An apparatus and method for controlling fluid flow

Abstract

A flow control device (1, 100) is provided having a body member (10, 110) and a moveable member (30, 130) that is moveable between a first configuration and a second configuration. In the first configuration passage of fluids is permitted through a port (16, 116) formed in the body member (10, 110). In the second configuration, passage of the fluids through the port (16, 116) is obstructed. A biasing device (60), housed within a chamber (40), is configured to urge the moveable member (30, 130) towards either of the first configuration or the second configuration. The flow control device (1, 100) also has an opening (70) that is adapted to permit the flow of solids out of the chamber (40).

Description

[0001] TITLE

[0002] “An apparatus and method for controlling fluid flow”.

[0003] FIELD OF THE INVENTION

[0004] The present invention relates to a fluid control apparatus and method, and more particularly but not exclusively, relates to a downhole fluid flow control device for controlling the flow of naturally produced fluids, injected fluids or pumped produced fluids, and a method thereof.

[0005] BACKGROUND OF THE INVENTION

[0006] Biasing devices (such as springs) play a critical role in the functionality of many downhole tool. However, the performance of such biasing devices can be compromised by even small amounts of deposits that can become stuck. In order to extend the service life and reduce the risk of malfunctions in the biasing device, conventionally used biasing devices (such as spring assemblies) within downhole tools are typically designed such that the biasing devices are completely isolated from the rest of the tool and in particular from the flow of downhole fluid. However, despite best efforts being made to completely isolate biasing devices from the downhole fluids (and the abrasive particles, corrosive elements, or extreme temperatures contained therein), contamination (e.g. abrasive particles, corrosive elements) of the biasing devices is still a frequent issue.

[0007] STATEMENTS OF THE INVENTION

[0008] According to a first aspect of the present invention, there is provided a flow control device comprising: a body member having a throughbore formed therein; at least one port formed in the body member; a moveable member, wherein in use the moveable member is moveable between a first configuration and a second configuration, whereby in the first configuration passage of fluids comprising at least one of liquids and solids through the port is permitted and in the second configuration passage of said fluids through the port is obstructed; a chamber; a biasing device housed within said chamber, wherein the biasing device is configured to urge the moveable member towards either of the first configuration or the second configuration; and characterised by further comprising at least one opening adapted to permit the flow of solids out of the chamber.

[0009] According to a second aspect of the present invention, there is provided a flow control device.

[0010] Optionally, according to the second aspect of the present invention, the flow control device further comprises a body member.

[0011] Optionally, according to the second aspect of the present invention, the body member comprises a throughbore formed therein.

[0012] Optionally, according to the second aspect of the present invention, the flow control device further comprises at least one port. Optionally, said at least one port is formed in the body member.

[0013] Optionally, according to the second aspect of the present invention, the flow control device further comprises a moveable member. Optionally, in use the moveable member is moveable between a first configuration and a second configuration. Optionally, in said first configuration passage of fluids comprising at least one of liquids and solids through the port is permitted. Optionally, in said second configuration passage of said fluids through the port is obstructed.

[0014] Optionally, according to the second aspect of the present invention, the flow control device further comprises a chamber.

[0015] Optionally, according to the second aspect of the present invention, the flow control device further comprises a biasing device. Optionally, the biasing device is housed within a chamber. Optionally, the biasing device is configured to urge a moveable member towards either of a first configuration or a second configuration.

[0016] Optionally, according to the second aspect of the present invention, the flow control device further comprises at least one opening. Optionally, said at least one opening is adapted to permit the flow of solids through the chamber.

[0017] Optionally, the fluid flow control device is for use in a wellbore. Optionally, the wellbore is an oil and gas wellbore.

[0018] Optionally, the fluid flow control device is a downhole fluid flow control device. Optionally, the downhole fluid flow control device is for controlling the flow of naturally produced fluids, injected fluids or pumped produced fluids. Optionally, the downhole fluid flow control device is for inclusion in production tubing used for producing fluid from a reservoir to the surface.

[0019] Optionally, the at least one port is a plurality of ports. Optionally, the plurality of ports formed in the body member are adapted to encourage solids present in the fluid to settle on the outside of the body member.

[0020] Optionally, the fluid flow control device comprises a diverter apparatus. Optionally, the moveable member is a diverter device. Optionally, the moveable member comprises a diverter device. Optionally, the moveable member is provided internally within the throughbore of the body member. Optionally, when the moveable member is provided internally within the throughbore of the body member, the moveable member may optionally comprise an outer surface which is substantially congruent with (and / or has at least a portion that is substantially congruent with) an inner surface of the throughbore of the body member (and / or at least a portion of an inner surface of the throughbore of the body member), and optionally such that when the moveable member is in the second configuration said outer surface (and / or optionally a portion thereof) of the movable member envelopes the port to thereby obstruct the passage of fluids through the port.

[0021] Typically, the body member and the moveable member are defined as two concentrically arranged tubular members. Typically, the body member is the outer tubular member of said two concentrically arranged tubular members. Typically, the movable member is the inner tubular member of said two concentrically arranged tubular members.

[0022] Optionally, in an alternative embodiment, the moveable member is provided externally to the body member. Optionally, the moveable member is provided externally around the body member. Optionally, when the moveable member is provided externally to (and / or) the body member, the moveable member may optionally comprise an inner surface which is substantially congruent with (and / or has at least a portion that is substantially congruent with) an outer surface of the body member (and / or at least a portion of an outer surface of the body member), and optionally such that when the moveable member is in the second configuration said inner surface (and / or optionally a portion thereof) of the movable member envelopes the port to thereby obstruct the passage of fluids through the port. Optionally, when the moveable member is in the second configuration, the moveable member at least partially envelopes the port to thereby at least partially obstruct the passage of fluid through the port. Optionally, when the moveable member is in the second configuration, the moveable member wholly envelopes the port to thereby wholly obstruct the passage of fluid through the port.

[0023] Optionally, when the moveable member is in the first configuration, the moveable member is at least partially retracted from the port such that the port is at least partially open to thereby at least partially permit the passage of fluid through the port. Optionally, when the moveable member is in the first configuration, the moveable member is completely retracted from the port such that the port is wholly open to thereby permit the passage of fluid through the port.

[0024] Optionally, the solids are solid deposits carried within liquid which flows within the wellbore. Hereinafter, the term “fluid” and / or “fluids” unless otherwise specified can comprise a combination of liquid and solid material and hereinafter the term “solid” and / or “solids” unless otherwise specified comprises solid material.

[0025] Optionally, the opening is configured to permit the evacuation of solids from the chamber. Optionally, the opening is configured to permit the evacuation of fluids from the chamber. Optionally, the opening is configured to permit the flow of fluids into the chamber. Optionally, the opening is configured to promote the evacuation of solids from the chamber. Optionally, the opening is configured to promote the evacuation of fluids from the chamber. Optionally, the opening is configured to promote the flow of fluids into the chamber. Advantageously, when the opening is configured to permit / promote the flow of fluids into the chamber and / or permit / promote the evacuation of fluids / solids from the chamber, the flow of fluid in / out / through the chamber is operable to flush (at least) the solids out from the chamber to prevent solids (e.g. abrasive particles, corrosive elements) from remaining in the chamber (particularly from remaining in the chamber when the volume of the chamber is reduced such as when the biasing member is being compressed or is compressed, and thus preventing (or at least mitigating the risk of) damage to the biasing member.

[0026] Optionally, the at least one opening is adapted to also permit the flow of fluids through the chamber. Optionally, the fluid is downhole fluid. The downhole fluid may comprise abrasive particles, corrosive elements, solids (such as sand or rock or other material from the surrounding formation) or extreme temperatures that can degrade the performance of the biasing device over time.

[0027] Optionally, said at least one opening is a plurality of openings.

[0028] Optionally, said at least one opening is provided on the body member. Optionally, when the at least one opening is provided on the body member, the opening to the chamber is proximate to the at least one port on the body member.

[0029] Preferably, said at least one opening comprises an opening formed through a sidewall of the body member.

[0030] Preferably, the opening to the chamber is in communication (and optionally fluid communication) with the external surroundings of the body member, such that the inner volume of the chamber is preferably in fluid communication with the external surroundings of the body member. More preferably, the opening to the chamber permits fluid to flow at least ii) (and most preferably both of i) and ii):- i) into the chamber from the outer environment; and ii) out of the chamber into the outer environment.

[0031] Advantageously, the opening to the chamber being in communication with the external surroundings of the body member enables the removal of solids from the chamber to the surroundings such as the environment outside of the flow control device such as the wellbore.

[0032] Optionally, said at least one opening is provided on the moveable member.

[0033] Optionally, the plurality of openings are arranged in an array.

[0034] Optionally, the at least one opening comprises an elongated shape. As the skilled person will understand, elongated shape refers to any shape that is much longer than it is wide.

[0035] Optionally, the at least one elongate opening is axially aligned to at least one of or any combination of the chamber, the biasing device, the moveable member, the body member (or the throughbore thereof). Optionally, the at least one elongate opening comprises a first end and a second opposite end. Optionally, the first end of the elongate opening is provided proximate to the port. Optionally, the second opposite end of the elongate opening is provided at a location distal to the port. Preferably, the at least one elongate opening comprises a slot having a first end and a second opposite end and an uninterrupted middle portion joining said first and second ends. More preferably, the at least one elongate slot comprises a length (the distance between the first and second ends) that is less than or equal to the length of the chamber at least when chamber is at its maximum length (that is, when the biasing device is fully extended i.e. is not compressed).

[0036] Optionally, the at least one opening comprises a width that is dimensioned to be at least wide enough to permit solids of a given particle size to exit via said at least one opening from the chamber. For example, the size of sand particles may typically range from around 0.05 to 2.0 mm. Therefore, in applications specifically including sand particles (i.e. having particle sizes falling within said range of around 0.05 to 2.0 mm), the width of the at least one opening would preferably comprises a width of at least 0.05 mm (to at least accommodate the smallest particles of said range), and more preferably the width of said at least one opening would be at least 2.0 mm (to at least accommodate the full range of said particles sizes). Preferably, in applications specifically including sand particles, the width of the at least one opening comprises a minimum width that is at least 2 times the size of a sand particle, more preferably at least 5 times the size of a sand particle, and most preferably at least 10 times the size of a sand particle. However, as the skilled person will understand the width of the at least one opening can comprises any suitable width that is at least large enough to permit any solids of a given particle size in the given application to exit via said at least one opening from the chamber.

[0037] Optionally, a surface of the moveable member defines at least one internal surface of the chamber. Optionally, a surface of the moveable member at least partially defines at least one internal surface of the chamber. Optionally, a surface of the body member defines at least one internal surface of the chamber. Optionally, a surface of the body member at least partially defines at least one internal surface of the chamber. Optionally, the inner surface of the body member defines at least one internal surface of the chamber. Optionally, the inner surface of the body member at least partially defines at least one internal surface of the chamber. Optionally, the outer surface of the body member defines at least one internal surfaces of the chamber. Optionally, the outer surface of the body member at least partially defines at least one internal surface of the chamber.

[0038] Optionally, a sleeve is provided between the chamber and the moveable member, such that the sleeve defines the internal surface of the chamber. Optionally, when a sleeve is provided between the chamber and the moveable member, the sleeve further defines the external surface of the chamber.

[0039] Optionally, the chamber comprises a volume. Optionally, said volume of the chamber changes with respect to which of the first configuration and the second configuration the moveable member is in. Optionally, as the moveable member moves from the first configuration to the second configuration the volume of the chamber reduces. Optionally, as the moveable member moves from the second configuration to the first configuration the volume of the chamber increases.

[0040] Preferably, aside from the at least one opening, the inner volume of the chamber is substantially enclosed.

[0041] Optionally, the chamber is provided adjacent to the moveable member. Optionally, the chamber is provided adjacent to the body member. Optionally, the chamber is provided adjacent to the moveable member and the body member. Optionally, the chamber is provided between the moveable member and the body member. Optionally, the chamber is provided radially between the moveable member and the body member.

[0042] Optionally, an annulus is provided between the body member and the moveable member. Optionally, the chamber is defined by said annulus between the body member and the moveable member.

[0043] Optionally, the moveable member comprises at least a first a flange or protrusion which defines a first boundary of the chamber. Optionally, the moveable member further comprises at least a second flange or protrusion which defines a second boundary of the chamber. Optionally, the body member comprises at least a first flange or protrusion which defines a first boundary of the chamber. Optionally, the body member further comprises at least a second flange or protrusion which defines a second boundary of the chamber.

[0044] Optionally, the first flange or protrusion (of either or both of the body member or the movable member) is oppositely arranged to the second flange or protrusion (of either or both of the body member or the movable member). Optionally, the first flange or protrusion defines an upper wall of the chamber, and optionally second flange or protrusion defines a lower wall of the chamber, or vice versa.

[0045] Optionally, the inner surface of the through bore of the body member defines a first sidewall of the chamber. Optionally, the outer surface of the moveable member defines a second sidewall of the chamber.

[0046] Optionally, when the inner surface of the through bore of the body member defines a first sidewall of the chamber and the outer surface of the moveable member defines a second sidewall of the chamber, the first flange or protrusion (of either or both of the body member or the movable member) and the oppositely arranged second flange or protrusion (of either or both of the body member or the movable member) provide a seal to the chamber.

[0047] Optionally, the outer surface of the body member defines a first sidewall of the chamber. Optionally, the inner surface of the moveable member defines a second sidewall of the chamber.

[0048] Optionally, the moveable member is actuatable to move in response to an external force or signal.

[0049] Optionally, the moveable member is adapted to remotely and / or selectively move between the first and second configurations in response to changes in fluid flow rate. Optionally, the moveable member is adapted to remotely and / or selectively move between the first and second configurations in response to changes in fluid pressure. Optionally, the moveable member is adapted to remotely and / or selectively move between the first and second configurations in response to changes in both of the fluid flow rate and fluid pressure.

[0050] Optionally, the moveable member is rotationally movable.

[0051] Optionally, the moveable member is axially movable.

[0052] Optionally, the fluid flow control device comprises a fluid flow promoting means configured for promoting fluid flow in the body member.

[0053] Optionally, the fluid flow control device comprises a fluid flow promoting means configured for promoting fluid flow in the annulus between the body member and the wellbore.

[0054] Preferably, the biasing device is wholly housed within the inner volume of the chamber. Optionally, the biasing device is at least partially housed within the chamber.

[0055] Optionally, the biasing device may comprise a first end and a second opposite end.

[0056] Optionally, the first end of the biasing device is configured to connect to a wall of the chamber, and optionally the first end of the biasing device is configured to connect to an upper wall or upper portion of the chamber. Optionally, the first end of the biasing device is configured to engage with a wall of the chamber, and optionally the first end of the biasing device is configured to engage with an upper wall or upper portion of the chamber. Optionally, the first end of the biasing device is configured to abut against a wall of the chamber, and optionally the first end of the biasing device is configured to abut against an upper wall or upper portion of the chamber. Optionally, the second end of the biasing device is configured to connect to a wall of the chamber, and optionally the second end of the biasing device is configured to connect to a lower wall or lower portion of the chamber. Optionally, the second end of the biasing device is configured to engage with a wall of the chamber, and optionally the second end of the biasing device is configured to engage with a lower wall or lower portion of the chamber. Optionally, the second end of the biasing device is configured to abut against a wall of the chamber, and optionally the second end of the biasing device is configured to abut against a lower wall or lower portion of the chamber.

