DOWNHOLE FLUID FLOW CONTROL DEVICE

Description

FIELD OF THE INVENTION

The present invention relates to a fluid flow control device for use with downhole apparatus, such as oil and gas well equipment, and particularly, but not exclusively, to a hydraulically actuatable fluid flow control device for controlling the flow of fluid from one region of a downhole apparatus, such as the production tubing/string, to another region, such as the annulus between the tubing/string and the outer casing or well bore.

BACKGROUND TO THE INVENTION

The use of fluid flow control devices in downhole apparatus, such as oil and gas wells, is well known. In downhole oil and gas operations downhole equipment, such as valves, sleeves, inflow control devices (ICDs), packers, and the like, may be operated by the use of pressure.

For example, some equipment may be operated by the use of hydrostatic pressure within the wellbore. Other equipment may be actuated by the use of pressure differentials, for example the use of internal tubing pressure and external annulus pressure.

There are various methods of controlling such fluid flow devices, such as the use of electromagnetic devices, hydrostatic pressure, or the like.

Often, a fluid flow control device is required to control the fluid flow from one part of a downhole apparatus, such as inside a production string, to another part of the downhole apparatus, such as the annulus between the string and the outer casing or the well bore. For example, it is desirable to selectively control the flow of oil and gas, and other fluids, from a formation into the production string. Inflow control devices are one such method of controlling the flow of fluid from formation to the production string and ultimately to surface.

Other applications of fluid flow control include when setting a packer. For example, a fluid flow control device may be used to directly apply the required pressure to set the packer, or may be used as a control device to activate a further fluid flow device to set the packer.

The present inventors have appreciated that some known types of fluid flow control devices used downhole have some drawbacks.

For example, some known devices need to be scaled in size to fit different bore sizes, due to the design of the fluid flow control device.

Some fluid flow devices are known to be moved to an open state or open position when positive pressure is applied to the device. Such a method of opening the fluid flow device may risk damage to the well bore, at least in some applications.

Some electronic and/or magnetic-based fluid flow devices typically rely on the use of electromagnetic fields to actuate valves and the like. By their very nature, these fluid flow devices require a certain complexity of design and of course require the presence of electronic and/or magnetic components.

It is commonplace that a defined sequence of events is required to operate some downhole tools. If each event is initiated by pressure then there is a risk of premature function of an event. For example, pressure testing is often required in downhole operations in order to confirm pressure integrity of the completion string during or after deployment.

However, if one or more pressure operated devices are included in the completion then a risk that such devices could be prematurely activated exists.

Without wishing to be bound by theory, some fluid flow control devices for use downhole are thought to be oversized for the requirements of the target application, and therefore it would be desirable to design a fluid flow control device that lends itself to being more compact than existing designs.

The failure rate of some downhole components is also a consideration in designing fluid flow devices, and it would therefore be desirable to provide a device that is more robust than existing devices and methods of controlling the flow of fluid.

STATEMENTS OF INVENTION

According to a first aspect of the present invention there is provided a fluid flow control device for a downhole apparatus, the device comprising:

• • a body portion comprising a first fluid flow port and a second fluid flow port;
  • a fluid flow path from the first fluid flow port to the second fluid flow port; and
  • a valve member located in the fluid flow path and configured to be movable from a first, closed position in which the fluid flow path is blocked by the valve member, and a second, open position in which the fluid flow path is open;
  • wherein the valve member is configured to be movable from the first, closed position to the second, open position in response to a valve pressure cycle comprising:
  • application of a positive differential pressure from the first flow port to the second flow port; and
  • removal of the positive differential pressure.

The first and second fluid flow ports can be of any suitable shape, geometry and design, and the term “port” is not intended to convey any particular type or shape of fluid flow port beyond what the context in this patent specification provides.

The fluid flow control device may be configurable between a first, closed state in which fluid cannot flow between the first and second fluid flow ports, and a second, open state in which fluid can flow therebetween. The fluid flow control device may be configurable between a first, closed state in which fluid cannot flow between the first and second fluid flow ports, and a second, open state in which fluid can flow from the second fluid flow port to the first fluid flow port.

The fluid flow control device may be configured to permit fluid to flow from the second flow port to the first flow port, and/or from the first flow port to the second flow port, when the device is in the second, open state. The fluid flow control device may be configured to prevent or restrict fluid flow from the first fluid flow port to the second fluid flow port when the device is in the second, open state.

