WO2016030658A2

WO2016030658A2 - Flow system

Info

Publication number: WO2016030658A2
Application number: PCT/GB2015/051781
Authority: WO
Inventors: Keith Donald Woodford
Original assignee: Tco In-Well Technologies Uk Ltd
Priority date: 2014-08-28
Filing date: 2015-06-18
Publication date: 2016-03-03
Also published as: GB201415275D0; WO2016030658A3

Abstract

A device and system and associated methods or operating and producing the device, the device being configured to control flow in a line, conduit or capillary. The device includes at least one inlet, at least one outlet and at least one flow path extending between the at least one inlet and the at least one outlet. The at least one inlet and/or outlet is connectable to the line, conduit or capillary. The device includes at least a first part and a second part. The first part includes at least one engagement or attachment member. The second part has at least one cooperating arrangement. The first part is movable in a first direction into a configuration where at least one of the engagement or attachment members engages, attaches or is attachable to or engagable with at least one of the cooperating arrangements of the second part. The first part is movable in a second direction whilst at least one of the engagement or attachment members of the first part is engaged or attached to at least one of the cooperating engagements of the second part so as to move the second part and thereby vary opening of and/or open and/or close the flow path. Optionally, at least one or each of the engagement or attachment members and/or at least one or each of the cooperating arrangements forms part of a ratchet mechanism..

Description

FLOW SYSTEM

FIELD

The present invention relates to a flow system, and in particular, but not exclusively, to a flow system for use in downhole injection.

BACKGROUND

Many wells, such as oil and/or gas wells, require fluid to be injected for a variety of requirements. These may include but are not limited to:

• Chemical Injection - where chemicals for the mitigation of phenomena such as scaling, wax build up, salt built up etc. are addressed by the injection of speciality chemicals which are formulated to address such issues. These applications tend to be performed at very low flow rates which are a very small fraction of the flow rates of the actual produced reservoir well fluids.

• Water De-Salting Injection -where water of either a pure or derived composition is injected to assist in the flushing away of salt deposits in the oil producing region in oil or gas formations. These applications are generally performed at moderate rates of flow which are a small fraction of the flow rates of the actual produced reservoir well fluids.

• Diluent Injection - where a fluid of a special composition is injected with the specific purpose of acting as a solvent to reduce viscosity and density of reservoir fluids in order to allow them to be more pumpable to improve or allow production to surface by methods such as a down hole mechanical pump, a down hole electric submersible pump (ESP), gas lift or other such methods of artificial lift. These applications tend to be performed at moderate to high flow rates which are a greater fraction of the flow rates of the actual produced reservoir well fluids.

• Direct Water injection - where water recovered from another well is injected in order to replenish reservoir pressures and volumes in order to assist in the production of other wells. This is generally performed at very high rates of flow comparable to the production flow rates that may occur form other producing wells.

Injection devices or valves are typically used to facilitate injection into a wellbore. Different types of injection device may be used depending on the nature of the injection, such as chemical type, flow rates etc. Some valves are operable to provide a fixed pressure differential between inlet and outlet, for example by use of a power spring acting against a valve member. Further, some valves, such as disclosed in WO 2014/037584, the disclosure of which is incorporated herein by reference, seek to maintain an injection line in positive pressure, to avoid issues associated with negative or reduced pressures being present, for example caused by a U-tube effect, which might occur where injection fluids cascade through the injection line and injection valve to seek a hydrostatic equilibrium with the wellbore at the point of injection.

Many valves have an abrupt opening characteristic, wherein opening of the valve can cause a sudden increase or surge in fluid pressure and/or flow. This may particularly apply to burst valves or other valves that operate using a shearing, rupturing, bursting or breaking operation. In addition, such valves are typically single use devices that can be used once and are then redundant. Furthermore, operation of such valves can often result in debris being released into the fluid being carried through the valve, which could lead to fouling or blocking of other components.

SUMMARY

An aspect of the present invention relates to a device. The device may be, comprise or be comprised in a device for closing a line, conduit or capillary, such as an injection line or conduit in an injection system, e.g. a downhole injection system. The device may be configured to remain closed during one or more and preferably a plurality of pressure cycles. The device may be operable to selectively open the line, conduit or capillary, e.g. by opening the flow path from the inlet of the device to the outlet. The device may be configured to vent or relieve the line, capillary or conduit.

The device may comprise a flow path extending between at least one inlet and at least one outlet.

The device may comprise at least a first part and a second part.

The first part may comprise at least one engagement or attachment member.

The second part may comprise at least one cooperating arrangement. The first part may be movable in a first direction, e.g. into a configuration where at least one of the engagement or attachment members engages, attaches or is attachable to or engageable with at least one of the cooperating arrangements of the second part.

The first part may be movable in a second direction, e.g. whilst at least one of the engagement or attachment members of the first part is engaged or attached to at least one of the cooperating engagements of the second part, for example, so as to move the second part and may thereby vary the flow path, e.g. open or close the flow path.

The first direction may be opposite to the second direction.

At least one or each of the engagement or attachment members and/or at least one or each of the cooperating arrangements may comprise or be comprised in a oneway mechanism, which may allow motion of the first part relative to the second part in the first or second direction but resist motion of the first part relative to the second part in the other of the first or second directions.

At least one or each of the engagement or attachment members and/or at least one or each of the cooperating arrangements may be, comprise or be comprised in a ratchet mechanism, such as a first ratchet mechanism.

The device may be configured to receive or create a differential pressure between the inlet and the outlet, in at least one configuration of the device, in use.

At least the first part may be in pressure communication with the flow path on upstream or inlet and downstream or outlet sides of the device. At least the first part may be driven or drivable by a differential pressure, which may be the differential pressure between upstream or inlet and downstream or outlet sides thereof. The first part may be movable in the first and/or second direction, e.g. under the pressure differential.

The device may comprise a first biasing means, such as a spring, piston, pressurized and/or pressurisable device, resiliently deformable member, elastomeric member, thrust washer or other thrust arrangement, and/or the like. The first biasing means may be operable to bias the first part in the first and/or second directions, e.g. in a different one of the first or second directions to the direction in which the first part is moved or movable under the pressure differential. The first biasing means may be operable to bias the first part in an opposite direction to the direction in which the first part is moved or movable under the pressure differential. The device may be configured such that the first biasing means is compressible, resettable, pressurisable retractable, and/or contractible by the pressure differential when the pressure differential is greater than a first pressure differential threshold. The first pressure differential threshold may be predefined or pre-set, e.g. by selection of an appropriate construction or arrangement of the first biasing means and/or may be selectable or adjustable, e.g. by providing variable biasing means, such as a pre-load applying arrangement configured to apply a variable pre-load to the first biasing means, e.g. a threaded compression nut and/or the like.

The first biasing means may be configured to provide a force that is greater than a hydrostatic pressure at the inlet, in use. In other words, the pressure differential threshold may be greater than the pressure differential associated with the hydrostatic pressure at the input, in use.

The first part may be movable in the first or second direction when the pressure differential is greater than the pressure differential threshold. The first biasing means may be configured to move the first part in the other of the first or second directions when the pressure differential is less than the pressure differential threshold.

The device may be adapted such that the second part is movable relative to the first part, e.g. in the second direction, by applying one or more pressure cycles, wherein each pressure cycle may comprise applying a differential pressure between the inlet and the outlet greater than the first differential pressure threshold and, optionally subsequently, applying a differential pressure between the inlet and the outlet less than the first differential pressure threshold. The device may be adapted to apply a plurality of pressure cycles, wherein each pressure cycle may sequentially move the second part relative to the first part, e.g. in the second direction.

The device may be configured such that at least one or each of the flow paths is varied, e.g. opened or partially opened, and/or the device is placed in an open configuration, such as a first or restricted open configuration by application of one or more pressure cycles. The device may be switchable between a closed configuration and an open or partially open configuration, e.g. the first open configuration, by application of one or more pressure cycles. The device may be switchable between the first open configuration and a second open configuration by applying one or more further pressure cycles. The first open configuration may be associated with a lower flow rate and/or smaller opening area than the second open configuration.

The device may be adapted such that the second part is movable relative to the first part, e.g. in the second direction, by applying one or more movement cycles, wherein each movement cycle may comprise moving the first part in the first direction relative to the second part and then moving the first and second parts (e.g. together) in the second direction. The device may be adapted to apply a plurality of movement cycles, wherein each movement cycle may sequentially move the second part relative to the first part, e.g. in the second direction.

The device may be configured such that at least one or each of the flow paths is varied, e.g. opened or partially opened, and/or the device is placed in an open configuration, such as the first or restricted open configuration by application of one or more movement cycles. The device may be switchable between a closed configuration and an open or partially open configuration, e.g. the first or restricted open configuration, by application of one or more movement cycles. The device may be switchable between the first open configuration and a second open configuration by applying one or more further movement cycles. The first or restricted open configuration may be associated with a lower flow rate and/or smaller opening area than the second open configuration.