[0057] Advantageously, when the first end of the biasing device is configured to connect to, engage with, or abut against an upper wall or upper portion of the chamber and the second end of the biasing device is configured to connect to, engage with, or abut against a lower wall or lower portion of the chamber, the biasing device is arranged such that the biasing device is operable to bias the first end of the biasing device (and therefore the upper wall or upper portion of the chamber) either towards or away from the second end of the biasing device (and therefore the lower wall or lower portion of the chamber) to thereby bias the moveable member towards or away from either of the first and second configurations.

[0058] Preferably, the biasing device is at least one spring, and more preferably the biasing device is at least one coiled spring. Typically, the at least one coiled spring is defined by a helical shape. Optionally, the helical shape of the at least one coiled spring is arranged such that the coils of the at least one coiled spring are wound around at least one of the moveable member or the body member in a spiral pattern.

[0059] Optionally, the spring is a compression spring. Typically, when the at least one spring is compression spring the spring is configured to operate with a compression load such that the spring gets shorter as the load is applied to it. Optionally, when the at least one spring is compression spring, the spring may be configured to bias the moveable member either axially away from the port or axially towards the port, and optionally as the compression load is applied to the spring the shortening of the spring thereby axially moves the moveable member to either of the first configuration or the second configuration.

[0060] Optionally, the spring is a tension / extension spring. Typically, when the spring is a tension / extension spring, the spring is configured to operate with a tension load such that the spring stretches as the load is applied to it. Optionally, when the at least one spring is tension or extension spring, the spring may be configured to bias the moveable member either axially away from the port or axially towards the port, and optionally as a tension load is applied to the spring the axial lengthening of the spring thereby axially moves the moveable member to either of the first configuration or the second configuration.

[0061] Optionally, the at least one spring is a torsion springs. Typically, when the at least one spring is a torsion springs, the spring is configured to operate with a rotational / torsional load such that the spring is designed to resist twisting forces, optionally in a clockwise or an anticlockwise direction. Optionally, when the at least one spring is a torsion spring, the spring may be configured to bias the moveable member either rotationally away from the port or rotationally towards the port, and optionally as a torsion load is applied to the spring the rotational winding / tightening or unwinding / loosening of the spring thereby rotationally moves the moveable member to either of the first configuration or the second configuration.

[0062] Optionally, the at least one spring is a cantilever spring.

[0063] Optionally, the biasing device is a plurality of springs. Optionally, the biasing device is a plurality of coiled spring. Optionally, the arrangement of springs are circumferentially arranged, optionally in an array, around the central axis of the body member and / or the movable member.

[0064] Optionally, the biasing device comprises an arrangement of springs. Optionally, the arrangement of springs are circumferentially arranged in an array around the central axis of the body member and / or the movable member.

[0065] Optionally, however, as will be appreciated by those skilled in the relevant art, any suitable biasing mechanism or biasing device could be used to axially bias, rotationally bias or otherwise bias / urge the moveable member towards at least the first configuration or second configuration, or otherwise.

[0066] Optionally, the port is a bypass port.

[0067] Optionally, the throughbore comprises first and second throughbore portions.

[0068] Optionally, in the first configuration passage of fluid between the first throughbore portion and second throughbore portion is obstructed. Optionally, in the second configuration passage of fluid through the first throughbore portion and second throughbore portion is permitted.

[0069] Optionally, the moveable member is moveable between a second configuration which defines a first fluid flow path between the first and second throughbore portions and a first configuration which defines a second fluid flow path between the first throughbore portion and the at least one port.

[0070] Optionally, the moveable member is configured such that when in the first configuration it is adapted to permit fluid flow in the first fluid flow path and prevent fluid flow in the second fluid flow path. Optionally, the moveable member is configured such that when in the second configuration it is adapted to permit fluid flow in the second fluid flow path and prevent fluid flow in the first fluid flow path.

[0071] Optionally, the moveable member is adapted to remotely and / or selectively move between the first and second configurations in response to either or both of changes in fluid flow rate and fluid pressure in either of the first or second fluid flow paths. Optionally, the moveable member may be remotely operated by backup actuation means such as electrical or hydraulic signals from surface or by mechanical wireline actuation means.

[0072] Optionally, the moveable member is adapted to open the at least one port when in the first configuration and to obturate the at least one port when in the second configuration. Optionally, the moveable member is adapted to close the throughbore between the first and second throughbore portions when in the first configuration. Optionally, the moveable member is adapted to permit fluid flow in the throughbore between the first and second throughbore portions when in the second configuration.

[0073] Optionally, the moveable member comprises a first sealing means which is adapted to seal the at least one port from the throughbore when the movable member is in the second configuration. Optionally, the moveable member comprises a second sealing means which is adapted to seal the throughbore between the first and second throughbore portions when the moveable member is in the first configuration.

[0074] Optionally, the second sealing means comprises a sealing plug member having a sealing head portion which selectively seals the throughbore thereby creating a first or an upper throughbore portion and a second or lower throughbore portion, the first or upper throughbore portion being sealed from the second or lower throughbore portion. Optionally, the first sealing means comprises a sidewall portion of the moveable member. Optionally, the sidewall portion is capable of selectively sealing the at least one port from the throughbore.

[0075] Optionally, the moveable member translates between the first and the second configurations by movement of the moveable member in a direction substantially parallel to the longitudinal axis of the body member.

[0076] Optionally, the body member comprises a sealing seat provided within the throughbore. Optionally, translation of the moveable member to the first configuration comprises movement of the sealing head portion into contact with a sealing seat typically to form a seal therebetween. Optionally, the sealing head portion only permits flow of fluid through the second or lower throughbore portion when the at least one port is substantially obturated by the side wall portion.

[0077] Optionally, the sealing plug member is provided with at least one aperture therein through which fluid can flow when the moveable member is in the second configuration. Therefore, the at least one aperture provides fluid communication between the first / upper and second / lower throughbore portions when the at least one port is substantially obturated by the side wall portion.

[0078] Optionally, the sealing plug member comprises a substantially tubular member having a substantially closed base. Optionally, the at least one apertures are provided in the side walls of the tubular member in order to selectively allow flow of fluids therethrough. Optionally, the substantially tubular sealing plug member is of dimensions which allow the sealing plug member to be moved in the direction substantially parallel to the longitudinal axis of the body member by the fluid flow when the substantially tubular member contains or is substantially filled by solid particles. Optionally, the at least one port is adapted to encourage solids present in the fluid to settle on the outside of the body member rather than on the sealing plug member when the diverter device is in the first configuration optionally when at least a portion of the sealing plug member contains solids. Optionally, the at least one port comprise holes formed through the body member which are at a tangent to the longitudinal axis of the body member and which are optionally at a downwardly directed angle to the direction perpendicular to the longitudinal axis of the body member.

[0079] Optionally, the sealing plug member is adapted to selectively remain in the second configuration which allows flow of fluid along the first path when at least a particular rate (which may be a pre-determined rate) of fluid flow acts against a first face (which may be a lower face of the sealing plug member). Optionally, the flow of fluid acting against the first face is provided by a pump means which may be an Electrical Submersible Pump.

[0080] Optionally, the moveable member translates from the first configuration to the second configuration when the pump means is activated and optionally remains in the first configuration whilst the pump means remains in operation. Optionally, the moveable member translates from the second configuration to the first configuration when the pump means is deactivated and optionally remains in the first configuration whilst the pump means remains deactivated.

[0081] Optionally, the sealing plug member remains in the second configuration due to a pressure differential across a portion thereof. Optionally, the said portion comprises a sealed flange portion having a first side (which is optionally in communication with the throughbore) and a second side (which is optionally in communication with the wellbore annulus) optionally such that a higher pressure within the throughbore compared with a lower pressure in the annulus results in a pressure differential acting upon the first side. The second side is optionally in communication with the wellbore annulus by way of a vent. Alternatively, the sealing plug member comprises a first face which is in communication with the first throughbore portion, such that the fluid flow in the first throughbore portion may act thereon, and this alternative allows the sealing plug member to actuate between the first and second configurations due to a change in the flow rate of fluid through the apparatus rather than due to pressure differentials.

[0082] Optionally, the sealing plug member is adapted to selectively remain in the first configuration which allows flow of fluid through the at least one port when there is an absence of fluid flow rate acting against the first face of the sealing head portion or when the fluid flow rate acting against the first face is below a particular rate, which may be a pre-determined rate. Optionally, the sealing plug is adapted to allow fluid flow along the second flow path when the predetermined rate is substantially zero. Optionally, the sealing plug member is encouraged into the first configuration by an urging means which may include gravity but which may also include, or which may alternatively include, a biasing means acting thereon.

[0083] Optionally, the sealing plug member is provided with a one-way valve which optionally allows fluid flow in a first direction along the first flow path and optionally restricts or substantially prevents fluid flow in a second direction along the first flow path. This allows the sealing plug member to be selectively urged toward the first configuration when fluid attempts to flow in the second direction.

[0084] This allows any hydrostatic head present across the flange portion which tends to hold the sealing plug member toward the second configuration, to be instead utilised in order to urge the sealing plug member to move toward the first configuration when desired (e.g. when an Electrical Submersible Pump (ESP) has been switched off). In this way the sealing plug member automatically allows the at least one port to be opened and obturated depending on whether it is desirable to have flow along the first or second path and that when the at least one port is closed the sealing head portion allows fluid to flow through the first and second throughbore portions. Therefore, the apparatus may be used in for example, downhole wellbore applications in order to divert fluid between production tubing and a wellbore casing annulus. Accordingly, certain embodiments of the present invention have the advantage that they do not have to overcome the hydrostatic head of a full column of fluid in the production tubing on reactivation.

[0085] Optionally, the body member is connected to tubing at one end in order to transport the fluid away from, or toward, the device. Optionally, the body of the device is connected to an Electrical Submersible Pump at the other end.

[0086] Optionally, in the second configuration passage of fluid through the first throughbore portion and second throughbore portion is permitted. Optionally, in the first configuration passage of fluid between the first throughbore portion and second throughbore portion is obstructed.

[0087] Optionally, in the second configuration passage of fluid between the first throughbore portion and the at least one port is obstructed. Optionally, in the first configuration passage of fluid between the first throughbore portion and the at least one port is permitted.

[0088] Optionally, the downhole fluid flow control device is arranged such that the moveable member is maintained in the second configuration due to a pressure differential across a portion thereof.

[0089] Optionally, when the downhole fluid flow control device is for inclusion in production tubing used for producing fluid from a reservoir to the surface and the flow of fluid from said reservoir into the second throughbore portion is above a particular rate, the moveable member is adapted to move into, and / or is maintained in, the second configuration such that the fluid from the reservoir is arranged to flow along the first fluid flow path, through a throughbore of the production tubing and on toward the surface. Optionally, when the flow of fluid from the reservoir into the second throughbore portion is below a particular rate, the moveable member is adapted to move into, and / or is maintained in, the first configuration (optionally, such that the fluid in the throughbore of the production tubing is prevented from travelling back along the first fluid flow path and instead is diverted to flow along the second fluid flow path).

[0090] Optionally, the body member is connected to tubing at one end in order to transport the fluid away from, or toward, the movable member and the body of the moveable member is connected to an Electrical Submersible Pump at the other end.

[0091] According to the first aspect of the present invention, there is provided a method for controlling the flow of fluids, the method comprising the steps of:

[0092] (A) providing a body member having a throughbore formed therein, and a port formed therein;

[0093] (B) providing a biasing device housed within a chamber;

[0094] (C) urging a moveable member with the biasing device towards either of: a first configuration in which passage of fluid through the port is permitted; or a second configuration in which passage of fluid through the port is obstructed;

[0095] (D) controlling the flow of fluids by moving the moveable member between said first and second configurations; and

[0096] (E) permitting the flow of solids through the chamber via an opening to the chamber. According to the second aspect of the present invention, there is provided a method for controlling the flow of fluids.

[0097] Optionally, according to the second aspect of the present invention, the method comprises the step of: providing a body member having a throughbore formed therein, and a port formed therein.

[0098] Optionally, according to the second aspect of the present invention, the method comprises the step of permitting the flow of solids through a chamber via an opening to said chamber.

[0099] Optionally, according to the second aspect of the present invention, the method comprises the step of providing a biasing device housed within a chamber.

[0100] Optionally, according to the second aspect of the present invention, the method comprises the step of urging the moveable member with the biasing device towards either of a first configuration in which passage of fluid through the port is permitted; or a second configuration in which passage of fluid through the port is obstructed.

[0101] Optionally, according to the second aspect of the present invention, the method comprises the step of (controlling the flow of fluids by) moving the moveable member between said first and second configurations.

[0102] Optionally, according to the second aspect of the present invention, the method comprises the step of: providing an opening to the chamber to thereby permit the flow of solids through the chamber.

[0103] Optionally, according to the second aspect of the present invention, the method comprises the step of: permitting the flow of solids through the chamber via an opening to the chamber. Optionally, the method is directed to controlling the flow of naturally produced fluids, injected fluids or pumped produced fluids downhole.

[0104] Optionally, the method is directed to selectively pumping fluid along one of a first and second flow path within a wellbore.

[0105] Optionally, the method of controlling flow of fluid comprises selectively diverting flow of fluid between the first and second flow paths and optionally further comprises the step of automatically and / or remotely moving the moveable member in response to fluid flow conditions within a downhole wellbore.

[0106] Optionally, the method comprises the step of providing a first pumping means.

[0107] Optionally, the throughbore of the body member is capable of accommodating fluid flow.

[0108] Optionally, the method comprises the step of providing at least one port in the body member.

[0109] Optionally, the method comprises the step of opening the port and optionally substantially obturating the throughbore at a location above the first pumping means when the first pumping means is dormant.

[0110] Optionally, the method comprises the step of closing the port, optionally when the first pumping means is active.

[0111] Optionally, the method further comprises the step of activating the first pumping means when the pumping effect from a second pumping means is reduced or has ceased. Optionally, the second pumping means comprises an Electrical Submersible Pump. Optionally, the second lifting means comprises natural lift within the wellbore.

[0112] According to a third aspect of the present invention, there is provided a seal arrangement for use in a downhole tool having two concentrically arranged tubular members, said seal arrangement comprising: a pair of seals provided on one or more of the tubular members, said pair of seals configured to provide sealing contact between the two concentrically arranged tubular members; and a void arrangement including a void located in between said pair of seals and being arranged in use to provide a haven for at least one solid particle.

[0113] According to a fourth aspect of the present invention, there is provided a seal arrangement for use in a downhole tool having two concentrically arranged tubular members.

[0114] Optionally, according to a fourth aspect of the present invention, the seal arrangement comprises a pair of seals.

[0115] Optionally, according to a fourth aspect of the present invention, the pair of seals are provided on one or more of the tubular members.

[0116] Optionally, according to a fourth aspect of the present invention, the pair of seals are configured to provide sealing contact between the two concentrically arranged tubular members.

[0117] Optionally, according to a fourth aspect of the present invention, the seal arrangement comprises a void arrangement. Optionally, according to a fourth aspect of the present invention, the void arrangement includes a void located in between the pair of seals.

[0118] Optionally, according to a fourth aspect of the present invention, the void is arranged in use to provide a haven for at least one solid particle.

[0119] Typically, the voids are arranged in use to provide a haven for at least one solid particle to thereby prevent damage to said seals.

[0120] Optionally, the void comprises a void opening.

[0121] Optionally, the void opening is a single void opening. Optionally, said single opening of the void provides both an inlet and outlet for abrasive particles to enter and exit the void, and which therefore defines a mouth to the volume of the void therein. Optionally, the void comprises an inner surface, which together with the mouth of the void defines the volume of the void.

