solely from the formation 20 since, in other examples, the fluids could be injected into a formation, the fluids could be both injected and produced from a formation, etc.

[0022] It is not necessary that each of the well screen 24 and the flow control system 25 be positioned between each adjacent pair of the sealing gaskets 26. It is not necessary that only one flow control system 25 be used in conjunction with only one well screen 24. Any number, arrangement and / or combination of these components may be used.

[0023] It is not necessary for any flow control system 25 to be used with a single well screen 24. For example, in injection operations, the injected fluid can pass through a flow control system 25, without also passing through a well screen 24.

[0024] It is not necessary for the well screens 24, flow control systems 25, sealing gaskets 26 or any other component of the casing column 22 to be positioned in the uncased sections 14, 18 of the borehole 12. Any section of the borehole 12 may be cased or uncased, and any part of the casing column 22 may be positioned in a cased or uncased section of the borehole, in accordance with the principles of this disclosure.

[0025] It is therefore important to understand that this disclosure describes how to manufacture and use certain examples, but that the principles of the disclosure are not limited to the details of these examples. On the contrary, these principles can be applied to a variety of other examples using the knowledge gained from this disclosure.

[0026] It will be appreciated by those skilled in the art that it would be advantageous to be able to regulate the flow of fluids 30 in the casing 22 from each zone of the formation 20, for example, to prevent water coning 32 or gas coning 34 into the formation. Other uses of flow regulation in a well include, but are not limited to, balancing production from (or injection into) multiple zones, minimizing the production or injection of undesirable fluids, maximizing the production or injection of desired fluids, reducing well erosion, reducing corrosion inside the well, etc.

[0027] Examples of flow control systems described in more detail herein can offer these advantages by providing constant fluid flow between the inlet and outlet parts of the flow control system in order to reduce pressure drop and erosion potential in the well.

[0028] Whether a fluid is desired or undesired depends on the objective of the production or injection operation being carried out. For example, if it is desirable to produce oil from a well, but not water or gas, oil is a desired fluid and water and gas are undesired fluids. If it is desirable to produce gas from a well, but not water or oil, gas is a desired fluid and water and oil are undesired fluids. If it is desirable to inject steam into a formation, but not water, steam is a desired fluid and water is an undesired fluid.

[0029] It should be noted that at the temperature and pressure at the bottom of the well, hydrocarbon gas may in fact be completely or partially in the liquid phase. It should therefore be understood that when the term "gas" is used here, the supercritical, liquid, and / or gaseous phases are included within the scope of this term.

[0030] Referring now to [Fig. 2], an enlarged cross-sectional view of one of the flow control systems 25 and a portion of one of the well screens 24 is representatively illustrated. In this example, a fluid composition 36 (which may comprise one or more fluids, such as oil and water, liquid water and steam, oil and gas, gas and water, oil, water and gas, etc.) flows into the well screen 24, is thus filtered, and then flows into an inlet 38 of the flow control system 25.

[0031] A fluid composition may include one or more unwanted or desired fluids. Steam and water can both be combined in a fluid composition. By way of another example, oil, water, and / or gas can be combined in a fluid composition.

[0032] The flow of the fluid composition 36 through the flow control system 25 is prevented based on one or more characteristics (such as density, viscosity, velocity, etc.) of the fluid composition. The fluid composition 36 is then discharged from the flow control system 25 into the casing column 22 via an outlet 40.

[0033] In other examples, the well screen 24 may not be used in conjunction with the flow control system 25 (e.g. in injection operations), the fluid composition 36 may flow in opposite directions through the various elements of the well system 10 (e.g. in injection operations), a single flow control system may be used in conjunction with several well screens, several flow control systems may be used with one or more well screens, the fluid composition may be received or discharged in regions of a well other than a casing ring or column, the fluid composition may flow through the flow control system before flowing through the well screen, any other component may be interconnected upstream or downstream of the well screen and / or the flow control system, etc.Therefore, it will be appreciated if the principles of this disclosure are not at all limited to the details of the example shown in [Fig.2] and described here.