The device may be configured to such that application of one or more or each pressure cycle results in the device undergoing corresponding one or more or each movement cycles.

For example, the device may be adapted such that movement of the second part associated with one or more pressure and/or movement cycles may place the device in the first or restricted open configuration, e.g. by opening one or more first openings in the flow channel so as to allow flow between the inlet and the outlet. The device may be adapted such that movement of the second part associated with one or more further pressure and/or movement cycles may place the device in the second open configuration, e.g. by opening one or more second openings in the flow channel so as to allow flow between the inlet and the outlet. The one or more second openings may comprise a higher opening area and/or be associated with a higher flow rate than the one or more first openings. The at least one first opening may comprise or define a restriction.

The first part may have a defined stroke range, e.g. by providing limiting portions for engaging a housing or sleeve at one or more limits of motion.

At least one or each of the engagement or attachment members may be or comprise an engaging, gripping or fixing member, which may be configured to engage, grip or fix to the cooperating arrangement(s). At least one or each of the engagement or attachment members may comprise a pawl, lock ball, extending or locking member, protrusion, hook, cam follower and/or the like.

At least one or each of the cooperating arrangements may comprise a recess, shoulder, flange, groove, projection, cam surface, protrusion, shelf, step and/or the like.

At least one or each of the engagement or attachment members and/or at least one or each of the cooperating arrangements may be configured to permit motion of the attachment member(s) past or over the at least one or each of the cooperating arrangements in the first or second direction but resist movement of the engagement or attachment member(s) over or past the cooperating arrangement(s) in the other of the first or second directions and/or be configured to engage or attach to the cooperating arrangement(s) when the engaging or fixing members are moved in the other of the first or second directions.

For example, at least one or each of the cooperating arrangements may comprise a cam surface shaped to permit the engagement or attachment member(s) to pass over the cooperating arrangement(s) in one (e.g. the first or second) direction but to engage or attach to the engagement or attachment member(s) when they are moved in another or opposite direction (e.g. the other of the first and second directions).

The second part may comprise a plurality of cooperating arrangements. The cooperating arrangements may be distributed in the first and/or second directions and/or a longitudinal or axial direction of the second part. The second part may comprise one or more first, one or more second (and optionally one or more subsequent) cooperating arrangements, wherein the first, second and subsequent cooperating arrangements are separated or distributed in the first and/or second directions and/or a longitudinal or axial direction of the second part relative to the other of the first, second and subsequent cooperating mechanisms.

The device may be configured such that the first part is movable in the first direction, which may be under the action of the pressure differential, e.g. into a position where the one or more or each engagement or attachment member attaches or is attachable to the first cooperating arrangement. The first and second parts may subsequently be movable (e.g. movable together or joined) in the second direction, which may be under the action of the first biasing means. The first part may subsequently be further movable in the first direction, which may be under the action of the pressure differential, e.g. into a position where the one or more or each engagement or attachment member attaches or is attachable to the second cooperating arrangement. The first and second parts may subsequently be movable (e.g. movable together or joined) in the second direction, which may be under the action of the first biasing means. The first part may subsequently be further movable in the first direction, which may be under the action of the pressure differential, e.g. into a position where the one or more or each engagement or attachment member attaches or is attachable to the subsequent cooperating arrangement(s).

The device may be configured to move or reposition the second part, e.g. in the second direction, relative to the first part by sequentially moving the first part in the first direction, which may be under the action of the pressure differential, so that at least one or more of the engagement or attachment members engages or attaches to one or more corresponding cooperating arrangements then moving the first and second parts in the second direction (e.g. movable together or joined), which may be under the action of the first biasing means. Each sequential movement of the first part in the first direction may result in at least one or more of the engagement or attachment members engaging or attaching to respective one or more corresponding cooperating arrangements that are spaced apart in the first direction relative to the one or more corresponding cooperating arrangements engaged by or attached to the one or more of the engagement or attachment members during the previous sequential movement.

The device may be configured to selectively receive, apply or vary the pressure at the inlet and/or the pressure differential. For example, the device may be configured to receive or apply a pressure differential higher than the pressure differential threshold in order to move the first part in the first or second direction and to receive or apply a pressure differential lower than the pressure differential threshold in order to move the first part in the other of the first or second directions, e.g. using the first biasing means.

The device may comprise a third part. The third part may be arranged to interact with the second part so as to resist motion of the second part in the first direction but allow motion of the second part in the second direction.

The third part may be or comprise or be comprised in a fixed or stationary part. The second part may be movable relative to the third part, e.g. in the second direction. The second part may be movable by the first part and/or under the action of the first biasing means and/or the pressure differential.

The third part may comprise at least one engagement or attachment member. The engagement or attachment member(s) of the third part may be adapted to attach or engage with one or more or each of the cooperating mechanisms of the second part.

The second part may be movable in the second direction relative to the third part. The system may be adapted such that one or more or each of the engagement or attachment members of the third part engages, attaches or is attachable to or engagable with one or more or each cooperating engagements of the second part. The second part may be movable in the second direction into the configuration in which one or more or each of the engagement or attachment members of the third part engages, attaches or is attachable to or engagable with the one or more cooperating engagements of the second part.

The engagement or attachment members of the third part may be configured to allow motion of the second part in the second direction relative to the third part. The engagement or attachment members of the third part may be configured to engage or attach to the cooperating mechanism(s) of the second part so as to resist motion of the second part in the first direction relative to the third part.

For example, one or more of the cooperating members and/or one or more of the engagement or attachment members may comprise a cam surface. One or more or each of the engagement or attachment members may be configured to cam over the one or more of the cooperating members in one direction (such as the second direction) and to engage or lock in the other direction (such as the first direction).

The engagement or attachment members of the third part and the cooperating mechanisms of the second part may be, comprise or be comprised in a ratchet mechanism, such as a second ratchet mechanism.

The second part may be movable away from or out of contact with the third part, e.g. the second part may be locatable in a configuration in which it is displaced or spaced apart from the third part in the second direction. The system may be configured such that the second part may be movable into the configuration in which it is displaced or spaced apart from the third part in the second direction, e.g. by sequentially applying one or more pressure cycles and/or movement cycles.

The device may comprise a device body. The first, second and/or third parts may be located or locatable within the device body. At least one or more or each of the first and/or second openings may be through a wall of the device body, e.g. a circumferential wall of the device body.

The device may comprise sealing or closing means for selectively sealing or closing one or more or each of the openings or passages (e.g. one or more or each of the first openings or passages). The sealing or closing means may be comprised on or in the second part. The sealing or closing means may be configured to selectively open, close and/or vary the system flow path. The sealing or closing means may be movable or operable by the second part, e.g. by movement of the second part. The sealing or closing means may be movable between a configuration in which they close one or more of the openings or passages and/or the flow path and a configuration in which they open or partially open one or more of the openings or passages (e.g. one or more or each of the first openings or passages) and/or the flow path, e.g. by movement of the second part, such as in the second direction.

The sealing or closing means may comprise a sleeve or sheave or other suitable sealing arrangement. The sealing or closing means may be movable or slidable, for example, in the first and/or second direction.

The sealing or closing means and/or the second part may comprise mutually engagable portions, such as corresponding shoulders, projections, radially extending members, slots, recesses, protrusions and/or the like. The mutually engagable portions of the sealing or closing means may be spaced apart from the mutually engaeable portions of the second part, at least in an initial configuration, such that they may be brought into engagement once the second part has moved a selected or predefined distance, e.g. by the first part, which may be after a defined or predetermined number of differential pressure and/or movement cycles.

The sealing or closing means may be biased, e.g. by the second biasing means, into a closed configuration in which at least one or more of the passages or apertues, e.g. the first passages or apertures are closed. The second biasing means may have a spring constant or force less than the first biasing means. The second biasing means may be compressible, retractable or pressurizable by a force applied by the second part, e.g. when the second part is moved by the first biasing means.

The system may be configured such that at least one of the openings or passages (e.g. one or more or each of the first openings or passages) is opened when the third part is displaced or spaced apart from the second part. The system may be configured such that at least one of the openings or passages (e.g. one or more or each of the first openings or passages) is opened after one or more pressure and/or movement cycles, e.g. a selected or predetermined number of pressure and/or movement cycles.