[0122] Optionally, the void opening has a first end. Optionally, the void opening has a second end. Optionally, the pair of seals includes a first seal and second seal. Optionally, the first end of the void opening is provided proximate relative to the first seal. Optionally, the second end of the void opening is provided proximate relative to the second seal. Optionally, the width of the void opening is defined by the length between said first end and said second end.

[0123] Optionally, the two concentrically arranged tubular members are configured to be selectively sealed. Optionally, the two concentrically arranged tubular members are moveable axially with respect to one another. Optionally, the two concentrically arranged tubular members are axially moveable with respect to one another between a first configuration and a second configuration. Optionally, a fluid channel is provided between at least a portion of the two concentrically arranged tubular members. Optionally, the two concentrically arranged tubular members include an inner tubular member and an outer tubular member. Optionally, said fluid channel is provided between at least a portion of an inner surface of the outer tubular member and an end portion of the inner tubular member. Alternatively, and / or additionally, the fluid channel may optionally be provided between at least a portion of an inner surface of the outer tubular member and an outer surface of the inner tubular member.

[0124] Optionally, the first configuration is a sealed configuration in which sealing contact is provided between the two concentrically arranged tubular members, optionally such that passage of fluid through the fluid channel is prevented. Optionally, in the first configuration, the opening of the void is obturated or closed off by at least one of the tubular members such that solid particles can be housed or otherwise find a haven therein.

[0125] Optionally, the second configuration is an unsealed configuration in which the two concentrically arranged tubular members are separated at least axially, optionally such that passage of fluid through the fluid channel is permitted. Optionally, in the second configuration, the opening of the void is open such that solid particles can flow in and out thereof.

[0126] Optionally, when the two concentrically arranged tubular members are in a sealed configuration, the void is located in between the contact surfaces of the said pair of seals.

[0127] Optionally, the void arrangement includes at least one clearance gap provided between at least one seal of the pair of seals and the void opening. Typically, the at least one clearance gap forms part of the fluid channel between the two concentrically arranged tubular members. Optionally, said clearance gap is an annular clearance gap. Optionally, the void arrangement includes a clearance gap provided on either side (preferably on each side) of the void opening. Optionally, the void arrangement includes a first clearance gap between the first end of the void opening and the contact surface of a first seal (of the pair of seals). Optionally, the void arrangement includes a second clearance gap between the second end of the void opening and the contact surface of a second seal (of the pair of seals).

[0128] Optionally, the void comprises a depth. Optionally, the void comprises a maximum depth.

[0129] Optionally, the maximum depth of the void is defined as the larger of: the maximum radial distance between the inner and the outer tubular member at any point along the width of the void opening; and the maximum axial distance between the inner and the outer tubular member at any point along the width of the void opening.

[0130] Optionally, the void comprises a depth, where the depth typically extends in a direction substantially perpendicular to a longitudinal axis of the downhole tool. Optionally, the void comprises a maximum depth.

[0131] Optionally, each clearance gap comprises a depth, where the said clearance gap depth typically extends in a direction substantially perpendicular to a longitudinal axis of the downhole tool.

[0132] Optionally, the clearance gap is an annular clearance gap and which preferably comprises a medial axis. Optionally, said medial axis is defined as the locus of points equidistant to the opposing surfaces of the inner and tubular members. Optionally, the depth of the clearance gap is defined as the maximum radius of a circle centred on the medial axis and tangent to both the outer surface of the first tubular member and the inner surface of the second tubular member at any point along the axial length of the clearance gap. Optionally, the clearance gap comprises a maximum depth. Optionally, the maximum depth of the clearance gap is defined as the largest maximum radius of a circle centred on the medial axis and tangent to both the outer surface of the first tubular member and the inner surface of the second tubular member along the axial length of the clearance gap.

[0133] Typically, the maximum depth of the void is greater than the maximum depth of the or each clearance gap adjacent thereto.

[0134] Optionally, the void comprises a maximum depth that is at least 1.5 times greater than the maximum depth of the clearance gap. Optionally, the void comprises a maximum depth that is at least 2 times greater than the maximum depth of the clearance gap. Optionally, the void comprises a maximum depth that is at least 2.5 times greater than the maximum depth of the clearance gap. Optionally, the void comprises a maximum depth that is at least 3 times greater than the maximum depth of the clearance gap. Optionally, the void comprises a maximum depth that is at least 4 times greater than the maximum depth of the clearance gap. Optionally, the void comprises a maximum depth that is at least 5 times greater than the maximum depth of the clearance gap.

[0135] Optionally, the maximum depth of the void is between 1.5 and 10 times greater than the maximum depth of the clearance gap. Optionally, the maximum depth of the void is between 2 and 8 times greater than the maximum depth of the clearance gap. Optionally, the maximum depth of the void is between 2.5 and 6 times greater than the maximum depth of the clearance gap. Optionally, the maximum depth of the void is between 3 and 5 times greater than the maximum depth of the clearance gap.

[0136] Optionally, the width of the void opening is at least 20% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is at least 30% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is at least 40% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is at least 50% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is at least 60% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is at least 70% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is at least 80% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is at least 90% of the total distance between the respective contact surfaces of each of the pair of seals.

[0137] Optionally, the width of the void opening is a maximum of 30% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is a maximum of 40% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is a maximum of 50% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is a maximum of 60% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is a maximum of 70% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is a maximum of 80% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is a maximum of 90% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is up to 100% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is between 20% and 100% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is between 30% and 95% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is between 40% and 90% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is between 50% and 85% of the total distance between the respective contact surfaces of each of the pair of seals. Optionally, the width of the void opening is between 60% and 80% of the total distance between the respective contact surfaces of each of the pair of seals.

[0138] Optionally, the clearance gap may effectively be a single point provided directly adjacent to a contact surface of the respective seal thereof, optionally such that an end of the void opening may in effect be directly adjacent to the contact surface of one of the pair of seals thereof.

[0139] Optionally, the clearance gap includes a length, which may extend from the contact surface of a respective seal to an end of the void opening. Optionally, the depth of the clearance gap is substantially constant along the length thereof which may preferably be the axial extending length thereof (i.e. the respective length between the contact surface of said respective seal and the end of the void opening). Optionally, the clearance gap has a substantially constant depth along the length thereof within + / - 20% of the maximum depth of the clearance gap. Optionally, the clearance gap has a substantially constant depth along the length thereof within + / - 15% of the maximum depth of the clearance gap. Optionally, the clearance gap has a substantially constant depth along the length thereof within + / - 10% of the maximum depth of the clearance gap.

[0140] Optionally, at least one void recedes radially into the tubular member in which it is formed within. Optionally, at least one void recedes axially into the tubular member in which it is formed within. Optionally, at least one void recedes both axially and radially into the tubular member in which it is formed within and preferably at least one void recedes both axially and radially into a sidewall of the tubular member in which it is formed within.

[0141] Optionally, at least one seal is formed by metal-to-metal contact between the two concentrically arranged tubular members. Optionally, said metal-to-metal contact seal may provide and / or acts as the primary seal in the sealing arrangement. Optionally, said metal-to-metal contact seal may be formed by a fluid tight sealing contact between corresponding contact I sealing surfaces of each of the inner and outer tubular members. Optionally, said metal-to- metal contact seal may be formed by metal-to-metal contact between the inner surface of the outer tubular member and an outer surface of the inner tubular member and more preferably the said outer surface of the inner tubular member may be an end portion of the inner tubular member. Optionally, the outer tubular member comprises a sealing seat provided within the throughbore thereof. Optionally, the sealing seat is provided around the internal circumference of the outer tubular member. Optionally, the inner tubular member comprises a sealing head at said end portion thereof. Optionally, translation of the inner tubular member to the sealed configuration comprises movement of the sealing head into contact with the sealing seat to form the seal therebetween. Optionally, the sealing seat of the outer tubular member and the sealing head of the inner tubular member each include corresponding conical portions which define the contact points length between the inner and outer tubular members, which forms the metal-to-metal seal. These matching conical portions typically assist in centring and aligning the tubular members (i.e. when in (and / or moving into) the closed and sealed configuration) and convert axial force into a high local contact stress to form the metal-to-metal seal. Further, having such matching conical portions in preferred embodiments of the present invention ensures the metal-to-metal seal provides a uniform and tight seal between the concentric tubular members. Optionally, at least one seal is an elastomeric seal. Optionally, said elastomeric seal is an elastomeric ring-shaped seal. Optionally, said elastomeric seal is housed within a groove. Optionally, said elastomeric seal is housed within an annular groove. Optionally, said groove is formed around the circumference of the one or more of the tubular members which the seals are provided on.

[0142] Optionally, the sealing arrangement comprises a second pair of seals provided on one or more of the tubular members. Optionally, said second pair of seals is also configured to provide sealing contact between the two concentrically arranged tubular members. Optionally, the void arrangement comprises a second void. Optionally, the second void is located in between the second pair of seals. Optionally, the second void is arranged in use to provide a haven for at least one solid particle or preferably a plurality of solid particles (which may be solid abrasive particles) to prevent damage / wear of either of said seals of the second pair of seals.

[0143] Optionally, one of the seals of said second pair seals is also one of the seals of the first pair of seals. Optionally, the second pair of seals include the second seal and a third seal. Alternatively, the second pair of seals may optionally include a third seal and a fourth seal.

[0144] Optionally, the sealing arrangement comprises a third pair of seals provided on one or more of the tubular members. Optionally said third pair of seals is configured to provide sealing contact between the two concentrically arranged tubular members. Optionally, the void arrangement comprises a third void. Optionally, the third void is located in between the third pair of seals. Optionally, the third void is arranged in use to provide a haven for abrasive and / or solid particles to prevent damage / wear of either of said seals of the third pair of seals. As the skilled person will understand, sealing arrangements in accordance with embodiments of the present invention may include any suitable number of seals. Similarly, the skilled person will also understand that void arrangements in accordance with embodiments of the present invention may include any suitable number of voids.

[0145] Optionally, at least one of the pairs of seals includes a seal that is formed by metal-to-metal contact between the two concentrically arranged tubular members and also includes a seal that is an elastomeric seal. Optionally, at least one of the pairs of seals includes a seal that is an elastomeric seal and also includes another seal that is also an elastomeric seal. However, as the skilled person will understand, sealing arrangements in accordance with embodiments of the present invention may include any suitable arrangement and types of seals.

[0146] Optionally, the void arrangement further includes a tapered lead in surface. Optionally, the tapered lead in surface is provided directly adjacent to a seal. Optionally, the tapered lead in surface is provided on the outermost side of an outermost seal of the sealing arrangement. Optionally, when the sealing arrangement includes a seal which is formed by metal-to-metal contact between the two concentrically arranged tubular members (and which is provided and / or acts as the primary seal in the sealing arrangement), the tapered lead surface may be provided at the opposite end of the sealing arrangement from said metal-to-metal contact seal.

[0147] Optionally, the tapered lead in surface is defined by a tapered face. Optionally, when the tapered lead in surface is provided on the outer tubular member, the tapered face of the tapered lead in surface may extend in a radially outward and axially outward (i.e. axially outward from the sealing arrangement) direction from the most radially inward edge of the outermost side of the groove (which houses a seal therein). Optionally, when the tapered lead in surface is provided on the inner tubular member, the tapered face of the tapered lead in surface may extend in a radially inward and axially outward (i.e. axially outward from the sealing arrangement) direction from the most radially outward edge of the outermost side of the groove (which houses a seal therein). This tapered lead in surface assists in preventing or at least mitigating abrasive and / or solid particles from causing abrasive damage to the seals and also to portions of the inner tubular member and the outer tubular member (e.g. the portions that define the clearance gaps therebetween). This is particularly effective as the tool moves from the closed configuration (i.e. sealed state) to the open configuration (i.e. unsealed state), because rather than being locked between the inner tubular member and the outer tubular member, any abrasive and / or solid particles that may have collected beneath the seal proximate the tapered lead in surface are free to move in, and importantly out of, the enlarged opening that is provided for by this tapered lead in surface.

[0148] Optionally, when the tapered lead in surface is provided on the outer tubular member, the tapered lead in surface may extend in a radially outward and axially outward direction at an angle relative to the longitudinal axis of the tubular members. Optionally, when the tapered lead in surface is provided on the inner tubular member, the tapered lead in surface may extend in a radially inward and axially outward direction at an angle relative to the longitudinal axis of the tubular members. Optionally, said angle of the tapered lead in surface is approximately 20° relative to the longitudinal axis of the tubular members. Optionally, said angle of the tapered lead in surface is approximately 30° relative to the longitudinal axis of the tubular members. Optionally, said angle of the tapered lead in surface is approximately 40° relative to the longitudinal axis of the tubular members. Optionally, said angle of the tapered lead in surface is approximately 50° relative to the longitudinal axis of the tubular members. Optionally, said angle of the tapered lead in surface is approximately 60° relative to the longitudinal axis of the tubular members. Optionally, said angle of the tapered lead in surface is approximately 70° relative to the longitudinal axis of the tubular members. Optionally, said angle of the tapered lead in surface is between 10° and 90° relative to the longitudinal axis of the tubular members. Optionally, said angle of the tapered lead in surface is between 20° and 80° relative to the longitudinal axis of the tubular members. Optionally, said angle of the tapered lead in surface is between 30° and 70° relative to the longitudinal axis of the tubular members.

[0149] Optionally, there is provided a downhole tool comprising two concentrically arranged tubular members, said downhole tool comprising the seal arrangement in accordance with the third and / or fourth aspects of the present invention.

[0150] According to the third aspect of the present invention, there is provided a method for sealing a fluid channel between two concentrically arranged tubular members, the method comprising the steps of:

[0151] (A) providing a pair of seals on one or more of the tubular members;

[0152] (B) providing a void between said pair of seals.

[0153] (C) moving the two concentrically arranged tubular members from an unsealed configuration to a sealed configuration, in which sealing contact between the two concentrically arranged tubular members is made via the pair of seals; and

[0154] (D) collecting at least one solid particle within the void as the two concentrically arranged tubular members move from the unsealed configuration to the sealed configuration to thereby prevent at least one solid particle from damaging the seals.

[0155] According to the fourth aspect of the present invention, there is provided a method for sealing a fluid channel between two concentrically arranged tubular members. Optionally, according to the fourth aspect of the present invention, the method comprises the step of: providing a pair of seals on one or more of the tubular members.

[0156] Optionally, according to the fourth aspect of the present invention, the method comprises the step of: providing a void between the pair of seals.

[0157] Optionally, according to the fourth aspect of the present invention, the method comprises the step of: moving the two concentrically arranged tubular members from an unsealed configuration to a sealed configuration, in which sealing contact between the two concentrically arranged tubular members is made via the pair of seals.

[0158] Optionally, according to the fourth aspect of the present invention, the method comprises the step of: collecting at least one solid particle within the void as the two concentrically arranged tubular members move from the unsealed configuration to the sealed configuration to thereby prevent at least one solid particle from damaging the seals.

[0159] Optionally, the method further comprises the step of moving the two concentrically arranged tubular members from the sealed configuration back to the unsealed configuration.

[0160] Optionally, the method further comprises the step of releasing at least one solid particle that has / have been collected within the voids when the two concentrically arranged tubular members have moved back to the unsealed configuration.

[0161] Optionally, the third and fourth aspects of the present invention may be provided alone or in combination with the first and / or second aspects of the present invention. Also, optional features described in relation to the first and / or second aspects of the present invention can typically be combined alone or together with other features described in relation to the third and / or fourth aspects of the present invention.