[0034] Although the well screen 24 shown in [Fig. 2] is of the type known to those skilled in the art as a wire-wrapped well screen, other types or combinations of well screens (such as sintered, expanded, pre-packed, wire-mesh, etc.) may be used in other examples. Additional components (such as guy wires, branch tubes, conduits, instruments, sensors, inlet control devices, etc.) may also be used, if desired.

[0035] The flow control system 25 is shown in a simplified manner in [Fig. 2], but in one example, the system may include various passages and devices to perform various functions, as described in more detail below. Furthermore, the system 25 may extend at least partially around the circumference of the casing column 22, or the system may be formed within a wall of an interconnected tubular structure as part of the casing column.

[0036] In other examples, the system 25 may not extend over the circumference of a casing column or be formed within a wall of a tubular structure. For example, the system 25 may be formed within a flat structure, etc. The system 25 may be located in a separate housing that is attached to the casing column 22, or it may be oriented so that the axis of the outlet 40 is parallel to the axis of the casing column. The system 25 may be on a logging column or attached to a device that is not tubular in shape. Any orientation or configuration of system 25 may be used in accordance with the principles of this disclosure.

[0037] With primary reference to [Fig. 3], a configuration of a flow chamber 46 of the flow control system 25 of [Fig. 2] is illustrated. The flow chamber 46 of [Fig. 3] comprises a single inlet 38 and a single outlet 40. The fluid composition 36 will flow around the chamber 46 before exiting through the outlet 40. Since, in this example, the chamber 46 has a cylindrical shape with a central outlet 40, and the fluid composition 36 spirals around the chamber 46, increasing its speed as it approaches the outlet, driven by a pressure difference between the inlet 38 and the outlet 40, the chamber can be described as a "vortex" chamber. Furthermore, a non-cylindrical chamber, such as a square or rectangular chamber comprising an inlet 38 which is perpendicular to an outlet 40, for example, will always produce a circular flow, i.e. a vortex.It must be understood that the inlet 38 does not necessarily have to be perpendicular to the outlet 40 for the chamber 46 to produce a circular flow, e.g., a vortex of the fluid composition 36. Thus, other embodiments are envisaged in which the inlet 38 is not perpendicular to the outlet 40. Furthermore, it must be understood that even if the inlet 38 were oriented directly towards the outlet 40 so that the fluid composition 36 flows directly towards the outlet 40 when it exits the inlet 38, a circular flow, e.g., a vortex of the fluid composition 36, can still occur. Thus, other embodiments are envisaged in which the inlet 38 is oriented directly towards the outlet 40 so that the fluid composition 36 flows directly towards the outlet 40, for example.

[0038] Referring now to [Fig. 4], another flow control system 25' is illustrated. The flow control system 25' comprises a chamber 46 having a single inlet 38 and a single outlet 40, similar to the flow control system 25 of [Fig. 3]. The flow control system 25' further comprises a projection, or flow control structure 51, which extends inside the chamber 46. In the illustrated embodiment, the flow control structure 51 is oriented perpendicularly to the incoming fluid composition 37 from the inlet 38, so that the incoming fluid composition 37 is directed towards the outlet 40.However, other embodiments are envisaged in which the flow control structure 51 and the inlet fluid composition 37 are oriented at different angles to each other by modifying the relative positions of the flow control structure 51 and the inlet 38, for example. In the illustrated embodiment, the flow structure 51 is a single-piece structure with flat edges. However, other embodiments are envisaged in [reference missing]. in which the flow structure 51 is discontinuous, has curved edges, has rounded edges, has bends or joints, and / or is corrugated, for example. In any case, the flow control structure 51 disrupts the circular flow that would otherwise be produced by the chamber 46, as illustrated in [Fig. 3]. To achieve this, the flow control structure 51 is positioned inside the chamber 46 so that the velocity of the circular flow is reduced and the vortex is eliminated or substantially reduced. In other words, the vortex created by the fluid composition in the chamber 46 of [Fig. 3] is eliminated and / or substantially reduced. In the illustrated embodiment, the flow control structure 51 is oriented perpendicular to the inlet 38 at a radial position close to the inlet 38.However, other embodiments are envisaged, in which the structure 51 is placed at any radial position around the outlet 40, for example. The flow control structure 51 will reduce, disrupt, and / or eliminate turbulent flow in the chamber 46, regardless of its radial position around the central outlet 40. The flow control structure 51 reduces, disrupts, and / or eliminates turbulent flow regardless of the composition of the fluid mixture, for example, comprising one or more fluids, such as oil and water, liquid water and steam, oil and gas, gas and water, oil, water, and gas, etc. Furthermore, even if the flow of the fluid mixture 36 through the flow control system 25 is impeded according to one or more characteristics (such as density, viscosity, velocity, etc.), the structure will still be able to control the flow.) of the fluid composition, the flow control structure 51 substantially reduces, disrupts and / or eliminates turbulent flow in chamber 46, regardless of the characteristics of the fluid composition.