The fluid flow control device may comprise a plurality of first fluid flow ports and/or a plurality of second fluid flow ports.

The first fluid flow port may be located at a first end of the body portion and the second fluid flow port may be located at a second end of the body portion. The first and second ends of the body portion may be opposite ends thereof. The body portion may be an elongate member. The body portion may comprise a longitudinal axis. The body portion may be elongate along the longitudinal axis thereof. The fluid flow path may be generally along the longitudinal axis of the body portion. The body portion may be a cylindrical or cuboidal member, or any suitable shape. The body portion may be fluid impermeable. The first and second fluid flow ports may be openings, or the like. It will be understood that in some example embodiments, it may be desirable for the body portion or the fluid flow ports to have connectors, such as threaded parts or flanges, for connecting to a further component.

The first and second fluid flow ports may be configured to permit bi-directional fluid flow.

The valve member may be configured to be movable from the first, closed position to an intermediate closed position, in which the valve member continues to block the fluid flow path. The valve member may be movable from the intermediate closed position to the second, open position.

The body portion may include one or more stop members configured to stop the valve member at the intermediate closed position. The stop member may be a flange, or the like.

The valve member may be a piston. The valve member may be a fluid impermeable member. The valve member may be an elongate longitudinal member. The valve member may include a head portion. The head may be a piston head. The head may be configured to receive positive pressure from the first fluid flow port.

The body portion may include a housing for receiving at least a portion of the valve member therein. The housing may be a cylinder. The one or more stop members may be located at a wall of the housing. The valve member may be slidably engageable with the housing.

A first end of the housing may be fluidly connected to the first fluid flow port. A second end of the housing may be fluidly connected to the second fluid flow port. The housing may define a portion of the fluid flow path when the valve member is in the second, open position.

The valve member may be configured to be movable in a first direction in response to the application of positive differential pressure. The valve member may be configured to be movable in a second direction in response to the removal of the positive differential pressure.

The first direction may be a straight direction. The second direction may be a straight direction. The first and second directions may be opposite directions. The first direction may be towards the second fluid flow port. The second direction may be towards the first fluid flow port.

The valve member may be movable from the first, closed position to the second, open position by moving in the first direction and then moving in the second direction. The valve member may be movable in the first direction from the first, closed position to the intermediate closed position, and movable in the second direction from the intermediate closed position to the second, open position.

The valve member may be configurable between a first, locked state, in which the valve member cannot be moved to the second, open state, and a second, unlocked state, in which the valve member can be moved to the second, open state.

The valve member may be configurable from the first, locked state to the second, unlocked state in response to application of the positive differential pressure from the first flow port to the second flow port.

The valve member may include a locking mechanism for locking the valve member in the first, locked state. The locking mechanism may be an irreversible locking mechanism. The locking mechanism may be irreversibly breakable. The locking mechanism may include one or more locking members. The locking member(s) may be shear pins, or the like.

The fluid flow control device may comprise two or more valve members, each movable between a first closed position and a second open position. The fluid flow control device may comprise any suitable number of valve members, each of which may open or close a different part of the fluid flow path.

The valve member may be configured as a one-way valve. The valve member may be a one-way valve in the second, open position.

The valve member may be a hydraulically actuatable valve. The valve member may be hydraulically actuatable from the first, closed position to the second, open position. The valve member may be hydraulically actuatable from the first, closed position to the intermediate closed position. The valve member may be hydraulically actuatable from the intermediate closed position to the second, open position.

The valve member may comprise a first end in fluid communication with the first flow port and a second end in fluid communication with the second fluid flow port. The first and second ends may be fluidly isolated when the valve member is in the first, closed position. The first and second ends may be fluidly isolated when the valve member is in the intermediate closed position.

The fluid flow control device may be configured to apply a biasing force to the valve member towards the second, open position. The valve member may include a valve biasing mechanism. The valve biasing mechanism may be configured to bias the valve member towards the second, open position. The valve biasing mechanism may be configured to move the valve member to the second, open position during the step of removing the positive differential pressure of the valve pressure cycle. The valve biasing mechanism may be a mechanical biasing mechanism. The valve member may include a valve biasing mechanism. The valve biasing mechanism may be configured to bias the valve member towards the second, open position. The valve biasing mechanism may include one or more spring members. The spring member(s) may be helical spring members, or the like. The spring members may be located at or around one or more walls of the valve member. The biasing mechanism may include a spring support for fixing the spring relative to the valve member. The spring may be fixedly connected to the spring support and to the valve member. The valve biasing mechanism may apply the biasing force to the head of the valve member and/or at least one wall thereof.