The at least one second opening or passage may be switchable between a closed and an open configuration, e.g. under the action of the pressure differential, e.g. between the inlet and the outlet. The at least one second opening or passage may be switchable between a closed and an open configuration when the pressure differential is below a second pressure differential threshold, which may be lower than the first pressure differential threshold. The at least one second opening or passage may be switchable between a closed and an open configuration by relative movement of at least two parts of the device, such as fourth and fifth parts. The first, second and/or third parts may be comprised or provided in the fourth part. The system may comprise a third biasing means. The third biasing means may be provided, or arranged to act, between the fourth and fifth parts. The third biasing means may be compressible, retractable, contractable and/or pressurisable by the pressure differential, e.g. when the pressure differential is greater than the second threshold pressure differential. In other words, the second pressure differential may be set or defined by the third biasing means.

The at least one second opening or passage may be configured to open when the pressure differential is less than the second pressure differential threshold, e.g. under the action of the third biasing means.

In this way, the pressure differential may be reduced by opening the at least one first passage, e.g. by applying one or more pressure or movement cycles. Once the pressure differential falls below the second pressure differential threshold, then the at least one second passage or opening may open.

The device may comprise a locking mechanism, which may be operable to selectively lock and/or unlock the one or more second openings or passages, e.g. in the closed position and/or selectively lock and/or unlock the fourth and fifth parts, e.g. so as to prevent relative motion there-between. The locking mechanism may comprise lock balls, slidable engaging devices, shear pins and/or the like.

The pressure differential may be controllable by controlling the pressure in the injection line. The pressure may be controlled by controlling a pump attached to or in communication with the injection line or input, such as an injection pump, which may be located at the surface.

The first part may comprise a seat, such as a ball seat. The seat may be configured to receive an operation body, such as a ball, which may be provided to the input, e.g. via the flow and/or via the injection line. The device may be configured such that location of the operation body on the seat may at least partially or fully block the flow channel. The device may be configured such that when the operation body is located in the seat and the input is provided with flow, then the pressure differential between the input and the output increases and/or becomes higher than the first pressure differential threshold. This may allow the first part to move in the first direction, e.g. into a position where one or more or each of the engagement or attachment members engage, attach or are engagable with or attachable to one or more or each of the cooperating mechanisms on the second part, for example, by compressing, contracting, retracting and/or pressurizing the first biasing means.

The device may comprise one or more bypass channels, such as restricted bypass channels, which may bypass the seat, e.g. so as to at least partially form one or more restricted bypasses between the inlet and the outlet. Reduction in the pressure differential, for example, by reducing or stopping flow to the inlet and/or allowing fluid to drain through the bypass channels, may permit the first and second means to move in the second direction, e.g. under the action of the first biasing means, for example, when the pressure differential reduces to below the first pressure differential threshold. The flow path may be openable by movement of the first and second parts. For example, the first and/or second part may comprise or be configured to engage and/or move one or more sealing or closing member and/or align two through passages, e.g. after being moved together in the second direction.

The device may be configured to remain closed, e.g. such that the flow channel is substantially closed, during one or more pressure cycles. Each cycle may comprise pressurising the injection line so that the pressure differential is above the first pressure differential threshold and then reducing the pressure in the injection line such that the first pressure differential is below the first pressure differential threshold.

A second aspect of the present invention relates to a device for closing a line, conduit or capillary, such as an injection line or conduit in an injection system, e.g. a downhole injection system. The device may be configured to remain closed during one or more and preferably a plurality of pressure cycles. The device may be operable to selectively open the line, conduit or capillary, e.g. by opening the flow path from the inlet of the device to the outlet.

The device may comprise or be comprised in at least one device according to the first aspect. The device may be a downhole device. The device may be, comprise or be comprised in a valve used or usable in an injection system, such as a vent or relief valve or other device. The inlet may be attached to an injection line.

A third aspect of the present invention relates to a flow system, such as an injection system. The flow system may comprise a device according to the first aspect and/or second aspect. The flow system may be, comprise or be comprised in a downhole flow system, e.g. for injecting a fluid downhole. The flow system may comprise an injection line, which may be connected to the inlet of the device. The flow system may comprise a pump or other pressurising means, which may be attached or attachable to the injection line. The pump and/or other pressurising means may be operable to selectively control the pressure in the injection line and/or at the inlet and/or the pressure differential.

The flow system may be configured for use in chemical injection.

The flow system may be configured for use in water de-salting injection.

The flow system may be configured for use in diluent injection.

The flow system may be configured for use in direct water injection

A fourth aspect of the present invention relates to a method of operating a device according to the first aspect and/or second aspect.

The method may comprise applying one or more pressure cycles and/or movement cycles to the inlet. The pressure cycle may comprise applying a high pressure or pressure differential and a lower pressure or pressure differential. The high pressure or pressure differential may be or result in a pressure differential that is greater than the first pressure differential threshold, which may be higher than a hydrostatic pressure at the inlet or in the injection line, in use. The lower pressure or pressure differential may be, or result in, a pressure differential that is lower than the first pressure differential threshold. The pressure cycle may comprise sequentially applying the higher pressure or pressure differential and then the lower pressure or pressure differential. The method may comprise applying a plurality of pressure and/or movement cycles, e.g. until the device opens or is placed in a first or restricted open configuration, which may open the flow path from the inlet to the outlet of the device.

The method may comprise subsequently placing the device in a second opened configuration, which may be associated with a higher flow than the first opened configuration. The method may comprise placing the device in the second opened configuration by reducing the pressure differential below a second pressure differential threshold, which may be lower than the first pressure differential threshold.

The method may comprise providing an operation body at the inlet, e.g. via the injection line, for example to at least partially block the flow channel, for example, so as to increase the pressure or pressure differential and/or the provide the higher pressure or pressure differential.

The method may comprise controlling the pump so as to provide at least part or all of the pressure cycle.

A fifth aspect of the present invention relates to a method of testing an injection line or conduit. The method may comprise providing a device according to the first aspect and/or second aspect in or connected to or otherwise in communication with the injection line or conduit, e.g. to close the injection line or conduit. The method may comprise performing the method of the fourth aspect, e.g. by applying one or more pressure cycles. The higher pressure of the pressure cycle may be greater than a hydrostatic pressure at the inlet or in the injection line or conduit in use.

A sixth aspect of the present invention relates to a method of manufacturing or assembling a device according to the first aspect and/or second aspect and/or the system according to the third aspect. The method may comprise placing or providing the locking mechanism in the locked configuration, e.g. during assembly and/or before use and/or until the device or flow system is exposed to fluid flow. The method may comprise unlocking the locking mechanism in use and/or whilst the device and/or flow system is subject to flow.

It should be understood that terms such as "downstream" and "upstream" are used in a directional sense relative to the device or system, and in particular relative to the flow path which extends between the inlet and outlet. In this case the downstream direction is in a direction through the flow path from the inlet to the outlet, with the upstream direction opposite this. Also, a feature defined as being on an upstream side of a reference point in the device or system may be considered to be positioned on that side of the reference point which is closer to the inlet along the flow path. A feature defined as being on a downstream side of a reference point may be construed accordingly.

It should be understood that the individual features and/or combinations of features defined above in accordance with any aspect of the present invention or below in relation to any specific embodiment of the invention may be utilised, either alone or in combination with any other defined feature, in any other aspect or embodiment of the invention. Furthermore, the present invention is intended to cover apparatus configured to perform any feature or action described herein in relation to a method and/or a method of using, producing, assembling or manufacturing any apparatus feature described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic illustration of a wellbore system which includes injection capabilities;

Figure 2 is a diagrammatic illustration of an alternative wellbore system which includes injection capabilities; Figure 3 is a diagrammatic illustration of an injection check valve for use in the system of Figure 1 or Figure 2;

Figures 4 and 5 are illustrations of rupture disks used to test systems that include injection capabilities;

Figures 6 and 7 show an encapsulated rupture cartridge used to test systems that include injection capabilities;

Figure 8 shows a cross sectional view of a device for use in an injection system, such as that shown in Figures 1 or 2, wherein the device is in a closed configuration;

Figure 9 shows a cross sectional view of the device of Figure 8 after having been subjected to a plurality of pressure cycles;

Figure 10 shows a cross sectional view of the device of Figure 9 after having been subjected to additional pressure cycles so as to be placed in a first open and restricted flowing position;

Figure 1 1 shows a cross sectional view of the device of Figures 8 to 10 in a second open and flowing position;

Figure 12 shows a cross sectional view of an alternative device for use in an injection system, such as that shown in Figures 1 or 2, wherein the device is in a closed configuration;

Figure 13 shows a cross sectional view of a device, specifically a pressure relief valve or vent, for use in a wellbore injections system, wherein the device is in a closed position;

Figure 14 shows a cross sectional view of the device of Figure 13 in a first operated configuration;

Figure 15 shows a cross sectional view of the device of Figures 13 and 14 in a second operated configuration;

Figure 16 shows a cross sectional view of the device of Figures 13 to 15 in an open and flowing configuration; and

Figure 17 is a flowchart illustrating a method of using the device, such as that of figures 8 to 11.