[0039] In the illustrated embodiment, the flow control structure 51 is positioned next to the outlet 40 and extends towards an inner side wall 45 of the chamber 46, but does not extend all the way to the side wall 45. However, other embodiments are envisaged in which the flow control structure 51 extends all the way to the side wall 45, for example. In the illustrated embodiment, an inner end 52 of the flow control structure 51 is flush with the outlet 40. However, other embodiments are envisaged in which the flow control structure 51 extends laterally over a portion of the outlet 40, for example. Furthermore, other embodiments are envisaged in which there is a lateral gap between the outlet 40 and the inner end 52 of the flow control structure 51.Furthermore, in the illustrated embodiment, the inner end 52 of the flow control structure 51 converges towards a point. However, other embodiments are envisaged in which the inner end 52 and / or the outer end 53 are rounded, chamfered, threaded, etc.

[0040] Referring now to [Fig. 5], a configuration of another flow chamber 46' of the flow control system 25 is illustrated. The flow chamber 46' shown in [Fig. 5] has several inlets 38 and a single outlet 40. The fluid composition 36 will flow around the chamber 46' before exiting through the outlet 40. Since, in this example, the chamber 46 has a cylindrical shape with a central outlet 40, and the fluid composition 36 spirals around the chamber, increasing its speed as it approaches the outlet, driven by a pressure difference from the inlets 38 to the outlet 40, the chamber can be described as a "vortex" chamber. Furthermore, a non-cylindrical chamber, such as a square or rectangular chamber comprising several inlets 38 which are perpendicular to an outlet 40, for example, will always produce a circular flow, i.e. a vortex chamber.As stated above, with regard to the flow chamber 46, the inlets 38 and outlet 40 of the flow chamber 46' do not necessarily have to be perpendicular to each other to produce a vortex chamber. Thus, other embodiments are envisaged in which the inlets 38 and outlet 40 are not perpendicular to each other.

[0041] Referring now to [Fig. 6], another flow control system 25” is illustrated. The flow control system 25” comprises the chamber 46' having several inlets 38 and a single outlet 40, similar to the flow control system 25 of [Fig. 5]. The flow control system 25' further comprises a plurality of projections, or flow control structures 51 extending inside the chamber 46 on opposite sides of the outlet 40. In the illustrated embodiment, the flow control structures 51 are oriented perpendicularly to the incoming fluid composition 37 from the inlets 38, so that the incoming fluid composition 37 is directed towards the outlet 40.However, other embodiments are envisaged in which the flow control structures 51 and the inlet fluid composition 37 are oriented at different angles to each other by modifying the relative positions of the flow control structures 51 and the inlet T 38, for example. In the illustrated embodiment, each of the flow structures 51 is a single-piece structure with flat edges. However, other embodiments are envisaged in which the flow structure 51 is discontinuous, has curved edges, has rounded edges, has bends or joints, and / or is corrugated, for example. In all cases, the flow control structures 51 disrupt the circular flow that would otherwise be produced by the chamber 46, as illustrated in [Fig. 5].To achieve this, the flow control structures 51 are positioned inside the chamber 46 so that the speed of the circular flow is reduced and the vortex is eliminated or . substantially reduced. In other words, the vortex created by the fluid composition in chamber 46' of [Fig. 5] is eliminated and / or substantially reduced. The flow control structures 51 reduce, disrupt, and / or eliminate turbulent flow regardless of the composition of the fluid mixture, for example, comprising one or more fluids, such as oil and water, liquid water and steam, oil and gas, gas and water, oil, water and gas, etc. Furthermore, even if the flow of the fluid composition 36 through the flow control system 25" is impeded by one or more characteristics (such as density, viscosity, velocity, etc.) of the fluid composition, the flow control structures 51 substantially reduce, disrupt, and / or eliminate turbulent flow in chamber 46', regardless of the characteristics of the fluid composition.