The fluid flow control device may include one or more, or a plurality of fluid flow paths between the first and second fluid flow ports. The, or each fluid flow path may have an associated valve member.

The valve member may be configured to permit fluid to flow from the second fluid flow port to the first fluid flow port when the valve member is in the second, open position.

When the valve member is in the second, open position, the valve member may be configured to prevent or reduce the flow of fluid from the first fluid flow port to the second fluid flow port. The valve member may be configured to return from the second, open position to the first closed position or the intermediate position if positive pressure is applied from the first fluid flow port to the second fluid flow port.

The fluid flow control device may comprise a trigger mechanism. The trigger mechanism may be operable to convert the valve member from a secured state, in which the valve member cannot be moved, and an unsecured state, in which the valve member can be moved. In the unsecured state, the valve member may be unlockable.

The trigger mechanism may be a hydraulically actuatable trigger mechanism.

The trigger mechanism may comprise a trigger member. The trigger member may be operable to secure and to unsecure the valve member. The trigger mechanism may comprise at least one trigger member.

The trigger member may be a piston. The trigger member may be a fluid impermeable member. The trigger member may be an elongate longitudinal member. The trigger member may include a head portion. The head may be a piston head. The trigger head may be configured to receive positive pressure from the first fluid flow port.

The trigger mechanism may comprise one or more, or a plurality of trigger members.

The, or each trigger member may be operable to secure/unsecure the valve member, or one or more valve members, or two or more valve members.

The trigger member may be movable from a first position to a second position. The trigger mechanism may be configured to unsecure the valve member by moving the trigger member from the first position to the second position. The trigger member may be movable from the first position to an intermediate position. The trigger member may be movable from the intermediate position to the second position. The trigger member may be movable along a first trigger direction when moving from the first position to the intermediate position. The trigger member may be movable along a second trigger direction when moving from the intermediate position to the second position. The first trigger direction may be in the same direction as the first direction of the valve member. The second trigger direction may be in the same direction as the second direction of the valve member.

The body portion may include one or more stop members configured to stop the trigger member at the intermediate trigger position. The stop member may be a flange, or the like. The body portion may include a trigger housing for receiving at least a portion of the trigger member therein. The trigger housing may be a cylinder. The one or more stop members may be located at a wall of the trigger housing. The trigger member may be slidably engageable with the housing.

The trigger mechanism may comprise a securing mechanism for securing the valve member. The trigger member may be configured to operate the securing mechanism. Moving the trigger member from the first position to the second position may operate the securing mechanism. Moving the trigger member to the second position may operate the securing mechanism to unsecure the valve member.

The securing mechanism may be configured to restrict or prevent movement of the valve member along at least one axis of the body portion. The axis may be the longitudinal axis of the body portion.

The securing mechanism may include one or more securing members. The one or more securing members may be configured to engage with and secure the valve member in the first, closed position. The one or more securing members may be configured to engage with and secure the valve member in the first, closed position when the trigger member is in the first position. The one or more securing members may be engageable with a securing member receiving portion of the valve member. The receiving portion may be a recess, groove, channel, slot, or the like. The one or more securing members be a ball member, a bearing, or the like.

The securing mechanism may be configured to engage with and secure the one or more, or the two or more valve members.

The securing member may be engageable with the trigger member. The securing member may be configured to engage with and secure the valve member and to engage with or be in abutment with the trigger member when the trigger member is in the first position.

The one or more securing members may be disengaged from the valve member when the trigger member is in the second position. The one or more securing members may unsecure the valve member when the trigger member is in the second position.

The trigger member may be configured to move the securing member from a first, engaged position, in which the securing member engages and secures the valve member, and a second, disengaged position, in which the securing member is disengaged from and unsecures the valve member. The trigger member may move the securing member from the first, engaged position to the second, disengaged position when the trigger member moves from the first position to the second position. The trigger member may comprise a guide configured to move the securing member from the first, engaged position to the second, disengaged position when the trigger member moves from the first to second position. The guide may be a variable depth portion in a wall or walls of the trigger member, or the like. The guide may include a recess for accommodating at least a part of the securing member therein.

The securing member may be configured to move from the first, engaged position to the second, disengaged position along an axis that is substantially perpendicular to the longitudinal axis of the body portion.