DETAILED DESCRIPTION OF THE DRAWINGS

A typical wellbore completion installation with injection capabilities is diagrammatically illustrated in Figure 1. The wellbore, generally identified by reference numeral 10, comprises a casing string 12 located within a drilled bore 14 which extends from surface 16 to intercept a hydrocarbon bearing formation 18. A lower annulus area 20 defined between the casing 12 and bore 14 may be filled with cement 22 for purposes of support and sealing. A production tubing string 24 extends into the casing 12 from a wellhead 26 and production tree 28. A lower end of the production tubing string 24 is sealed against the casing 12 with a production packer 30 to isolate a producing zone 32. A number of perforations 34 are established through the casing 12 and cement 22 to establish fluid communication between the casing 12 and the formation 18. Hydrocarbons may then be permitted to flow into the casing 12 at the producing zone 32 and then into the production tubing 24 via inlet 36 to be produced to surface. Artificial lift equipment, such as an electric submersible pump (ESP) 37 may optionally be installed inline with the production tubing 24 as part of the completion to assist production to surface. The production tree 28 may provide the necessary pressure barriers and provides a production outlet 38 from which produced hydrocarbons may be delivered to a production facility (not shown), for example.

A small bore injection line or conduit 40, which is often referred to as a capillary line, runs alongside the production tubing 24 from a surface located injection fluid source 42 to a downhole target location, which in the illustrated example is a lower end of the production tubing 24, below the ESP 37. The injection line or conduit 40 is clamped to the outside of the production tubing 24 and is run inside the casing 12. The production tubing 24 may include an optional injection mandrel 44. An injection pump 46 is located at a topside location to facilitate injection of the injection fluid 42. The injection pump 46 is controllable so as to deliver fluid at a selectable or required injection pressure and at a controlled flow rate, as required.

An injection valve 48 is located in a lower region of the injection line 40 and functions to permit fluid injection into the production tubing 24, in some cases preferentially at a constant injection rate, while preventing reverse flow back into the injection line 40, for example via a non-return or check valve 50, such as that illustrated in Figure 3.

The check valve 50 can be placed at a lower or downstream end of the injection line or conduit 40, near the point of injection and acts to allow flow of injection fluid from the fluid source 42 through the injection line or conduit 40 to the point of injection but prevents flow of well fluids in the reverse direction. The check valve 50 can take the form of a ball 52, poppet or piston located in a flow channel 54. The ball 52 is biased toward an inlet 56 of the valve so as to close the flow channel 54 by a spring 58 or other suitable biasing means. The ball 52 is movable in an axial direction against a force applied by the spring 58 under the flow of fluid supplied to the inlet 56 of the check valve 50 in order to allow flow from the inlet 56 to an outlet 60 of the check valve 50. When the flow direction is reversed (i.e. from the outlet 60 to the inlet 56) then the spring 58, in conjunction with the pressure applied by the reverse flow, is operable to force the ball 52 against the inlet 56, thereby closing the check valve 50.

In the system 10 of Figure 1 injection is provided via a small bore injection line

40. For example, the injection line can be ¼" (63mm), 3/8" (95mm) or ½" (126mm) outer diameter in size, but is not limited to these sizes. Injection may be provided to deliver a diluent to reduce the viscosity of the wellbore fluids and permit easier lifting by the ESP 37. In other cases injection may deliver treating chemicals into the wellbore system, for example to inhibit scale, rust, wax, emulsions and the like.

In some instances, however, very high flow rate injection is necessary, for example for water injection into the formation 18. In such cases a small bore injection line 40 may be inappropriate to accommodate the necessary flow rates. As such, large bore systems may be utilised. An example of a higher injection rate system 10' is shown in Figure 2. Like reference numerals are used to indicate like components. Reference numerals provided with an apostrophe indicate similar or equivalent but modified or different components.

The system 10' of Figure 2 comprises a larger injection line or conduit 40' to facilitate higher rates of flow. Whilst the larger injection line or conduit 40 can be run on the outside of the production tubing 24 within the casing 12, for larger flows the injection line or conduit 40' comprises a larger upper tubing section 41 , so called 'slim tubing', that is located within the production tubing 24. The injection line or conduit 40' is then diverted around other equipment such as the ESP 37 near the point of injection.

However, even in such large bore systems, injection valves are still typically used, for example to check any flow in a reverse direction.

Although various examples of injection system are shown and described, it will be appreciated that there are many variations of injection system that would be apparent to a skilled person, and the present invention is not necessarily applicable only to the injection systems illustrated in Figures 1 and 2.

In all such applications where an injection line or conduit 40, 40' of whatever size is used for the purposes of fluid injection, there is a need at the time of well completion to verify the pressure sealing integrity of the injection line or conduit 40, 40'. Since the injection line or conduit 40, 40' inherently allows forward flow from the fluid source 42, via the injection line or conduit 40, 40' line to the point of injection, applying an elevated pressure for the purposes of pressure integrity testing is problematic, as the pressurised fluid is simply dissipated to the injection point, making it difficult to achieve the required testing pressures and/or potentially leading to undesirable high pressure injection into the producing zone 32.

One option for overcoming this problem and allowing pressure testing of the injection line or conduit 40, 40' is to install a device 62 within the capillary line, generally near the lowest point of injection, that will block the line whilst a test pressure is applied to the injection line or conduit 40, 40'. After pressure testing of the injection line or conduit 40, 40' is completed, this device 62 can then be taken to a higher pressure which will shear out or rupture the blockage device 62 thus allowing forward flow and conventional operation of the injection system 10, 10' in use.

For example, this blockage device 62 can be a burst disk 62a such as those shown in Figures 4 and 5 or rupture cartridge 62b as shown in Figures 6 and 7.

The burst disk 62a operates on the principle of being able to maintain and hold a pressure in the injection line or conduit 40, 40' by providing a secure blockage of the injection line or conduit 40, 40' in the direction of the topside and fluid source 42. The burst disk 62a can take the form of a flat or curved thin metallic item. When a sufficient pressure is applied, it will burst to a fully open position thus allowing forward flow to occur.

Burst disks 62a however possess significant disadvantages in that, as they burst, they may emit debris into the fluid injection system which may be detrimental to any device that is included in the injection system downstream of the burst disk 62a.

For example, if the burst disk 62a is upstream of the check valve 50, debris from the burst disk 62a may undesirably lodge in the check valve 50.

An alternative to a burst disc 62a is an encapsulated rupture cartridge 62b, such as that shown in Figures 6 and 7, which is based on an enclosed chamber 64 with a movable piston 66. This piston 66 rests on a cylindrical body 68 that is designed to axially shear at a predefined applied pressure allowing movement of the movable piston 66 thus opening a flow path through the cartridge 62b.

However, whenever a shear or rupture device is employed, there may potentially be disadvantages. For example, in order to open the rupture device 62a,

62b, then an over pressure above a rupture threshold must be applied. This involves applying a high pressure to the upstream portion of the injection line or conduit 40, 40'.

When the rupture device 62a, 62b ruptures, the resulting sudden release of the high pressure fluid can produce a pressure shock effect which could potentially be damaging to any device downstream of the rupture device 62a, 62b. Even if the burst disk 62a or rupture cartridge 62 is mounted downstream of any such device, a high rate of flow can still occur as the pressure in the injection line or conduit 40, 40' is dissipated during the rupture process.

Another potential disadvantage of using a rupture device 62a, 62b is that the rupture device 62a, 62b can generally only be used once, i.e. the rupture device 62a, 62b can be opened once by rupturing the device 62a, 62b when the predefined opening pressure is reached. However, in some cases it may be desirable to have the facility to apply a pressure to the capillary line a number of times.

For example, some wells are run with the injection line or conduit 40, 40' split (see e.g. Figure 2) and connected later by a device that will allow down hole coupling of the injection line or conduit 40, 40'. In such instances there may be a need to pressurise the whole completion for other purposes such as the setting of a production packer and then performing further integrity pressure testing of the well completion. In this scenario it is therefore problematic if an injection capillary line is fitted with a device that can only be used and/or taken to a peak pressure once.

Figure 8 shows a device 100 that can be used instead of a rupture device 62a, 62b such as those shown in Figures 4 to 7, e.g. in an injection system 10, 10' such as those shown in Figures 1 and 2. The device 100 is configured to close the injection line or conduit 40, 40' whilst one or more pressure cycles are applied to the injection line or conduit 40, 40', but be selectively openable to allow normal operations using the injection line or conduit 40, 40'.