[0042] In the illustrated embodiment, the flow control structures 51 are oriented perpendicular to the inlets 38 and between the inlets 38. However, other embodiments are envisaged, in which the structures 51 are placed at any radial position around the outlet 40 on either side of the outlet 40, for example. Other embodiments are envisaged in which the flow control structures 51 are not mirror images of each other around the outlet 40. In all cases, the flow control structures 51 will reduce, disrupt, and / or eliminate turbulent flow in the chamber 46', regardless of their radial positions around the central outlet 40.

[0043] In the illustrated embodiment, the flow control structures 51 are positioned next to the outlet 40 and extend towards the inner side wall 45 of the chamber 46', but do not extend all the way to the side wall 45. However, other embodiments are envisaged in which both flow control structures 51 extend all the way to the side wall 45, for example. Furthermore, other embodiments are also envisaged in which only one structure 51 on one side of the outlet 40 extends all the way to the side wall 45, for example. In the illustrated embodiment, an inner end 52 of the flow control structures 51 is flush with the outlet 40. However, other embodiments are envisaged in which the flow control structures 51 extend over a portion of the outlet 40, for example.Furthermore, other embodiments are envisaged in which there is a lateral space between the outlet 40 and an inner end 52 of the flow control structures 51. In addition, in the illustrated embodiment, the inner end 52 of each of the flow control structures 51 converges to a point. However, other embodiments are envisaged in which the inner end 52 and / or the outer end 53 are rounded, chamfered, threaded, etc.

[0044] Referring primarily to [Fig. 7], the chamber 46 comprises a lower wall 47 and an upper wall 48 opposite the lower wall. The walls 47, 48 extend between the side walls 45 of the chamber 46. [Fig. 7] further illustrates the flow control structure 51 extending from the lower wall 47 to the upper wall 48, but not entirely to the upper wall 48. However, other embodiments are envisaged, in which the structure 51 extends completely between the upper and lower walls 47, 48, for example. Similarly, [Fig. 8] illustrates structures 51 extending partially from the lower wall 47 to the upper wall 48 of the chamber 46'. However, other embodiments are envisaged, in which the structure 51 extends completely between the upper and lower walls 47, 48, for example.

[0045] With primary reference to [Fig. 9] and [Fig. 10], alternative embodiments of the flow control structures 51 inside the chambers 46' and 46" are illustrated. Specifically, in [Fig. 9], the flow control structure 51 extends downwards from the upper wall 48 to the lower wall 47, but not entirely to the lower wall 47. However, other embodiments are envisaged, in which the structure 51 extends completely between the upper and lower walls 47, 48, for example. Furthermore, [Fig. 10] illustrates several flow control structures extending downwards from the upper wall 48 to the lower wall 47, but not entirely to the lower wall 47. However, other embodiments are envisaged, in which the structures 51 extend completely between the upper and lower walls 47, 48, for example.

[0046] In addition to the above, other embodiments are envisaged in which the structure(s) 51 extend from the side wall 45 to the outlet 40, between the lower wall 47 and the upper wall 48 of the chambers 46', 46", for example. Other embodiments are envisaged in which one or more flow control structures are bolted to the flow control system 25', 25" such that the flow control structures float above the outlet 40 between the walls 47, 48 of the chamber.

[0047] In the illustrated embodiments, the flow chambers 46, 46' are rounded or circular, thus promoting the circular flow of the fluids 36, which are then separated by the flow control structures 51, for example. However, other embodiments are envisaged in which the flow chamber(s) are rectangular or square. The flow control structures 51 described herein act to reduce and / or prevent turbulent flow (i.e., vorticity) within the flow chamber, even if the flow chamber is rectangular or square.