[0162] The accompanying drawings illustrate presently exemplary embodiments of the disclosure and together with the general description given above and the detailed description of the embodiments given below, serve to explain, by way of example, the principles of the disclosure.

[0163] In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawings are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form, and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments of the present invention are shown in the drawings, and herein will be described in detail, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce the desired results.

[0164] Reference to up or down will be made for purposes of description with the terms "above", "up", "upward" or "upper" meaning away from the bottom of the borehole toward the subsea surface and "below", "down", "downward" or "lower" meaning toward the bottom of the borehole and away from the subsea surface and deeper into the borehole.

[0165] The various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one embodiment can typically be combined alone or together with other features in different embodiments of the invention. Additionally, any feature disclosed in the specification can be combined alone or collectively with other features in the specification to form an invention.

[0166] Various embodiments and aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features, and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates a number of exemplary embodiments and aspects and implementations. The invention is also capable of other and different embodiments and aspects, and its several details can be modified in various respects, all without departing from the spirit and scope of the present invention.

[0167] Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention.

[0168] Accordingly, the drawings and descriptions are to be regarded as illustrative in nature, and not as restrictive. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including", "comprising", "having", "containing" or "involving" and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. In this disclosure, whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting essentially of”, "consisting", "selected from the group of consisting of”, “including” or "is" preceding the recitation of the composition, element or group of elements and vice versa. In this disclosure, the words “typically” or “optionally” are to be understood as being intended to indicate optional or non-essential features of the invention which are present in certain examples but which can be omitted in others without departing from the scope of the invention.

[0169] All numerical values in this disclosure are understood as being modified by "about". All singular forms of elements, or any other components described herein including (without limitations) components of the apparatus described herein are understood to include plural forms thereof and vice versa.

[0170] BRIEF DESCRIPTION OF THE DRAWINGS

[0171] Fig. 1 shows an outer side view of a fluid control device in accordance with a first embodiment of the present invention, with the moveable member in a first configuration in which passage of fluids through the port is permitted;

[0172] Fig. 2 shows the side view of the fluid control device of Fig. 1 , but with a quarter portion of the body member removed to show a portion of the outer surface of the moveable member within the body member when said moveable member is in the said first configuration;

[0173] Fig. 3 is a half cross-sectional side view of the fluid control device of Fig. 1 , which shows the internal arrangement of the body member and the moveable member provided there within, when in the said first configuration;

[0174] Fig. 4 is a part sectional side view of the fluid control device of Fig. 1 , which shows the internal arrangement of the first configuration of the body member and the moveable member provided there within, but also shows a portion of the outer surface of the body member in order to provide reference for the internal arrangements of the body member and the moveable member relative to the outer surface of the body member when in the said first configuration; Fig. 5 shows an outer side view of a fluid control device in accordance with a first embodiment of the present invention, with the moveable member in a second configuration in which passage of fluids through the port is obstructed;

[0175] Fig. 6 shows the side view of the fluid control device of Fig.5, but with a quarter portion of the body member removed to show a portion of the outer surface of the moveable member within the body member when said moveable member is in the said second configuration;

[0176] Fig. 7 is a cross-sectional side view of the fluid control device of Fig. 5, which shows the internal arrangement of the body member and the moveable member provided there within, when in the said second configuration;

[0177] Fig. 8 is a part sectional side view of the fluid control device of Fig. 5, which shows the internal arrangement of the said second configuration of the body member and the moveable member provided there within, but also shows a portion of the outer surface of the body member in order to provide reference for the internal arrangements of the body member and the moveable member relative to the outer surface of the body member when in the said second configuration;

[0178] Fig. 9 shows a perspective view of the fluid control device from an upper viewpoint, corresponding to Fig. 1 ;

[0179] Fig. 10 shows a perspective view of the fluid control device from an upper viewpoint, corresponding to Fig. 2;

[0180] Fig. 11 is a part sectional perspective view of the fluid control device from an upper viewpoint, corresponding to Fig. 3;

[0181] Fig. 12 is a cross-sectional perspective view of the fluid control device from an upper viewpoint, corresponding to Fig. 4;

[0182] Fig. 13 shows a perspective view of the fluid control device from an upper viewpoint, corresponding to Fig. 5;

[0183] Fig. 14 shows a perspective view of the fluid control device from an upper viewpoint, corresponding to Fig. 6;

[0184] Fig. 15 is a part sectional perspective view of the fluid control device from an upper viewpoint, corresponding to Fig. 7; Fig. 16 is a cross-sectional perspective view of the fluid control device from an upper viewpoint, corresponding to Fig. 8;

[0185] Fig. 17 shows a perspective view of the fluid control device from a lower viewpoint, corresponding to Figs. 1 and 9;

[0186] Fig. 18 shows a perspective view of the fluid control device from a lower viewpoint, corresponding to Figs. 2 and 10;

[0187] Fig. 19 is a part sectional perspective view of the fluid control device from a lower viewpoint, corresponding to Figs. 3 and 11 ;

[0188] Fig. 20 is a cross-sectional perspective view of the fluid control device from a lower viewpoint, corresponding to Figs. 4 and 12;

[0189] Fig. 21 shows a perspective view of the fluid control device from a lower viewpoint, corresponding to Figs. 5 and 13;

[0190] Fig. 22 shows a perspective view of the fluid control device from a lower viewpoint, corresponding to Figs. 6 and 14;

[0191] Fig. 23 is a part sectional perspective view of the fluid control device from a lower viewpoint, corresponding to Figs. 7 and 15;

[0192] Fig. 24 is a cross-sectional perspective view of the fluid control device from a lower viewpoint, corresponding to Figs. 8 and 16;

[0193] Fig. 25 shows a perspective view of the fluid control device of Fig. 9, but from an alternative upper viewpoint;

[0194] Fig. 26 shows a perspective view of the fluid control device Fig. 10, but from an alternative upper viewpoint;

[0195] Fig. 27 is a part sectional perspective view of Fig. 11 , but from an alternative upper viewpoint;

[0196] Fig. 28 is a cross-sectional perspective view of the fluid control device of Fig. 12, but from an alternative upper viewpoint;

[0197] Fig. 29 shows a perspective view of the fluid control device of Fig. 13, but from an alternative upper viewpoint;

[0198] Fig. 30 shows a perspective view of the fluid control device of Fig. 14, but from an alternative upper viewpoint;

[0199] Fig. 31 is a part sectional perspective view of the fluid control device of Fig. 15, but from an alternative upper viewpoint; Fig. 32 is a cross-sectional perspective view of the fluid control device of Fig. 16, but from an alternative upper viewpoint;

[0200] Fig. 33A is a sectional side view of a second embodiment of a fluid control device in accordance with the first aspect of the present invention, with the moveable member in a first configuration in which passage of fluids through the port is permitted, and Fig. 33A is also a sectional side view of an embodiment of a fluid control device which includes a sealing arrangement in accordance with the second aspect of the present invention, which is configured to reduce the effects of abrasive particles on components;

[0201] Fig. 33B is an enlarged view of Fig. 33A, showing the general section of the fluid control device where the sealing arrangement is located;

[0202] Fig. 33C is an enlarged view of Fig. 33B, showing a detailed view of the seals and voids of the sealing arrangement;

[0203] Fig. 34A is a sectional side view of the second embodiment of the fluid control device shown in Fig. 33A in accordance with the first aspect of the present invention, but with the moveable member now in a second configuration in which passage of fluids through the port is obstructed, and Fig. 34A is also a sectional side view of the embodiment of the fluid control device which includes a sealing arrangement in accordance with the second aspect of the present invention, which is configured to reduce the effects of abrasive particles on components;

[0204] Fig. 34B is an enlarged view of Fig. 34A, showing the general section of the fluid control device where the sealing arrangement is located;

[0205] Fig. 34C is an enlarged view of Fig. 33B, showing a detailed view of the seals and voids of the sealing arrangement;

[0206] Fig. 34D shows an enlarged view of Fig. 34C, showing a detailed view of the first void;

[0207] Fig. 34E shows an enlarged view of Fig. 34C, showing a detailed view of the second void; and

[0208] Fig. 34F shows an enlarged view of Fig. 34C, showing a detailed view of the tapered lead in surface. DETAILED DESCRIPTION OF DRAWINGS

[0209] Figs. 1-4, 9-12, 17-20 and 25-28 shows a side view of a fluid control device 1 in accordance with a first embodiment of the present invention, with the moveable member in a first configuration (in which, as will be further described subsequently, passage of fluids through the port 16 is permitted).

[0210] Figs. 5-8, 13-16, 21-24 and 29-32 show a fluid control device 1 in accordance with a first embodiment of the present invention, with the moveable member in a second configuration (in which, as will be further described subsequently, passage of fluids through the port 16 is obstructed).

[0211] The flow control device 1 comprises a body member 10 having a throughbore 11 formed therein such that the body member 10 is substantially tubular. The body member 10 may comprise an upper tubular member 12 having an upper throughbore portion 12p formed therein. The body member may also comprise a middle tubular member 13 having a middle throughbore portion 13p formed therein. The body member may also comprise a lower tubular member 14 having a lower throughbore portion 14p formed therein. In the example shown, the upper tubular member 12 is adjoined to the middle tubular member 13, which in turns is adjoined to the lower tubular member 14 to form the body member 10.

[0212] The flow control device 1 may further comprise a plurality of ports 16 formed through the sidewall 17 of the body member 10, such as through the sidewall of the upper tubular member 12, such that fluid may flow from outside the body member 10 and into the throughbore 11 of the body member 10 and vice versa. In the example shown in Fig. 1 , there are four ports 16 uniformly positioned in a circular array around the body member 10 such that each of the ports 16 are equally spaced around the body member 10 at the same axial position along the length of the body member 10 (in that example at 90 degree intervals). The ports 16 are formed at a downwardly directed angle to the direction perpendicular to the longitudinal axis L of the body member 10. Advantageously, this facilitates the gravity fall out of solids as they fall back down the fluid in tubing or upper tubular member 12 (for example, when an ESP (not shown but which is included in the same tubing string that the fluid control device 1 is included) is switched off and there remains a static level of fluid above the ESP, as will be described subsequently).

[0213] The flow control device 1 further comprises a moveable member 30. The moveable member 30 is moveable between a first configuration and a second configuration. As will be further described subsequently, in the first configuration, passage fluids through the port(s) 16 is permitted and in the second configuration passage of fluids through the port(s) 16 is obstructed. In the example shown, the moveable member 30 is provided within the body member 10 and is longitudinally moveable along the longitudinal axis L of the body member 10. The moveable member 30 has a lower head portion 31 located at its lower end; the lower head portion 31 having a lowermost face 31 L. Side walls 32 extend upwardly from the lower head portion 31. The length of the side walls 32 is arranged or chosen such that they do not obstruct the ports 16 when the moveable member 30 is at its lowest position (i.e. in the first configuration) as best shown in Figs.1 to 4. The outer surface of the sidewalls 32 of the moveable member 30 is substantially congruent with a portion of the inner surface 18 of the body member 10 (and specifically the portion of the inner surface 18 of the body member 10 that is proximate to the ports 16 formed in the body member 10) such that when the moveable member 30 is in the second configuration said outer surface of the sidewalls 32 of the movable member 30 envelopes the port 16 to thereby obstruct the passage of fluid through the port(s) 16.

[0214] The flow control device 1 is arranged such that moveable member 30 is obstructed from moving downwardly past a first lower location relative to the body member 10. In the example shown, a lower seal seat 19 is provided around the internal circumference of the body member 10 and is positioned such that the lower head portion 31 of the moveable member 30 abuts against the lower seal seat 19 when the moveable member 30 is in its lowest position (as best shown in Figs. 1 to 4) thereby obstructing the moveable member 30 from moving downwardly past the first lower location relative to the body member 10. When the moveable member 30 is in this lower position (with its lower head portion 31 abutted against the lower seal seat 19) it will be understood that the moveable member 30 is completely retracted or spaced apart from the port(s) 16such that the port(s) 16 is wholly (and / or at least partially) open to thereby permit the passage of fluid through the port 16(s) and hence through the throughbore 11 of the body member 10.

[0215] The flow control device 1 is also arranged such that moveable member 30 is obstructed from moving upwardly past a second upper location relative to the body member 10. In the example shown, an upper seal seat 20 is provided around the internal circumference of the upper throughbore portion 12p of the body member 10 and is positioned such that the extreme (or uppermost) end of the side walls 32 of the movable member 30 abut against the upper seal seat 20 when the moveable member 30 is in its upper position (as best shown in Figs. 5 to 8). When the moveable member 30 is in this upper position (with its side walls 32 uppermost end abutted against the upper seal seat 20) it will be understood that a seal is formed by the contact between the outer surface of the sidewalls 32 of the movable member 30 and the inner surface 18 of the body member 10, which envelopes the port 16 to thereby obstruct the passage of fluids through the port 16.

[0216] The flow control device 1 further comprises a chamber 40. The flow control device 1 further comprises a biasing device 60 housed within said chamber 40. In the example shown, the chamber 40 is provided radially in the annular region between the side walls 32 of the moveable member 30 and the inner surface 18 of the body member 10, such that the side walls 32 of the moveable member 30 define an inner wall 43 of the chamber 40, and also such that the inner surface 18 of the body member 10 defines an outer wall opposite lower end 42. In the example shown, the upper end 41 of the chamber 40 is provided proximate to and directly below the ports 16 formed in the body member 10 and such that the lower end 42 of the chamber 40 is provided below the ports 16 formed in the body member 10 but at a more distal location from the ports 16 relative to the upper end 41 of the chamber 10.

[0217] The flow control device 1 further comprises a first flanged portion 41 which defines an upper wall 41 of the chamber 40 (and also therefore defines the upper end 41 of the chamber 40). In the example shown in the drawings, the body member 10 comprises said first flanged portion 41 , and the first flanged portion 41 is provided proximate to and directly below the ports 16 formed in the body member 10. The first flanged portion 41 uniformly projects annularly inwards from the inner wall 18 of the body member 10. The length of the first flanged portions 41 inward projection is arranged or chosen such that the innermost surface or point of the first flanged portion 41 is substantially congruent with the outer surface of the sidewall 32 of the moveable member 30 such that a seal is formed therebetween.

[0218] The flow control device 1 further comprises a second flanged portion 42 which defines a lower wall 42 of the chamber 40 (and also therefore defines the lower end 42 of the chamber 40). In the example shown in the drawings, the moveable member 30 comprises said second flanged portion 42. The second flanged portion 42 uniformly projects annularly outwards from the outer wall 32 of the moveable member 30. The length of the second flanged portion’s 42 inward projection is arranged or chosen such that the outermost surface or point of the second flanged portion 42 is substantially congruent with the inner surface of the sidewall 32 of the body member 30 such that a seal is formed therebetween.

[0219] In the example shown, the longitudinal length of the chamber 40 is defined by the longitudinal distance between the first flanged portion 41 (defining the upper wall or upper end of the chamber 40) and the second flanged portion 42 (defining the lower wall or lower end of the chamber 40) at any given time. It will be understood that, given that the second flanged portion 42 is formed on the moveable member 30 (in the example shown), when the moveable member 30 longitudinally moves relative to the body member 10 (i.e. between the first configuration and the second configuring), the second flanged portion 42 will also move relative to the body member 10. On the other hand, it will be understood that given that the first flanged portion 41 is formed on the body member 10 (in the example shown), when the moveable member 30 longitudinally moves relative to the body member 10 (i.e. between the first configuration and the second configuring), the first flanged portion 41 will remain fixed in position relative to the body member 10 that it is formed on. Accordingly, as the moveable member 30 moves between the first configuration and the second configuration, the second flanged portion 42 will longitudinally move relative to the first flanged portion 41 . More specifically, when the moveable member 30 moves from the first configuration towards the second configuration, the second flanged portion 42 will move upwardly towards the first flanged portion 41 such that the longitudinal distance between the first flanged portion 41 and the second flanged portion 42 reduces (and also such that the volume of the chamber 40 therefore reduces). On the other hand, when the moveable member 30 moves from the second configuration towards the first configuration, the second flanged portion 42 will move downwardly away from the first flanged portion 41 such that the longitudinal distance between the first flanged portion 41 and the second flanged portion 42 increases (and also such that the volume of the chamber 40 therefore increases).