The device 100 comprises a device body 102 (e.g. a fifth part of the device 100) that defines an inlet 104 and an outlet 106, with a flow channel 108 extending therebetween. In use in an injection system, such as those of Figures 1 and 2, the inlet 104 is connected or connectable to the injection tubing 40, 40' so as to receive fluid from the fluid source 52 (i.e. uphole), whilst the outlet 106 is in fluid communication with the injection point, i.e. a downhole side of the device 100.

A hollow inner part 1 10 (e.g. a fourth part of the device 100) is provided within the flow channel 108 between the inlet 104 and the outlet 106. In the closed or initial configuration shown in Figure 8, the inner part 1 10 is sealably mounted to the device body 102 and locked against motion relative to the device body 102 by a locking mechanism 1 12 so as to close the flow channel 108. The hollow chamber 1 13 within the inner part 110 is in communication with the outlet 106 of the device 100.

Provided within the inner part 1 10 is a first part in the form of a first actuating assembly 1 14, wherein the actuating assembly comprises an actuating piston 1 16. A portion of the actuating piston 1 16 extends inside and seals an inlet opening 118 in the inner part 1 10 so as to be in fluid communication with the inlet 104 side of the flow channel 108. The first actuating assembly 1 14 further comprises a first ratchet arm extending from an end of the actuating piston 116 that is away from the inlet opening 1 18 of the inner part 110.

Also provided in the inner part is a second part in the form of a ratchet pin 122 and a third part in the form of a second ratchet arm 124.

The first actuating assembly 1 14 is slidably mounted within the inner part 110, so as to be slidably movable in a longitudinal or axial direction of the inner part 120. A first biasing means in the form of a sensor spring 125 extends between the first actuating assembly 1 14 and the inner part 110 in order to bias the first actuating assembly 1 14 towards an end of the hollow chamber 1 13 of the inner part 110 having the inlet opening 1 18. The sensor spring 125 is mounted via an adjusting nut 127 for adjusting the force exerted by the sensor spring 125.

The force applied by the sensor spring 125 equates to a first pressure differential threshold required to move the first actuating assembly 114. This first pressure differential threshold is set to be greater than the hydrostatic pressure that will occur in the injection line or conduit 40 between the fluid source 42 (i.e. at the surface) and the device 100 by appropriate selection of the sensor spring 125 and/or adjustment of the adjusting nut 127. This hydrostatic pressure is a function of the fluid density and the vertical height. The sensor spring 125 is therefore selected and/or adjusted using the adjusting nut 127 to provide a force that will require a pressure differential between the inlet 104 and the outlet 106 generated by an applied pressure in the injection line or conduit 40 to be greater than the hydrostatic pressure in the injection line or conduit 40. Therefore, even when the hydrostatic pressure is applied to the inlet 104, the sensor spring 125 retains the actuating assembly 1 14 in its home position, i.e. at a limit of its range of motion toward the inlet opening 1 18.

The actuating assembly 1 14 is provided with longitudinally extending recesses 129, which receive corresponding guide members of the inner part 110, in order to control the range of motion of the actuating assembly 1 14.

The second ratchet arm 124 is fixed to the inner part 1 10.

An outer circumferential surface of the ratchet pin 122 is provided with a plurality of cooperating mechanisms in the form of sloped protrusions 126. The plurality of sloped protrusions 126 are distributed longitudinally or axially on a portion of the ratchet pin 122. Each sloped protrusion 126 comprises an obliquely sloped or camming face 128 that faces towards the inlet opening 1 18 of the inner part 1 10 and a substantially radially extending or engaging face 130 that faces away from the inlet opening 1 18 of the inner part 1 10.

Each of the first and second ratchet arms 120, 125 comprise a plurality of pawls 132a, 132b that are configured to engage with the protrusions 126 of the ratchet pin 122. In particular, each pawl 132, 132b comprises an obliquely sloping or camming face 132 arranged to engage the obliquely sloping or camming faces 128 of the protrusions 126 of the ratchet pin 122 and a substantially radially extending or engaging face 136 arranged to engage the substantially radially extending or engaging face 130 of the protrusions 126 of the ratchet pin 122. In this way, relative movement together of the sloping or camming faces 128, 134 of the protrusions 126 of the ratchet pin 122 and the pawls 132a, 132b cause the respective pawl 132 to flex or pivot such that the pawl 132 cams or passes over the respective protrusion 126. However, relative movement of the pawls 132 and the ratchet pin 122 in the opposite direction, i.e. such that the substantially radially extending or engaging faces 130, 136 of the protrusions 126 of the ratchet pin 122 and the respective pawls 132 contact together causes the pawls 132 to engage, hook or attach to the respective protrusion 126.

The ratchet pin 122 is movable relative to the inner part 1 10 in a second direction (e.g. towards the inlet opening 1 18 of the inner part 1 10) by varying the differential pressure applied between the inlet 104 and the outlet 106 in order to operate the first actuating assembly 1 14, the first ratchet arm 120, the ratchet pin 122 and the second ratchet arm 125 in order to move the ratchet pin 122 in the second direction using a ratcheting operation.

In particular, when a positive pressure is applied to the injection line or conduit 40, 40' and thereby to the inlet 104, e.g. using the injection pump 46, then that increased pressure acts on the portion of the actuating piston 116 located in the inlet opening 1 18 of the inner part 110. Applying a sum of the positive pressure and hydrostatic pressure that results in a pressure differential between the inlet 104 an the outlet 106 that is greater than the pressure differential threshold governed by the force applied by the sensor spring 125 acts to move the actuating assembly 1 14 in a first direction (i.e. away from the inlet opening 1 18 end of the inner part 1 10) by compressing the sensor spring 125.

The pawls 132b of the second ratchet arm 124 cooperate with the protrusions 126 of the ratchet pin 122 to prevent the ratchet pin 122 from moving in the first direction (i.e. away from the inlet opening 1 18). As such, the motion of the actuating assembly 1 14 under the pressure differential seen by the actuating piston 116 at the inlet opening 1 18 causes the first ratchet arm 120 to move in the first direction relative to the ratchet pin, with the pawls 132a of the first ratchet arm 120 camming off the obliquely sloping surfaces 128 of one or more protrusions 126 of the ratchet pin 122 so as to ride over the protrusions 126 until the limit of motion of the actuating assembly 1 14 (set by the recesses 129) is reached.

Thereafter, the pressure applied to the inlet 104 via the injection line or conduit 40, 40' by the injection pump 46 is reduced. As a result, the pressure at the inlet opening of the inner part 1 10 is also reduced until the pressure differential between the inlet 104 and the outlet 106 is less than the first pressure differential threshold. When this happens, the spring overcomes the applied pressure and moves the actuating assembly 1 14 in the second direction to return it to its original starting home position (at its limit of motion toward or closest to the inlet opening 118).

When the actuating assembly 1 14 is moved in the second direction, this causes the radially extending or engaging faces 136 of the pawls 132a of the first ratchet arm 120 to engage, hook or attach the radially extending or engaging faces 130 of the corresponding protrusions 126 on the ratchet pin 122. This causes the ratchet pin 122 to move with the actuating assembly 1 14 whilst the pawls 132b of the second ratchet arm cam over the protrusions 126 of the ratchet pin 122. This moves the ratchet pin 122 in the second direction (i.e. towards the inlet opening 1 18) by a distance defined by the stroke of the actuating assembly 1 14 (i.e. by the recesses 129 and corresponding guides), as shown in Figure 9.

Once in this position, the ratchet pin 122 is retained in this position by the second ratchet arm, which prevents the ratchet pin 122 from moving in the first direction back towards its original position.

This pressure cycling operation of increasing pressure so as to create a pressure differential greater than the first pressure differential threshold before to move the actuating assembly 114 in the first direction relative to the ratchet pin 122 and then lowering the pressure so that the pressure differential is below the first pressure differential threshold so that the actuating assembly 1 14 engages the ratchet pin 122 and both the actuating assembly 1 14 and the ratchet pin 122 move in the second direction under the action of the sensor spring 129, can be repeated a plurality of times in order to successively move the ratchet pin 122 further in the second direction relative to the actuating assembly 1 14 and/or the second ratchet arm 124. The above ratchet mechanism allows the device 100 to be operated by application of one or more high and low pressure cycles. This may permit application of more than one high pressure test operation on the injection line or conduit 40, 40', if so desired.

Furthermore, the device 100 does not include any bursting or shear off devices or members. As such, release of debris due to bursting or shearing components may be minimised or eliminated.

The ratchet pin is provided with the locking mechanism 1 12, which selectively secures the inner part 110 to the body 102 in order to seal the flow channel 108 through the device 100. This allows the device 100 to be assembled and handled without any pressure being applied and allow for the inclusion of an opening spring 138 which is configured to push the inner part 110 and the device body 102 apart from one another.