[0048] Here are some examples of the embodiments mentioned above:

[0049] Example 1 is a flow control system for use in controlling the flow of a fluid composition in an underground well, the flow control system comprising: a flow chamber having an inlet and an outlet oriented such that the fluid composition flows in the chamber, forming a vortex at least at the outlet; and at least one flow control structure formed and placed in the flow chamber such that a velocity of the circular flow is reduced and the vortex is eliminated or substantially reduced.

[0050] In Example 2, embodiments of any preceding paragraph or combination thereof further include the fact that a portion of at least one flow control structure is located next to or flush with the outlet.

[0051] In Example 3, embodiments of any preceding paragraph or combination thereof further include the fact that an inner end of at least one outlet-oriented flow control structure converges to a point.

[0052] In Example 4, embodiments of any preceding paragraph or combination thereof further include the fact that the flow control structure includes at least one of the following: curved edges, rounded edges, elbows, joints or a corrugated profile.

[0053] In example 5, embodiments of any preceding paragraph or combination thereof further include the fact that the flow control structure comprises either a monobloc structure or a discontinuous structure.

[0054] In example 6, embodiments of any preceding paragraph or combination thereof further include several flow control structures.

[0055] In Example 7, embodiments of any preceding paragraph or combination thereof further include the flow chamber further comprising an inner side wall around the flow chamber with a lower wall and an upper wall extending through the flow chamber and the flow control structure extending from the lower wall or the upper wall to, but not entirely, the other upper wall or the lower wall; or the flow control structure extending completely between the upper wall and the lower wall.

[0056] In Example 8, embodiments of any preceding paragraph or combination thereof further include the fact that the flow control system can be installed in or on a casing column at the bottom of the underground well and is configured to control the flow of the fluid composition towards the casing column.

[0057] Example 9 is a method for controlling the flow of a fluid composition in an underground well through an underground formation, comprising: the location of a casing column at the bottom of the underground well, the casing column including a flow control system; the flow of the fluid composition from the underground formation to a flow chamber of the flow control system through an inlet so as to induce a circular flow inside the flow chamber; the flow of the fluid composition out of the flow control system and back into the casing column through an outlet of the flow control system, the flow out of the flow control system forming a vortex at least at the outlet;and the perturbation of the circular flow by at least one flow control structure in the flow chamber in order to reduce the velocity of the circular flow and to eliminate or substantially reduce vorticity.

[0058] In Example 10, embodiments of any preceding paragraph or combination thereof further include the fact that a portion of at least one flow control structure is located next to or flush with the outlet.

[0059] In Example 11, embodiments of any preceding paragraph or combination thereof further include the fact that an inner end of at least one outlet-oriented flow control structure converges to a point.

[0060] In Example 12, embodiments of any preceding paragraph or combination thereof further include the fact that the flow control structure includes at least one of the following: curved edges, rounded edges, elbows, joints or a corrugated profile.

[0061] In Example 13, embodiments of any preceding paragraph or combination thereof further include the fact that the flow control structure comprises either a monobloc structure or a discontinuous structure.

[0062] In Example 14, embodiments of any preceding paragraph or combination thereof further include the casing column comprising several flow control systems.

[0063] In Example 15, embodiments of any preceding paragraph or combination thereof further include the fact that the flow control system further includes several flow control structures.

[0064] Example 16 is a production system for producing at least part of a fluid composition from an underground formation, the production system being able to be placed in an underground well extending through the formation, the production system comprising: a casing column being able to be placed at the bottom of the underground well and comprising a flow control system for controlling the flow of the fluid composition towards the casing column, in which the flow control system comprises: a flow chamber including an inlet and an outlet oriented such that the fluid composition flows within the chamber, forming a vortex at least at the outlet; and at least one flow control structure formed and placed within the flow chamber such that a velocity of the circular flow is reduced and the vortex is eliminated or substantially reduced.

[0065] In Example 17, embodiments of any preceding paragraph or combination thereof further include the fact that a portion of at least one flow control structure is located next to or flush with the outlet.

[0066] In Example 18, embodiments of any preceding paragraph or combination thereof further include the fact that an inner end of at least one outlet-oriented flow control structure converges to a point.