[0220] Upper pressure ring-seal (not shown) and lower pressure ring-seal (not shown) may be used (which could be formed of elastomeric material). Such ring-seals may be partially housed in recessed portions of the side walls 32 of the moveable member 30 and / or the sidewalls of the body member and may extend around the outer circumference of the side walls 32 of the moveable member 30 and / or around the inner circumference body member 10, serving to prevent fluid from entering the chamber 40 via its upper end 41 and / or its lower end 42.

[0221] In the example shown, the biasing device 60 is a spring, and more specifically a coiled spring. The coiled spring 60 is defined by a helical shape. The helical shape of the coiled spring 60 is arranged such that the coils of the coiled spring 60 follow a spiral path around the central longitudinal axis L of the flow control device 1 . In this way, the coils of the coiled spring 60 are wound around the sidewalls 32 of the moveable member 30.

[0222] In the example shown, a single spring 60 is provided. However, as will be appreciated by those skilled in the relevant art, alternative embodiments in accordance with the present invention may alternatively comprise a plurality of springs, which may, for instance, be provided in a circumferential arrangement in an array around the central axis L of the movable member. As hereinabove explained, the biasing device 60 is housed within the chamber 40. In the particular embodiment shown in the drawings, the coiled spring 60 is a compression spring. Accordingly, in the present embodiment, the spring 60 is configured to operate with a compression load such that the spring 60 gets shorter as the load is applied to it and also such that the spring 60 is configured to bias the moveable member 30 axially away from the port 16. However, as will be appreciated by those skilled in the relevant art, any suitable biasing mechanism or biasing device could be used to axially bias, rotationally bias or otherwise bias / urge the moveable member 30 towards at least the first configuration or second configuration, or otherwise.

[0223] The coiled spring 60 has a first end and 60A a second opposite end 60B, and in the embodiment shown, the coiled spring 60 is arranged such that its first end 60A is abutted against the first flanged portion 41 of the body member 10, and its second end 60B is abutted against the second flanged portion 42 of the moveable member 30. This arrangement enables the coiled spring 60 to urge the moveable member 30 axially towards of the first configuration and thereby axially away from the second configuration.

[0224] The flow control device 1 further comprises a plurality of openings 70. In the example shown, there are four openings 70, each of which is formed through the body member 10 and positioned proximate to the ports 16 of the body member 10. Each of the openings 70 is configured to permit / promote the evacuation of solids and fluids from the chamber 40. The fluid may be downhole fluid, which may comprise abrasive particles, corrosive elements, solids (such as sand or rock or other material from the surrounding formation) or extreme temperatures that can degrade the performance of the biasing device 60 over time; the most important factor for a skilled person to wish to be evacuated from the chamber 40 is likely to be solids such as sand or rock or other material from the surrounding formation. The openings 70 to the chamber 40 are in fluid communication with the external surroundings of the body member 10 (i.e. the downhole wellbore environment), such that the inner volume of the chamber 40 is in fluid communication with the external surroundings of the body member 10 (i.e. via the openings 70). The openings 70 to the chamber 40 permit fluid to flow into the chamber 40 from the outer environment; and subsequently and more importantly out of the chamber 40 into the outer environment. Conveniently, the openings 70 to the chamber 40 being in communication with the external surroundings of the body member 10 enables the removal of solids from the chamber 40 to the surroundings such as the environment outside of the flow control device 1 such as the downhole wellbore.

[0225] The openings 70 are arranged in an array, and each preferably comprise an elongated shape. Each of the elongate openings 70 is preferably axially aligned to the longitudinal axis of the chamber 40, the biasing device 60 (and therefore coincidentally are also axially aligned with the moveable member 30, the body member 10 (and the throughbore thereof)). Each elongate opening 70 may comprise a first end 70A and a second opposite end 70B. The first end 70A end of each of the elongate openings 70 is provided relative to the ports 16. The elongate openings 70 each comprise a longitudinally arranged slot (i.e. a slot 70 formed in a direction parallel to the longitudinal axis of the body member 10) having a first end and a second opposite end and an uninterrupted middle portion joining said first and second ends. The length of each slot 70 (i.e. the distance between the first and second ends) is relatively equal to the length of the chamber 40 when the chamber 40 is at its maximum length (that is, when the biasing device 60 is fully extended i.e. is not compressed). Advantageously, having this arrangement of openings 70 enables the flow of fluid (or more particularly, liquid) in / out / through the chamber 40 to flush (at least) the solids out from the chamber 40 to prevent solids (e.g. abrasive particles, corrosive elements) from remaining in the chamber 40, particularly from remaining in the chamber 40 when the volume of the chamber 40 is reduced such as when the biasing member 60 is being compressed or is compressed, and thus preventing (or at least mitigating the risk of) damage to the biasing member 60. A common issue that can occur with the openings 70 to the chamber 40 is the blockage of the opening 70, particularly when the opening 70 is too small. Given that the fluid in the chamber 40 is typically incompressible, such blockage can subsequently lead to the locking of the chamber 40. However, each of the specific features of the arrangement of the openings / slots 70, namely:

[0226] • the multiple openings / slots 70;

[0227] • the positioning / arrangement of the openings / slots 70;

[0228] • the width of the openings / slots 70 (being wide enough to prevent blockage occurring);

[0229] • the longitudinally arranged openings / slots 70; and / or

[0230] • the length of each slot being relatively equal to the length of the chamber 40 when the chamber 40 is at its maximum length, conveniently each independently (but more so in combination) assist in preventing blockage of the openings 70 and therefore assist in preventing locking of the chamber 40. The moveable member 30 may be actuatable to move in response to an external force or signal. In the example shown in the figures, the moveable member 30 is adapted to remotely and / or selectively move between the first and second configurations in response to changes in flow rate I pressure of fluid within the throughbore 11 of the body member 10. However, as will be appreciated by those skilled in the relevant art, any suitable actuation mechanism could be used to actuate movement (axial, rotational or otherwise) of the moveable member 30 towards at least the first configuration or second configuration, or otherwise. Conveniently, when the moveable member 30 is actuatable to move in response to changes in fluid flow rate I fluid pressure, this enables the moveable member 30 to be operable to remote actuating to control the movement of the moveable member 30 between the first and second configurations, which is crucial in situations where manual operation is not feasible or safe.

[0231] As hereinabove explained, the body member 10 may comprise an upper tubular member 12 having an upper throughbore portion 12p formed therein. The body member may also comprise a middle tubular member 13 having a middle throughbore portion 13p formed therein. The body member may also comprise a lower tubular member 14 having a lower throughbore portion 14p formed therein. In the example shown, the upper tubular member 12 is adjoined to the middle tubular member 13, which in turns is adjoined to the lower tubular member 14 to form the body member 10. In addition to the moveable member 30 being operable to open and close passage to the port 16 (to thereby permit and obstruct the passage of fluids between throughbore 11 of the body member 10 and the outside of the body member 10), the moveable member 30 may be further adapted to operably permit and obstruct the passage of fluids through the throughbore 11 and specifically between the middle throughbore portion 13p and the lower throughbore portion 14p, as will be described subsequently. Through ports 35 are provided on the side walls 32 of the moveable member 30 adjacent the lower head portion 31 .

[0232] A sealing block 21 is provided adjacent the lower seal seat 19, the purpose of which will be described subsequently.

[0233] The lower tubular member 14 may be connected (either directly or indirectly via a further tubular component (not shown)) to the upper end of an Electrical Submersible Pump (ESP) (not shown).

[0234] OPERATION OF THE FLOW CONTROL DEVICE 1

[0235] In use, the upper end of the upper tubular member 12 of the flow control device 1 is generally positioned downhole within a wellbore (not shown) on the lower end of tubing (not shown), which is typically production tubing, which extends to the surface of the well. If the well has sufficient pressure such that it can produce hydrocarbons naturally (i.e. without artificial lift being required by an ESP provided at the lower most end of the production tubing (i.e. below the flow control device 1 ) then the flow control device 1 will remain in the first configuration as shown in Figure 1 and the produced fluids will flow into the production tubing via the ports 16 and will flow up through the upper throughbore portion 12p and into the production tubing and will flow up to the surface.

[0236] When fluid is to be pumped to the surface via the ESP (such as when the pressure of the formation has reduced which tends to happen after a period of production has elapsed), the operator can switch on the ESP from the control system at the surface and therefore the fluids from the formation will be pumped upwards from the EPS such that the output from the ESP flows into the lower throughbore portion 14p of the body member 10. This increases the pressure in the lower throughbore portion 14p. The increased pressure initially acts upon the lower head portion 31 of the moveable member 30 such that the lower head portion 31 and the moveable member 30 are progressed up the inner bore 11 of the body member 10. It should be noted here that whilst the lower head portion 31 progresses along the length of the sealing block 21 it is not possible for fluid from the ESP to escape around the side of the lower head portion 31 and into the through ports 35. Therefore, the pressure of the fluid continues to progress the moveable member 30 until the lower head portion 31 has passed the end of the sealing block 21 , as shown in Figs. 5 to 8. It should be noted that when the lower head portion 31 passes the end of the sealing block 21 , the ends of the side walls 31 obstruct the bypass ports 16; in other words, the longitudinal length of the inside surface of the sealing block 21 substantially matches the diameter of the innermost ends of the ports 16. The fluid is then able to progress from the ESP, past the lower head portion 31 and into the annulus 56 (as best shown in Figs. 7 and 8) between the outer cylindrical surface of the moveable member 30 and the internal diameter of the body member 10 until it reaches a piston block 33. The piston block 33 and the lower pressure ring-seal (not shown) prevents the fluid from progressing any further up this annulus 56 and also prevents the fluid from entering the chamber 40 via its lower end 42. The fluid is therefore forced to pass through the through ports 35 in the moveable member 30 and is then free to progress up the upper portion of the moveable member 30 toward upper tubular member 12 which provides a conduit for flow of the fluid to the surface.

[0237] When the moveable member 30 is opened in this way, the flow of fluid will continue to progress the moveable member 30 up the throughbore 11 of the body member 10 until the end of the side walls 32 of the moveable member 30 abut against the upper seal seat 20, at which point it is prevented from progressing any further up the throughbore 11 of the body member 10. In this position the side walls 32 of the moveable member 30 obturate the bypass ports 16 and thus prevent fluid from passing through the bypass ports 16. The upper seal seat 20 also prevents fluid passing through the throughbore 11 of the body member 10 from escaping between the end of the side wall 32 of the moveable member 30 and the inner wall 18 of the body member 10. This therefore also prevents fluids pumped from the output of the ESP from recirculating back into the ESP intake (via the annulus 65). The moveable member 30 may therefore be considered to be a diverter.

[0238] When flow of fluid to the surface and hence the flow control device 1 is stopped (e.g. by switching off the ESP) the pressure holding the moveable member 30 in the second configuration is no longer present therefore the moveable member 30 tends to return to the first configuration. Return of the movable member 30 to the first configuration may likely be assisted by the hydrostatic head of fluid above it as well as by gravity. However, in certain situations the hydrostatic head can cause the moveable member 30 to stay in the second configuration. The coiled spring 60 is therefore conveniently and advantageously employed to urge the moveable member 30 to return to the first configuration and also holds it there, irrespective of the deviation of the well, in order to prevent solids from flowing further down into the ESP. It will be understood by the reader that the resilient force provided by the biasing mechanism 60 (i.e. the coiled spring 60) may be calibrated during manufacture of the flow control device 1 to be considerably lower than the pressure force likely to be acting on the moveable member 30 when fluid flows (upwards) through the moveable member 30.

[0239] It should be noted that in reverse of the opening procedure (i.e. moving from the second configuration to the first configuration), as the moveable member 30 returns to the first configuration, the side walls 32 of the moveable member 30 slide down the throughbore 11 of the body member 10 such that the ports 16 are once again open.

[0240] When the ESP is switched off causing the cessation of fluid flow to the surface, the fluid within the tubing or upper tubular portion 12p will tend to flow back down the tubing and the upper tubular portion 12p due to the hydrostatic head and gravity acting upon it. It should be noted that the ESP tends to draw much greater amounts of debris when compared to natural flow, and there is typically therefore a very high amount of solids (such as sand, grit etc.) suspended within the fluid at this point. Any such solids will also flow back down the tubing and upper tubular portion 12p and are able to pass through the (now open) ports 16 and into the casing annulus (not shown) of the wellbore. In this way only a minimal amount of solids may settle in the flow control device 1 . This amount is therefore small enough to allow the moveable member 30 to reliably open again (e.g. when the ESP is restarted) such that fluid will flow therethrough when required. However, as the fluid flows through the middle throughbore portion 13p, these solids can frequently find their way into the chamber 40. As previously mentioned, the performance of the biasing devices (i.e. the coiled spring 60) can be compromised by even small amounts of deposits that can become stuck. Advantageously, therefore, flow of fluid in / out / through the chamber 40 is permitted via the openings 70, which flush any solids out from the chamber 40 to prevent such solids (e.g. abrasive particles, corrosive elements) from remaining in the chamber 40, particularly from remaining in the chamber 40 when the volume of the chamber 40 is reduced such as when the biasing member (e.g. spring 60) is being compressed or is compressed, and thus preventing (or at least mitigating the risk of) damage to the biasing member 60.

[0241] Furthermore, when the moveable member 30 is in the first configuration (and the ports 16 are therefore open) fluid may be pumped under pressure from the surface down the tubing and the upper tubular portion 12p and out into the annulus via the ports 16. A first example of when this feature may be useful is when it is desirable to cease production from the well. In this case fluid is pumped into the well in order to send off or “kill” the well and the present invention allows this to be done without having to pump the injected fluid through the workings of the ESP. A second example is when fluids such as water or chemicals are injected into the formation for various wellbore and formation procedures. In some embodiments of the present invention, the moveable member may further comprise a check valve 38. Description and function of such a check valve 38 in accordance with the present invention is disclosed in terms of the one-way valve arrangement 38 in UK Patent Application GB2411416A the disclosure of which is incorporated herein by reference.

[0242] The present invention also allows the ESP pump to act as a backup to the natural lift (pressure) in the well. This is useful when there is need for the ESP to remain dormant for a considerable period of time while the well produces under the natural lift (of the reservoir pressure); the ESP being required at a later stage to produce fluid from the well when the well’s natural pressure drops off to a point where the well will no longer produce naturally, or when another form of artificial lift (e.g. another ESP or gas / water injection) fails. In this configuration natural lift urges fluid into the wellbore annulus (not shown). The fluid is thus forced to flow through the open ports 16 and up toward the surface via the production tubing. Thus, in this configuration, the ESP may be by-passed thereby preventing the ESP from turbining when it is not switched on and avoiding premature damage of the ESP. In addition, producing through a dormant ESP leaves the ESP vulnerable to scale build up which can hinder operation of the ESP when it is eventually called upon to do so. When natural lift becomes insufficient the ESP can then be switched on in order to boost the pressure of the fluid progressing up the well. When this is done all fluid flow will be through the ESP since the ports 16 will now be closed as described previously.