The locking mechanism 112 comprises a plurality of balls 140 which, in a closed or initial configuration, are disposed in an aperture 141 in the body 102 and are located between a projecting portion 142 of a shaft 143 of the ratchet pin 122 and a wall of a cavity 144 in the inner part 1 10, in order to trap the balls 140 in both the aperture 141 of the body 102 and the cavity 144 of the inner part 1 10, thereby locking the inner part 1 10 and the device body 102 against relative motion. However, once the ratchet pin 122 has been moved sufficiently far in the second direction by the ratcheting action of the actuating assembly 114 (corresponding to a defined number of pressure cycles), then the projecting portion 142 of the ratchet pin 122 no longer bears against the balls 140, which are then free to move out of the cavity in the inner part 1 10, effectively unlocking the inner part 1 10 from the device body 102.

This locking mechanism 112 is for assembly purposes because when the device 100 is in use, there will be a hydrostatic pressure applied to the inlet 104 and therefore the inner part 110. This pressure pushes the inner part 1 10 and the device body 102 together towards each other by virtue of the pressure at the outlet 106 of the device (in communication with the hollow interior of the inner part 110) being at a lower pressure than the pressure at the inlet 104. Therefore the higher inlet pressure will tend to keep the inner part 1 10 and the device body 102 together and engaged in use. As such, in the closed configuration in use, the inner part 1 10 is held in contact with the device body 102 by the pressure differential between the inlet 104 and the outlet 106. Although a locking mechanism 1 12 that uses lock balls 140 is described above, it will be appreciated that other locking mechanisms, e.g. using locking elements, a collet or other suitable mechanism may be used.

This locking mechanism 1 12 may permit easy assembly, handling and installation of the device 100.

The device 100 defines at least two sets of selectively openable passages 148, 150 between the inlet 104 and the outlet 106. In this case, a first set of flow passages 148 comprises restricted flow passages, having a smaller cross sectional area than the second flow passages 150 or by being formed of porous media, a series of very small or tortuous paths and/or other suitable restriction mechanism. The device 100 is configured such that the first (restricted) flow passages 148 are opened before the second flow passages 150.

In this way, opening of the device 100 releases pressure gradually and may reduce or minimise the effect of pressure shock.

In particular, the device 100 is provided with the first flow passages 148, which extend through the wall of the inner part 1 10 from an outside (i.e. an inlet 104 side) to an inner side (i.e. an outlet 106 side) thereof. A slidable closing member in the form of a sleeve 152 is provided inside the inner part 1 10 so as to sealably close the first flow passages 148 in the closed configuration of the device 100. The sleeve 152 is biased into the closing position by a sleeve spring 154 that is compressed between the inner part 1 10 and the sleeve 152. Shoulders 156 or other radially extending portions of the ratchet pin 122 are configured to engage the sleeve in a certain position of the ratchet pin 122, after it has undergone a corresponding number of ratcheting movements / pressure cycles in order to move the ratchet pin 122 a corresponding distance in the second direction, as shown in Figure 10.

Thereafter, further movement of the ratchet pin 122 in the second direction results in the shoulders 156 bearing against the sleeve 152 in order to move the sleeve 152 in the second direction with the ratchet pin 122, so as to compress the sleeve spring 154. This moves the sleeve 154 away from the first flow passages 148 in order to open them and permit restricted flow therethrough from the inlet 104 to the outlet 106.

This controlled or restricted flow allows the pressure differential between the inlet 104 and the outlet 106 to be gradually dissipated, which may thereby minimise or prevent shocks due to sudden release of pressure, e.g. as may be the case with a burst valve or cylinder. The device 100 is also provided with the compressed opening spring 138 that acts between the device body 102 and the inner part 1 10 so as to bias them apart. Since the locking mechanism 1 12 has been previously disengaged, once the differential pressure between the inlet 104 and the outlet 106 has reduced below a second pressure differential threshold determined by the opening spring 138 (which is lower than the first pressure differential threshold) by flow of fluid through the first flow passages 148, then the opening spring 138 forces the inner part 110 away from its seat on the device body 102, thereby opening the second flow passages 150, as shown in Figure 1 1 , which are configured for much higher flow rates than the first opening passages 148.

The differential pressure that results in the device body 102 and inner part 1 10 being separated from each by the opening spring 138 is defined only by the force and therefore equivalent pressure defined by the opening spring 138. As such, the differential opening pressure of the device 100 can be significantly reduced in comparison to a conventional burst type line block device.

This may also significantly reduce risk of pressure shocks occurring in the injection system and also greatly reduce any surge of flow from any entrained pressure in the injection line or conduit.

Advantageously, the above ratchet mechanism may allow for a variety of configurations. For instance it may be configured to allow for a large number, for example ten, pressure cycles in order to complete the opening process. By partially moving the ratchet pin 122 and/or actuating assembly 1 14 the device may be set up to open at five pressure cycles. The device 100 can therefore be set up to open at any number of cycles only limited by the number of potential ratchet positions provided in the ratchet pin 122.

Although one specific embodiment of the invention is described above, it will be appreciated that variations thereof may be provided within the scope of the present invention.

For example, an alternative device 100' is shown in Figure 12. The device 100' is substantially similar to that shown in Figures 8 to 1 1 but comprises a side inlet 104' that offers a higher available area and path for flow through the device 100' compared to the device 100 of Figures 8 to 11.

Although the examples given above relate to blocking devices for an injection line or conduit 40, 40', it will be appreciated that the above principles can also be applied to other applications. One example is shown in Figures 13 to 16, which show a pressure relief valve

100'.

In some instances the injection line or conduit 40' is conveyed through large bore tubing which may be run within the production tubing 24. This configuration allows the slim tubing to be used as a pulling tool to allow any equipment within the well completion below the injection line or conduit 40' to be removed. In the process of removal of this slim tubing and any associated equipment hung from the slim tubing, it is not desirable to pull this assembly with the slim tubing full of fluid as this may greatly increase weight. It is therefore desirable to provide a mechanism to allow for the slim tubing to be vented to the well annulus 20 or production tubing 24 to allow the slim tubing to drain off fluid as it is pulled from the well completion.

One possible means of providing this functionality is to use a ball drop relief system, where a ball is dropped into the slim tubing. This ball then travels down through the slim tubing until is encounters a physical restriction where the diameter or of the ball is deliberately larger than a physical stop it encounters. The restriction then allows pressure to be applied to the slim tubing which in turn will meet the restriction of the ball which in turn provides a pressure resistance. This positive pressure in the slim tubing can then be used to shear out a relief device or burst disk which then provides a means of relieving the fluid form the slim tubing.

This however introduces the risk of a pressure shock and debris, which can affect both down hole equipment as well as the topside pumping equipment.

The soft open approach and principle described above can also be used for this application and may be based on a multiple cycle/ratchet system or may be a single cycle actuation design where one application of a pressure cycle engages a relief mechanism to relieve fluid from the slim tubing.

As shown in Figure 13, the valve 100' comprises a valve body 202 defining an inlet 204, an outlet 206 and a flow path 20 there between. A first part in the form of an inner part 210 is slidably mounted within the valve body 202. A plurality of flow passages 212 extend through walls of the valve body 202 and, in a closed configuration of the valve 100', as shown in Figure 13, the flow passages are sealably closed by the inner part 210 and seals 214.

The inner part 210 also comprises apertures 215, corresponding to the flow passages 212. However, in the closed configuration, the inner part is located such that the apertures are longitudinally spaced from the flow passages 212, with the seals 214 being provided there between. A second part in the form of an engagement sleeve 216 is slidably mounted within the valve body 202. An operating spring 218 is compressed between the valve body 202 and the engagement sleeve 216 so as to bias the engagement sleeve 216 towards the inlet 204 and the flow passages 212. The engagement sleeve 216 is provided with a limiter 220, which is configured to engage with a corresponding limiter 222 on the inner wall of the valve body 202 so as to limit the motion of the engagement sleeve 216 in a second direction towards the inlet 204.

The engagement sleeve 216 is provided with lock collets 224 that are biased radially outwardly but, in the closed configuration of the valve 100' are retained against the bias in a recess 226 in the engagement sleeve 216 by the inner part 210. Although lock collets 224 are described, it will be appreciated that lock balls or other suitable locking mechanisms may be used.

In use, as shown in Figure 14, an actuating ball 227 is provided in the injection line or conduit 40' so that it comes to rest on a shoulder 228 on an inlet facing end of the engagement sleeve 216.

Since the ball 227 provides a restriction to flow, should a flow of a low to moderate value be applied the slim tubing line, pressure will build, thereby creating a differential pressure between the inlet 204 to the outlet 206.