[0067] In Example 19, embodiments of any preceding paragraph or combination thereof further include the fact that the flow control system comprises several flow control structures.

[0068] In Example 20, embodiments of any preceding paragraph or combination thereof further include the fact that the casing column includes several flow control systems spaced along the casing column.

[0069] Certain terms are used throughout the description and claims to refer to particular elements or components. As a competent person will understand, different people may refer to the same element or component by different names. This document is not intended to distinguish between components or elements that differ in name but not in function.

[0070] While the descriptions here may relate to "comprising" various components or steps, the descriptions may also "consist essentially of" or "consist of" various components and steps.

[0071] Unless otherwise indicated, all numbers expressing quantities are to be understood as being modified in all cases by the terms "about" or "approximately". Therefore, unless otherwise indicated, numerical parameters are approximations that may vary depending on the desired properties of this disclosure. As used herein, "about," "approximately," "substantially," and "significantly" will be understood by persons with ordinary skill in the art and will vary to some extent depending on the context in which they are used. If certain Uses of the term are not clear to people with ordinary skills in the art, given the context in which it is used, 'about' and 'approximately' will mean more or less 10% of the particular term and 'substantially' and 'significantly' will mean more or less 5% of the particular term.

[0072] The disclosed embodiments shall not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. It should be clearly recognized that the various teachings of the discussed embodiments may be used separately or in any appropriate combination to produce the desired results. Furthermore, any person competent in the art will understand that the description has broad application and that the discussion of any embodiment is intended only to give an example of that embodiment and is not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

Claims

Demands

1. A flow control system (25) for use in controlling the flow of a fluid composition (36) in an underground well, the flow control system comprising: a flow chamber (46) including an inlet (38) and an outlet (40) oriented such that the fluid composition flows in the flow chamber, forming a vortex at least at the outlet; and at least one flow control structure (51) formed and positioned in the flow chamber such that a circular flow velocity is reduced and the vortex is eliminated or substantially reduced, wherein an inner end (52) of the at least one flow control structure oriented towards the outlet converges to a point.

2. The system according to claim 1, wherein a portion of at least one flow control structure is located next to or flush with the outlet.

3. The system according to claim 1, wherein the flow control structure comprises at least one of the following: curved edges, rounded edges, elbows, joints or a corrugated profile.

4. The system according to claim 1, wherein the flow control structure comprises either a monobloc structure or a discontinuous structure.

5. The system according to claim 1, further comprising several flow control structures.

6. The system according to claim 1, wherein the flow chamber further comprises an inner side wall around the flow chamber, with a lower wall and an upper wall extending through the flow chamber, and wherein: the flow control structure extends from the lower wall or the upper wall to, but not entirely, the other of the upper wall or the lower wall; or the flow control structure extends completely between the upper wall and the lower wall.

7. The system according to claim 1, wherein the flow control system can be installed in or on a column casing (22) at the bottom of the underground well and is configured to control the flow of the fluid composition towards the casing column.

8. A method for controlling the flow of a fluid composition (36) in an underground well through an underground formation, comprising: the location of a casing column (22) at the bottom of the underground well, the casing column comprising a flow control system (25); the flow of the fluid composition from the underground formation to a flow chamber (46) of the flow control system through an inlet (38) so as to induce a circular flow within the flow chamber; the flow of the fluid composition out of the flow control system and back into the casing column through an outlet (40) of the flow control system, the flow out of the flow control system forming a vortex at least at the outlet;and the perturbation of the circular flow by at least one flow control structure (51) in the flow chamber in order to reduce a velocity of the circular flow and to eliminate or substantially reduce vorticity, wherein an inner end (52) of the at least one outflow-oriented flow control structure converges to a point.

9. The method according to claim 8, wherein a portion of at least one flow control structure is located next to or flush with the outlet.

10. The method according to claim 8, wherein the flow control structure comprises at least one of the following: curved edges, rounded edges, bends, joints or a corrugated profile.

11. The method according to claim 8, wherein the flow control structure comprises either a monobloc structure or a discontinuous structure.

12. The method according to claim 8, wherein the flow control system further comprises several flow control structures.

13. The method according to claim 8, wherein the casing column further comprises several flow control systems spaced along the casing column.

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