[0243] In a further alternative configuration, the flow control device 1 may be used in line with two ESPs (not shown) where one ESP acts as a backup and the other is the primary ESP to be used under normal operational conditions. In this configuration the flow control device 1 is positioned directly above the backup ESP such that when the primary ESP (which is generally situated below the backup ESP and the flow control device 1 ) is operating, fluid may pass up the annulus of the wellbore (not shown) and into the upper tubular portion 12p via the ports 16 in the flow control device 1 , thereby bypassing the backup (and in this case dormant) ESP. This prevents the backup ESP from being damaged when not in use, as previously described. When it is necessary to switch on the backup ESP (which may be due to failure in the primary ESP or in order to boost the pumping action of the primary ESP) the moveable member 30 will automatically move into the open position due to the pumping action of the (now operational) backup ESP. In doing so the moveable member 30 closes the ports 16 as previously described. Since the ports 16 are now closed (and in the case of the primary ESP remaining operational) to boost the pumping action, the fluid and hence pressure produced from the primary ESP will be communicated to the backup ESP.

[0244] The embodiments of flow control device 1 previously described may be entirely self-contained and requires no operating interference to or from the surface in order to operate effectively and is therefore automatic.

[0245] The embodiments of flow control device 1 may be integral with the production tubing and / or a wireline (not shown) such that the flow control device 1 can easily be retrieved to the surface in order to provide downhole access e.g. for well intervention tools.

[0246] SEALING ARRANGEMENT 180

[0247] Figure 33A shows a sectional side view of a second embodiment of a fluid control device 100 in accordance with the first and second aspects of the present invention, with the moveable member 130 in a first configuration in which passage of fluids through the port 116 is permitted. In this embodiment, the parts of the fluid control device 100 that are common to the first embodiment are indicated with the same reference numerals plus 100. In this embodiment, the fluid control device 100 further includes a sealing arrangement 180 in accordance with the third and fourth aspects of the present invention, which is configured to reduce the effects of abrasive particles on components. Figure 33B shows an enlarged view of Figure 33A, showing the general section of the fluid control device 100 where said sealing arrangement 180 is generally located. Figure 33C then shows an enlarged view of Figure 33B, showing a detailed view of the seals 182, 184, 186 (which as will be described below, are arranged to seal against respective contact surfaces 130-X, 184c, 186c of the moveable member 130 to form a seal to fluids therebetween) and voids 192, 194 of the sealing arrangement 180.

[0248] Figure 34A shows a sectional side view of the second embodiment of the fluid control device 100 shown in Figure 33A, with the moveable member 130 in a second configuration in which passage of fluids through the port 116 is obstructed. Figure 34B shows an enlarged view of Figure 34A, showing the general section of the fluid control device 100 where said sealing arrangement 180 is generally located. Figure 34C then shows an enlarged view of Figure 33B, showing a detailed view of the seals 182, 184, 186 and voids 192, 194 of the sealing arrangement 180.

[0249] In the example shown, the sealing arrangement 180 comprises three seals, including:

[0250] • a metal-to-metal contact seal 182

[0251] • a first elastomeric seal 184; and

[0252] • a second elastomeric seal 186.

[0253] However, as the skilled person will understand, sealing arrangements 180 in accordance with embodiments of the present invention may include any suitable number of seals (such as a fourth seal (not shown)), and each of the seals may be any suitable form of seal including but not limited to metal-to- metal contact seals or elastomeric seals.

[0254] METAL-TO-METAL CONTACT SEAL 182

[0255] As best shown in Figure 34C, the first seal 182 is a metal-to-metal contact seal which provides and / or acts as the primary seal in the sealing arrangement 180 in this example, and which is formed by a fluid tight sealing contact between corresponding contact I sealing surfaces of each of the inner and outer tubular members 130, 110.

[0256] As described above, the outer tubular member 110 includes an upper seal seat 120 which is provided around the internal circumference of the upper throughbore portion 112p of the body member 110. The upper seal seat 120 includes a conical portion 120-X which defines the contact point I length of the outer tubular member 110 which forms the metal-to-metal seal 182 (i.e. along with the corresponding contact point I length 130-X of the inner tubular member 130, as will be described subsequently). The inner tubular member 130 also includes a conical portion 130-X which defines the contact point I length of the inner tubular member 130, and which forms the metal-to-metal seal 182 (i.e. along with the corresponding contact point I length 120-X of the outer tubular member 110). The conical portion 130-X of the inner tubular member 130 is provided at an extreme (or uppermost) end of the outer side walls 132 of the movable member 130.

[0257] At least a part of and preferably a substantial part of and more preferably the majority of or in a most preferred embodiment the whole length of the conical portion 130-X and the conical portion 120-X are arranged to lie on respective planes. The plane of at least a part of and preferably a substantial part of and more preferably the majority of or in a most preferred embodiment the whole length of the conical portion 130-X of the inner tubular member 130 is provided at an angle to the longitudinal axis of the concentric tubular members 110, 130, which extends acutely in a radially outward and axially downward direction from said longitudinal axis. The plane of at least a part of and preferably of a substantial part of and more preferably the majority of or in a most preferred embodiment the whole length of the conical portion 120-X of the outer tubular member 110 is also provided at an angle to the longitudinal axis of the concentric tubular members 110, 130, which also extends acutely in a radially outward and axially downward direction from said longitudinal axis. The angles of each plane of said conical portion 120-X, 130-X are preferably the same for each of the concentric tubular members 110, 130 at the respective contact points I lengths thereof. In the example shown, each of the angles (i.e. at the respective contact points I lengths of the conical portion 120-X, 130-X) extend at an angle of around 45° in a radially outward and axially downward direction from said longitudinal axis. However, as the skilled person will understand said matching angles at the respective contact points I lengths of the conical portion 120-X, 130-X may be any suitable angle. These matching angled planes of the respective conical faces assist in centring and aligning the tubular members 110, 130 (i.e. when in (and / or moving into) the closed and sealed configuration) and convert axial force into a high local contact stress to form the seal 182. Further, having such matching conical faces at the respective contact points I lengths of the conical portion 120-X, 130-X ensures the metal-to-metal seal 182 provides a uniform and tight seal between the concentric tubular members 110, 130.

[0258] In the presently described example, the metal-to-metal seal 182 is the axially uppermost seal of the sealing arrangement 180. This is preferred as the metal-to-metal seal 182 ensures that fluid tight sealing contact is made and, in contrast to alternative seals (e.g. elastomeric seals), the metal sealing surfaces which form seal 182 are resistant to mechanical wear and loading. Additionally, metal-to-metal seals provide superior sealing performance under extreme pressures, and providing the metal-to-metal seal 182 in the axially uppermost position of the sealing arrangement 180 ensures that the primary pressure barrier is the most robust sealing arrangement, reducing the risk of leaks from the interface between corresponding contact I sealing surfaces of each of the inner and outer tubular members 110, 130.

[0259] SECOND SEAL 184 (FIRST ELASTOMERIC SEAL 184)

[0260] A second seal 184 in the form of a first elastomeric seal 184 is also provided in the example shown, which acts as secondary seal to that of the first metal- to-metal contact seal 182. The second seal 184 is an elastomeric ring-shaped seal that is provided in an “upper” (i.e. upper relative to a second “lower” annular groove which houses the third seal 186, as will be described subsequently) annular groove 185 formed around the internal circumference of the upper throughbore portion 112p of the body member 110. As this second seal 184 is an elastomeric ring-shaped seal 184, it is possible for the second seal 184 to effectively act as a wiper as the tool 100 moves between configurations which is advantageous in the present application (as will described in further detail below). This second seal 184 is axially positioned (i.e. within its respective annular groove 185) between the first metal-to-metal contact seal 182 and the uppermost end of the ports 116. The upper annular groove 185 and the second seal 184 housed therein are adapted such that suitable clearance gaps 184a, 184b are provided either side thereof between the two tubular members (i.e. the moveable member 130 and the body member 110) when in the sealed state, and such that the contact surface 184c of the second seal 184 protrudes radially inwardly far enough (i.e. a greater distance than the inner end of the clearance gaps 184a, 184b) to form the second seal 184 (as best shown in Figure 34C).

[0261] THIRD SEAL 186 (SECOND ELASTOMERIC SEAL 186)

[0262] A third seal 186 is also provided in the example shown, which much like the second seal 184 also acts as secondary seal to that of the first metal-to-metal contact seal 182 (and the third seal 186 also acts as a back up to the second seal 184). The third seal 186 is a ring-shaped elastomeric seal that is provided in a “lower” annular groove 187 formed around the internal circumference of the upper throughbore portion 112p of the body member 110. As this third seal 186 is also an elastomeric ring-shaped seal, it is (much like the second seal 184) possible for the second seal 184 to effectively act as a wiper as the tool 100 moves between configurations which again is advantageous in the present application (as will described in further detail below). This third seal 186 is axially positioned (i.e. within its respective annular groove 187) between the second seal 184 and the uppermost end of the ports 116. The lower annular groove 187 and the third seal 186 housed therein are adapted such that suitable clearance gaps 186a, 186b are provided between the two tubular members 130, 110 when in the sealed state, and such that the contact surface 186c of the third seal 186 protrudes radially inwardly far enough (i.e. a greater distance than the inner end of the clearance gaps 186a, 186b) to form the seal (as best shown in Figure 34E).

[0263] In this example, the outer surface of the inner tubular member 130 has a first portion 130a and a second portion 130b. The first portion 130a extends axially downwards from the lower end of the conical portion 130-X of the inner tubular member 130 such that first portion 130a takes the form of a constant diameter cylinder (i.e. such that its outer surface is parallel with the longitudinal axis of the tool 100) towards its junction with the second portion 130b, and the said junction forms a step out in diameter such that the second portion 130b comprises a slightly greater diameter than the first portion 130a. The second portion 130b then extends axially downwards from said first portion 130a such that it takes the form of a constant diameter cylinder (i.e. such that its outer surface is parallel with the longitudinal axis of the tool 100). The first portion 130a of the outer surface of the inner tubular member 130 is configured to engage with the second seal 184 when in the sealed configuration. The second portion 130b of the outer surface of the inner tubular member 130 is configured to engage with the third seal 186 when in the sealed configuration. In the example shown, the first portion 130a of the outer surface of the inner tubular member 130 has a first diameter, and the second portion 130b of the outer surface of the inner tubular member 130 has a second diameter which is different than that of the first diameter. As best shown in Figure 34E, in this example, the second portion 130b of the outer surface of the inner tubular member 130 has a raised outer profile or diameter relative to the outer profile or diameter of the first portion 130a of the outer surface of the inner tubular member 130. Accordingly, in the presently described example, the sealing arrangement 180 is such that the contact surface 186c of the third seal 186 is provided at a position radially spaced above or outer of the contact surface 184c of the second seal 184. To achieve this, the annular groove 187 which houses the third seal 186 may, for instance, be positioned at a slightly greater or more outer radial position than the annular groove 185 which houses the second seal 184. Advantageously, the second portion 130b of the outer surface of the inner tubular member 130 having a raised outer profile or diameter (i.e. relative to the outer profile or diameter of the first portion 130a) enables the movable member 130 to move between the open and closed configurations without the third seal 186 (i.e. which is at a slightly greater radial position relative to the second seal 184) contacting and thereby impeding the first portion 130a of the outer surface of the inner tubular member 130 as it moves between said open and closed configurations; which prevents unnecessary rubbing of the contact surface 186c of the third seal 186 against the first portion 130a of the outer surface of the inner tubular member 130.

[0264] VOID ARRANGEMENT 190

[0265] The sealing arrangement 180 also includes a void arrangement 190 having voids or gap regions 192, 194 that are configured to act as a haven for abrasive particles such that they can collect abrasive particles therein and thereby prevent damage to said seals 182, 184, 186, particularly at the moment the tool 100 is moved into and / or out of the closed configuration because the abrasive particles can be moved away from the seals 182, 184, 186 and into the voids 192, 194 (and thereby prevent damage that would otherwise occur to the seals 182, 184, 186 were the voids 192, 194 not present).

[0266] In the example shown, the void arrangement 190 includes: a first void 192 a second void 194; and a tapered lead in surface 196. However, as the skilled person will understand void arrangements 190 in accordance with embodiments of the present invention may include any suitable number and / or size of voids.

[0267] FIRST VOID 192

[0268] The void arrangement 190 shown includes a first void 192 which is provided within the upper throughbore portion 112p of the body member 110. Figure 34D shows an enlarged view of Figure 34C, showing a detailed view of said first void 192.

[0269] The first void 192 has a single opening 192-X which provides both an inlet and outlet for abrasive particles to enter and exit said first void 192, and which therefore defines a mouth 192-X to the volume of the void 192 therein. The single opening 192-X of the first void 192 is positioned at the inner surface of the upper throughbore portion 112p of the body member 110 between the contact surfaces 120-X, 130-X, 184c of the first 182 and the second 184 seals. The opening 192-X includes an upper end 192-U and a lower end 192- L (as best shown in Figure 34D) and which between them define the said mouth 192-X. The length between the upper end 192-U and the lower end 192-L of the opening 192-X defines the width of the opening 192-X. In the example shown, the width of the opening 192-X is around 60% of the length of the inner surface of the upper throughbore portion 112p of the body member 110 between the contact surfaces 120-X, 130-X, 184c of the first seal 182 and the second seal 184. The remaining length (i.e. which is around 40% in the example shown) is accounted for by the length 184-LA of the clearances gap 184a which is positioned directly on the lower end 192-L of the opening 192-X, such that said clearances gap 184a defines the length between the lower end 192-L of the opening 192-X and the most radially inward edge 185-L of the lower side of the groove 185 which houses the second seal 184. The first void 192 (including the opening 192-X thereof) is formed annularly within the upper throughbore portion 112p of the body member 110 such that the void 192 forms a continuous ring-shaped cavity for collecting the abrasive particles. This first void 192 recedes both axially and radially into the upper throughbore portion 112p of the body member 110. In this example, it is possible for the first void 192 to recede in an axially upwardly direction as there are no further components (e.g. seals) positioned directly above (i.e. in an axially upwardly direction (e.g. to the left - as best shown in Figs. 33C and 34C)) the void opening 192-X that would otherwise impede the positioning of the first void 192.

[0270] The cross-sectional shape of the first void 192, in the example shown, can be generally defined by a boundary generally formed by five sides 192 -A, 192-B, 192-C, 192-D, 192-E (as best shown in Figure 34D). Beginning at the upper end 192-U, the boundary follows along the side 192-A, then continues in order through sides 192-B, 192-C, 192-D, and 192-E, before arriving at the lower end 192-L.

[0271] Working clockwise around the boundary formed by the five sides 192-A, 192- B, 192-C, 192-D, 192-E, the upper (and also most radially inwards) end 192- II of the opening 192-X is defined by a tight inside fillet that sweeps approximately 120° clockwise from the conical portion 120-X of the outer tubular member 110, blending said conical portion 120-X of the outer tubular member 110 into the first side 192 -A of the void 192.

[0272] From the upper end 192-U of the opening 192-X, the first side 192-A then forms a long horizontal straight that runs perfectly upwards (i.e. which is leftward direction when referring to Figure 34D and which therefore forms a constant diameter cylinder), forming the lower wall of the first void 192, until it reaches the second side 192-B of the void 192. The first side 192-A of the void 192 is substantially straight and is therefore parallel to the longitudinal axis of the inner and outer tubular members 110, 130. From the upper most end of the first side 192 -A of the void 192, the second side 192-B of the void 192 then forms a large-radius internal arc that takes the form of a quarter circle lifting the path upward through 90° towards the third side 192-C.