This differential in pressure eventually overcomes the force applied by the operating spring 218 when the pressure differential becomes greater than a threshold value defined by the operating spring 218. This allows the engagement sleeve 216 and also the lock collect to move in a first (axial) direction away from the inlet 204 and towards the outlet 206, compressing the operating spring 218 in doing so.

Once the end of the lock collet 224 passes an end of the inner part 210, the lock collet 224 extends radially outwardly due to the bias on the collet 224 into recess slots or over the end or a shoulder of the inner part 210 to thereby engage, attach or hook the inner part 210, i.e. the inner part 210 has now been locked onto the engagement sleeve 216, as shown in Figure 15.

The line pressure in the slim tubing is then removed by reducing flow. During the flowing state the ball 227 offers a significant resistance to flow which is the mechanism to allow the differential pressure to occur. The valve 100' includes a very small internal leakage from the inlet 204 to the outlet 206 by way of a single or series of micro equalisation ports 230. These ensure that there can be no lock of pressure on the downstream side in a static condition where there is no flow present. Due to the equalisation effect, as flow and therefore pressure reduce, the operating spring 218 pushes the engagement sleeve 216 back towards its initial position. However as the lock collet has engaged the inner part 210, the operating spring 218 moves both the engagement sleeve 216 and inner part 210 to the rest position of the engagement sleeve 216.

This movement aligns the apertures 215 in the inner part 210 with the flow passages 212 in the valve body 202. These flow passages 212, which are significantly larger than the micro equalisation ports 230, communicate the inside of the valve body 202 to the annulus or another volume or region as is required for the vent and relief of fluid pressure.

In this way, as the slim tubing and the valve are withdrawn from the well, the exposed flow passages will allow any fluid to drain out, reducing the weight of the assembly being recovered.

A summary of a method of operating the devices, such as the device 100 shown in Figures 8 to 1 1 is shown in Figure 17.

The device 100 is initially in a closed configuration, thereby blocking the flow channel 108 between the inlet 104 and the outlet 106 (step 305).

A pressure cycle is performed, wherein an overpressure is applied at the inlet 104, to thereby cause a pressure differential between the inlet 104 and the outlet 106 that is greater than a first pressure differential threshold required to overcome the sensor spring 125 and actuate the first actuating assembly 1 14 in the first direction (Step 310). Whilst moving in the first direction, the pawls 132a of the first ratchet arm cam over one or more protrusions 126 on the ratchet pin 122 since the ratchet pin 122 is prevented from moving in the first direction by engagement between the pawls 132b of the second ratchet arm 124 and one or more protrusions 126 on the ratchet pin 122.

After the first actuating member 1 14 has moved over its range of motion as defined by the recess 129, the over pressure is removed and the pressure differential between the input 104 and the output is lowered to below the first pressure differential threshold. In this case the sensor spring 125 acts to move the actuating assembly 1 14 back in the second direction. This causes the radially extending faces 136 on the pawl 132a of the first ratchet arm 120 to engage with corresponding radially extending faces 130 of the protrusions 126 of the ratchet pin 122 thereby causing the ratchet pin 122 to move in the second direction along with the actuating assembly 114 (Step 315).

This ratcheting action is repeated in order to sequentially move the ratcheting pin 122 in the first direction until the locking mechanism 1 12 is unlocked and the shoulders 156 on the ratchet pin 122 engage and slide the sleeve 152 away from the first channel passages 148 (Step 320). In this case, flow between the inlet 104 and the outlet 106 can occur via the first passages 148.

This continues until the pressure differential between the inlet 104 and the outlet 106 is less than the second pressure differential threshold, whereupon the opening spring 138 is operable to separate the device body 102 and the inner part 110, thereby opening the second passages 150 and permitting full flow through the flow channel 108 (Step 325).

It should be understood that the embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope of the invention. For example, one or more features defined in relation to any one embodiment may be applied or utilised within or in combination with any other embodiment.

Claims

A device for controlling flow in a line, conduit or capillary, the device comprising at least one inlet, at least one outlet and at least one flow path extending between the at least one inlet and the at least one outlet, the at least one inlet and/or outlet being connectable to the line, conduit or capillary;

the device being operable to selectively open, close and/or vary a degree of opening and/or closing of the line, conduit or capillary by opening, closing and/or varying a degree of opening and/or closing the at least one flow path, and/or to vent or relieve the line, capillary or conduit;

the device comprising at least a first part and a second part;

the first part comprising at least one engagement or attachment member;

the second part comprising at least one cooperating arrangement;

the first part being movable in a first direction into a configuration where at least one of the engagement or attachment members engages, attaches or is attachable to or engagable with at least one of the cooperating arrangements of the second part; and

the first part being movable in a second direction whilst at least one of the engagement or attachment members of the first part is engaged or attached to at least one of the cooperating engagements of the second part so as to move the second part and thereby vary opening of and/or open and/or close the flow path.

The device according to claim 1 , wherein the line conduit or capillary comprises or is comprised in an injection line or conduit in or for a downhole injection system.

The device according to any preceding claim, wherein the device is configured to remain closed during one or more pressure cycles applied to the inlet.

The device according to any preceding claim, wherein at least one or each of the engagement or attachment members and/or at least one or each of the cooperating arrangements comprises or is comprised in a one-way mechanism that allows motion of the first part relative to the second part in the first or second direction but resists motion of the first part relative to the second part in the other of the first or second directions.

5. The device according to claim 4, wherein at least one or each of the engagement or attachment members and/or at least one or each of the cooperating arrangements is, comprises or is comprised in a ratchet mechanism, such as a first ratchet mechanism.

6. The device according to any preceding claim, wherein the device is configured to receive or create a differential pressure between the inlet and the outlet, in at least one configuration of the device, in use; wherein

at least the first part is in pressure communication with the flow path on upstream or inlet and downstream or outlet sides of the device; and

at least the first part is movable in the first and/or second direction by the pressure differential.

7. The device according to any preceding claim, comprising a first biasing means, the first biasing means being operable to bias the first part in the first and/or second directions.

8. The device according to claim 7 when dependent on claim 6, wherein the first biasing means is operable to bias the first part in a different one of the first or second directions to the direction in which the first part is moved or movable under the pressure differential; and/or in an opposite direction to the direction in which the first part is moved or movable under the pressure differential.

9. The device according to claim 7 or claim 8, wherein the first biasing means is compressable, resetable, pressurisable retractable, and/or contractable by the pressure differential when the pressure differential is greater than a first pressure differential threshold.

10. The device according to claim 9, wherein the first pressure differential threshold is selectable or adjustable.

1 1. The device according to any of claims 7 to 10, wherein the first biasing means is configured to provide a force that is greater than a hydrostatic pressure at the inlet, in use.

12. The device according to claim 9 or any claim dependent thereon, wherein the first part is movable in the first or second direction when the pressure differential is greater than the pressure differential threshold and the first biasing means is configured to move the first part in the other of the first or second directions when the pressure differential is less than the pressure differential threshold.

13. The device according to claim 12, wherein the second part is movable relative to the first part by applying one or more pressure cycles, wherein each pressure cycle comprises applying a differential pressure between the inlet and the outlet greater than the first differential pressure threshold and applying a differential pressure between the inlet and the outlet less than the first differential pressure threshold.

14. The device according to claim 13, wherein the device may be configured such that at least one or each of the flow paths is varied, opened or partially opened, and/or the device is placed in an open configuration, such as a first or restricted open configuration, and/or is switchable between an closed and an open configuration by application of one or more pressure cycles.

15. The device according to claim 14, wherein the device is switchable between the first open configuration and a second open configuration by applying one or more further pressure cycles and the first open configuration is associated with a lower flow rate and/or smaller opening area than the second open configuration.

16. The device according to any preceding claim, wherein the device is adapted such that the second part is movable in the second direction by applying one or more movement cycles, wherein each movement cycle comprises moving the first part in the first direction relative to the second part and then moving the first and second parts together in the second direction.

17. The device according to claim 16, wherein the device is adapted to apply a plurality of movement cycles, wherein each movement cycle sequentially moves the second part in the second direction.

18. The device according to claim 17, wherein the device is configured such that at least one or each of the flow paths is varied, opened or partially opened, and/or the device is placed in an open configuration, such as the first or restricted open configuration, by application of one or more movement cycles.

19. The device according to claim 18 when dependent on claim 15, wherein the device is configured to be switchable between the first open configuration and the second open configuration by applying one or more further movement cycles.

20. The device according to any of claims 16 to 19 when dependent on claim 13 or any claim dependent on claim 13, wherein the device is configured such that application of one or more or each pressure cycle results in the device undergoing corresponding one or more or each movement cycles.