[0273] From the uppermost and most radially outward end of the second side 192-B, the third side 192-C forms a relatively short straight that runs perfectly radially outwards (i.e. which is the upwards direction when referring to Figure 34D), forming a short side wall of the first void 192, until it reaches the fourth side 192-D of the void 192. The third side 192-C of the void 192 is substantially straight and is perpendicular to the longitudinal axis of the inner and outer tubular members 110, 130.

[0274] From the most radially outward end of the third side 192-C, the fourth side 192-D forms a long horizontal straight that runs perfectly axially downwards (i.e. which is the rightward direction when referring to Figure 34D), forming the upper wall of the first void 192, until it reaches the fifth side 192-E of the void 192. The fourth side 192-D of the void 192 is substantially straight and parallel to the longitudinal axis of the inner and outer tubular members 110, 130 and is substantially perpendicular to the short side wall (i.e. the third side 192-C) of the first void 192.

[0275] From the lowermost end of the fourth side 192-D of the void 192, the fifth side 192-E forms a long straight that runs diagonally in an axially downwards (i.e. which is the rightward direction when referring to Figure 34D) and radially inwards (i.e. which is the downward direction when referring to Figure 34D) direction at approximately 45° clockwise from the fourth side 192-D of the void 192, until it reaches the lower end 192-L of the opening 192-X. The junction between the lowermost end of the fourth side 192-D of the void 192 and the uppermost end of the fifth side 192-E of the void 192 includes a small inside fillet. The lower (and also most radially outward) end 192-L of the opening 192-X is defined by a loose inside fillet that sweeps approximately 30° anticlockwise from the clearance gap 184a of the outer tubular member 110, blending the fifth side 192-E of the void 192 into said clearance gap 184a of the outer tubular member 110.

[0276] From the lower (and also most radially outward) end 192-L of the opening 192-X, a long horizontal straight runs perfectly axially downwards (i.e. which is the rightward direction when referring to Figure 34D) until it reaches the most radially inward edge 185-U of the upper side of the groove 185 (which itself extends in a direction radially outward and axially upwards, and which houses the second seal 184), defining the length 184-LA of the upper clearance gap 184a of the second seal 184. The edge between the most radially inward edge 185-U of the upper side of the groove 185 and the lower edge of the length 184-LA of the upper clearance gap 184a is defined by a loose inside fillet that sweeps approximately 120° anticlockwise from the clearance gap 184a, blending the lower edge 185-U of the upper clearance gap 184a into the groove 185 edge. In the example shown, the length 184- LA of the upper clearance gap 184a of the second seal 184 is approximately a third smaller than the width of the opening 192-X.

[0277] When the two tubular members 130, 110 are in the sealed state, the opening 192-X of the first void 192 is closed off from the throughbore portion 112p, as when in this sealed state the outer surface of the sidewalls 132 of the movable member 130 (and specifically the outer surface of the sidewalls 132 of the movable member 130 between the contact surfaces 120-X, 130-X, 184c of the first seal 182 and the second seal 184) envelope the opening of the first void 192 and the clearance gap 184a thereby obstructing the passage of fluids and abrasive particles between the throughbore portion 112p and the void 192 I clearance gap 184a (as best shown in Figure 34D). However, in this sealed state, the opening 192-X of the first void 192 remains in fluid communication with the clearance gap 184a; this allows for abrasive particles that would otherwise be detrimentally collected in the clearance gap 184a and / or between the metal-to-metal seal 182 to instead be collected within the void 192.

[0278] SECOND VOID 194

[0279] The void arrangement 190 includes a second void 194 which is provided within the upper throughbore portion 112p of the body member 110. Figure 34E shows an enlarged view of Figure 34C, showing a detailed view of said second void 194.

[0280] The second void 194 has a single opening 194-X which provides both an inlet and outlet for abrasive particles to enter and exit said second void 194. The single opening 194-X of the second void 194 is positioned at the inner surface of the upper throughbore portion 112p of the body member 110 between the second seal 184 and the third seal 186.

[0281] The opening 194-X includes an upper end 194-U and a lower end 194-L (as best shown in Figure 34E). The length between the upper end 194-U and the lower end 194-L of the opening 194-X defines the width of the opening 194-X. In the example shown, the width of the opening 194-X accounts for around 60% of the length of the inner surface of the upper throughbore portion 112p of the body member 110 between the contact surfaces 184c, 186c of the second seal 184 and the third seal 186. The remaining length (i.e. which is around 40% in the example shown) of the inner surface of the upper throughbore portion 112p of the body member 110 between the contact surfaces 184c, 186c of the second seal 184 and the third seal 186 is accounted for by the lengths 184-LB, 186- LA of the clearances gaps 184b, 186a which are positioned directly on either sides of the opening 194-X, such that said clearances gaps 186a, 186b are each positioned between the opening 194-X and the respective contact surfaces 184c, 186c of the adjacent seal 184, 186 thereof. The second void 194 (including the opening 194-X thereof) is formed annularly within the upper throughbore portion 112p of the body member 110 such that the second void 194 forms a continuous and substantially ring- shaped cavity (albeit with tapered sides as shown in Fig. 34E) for collecting the abrasive particles. This second void 194 recedes radially outward into the upper throughbore portion 112p of the body member 110. In this example, it is not possible for the second void 194 to recede substantially in either an axially upward or downward direction as there are seals 184, 186 positioned both directly above (i.e., in an axially upward direction, which is leftward direction when referring to Figure 34D) and directly below (i.e. in an axially downward direction, which is leftward direction when referring to Figure 34D) the second void opening 194-X that impede or limit the axial extension of the volume of the second void 194.

[0282] The cross-sectional shape of the second void 194, in the example shown, can be generally defined by a boundary formed by three sides 194-A, 194-B, and 194-C (as best shown in Figure 34E). Beginning at the upper end 194-U, the boundary follows tapered or angled side 194-A, then continues in order through middle side 192-B and tapered or angled side 192-C, before arriving at the lower end 194-L.

[0283] Working clockwise around the boundary formed by the three sides 194-A, 194-B, and 194-C; the upper end 194-U of the opening 194-X is defined by a tight taper that sweeps at an angle of approximately 60° anticlockwise from the clearance gap 184b, blending said clearance gap 184b into the first side 194-A of the void 194 such that it projects radially outwardly a distance into the sidewall of the upper throughbore portion 112p of the body member 110 (although it can’t extend too far into the said sidewall in order to provide sufficient depth of sidewall to that part of the upper throughbore portion 112p). From the upper end 194-U of the opening 194-X, the first side 194-A then forms a long straight that runs diagonally in an axially downwards (i.e. which is the rightward direction when referring to Figure 34E) and radially outwards (i.e. which is the upward direction when referring to Figure 34E) direction at approximately 60° anticlockwise from the length 184-LB of the clearance gap 184b, until it reaches the upper end of the second side 194-B of the void 194.

[0284] From the lower end of the first side 194-A, the second side 194-B then forms a long horizontal straight that runs substantially perfectly axially downwards (i.e. which is the rightward direction when referring to Figure 34E), forming the upper wall of the second void 194, until it reaches the third side 194-C of the void 194. The second side 194-B of the void 194 is therefore substantially straight and parallel to the longitudinal axis of the inner and outer tubular members 110, 130. The junction between the lowermost end of the first side 194-A of the void 194 and the uppermost end of the second side 194-B of the void 194 includes an inside radiused fillet.

[0285] From the lower end of the second side 194-B, the third side 194-C then forms a long straight that runs diagonally in an axially downwards (i.e. which is the rightward direction when referring to Figure 34E) and radially inwards (i.e. which is the downward direction when referring to Figure 34E) direction at approximately 50° clockwise from the second side 194-B, until it reaches the upper end of the clearance gap 186a. The edge between the lowermost end of the second side 194-B of the void 194 and the uppermost end of the third side 194-C of the void 194 includes an inside radiused fillet.

[0286] From the lower end 194-L of the opening 194-X, a long horizontal straight 186-LA runs substantially perfectly axially downwards (i.e. such that its inner facing surface is parallel with the longitudinal axis of the tool 100 - and which is the rightward direction when referring to Figure 34E) until it reaches the most radially inward edge 187-U of the upper side of the groove 187 (which itself extends in a direction radially outward and axially upwards, and which houses the third seal 186), defining the length 186-LA of the upper clearance gap 186a of the third seal 186. The edge or junction between the most radially inward edge of the upper side of the groove 187 and the lower edge of the length 186-LA of the upper clearance gap 186a is defined by a loose inside radiused fillet that sweeps approximately 120° anticlockwise from the clearance gap 186a, blending the lower edge of the upper clearance gap 186a into the groove edge 187-U. Similarly, from the upper end 194-U of the opening 194-X, a long horizontal straight 184-LB runs perfectly axially upwards (i.e. which is the leftward direction when referring to Figure 34E) until it reaches the most radially inward edge 185-L of the lower side of the groove 185 (which itself extends in a direction radially outward and axially downwards, and which houses the second seal 184), defining the length 184- LB of the lower clearance gap 184b of the second seal 184. The edge 185-L between the most radially inward edge of the lower side of the groove 184and the upper edge of the length 184-LB of the lower clearance gap 184b is defined by a loose inside radiused fillet that sweeps approximately 120° clockwise from the clearance gap 184b, blending the upper edge of the lower clearance gap 184b into the groove edge 185-L. In the example shown, the length 186-LA of the upper clearance gap 186a of the third seal 186 is approximately equal to the length 184-LB of the lower clearance gap 184b of the second seal 184.

[0287] When the two tubular members 130, 110 are in the sealed state, the opening 194-X of the second void 194 is closed off from the throughbore portion 112p, as, when in this sealed state, the outer surface of the sidewalls 132 of the movable member 130 (and specifically, the portions of the outer surfaces 130a, 130b of the sidewalls 132 of the movable member 130 between the contact surfaces 184c, 186c of the second seal 184 and the third seal 186) envelope the opening of the second void 194 and the clearance gaps 184b, 186a thereby obstructing the passage of fluids and abrasive particles between the throughbore portion 112p and the void 194 I clearance gaps 184b, 186a (as best shown in Figure 34E). However, in this sealed state, the opening 194-X of the second void 194 remains in fluid communication with the clearance gaps 184b, 186a; this allows for abrasive particles that would otherwise be detrimentally collected in said clearance gaps 184b, 186a and / or between the seals 184, 186 and the outer surfaces 130a, 130b of the inner tubular member 130 to instead be collected within and / or find safe haven in the void 194.

[0288] As the skilled person will appreciate, the voids 192, 194 are distinct from the clearance gaps 184a, 184b, 186a, 186b because the said clearance gaps are specifically designed to be sufficient enough to provide a clearance between the inner and outer tubular members 110, 130 (so that they can moved relative to one another) but also to be as small as practically possible to prevent abrasive particles collecting therein, whereas the voids 192, 194 are instead configured to promote the collection of the abrasive particles therein.

[0289] When the tool 100 is in the open I unsealed state, the voids 192, 194 are open to the inner throughbore 112p. This allows any abrasive particles that have been collected within the voids 192, 194 to be flushed out (e.g. by fluid flowing through the throughbore 112p). As the moveable member 130 moves from the open configuration (i.e. unsealed state) to the closed configuration (i.e. sealed state), abrasive particles, that would otherwise be trapped in (such as for example in the clearance gaps 184a, 184b, 186a, 186b) between the two tubular members 110, 130, are encouraged into the voids 192, 194 which are configured to be large enough such that the voids 192, 194 can accommodate the abrasive particles therein.

[0290] Also, whilst the moveable member 130 moves from the open configuration to the closed configuration, the second and third seals 184, 186 effectively act as wipers in order to wipe or scrape material such as unwanted solids from the outer surface of the moveable inner tubular member 130. The seals 184, 186 contact the outer surface of the inner tubular member 130 uniformly around the circumference thereof as it moves between the open configuration (i.e. unsealed state) and the closed configuration (i.e. sealed state) causing abrasive particles to be swept in the voids 192, 194. More specifically, the contact surface 184c of the second seal 184 presses against the first portion 130a of the outer surface of the inner tubular member 130; and in doing so sweeps any abrasive particles on the lower side thereof into the second void 194 as the inner tubular member 130 moves from the open configuration (i.e. unsealed state) to the closed configuration (i.e. sealed state). Additionally, the contact surface 186c of the third seal 186 presses against the second portion 130b of the outer surface of the inner tubular member 130; and in doing so sweeps any abrasive particles on the lower side thereof off the outer surface of the inner tubular member 130 into the clearance gap 186b as the inner tubular member 130 moves from the open configuration (i.e. unsealed state) to the closed configuration (i.e. sealed state). When the tool 100 is in the closed (i.e. sealed state), the voids 192, 194 are closed off from the inner throughbore 112p. The voids 192, 194 house (i.e. they provide a haven to) the abrasive particles that have been collected therein when the inner tubular member 130 moved from the from the open configuration (i.e. unsealed state) to the closed configuration (i.e. sealed state).

[0291] As described above, the voids 192, 194 are configured to be large enough such that the voids 192, 194 can accommodate the abrasive particles therein. For use of example, in the embodiment shown, the width of first void 192 is around 0.234 inch (5.94 mm) and the height of first void 192 is around 0.111 inch (2.82 mm). Also, in the embodiment shown, the width of second void 194 is around 0.25 inch (6.35 mm) and the height of first void 192 is around 0.093 inch (2.36 mm), with a depth of clearance gap 184a, 184b on each of the upper and lower side of second seal 184 being around 0.019 inches (0.48 mm). Also, in the embodiment shown, the depth of clearance gap 186a, 186b on each of the upper and lower side of third seal 186 is around 0.024 inches (0.61 mm). The skilled person will however understand that the specific optimal sizes of the voids 192, 194 will vary on the application and that the sizes of the voids 192, 194 are not to be limited to those described directly above.

[0292] The specific optimal sizes of the respective voids 192, 194 will vary on the application. Factors that may determine specific optimal sizes for voids 192, 194 includes the size of the abrasive particles in a given application; for example, in applications where the abrasive particles include sand particles, the size of the sand particles can vary significantly based on the specific applications (e.g. based on the exact geographical location and also the well depth). Further, typical rates of flow and the concentration of abrasive particles in fluid in a given application can impact the specific optimal sizes for the voids 192, 194; as higher overall amounts of abrasive particles may require larger voids 192, 194 to effectively collect and accommodate the higher numbers of abrasive particles therein. Moreover, the overall proportion and size and / or design of the tool 100 can also determine the size of the voids 192, 194; for example, narrower wellbores may require more compact tool dimensions which may in turn limit the general dimensions of the voids 192, 194.

[0293] TAPERED LEAD IN SURFACE 196

[0294] The void arrangement 190 also includes a tapered lead in surface 196 which is provided within the upper throughbore portion 112p of the body member 110. Figure 34F shows an enlarged view of Figure 34C, showing a detailed view of said tapered lead in surface 196.

[0295] The tapered lead in surface 196 is defined by a tapered face which tapers from a first point 196A to a second point 196B. In this example, said first point 196A is axially positioned directly beneath the third seal 186 and is radially positioned at I proximate to the clearance 186b on the (axially) lower side of the third seal 186. The second point 196B is axially positioned directly above the ports 116 and is radially positioned proximate to the portion of the inner wall of the upper tubular member 112 where the uppermost end of the port 116 is located. In other words, the tapered face of the tapered lead in surface 196 extends in a radially outward and axially downward direction from the most radially inward edge 187-L of the lower side of the groove 187 (which itself extends in a direction radially outward and axially downwards, and which houses the second seal 186). This tapered lead in surface 196 assists in preventing abrasive particles from causing any abrasive damage to the third seal 186 and also to portions of the inner tubular member 130 and the outer tubular member 110 (e.g. the portions that define the clearance gap 186b therebetween). This is particularly effective as the moveable member 130 moves from the closed configuration (i.e. sealed state) to the open configuration (i.e. unsealed state), because rather than being locked between the inner tubular member 130 and the outer tubular member 110, any abrasive particles that may have collected beneath the third seal 186 are free to move in, and importantly out of, the large opening that is provided for by this tapered lead in surface 196 and are also free to exit through the port 116.

[0296] By way of example, in the embodiment shown, the tapered lead in surface 196 extends acutely in a radially outward and axially downward direction from said longitudinal axis at an angle of approximately 30°. The skilled person will however understand that the specific optimal sizes and shape of the tapered lead in surface 196 will vary on the application and that the sizes and shape of the tapered lead in surface 196 are not to be limited to those described directly above.

[0297] In the sealing arrangement 180 shown, the inner circumference of the upper through-bore 112p of body member 110 (where grooves 185, 187 and voids 192, 194 are located) is built from a series of discrete, ring-shaped inserts. Each of these insert carries the profile for sections of the inner side walls of the grooves 185, 187 and voids 192, 194, and when the inserts are stacked in sequence, they together generate the complete set of grooves 185, 187 and voids 192, 194. Advantageously, such an arrangement of discrete, ring- shaped inserts provides for easier assembly and replacement of the second and third seals 184, 186 and further reduces the risk of damage to the second and third seals 184, 186 during installation and / or replacement, as the seals 184, 186 are not required to stretch, fold or be pushed axially into the grooves; which risks twisting, over-stretching, and accidental nicking of the sealing surfaces 184c, 186c. However, in an alternative configuration in accordance with embodiments of the present invention, the same circumferential section may be machined or moulded as a single, integral component in which all grooves 185, 187 and voids 192, 194 are formed directly.

[0298] In the embodiment of the sealing arrangement 180 shown, the seals 182, 184, 186 and voids 192, 194 are generally provided within I relative to the internal circumference of the upper throughbore portion 112p of the body member 110. However, in an alternative configuration in accordance with embodiments of the present invention, the sealing arrangement 180 may instead be such that the seals 182, 184, 186 and voids 192, 194 are generally provided within I relative to the uppermost end of the outer side walls 132 of the movable member 130. In a further alternative configuration in accordance with embodiments of the present invention, the sealing arrangement 180 may instead be such that the some of the seals 182, 184, 186 and voids 192, 194 are provided within I relative to the uppermost end of the outer side walls 132 of the movable member 130 and the others are provided within I relative to the uppermost end of the outer side walls 132 of the movable member 130.

[0299] It should be understood that although the sealing arrangement 180 (and the seals 182, 184, 186 and voids 192, 194 thereof) is effective for use in a fluid control device, the skilled person will understand that the sealing arrangement 180 described herein is also suitable for any application where selective sealing of fluid channels between two tubular members is required, and especially in such applications where abrasive particles are present in fluid flowing therebetween. It should also be understood that whilst the embodiment of sealing arrangement 180 (and the seals 182, 184, 186 and voids 192, 194 thereof) in accordance with the third and fourth aspects of the present invention is effective when used in a fluid control device tool 100 that comprises slots 70 (such as those slots 70 that are hereinbefore described with reference to the embodiment of flow control device 1 ), the skilled person will understand that the sealing arrangement 180 described herein is also suitable for any other application (e.g. a downhole tool (not shown) that doesn’t require such slots 70). In other words, embodiments of a downhole tool in accordance with the present invention can comprise any combination of the first, second, third and fourth aspects of the present invention.

[0300] Modifications and improvements may be made to the hereinbefore described embodiments without departing from the scope of protection.

Claims

1 . A flow control device comprising: a body member having a throughbore formed therein; at least one port formed in the body member; a moveable member, wherein in use the moveable member is moveable between a first configuration and a second configuration, whereby in the first configuration passage of fluids comprising at least one of liquids and solids through the port is permitted and in the second configuration passage of said fluids through the port is obstructed; a chamber; a biasing device housed within said chamber, wherein the biasing device is configured to urge the moveable member towards either of the first configuration or the second configuration; and characterised by further comprising at least one opening adapted to permit the flow of solids out of the chamber.

2. A flow control device as claimed in claim 1 , wherein the fluid flow control device is a downhole fluid flow control device.

3. A flow control device as claimed in either of claim 1 or claim 2, wherein the at least one opening is adapted to also permit the flow of fluids through the chamber.

4. A flow control device as claimed in any preceding claim, wherein said at least one opening is a plurality of openings.

5. A flow control device as claimed in any preceding claim, wherein said at least one opening comprises an opening formed through a sidewall of the body member.

6. A flow control device as claimed in any preceding claim, wherein the chamber comprises an inner volume and the opening to the chamber is in fluid communication with the external surroundings of the body member, suchthat the inner volume of the chamber is in fluid communication with the external surroundings of the body member.

7. A flow control device as claimed in any preceding claim, wherein the opening to the chamber permits fluid to flow: i) into the chamber from the outer environment; and ii) out of the chamber into the outer environment.

8. A flow control device as claimed in any preceding claim, wherein the at least one opening comprises an elongated shape.

9. A flow control device as claimed in claim 8, wherein the at least one elongate opening is axially aligned to at least one of or any combination of the chamber, the biasing device, the moveable member, the body member or the throughbore thereof, wherein the at least one elongate opening comprises a first end and a second opposite end, wherein the first end of the elongate opening is provided proximate to the port, and wherein the second opposite end of the elongate opening is provided distal from the port.

10. A flow control device as claimed in claim 8 or 9, wherein the at least one elongate opening comprises a slot having a first end and a second opposite end, and wherein said slot includes an uninterrupted middle portion joining said first and second ends.

11. A flow control device as claimed in any of claims 8 to 10, wherein at least one elongate slot comprises a length that is less than or equal to the length of the chamber at least when chamber is at its maximum length.

12. A flow control device as claimed in any preceding claim,wherein the chamber comprises an inner volume, wherein as the moveable member moves from the first configuration to the second configuration the inner volume of the chamber reduces, and wherein as the moveable member moves from the second configuration to the first configuration the inner volume of the chamber increases.

13. A flow control device as claimed in either of claim 6 or claim 12, wherein, aside from the at least one opening, the inner volume of the chamber is substantially enclosed.

14. A flow control device as claimed in any preceding claim, wherein the biasing device is wholly housed within the chamber.

15. A flow control device as claimed in any preceding claim, wherein the biasing device comprises at least one coiled spring.

16. A flow control device as claimed in any preceding claim, wherein the moveable member translates between the first and the second configurations by movement of the moveable member in a direction substantially parallel to the longitudinal axis of the body member.

17. A flow control device as claimed in any preceding claim, wherein the chamber is provided radially between the moveable member and the body member.

18. A flow control device as claimed in claim 17, wherein an annulus is provided between the body member and the moveable member, and wherein the chamber is defined by said annulus between the body member and the moveable member.

19. A flow control device as claimed in any preceding claim, further comprising a seal arrangement, said seal arrangement comprising: a pair of seals provided on one or more of the moveable member and the body member, said pair of seals configured to provide sealing contact between the moveable member and the body member; and a void arrangement including a void located in between said pair of seals and being arranged in use to provide a haven for at least one solid particle.

20. A flow control device as claimed in claim 19, wherein the void arrangement includes at least one clearance gap provided between at least one seal of the pair of seals and the void opening.

21. A flow control device as claimed in claim 20, wherein the maximum depth of the void is defined as the larger of: the maximum radial distance between the inner and the outer tubular member at any point along the width of the void opening; and the maximum axial distance between the inner and the outer tubular member at any point along the width of the void opening, and wherein the maximum depth of the void is greater than the maximum depth of the or each clearance gap adjacent thereto.

22. A flow control device as claimed in claim 21 , wherein the void comprises a maximum depth that is at least 2 times greater than the maximum depth of the clearance gap.

23. A method for controlling the flow of fluids, the method comprising the steps of: providing a body member having a throughbore formed therein, and a port formed therein; providing a biasing device housed within a chamber; urging a moveable member with the biasing device towards either of:a first configuration in which passage of fluid through the port is permitted; or a second configuration in which passage of fluid through the port is obstructed; controlling the flow of fluids by moving the moveable member between said first and second configurations; and permitting the flow of solids through the chamber via an opening to the chamber.

24. A method for controlling the flow of fluids as claimed in claim 23, wherein the method further comprising the steps of: providing a first pumping means; providing at least one port in the body member; and opening the port and substantially obturating the throughbore at a location above the first pumping means when the first pumping means is dormant.

25. A method for controlling the flow of fluids as claimed in either of claim 23 or claim 24, wherein the method further comprising the steps of: sealing a fluid channel between the body member and the moveable member by:(A) providing a pair of seals on one or more of the body member and the moveable member;(B) providing a void between said pair of seals;(C) moving the body member and the moveable member from an unsealed configuration to a sealed configuration, in which sealing contact between the body member and the moveable member is made via the pair of seals; and(D) collecting at least one solid particle within the void as the body member and the moveable member move from the unsealed configuration to the sealed configuration to thereby prevent at least one solid particle from damaging the seals.

26. A method for controlling the flow of fluids as claimed in claim 25, wherein the method further comprising the step of: moving the body member and the moveable member from the sealed configuration back to the unsealed configuration.

27. A method for controlling the flow of fluids as claimed in claim 26, the method further comprising the step of: releasing at least one solid particle that has / have been collected within the void when the body member and the moveable member have moved back to the unsealed configuration.

28. A seal arrangement for use in a downhole tool having two concentrically arranged tubular members, said seal arrangement comprising: a pair of seals provided on one or more of the tubular members, said pair of seals configured to provide sealing contact between the two concentrically arranged tubular members; and a void arrangement including a void located in between said pair of seals and being arranged in use to provide a haven for at least one solid particle.

29. A seal arrangement as claimed in claim 28, wherein the two concentrically arranged tubular members are axially moveable with respect to one another between a first configuration and a second configuration.

30. A seal arrangement as claimed in claim 29, wherein a fluid channel is provided between at least a portion of the two concentrically arranged tubular members.

31. A seal arrangement as claimed in claim 30, wherein the first configuration is a sealed configuration in which sealing contact is providedbetween the two concentrically arranged tubular members, such that passage of fluid through the fluid channel is prevented.

32. A seal arrangement as claimed in claim 30 or 31 , wherein the second configuration is an unsealed configuration in which the two concentrically arranged tubular members are separated at least axially, such that passage of fluid through the fluid channel is permitted.

33. A seal arrangement as claimed in any of claims 28 to 32, wherein the void comprises a void opening, and wherein the void arrangement includes at least one clearance gap provided between at least one seal of the pair of seals and said void opening.

34. A seal arrangement as claimed in claim 33, wherein the void arrangement includes a first clearance gap between: a first end of the void opening, and a contact surface of a first seal of the pair of seals.

35. A seal arrangement as claimed in claim 34, wherein the void arrangement includes a second clearance gap between: a second end of the void opening, and a contact surface of a second seal of the pair of seals.

36. A seal arrangement as claimed in any of claims 33 to 35, wherein the maximum depth of the void is greater than the maximum depth of the or each clearance gap adjacent thereto.

37. A seal arrangement as claimed in claim 36, wherein the void comprises a maximum depth that is at least 1.5 times greater than the maximum depth of the clearance gap.

38. A seal arrangement as claimed in any of claims 33 to 37, wherein the width of the void opening is at least 20% of the total distance between the respective contact surfaces of each of the pair of seals.

39. A seal arrangement as claimed in any of claims 33 to 38, wherein the clearance gap includes a length which extends from the contact surface of a respective seal to an end of the void opening, and wherein the depth of the clearance gap is substantially constant along the length thereof.

40. A seal arrangement as claimed in claim 39, wherein the clearance gap has a substantially constant depth along the length thereof within + / - 20% of the maximum depth of the clearance gap.

41. A seal arrangement as claimed in any of claims 28 to 40, wherein at least one seal is formed by metal-to-metal contact between the two concentrically arranged tubular members.

42. A seal arrangement as claimed in of claims 28 to 41 , wherein at least one seal is an elastomeric seal.

43. A seal arrangement as claimed in any of claims 28 to 42, wherein the sealing arrangement comprises a second pair of seals provided on one or more of the tubular members, and wherein said second pair of seals is also configured to provide sealing contact between the two concentrically arranged tubular members.

44. A seal arrangement as claimed in claim 43, wherein the void arrangement comprises a second void which is located in between the second pair of seals, and wherein the second void is arranged in use to provide a haven for at least one solid particle.

45. A seal arrangement as claimed in any of claims 28 to 44, wherein the void arrangement further includes a tapered lead in surface, wherein said tapered lead in surface is provided on the outermost side of an outermost seal of the sealing arrangement, and wherein the tapered lead in surface is defined by a tapered face.

46. A seal arrangement as claimed in any of claims 28 to 45, wherein the downhole tool further comprises a flow control device, said flow control device comprising: a body member having a throughbore formed therein; at least one port formed in the body member; a moveable member, wherein in use the moveable member is moveable between a first configuration and a second configuration, whereby in the first configuration passage of fluids comprising at least one of liquids and solids through the port is permitted and in the second configuration passage of said fluids through the port is obstructed; a chamber; a biasing device housed within said chamber, wherein the biasing device is configured to urge the moveable member towards either of the first configuration or the second configuration; and at least one opening adapted to permit the flow of solids out of the chamber.

47. A seal arrangement as claimed in claim 46, wherein the opening to the chamber permits fluid to flow: i) into the chamber from the outer environment; and ii) out of the chamber into the outer environment.

48. A method for sealing a fluid channel between two concentrically arranged tubular members, the method comprising the steps of:(A) providing a pair of seals on one or more of the tubular members;(B) providing a void between said pair of seals;(C) moving the two concentrically arranged tubular members from an unsealed configuration to a sealed configuration, in which sealing contact between the two concentrically arranged tubular members is made via the pair of seals; and(D) collecting at least one solid particle within the void as the two concentrically arranged tubular members move from the unsealed configuration to the sealed configuration to thereby prevent at least one solid particle from damaging the seals.

49. A method for sealing a fluid channel between two concentrically arranged tubular members as claimed in claim 48, wherein the method further comprises the step of: moving the two concentrically arranged tubular members from the sealed configuration back to the unsealed configuration.

50. A method for sealing a fluid channel between two concentrically arranged tubular members as claimed in claim 49, wherein the method further comprises the step of: releasing at least one solid particle that has / have been collected within the voids when the two concentrically arranged tubular members have moved back to the unsealed configuration.

51. A method for sealing a fluid channel between two concentrically arranged tubular members as claimed in any of claims 48 to 50, wherein the method further comprises the steps of: providing a body member having a throughbore formed therein, and a port formed therein; providing a biasing device housed within a chamber; urging a moveable member with the biasing device towards either of: a first configuration in which passage of fluid through the port is permitted; ora second configuration in which passage of fluid through the port is obstructed; controlling the flow of fluids by moving the moveable member between said first and second configurations; and permitting the flow of solids through the chamber via an opening to the chamber.

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