21. The device according to any preceding claim, wherein the first part has a defined stroke range provided by limiting portions for engaging a housing or sleeve at one or more limits of motion of the first part.

22. The device according to any preceding claim, wherein at least one or each of the engagement or attachment members and/or at least one or each of the cooperating arrangements is configured to permit motion of the attachment member(s) past or over the at least one or each of the cooperating arrangements in the first or second direction but resist movement of the engagement or attachment member(s) over or past the cooperating arrangement(s) in the other of the first or second directions and/or be configured to engage or attach to the cooperating arrangement(s) when the engaging or fixing members are moved in the other of the first or second directions.

23. The device according to claim 22, wherein at least one or each of the cooperating arrangements comprises a cam surface shaped to permit the engagement or attachment member(s) to pass over the cooperating arrangement(s) in the first or second direction but to engage or attach to the engagement or attachment member(s) when they are moved in the other of the first and second directions.

24. The device according to any preceding claim, wherein the second part comprises a plurality of cooperating arrangements distributed in the first and/or second directions and/or a longitudinal or axial direction of the second part.

25. The device according to any preceding claim, wherein the device is configured to move or reposition the second part in the second direction by sequentially moving the first part in the first direction so that at least one or more of the engagement or attachment members engages or attaches to one or more corresponding cooperating arrangements then moving the first and second parts together or joined in the second direction, each sequential movement of the first part in the first direction resulting in at least one or more of the engagement or attachment members engaging or attaching to respective one or more corresponding cooperating arrangements that are spaced apart in the first direction relative to the one or more corresponding cooperating arrangements engaged by or attached to the one or more of the engagement or attachment members during the previous sequential movement.

26. The device according to any preceding claim, wherein the device is configured to selectively receive, apply or vary the pressure at the inlet and/or the pressure differential and/or the device is configured to receive or apply a pressure differential higher than the pressure differential threshold in order to move the first part in the first or second direction and to receive or apply a pressure differential lower than the pressure differential threshold in order to move the first part in the other of the first or second directions using the first biasing means.

27. The device according to any preceding claim, comprising a third part, the third part being arranged to interact with the second part so as to resist motion of the second part in the first direction but allow motion of the second part in the second direction.

28. The device according to claim 27, wherein the third part is or comprises or is comprised in a fixed or stationary part and the second part is movable relative to the third part in the second direction by the first part and/or under the action of the first biasing means and/or the pressure differential.

29. The device according to claim 27 or claim 28, wherein the third part comprises at least one engagement or attachment member adapted to attach or engage with one or more or each of the cooperating mechanisms of the second part.

30. The device according to claim 29, wherein the second part is movable in the second direction relative to the third part into a configuration in which one or more or each of the engagement or attachment members of the third part engages, attaches or is attachable to or engagable with the one or more cooperating engagements of the second part; and the engagement or attachment members of the third part are configured to engage or attach to the cooperating mechanism(s) of the second part so as to resist motion of the second part in the first direction relative to the third part.

31. The device of claim 30, wherein the engagement or attachment members of the third part and the cooperating mechanisms of the second part are, comprise or are comprised in a ratchet mechanism, such as a second ratchet mechanism.

32. The device according to any of claims 27 to 31 , wherein the second part is movable away from or out of contact with the third part.

33. The device according to claim 32, wherein the system is configured such that the second part is movable into the configuration in which it is displaced or spaced apart from the third part in the second direction by sequentially applying one or more pressure cycles and/or movement cycles.

34. The device according to any preceding claim, wherein the device comprises a device body and the first, second and/or third parts are located or locatable within the device body and at least one first and/or second opening is provided through a wall of the device body.

35. The device according to claim 34 comprising sealing or closing means for selectively sealing or closing one or more or each of the first and/or second openings or passages, the sealing or closing means being comprised on or in or movable or operable by the second part, the sealing or closing means being configured to selectively open, close and/or vary the system flow path.

36. The device according to claim 35, wherein the sealing or closing means are movable or slidable in the first and/or second direction and the sealing or closing means and the second part comprise mutually engagable portions, the mutually engagable portions of the sealing or closing means being spaced apart from the mutually engaeable portions of the second part in an initial configuration, and the device being configured such that they are brought into engagement once the second part has moved a selected or predefined distance.

37. The device according to any of claims 35 or 36, wherein the sealing or closing means are biased by a second biasing means into a closed configuration in which at least one or more of the passages or apertures are closed, wherein the second biasing means has a spring constant or force less than the first biasing means.

38. The device according to claim 37, wherein the second biasing means is compressible, retractable or pressurizable by a force applied by the second part when the second part is moved by the first biasing means.

39. The device according to claim 34 or any claim dependent thereon wherein the system is configured such that one or more or each of the first openings or passages is opened when the third part is displaced or spaced apart from the second part and/or after a selected or predetermined number of pressure and/or movement cycles.

40. The device according to claim 34 or any claim dependent thereon, wherein the at least one second opening or passage is switchable between a closed and an open configuration under the action of the pressure differential between the inlet and the outlet.

41. The device according to claim 40, wherein the at least one second opening or passage is switchable between a closed and an open configuration when the pressure differential is below a second pressure differential threshold that is lower than the first pressure differential threshold.

42. The device according to any of claims 40 or 41 , wherein the device further comprises fourth and fifth parts and the at least one second opening or passage is switchable between a closed and an open configuration by relative movement of the fourth and fifth parts.

43. The device according to claim 42, wherein the first, second and/or third parts are comprised or provided in the fourth part and the system comprises a third biasing means provided, or arranged to act, between the fourth and fifth parts.

44. The device according to claim 43, wherein the third biasing means is compressible, retractable, contractable and/or pressurisable by the pressure differential when the pressure differential is greater than the second threshold pressure differential; and/or the at least one second opening or passage is configured to open under the action of the third biasing means when the pressure differential is less than the second pressure differential threshold.

45. The device according to any preceding claim, wherein the device comprises a locking mechanism operable to selectively lock and/or unlock the one or more second openings or passages in the closed position and/or selectively lock and/or unlock the fourth and fifth parts so as to prevent relative motion therebetween.

46. The device according to any preceding claim, wherein the first part comprises a seat configured to receive an operation body provided to the inlet such that location of the operation body on the seat at least partially or fully blocks the flow channel, the device being configured such that when the operation body is located in the seat and the input is provided with flow, in use, the pressure differential between the input and the output increases and/or becomes higher than the first pressure differential threshold.

47. The device according to claim 46, wherein the device comprises one or more bypass channels that bypass the seat so as to at least partially form one or more restricted bypasses between the inlet and the outlet.

48. An injection system for injecting a fluid downhole, the system comprising:

at least one device according to any of claims 1 to 47; and

an injection line connected to the inlet of the device.

49. The system of claim 48, comprising a pump or other pressurising means, attached or attachable to the injection line, the pump and/or other pressurising means being operable to selectively control the pressure in the injection line and/or at the inlet and/or the pressure differential.

50. A method of operating a device according to any of claims 1 to 47, the method comprising applying one or more pressure cycles and/or movement cycles to an inlet of the device until the device opens or is placed in a first or restricted open configuration; wherein

the pressure cycle comprises sequentially applying a first or higher pressure or pressure differential then a second or lower pressure or pressure differential, wherein the first or higher pressure or pressure differential is or results in a pressure differential that is greater than the first pressure differential threshold of the device and the second or lower pressure or pressure differential is, or results in, a pressure differential that is lower than the first pressure differential threshold; and

the pressure cycle comprises sequentially applying the first or higher pressure or pressure differential and then the second or lower pressure or pressure differential.

51. The method of claim 50, wherein the first or higher pressure is higher than a hydrostatic pressure at the inlet or in the injection line, in use.

52. The method of claim 50 or claim 51 , comprising subsequently placing the device in a second opened configuration associated with a higher flow than the first opened configuration.

53. The method of claim 52, comprising placing the device in the second opened configuration by reducing the pressure differential below a second pressure differential threshold, which is lower than the first pressure differential threshold.

54. The method of any of claims 50 to 53, comprising providing an operation body at the inlet to at least partially block the flow channel so as to increase the pressure or pressure differential and/or provide the first or higher pressure or pressure differential and/or controlling the pump so as to provide at least part or all of the pressure cycle.

55. A method of testing an injection line or conduit, the method comprising providing a device according to any of claims 1 to 47 in or connected to or otherwise in communication with an injection line or conduit to close the injection line or conduit and performing the method of any of claims 50 to 54.

56. A method of manufacturing or assembling a device according to claim 45, the method comprising placing or providing the locking mechanism of the device in the locked configuration during assembly and/or before use and/or until the device or flow system is exposed to fluid flow and unlocking the locking mechanism in use and/or whilst the device and/or flow system is subject to flow.