The trigger member may be configured to be movable from a first, locked state, to a second, unlocked state. The trigger member may be movable from the first, locked state to the second, unlocked state in response to a trigger pressure cycle. The trigger pressure cycle may comprise application of a positive differential pressure from the first flow port to the second flow port. The application of positive differential pressure of the trigger pressure cycle may unlock the trigger member.

The trigger member may be movable from the first trigger position to the second trigger position in response to a trigger pressure cycle. The trigger pressure cycle may further comprise removal of the positive differential pressure. The trigger member may be movable from the first trigger position to the second trigger position in response to the trigger pressure cycle comprising:

• • application of a positive differential pressure from the first flow port to the second flow port; and
  • removal of the positive differential pressure.

The fluid flow control device may be configured to secure the valve member, and to then unsecure the valve member in response to the trigger pressure cycle. The fluid flow control device may be configured such that, when the valve member has been unsecured by the application of the trigger pressure cycle, the valve member is configured to be movable from the first, closed position to the second, open position in response to the valve pressure cycle.

The valve pressure cycle may open the fluid flow path. The trigger pressure cycle, followed by the valve pressure cycle may open the fluid flow path. The fluid flow control device may be configurable from the closed to the open state in response to the application of the trigger pressure cycle and the valve pressure cycle.

The trigger mechanism may comprise a trigger locking mechanism for locking the trigger member in the first, locked state. The trigger locking mechanism may be an irreversible locking mechanism. The trigger locking mechanism may be irreversibly breakable. The trigger locking mechanism may include one or more locking members. The locking member(s) may be shear pins, or the like.

The trigger member may comprise a first end in fluid communication with the first flow port and a second end in fluid communication with the second fluid flow port. The first and second ends may be fluidly isolated when the trigger member is in the first position. The first and second ends may be fluidly isolated when the trigger member is in the second position. The first and second ends may be fluidly isolated when the trigger member is in the intermediate position.

The valve pressure cycle may be applied using any suitable downhole fluids. For example, hydraulic fluid could be provided to the first fluid flow port, and the fluid in the annulus provided to the second fluid flow port.

The trigger pressure cycle may be applied using any suitable downhole fluids. For example, hydraulic fluid could be provided to the first fluid flow port, and the fluid in the annulus provided to the second fluid flow port. Fluid present in the annulus could be fluid from a reservoir or formation, or any other fluid found in, or commonly used in the annulus.

The fluid flow control device may be configured to apply a biasing force to the trigger member towards the second position. The trigger member may include a trigger biasing mechanism. The trigger biasing mechanism may be configured to bias the trigger member towards the second position. The trigger biasing mechanism may be configured to move the trigger member to the second position during the step of removing the positive differential pressure of the trigger pressure cycle. The trigger biasing mechanism may be a mechanical biasing mechanism. The trigger biasing mechanism may include one or more spring members. The spring member(s) may be helical spring members, or the like. The spring members may be located at or around one or more walls of the trigger member. The trigger biasing mechanism may include a spring support for fixing the spring relative to the trigger member. The spring may be fixedly connected to the spring support and to the trigger member. The trigger biasing mechanism may apply the biasing force to the head of the trigger member and/or at least one wall thereof.

The fluid flow control device may be configured to prevent the trigger member moving from the second position to the first position. The fluid flow control device may be configured to prevent the trigger member moving from the second position to the first position when the valve pressure cycle is applied.

The trigger mechanism may comprise a retainer configured to prevent the trigger member moving from the second position to the first position. The retainer may be configured to prevent movement of the trigger member from the second position in the first trigger direction. The retainer may be configured to engage with and retain the trigger member when the trigger moves to the second position. The retainer may include one or more protruding members for engaging with one or more corresponding retaining member receiving portions of the trigger member, and/or the trigger member may include one or more protruding members for engaging with one or more corresponding retaining member receiving portions of the retainer.

The trigger member and the retainer may comprise one or more complimentary abutment members arranged to be in abutment when the trigger member is in the second position. In this example, the abutment members prevent the trigger member moving from the second position to the first position.

The retainer may be slidably engageable with the trigger member.

The downhole apparatus may include, or may be an inflow control device, packer, a downhole valve, a downhole sliding sleeve, or the like.

The fluid flow control device may be configured for fluidly connecting production tubing to the annulus between the production tubing and the outer casing or the well bore. Other applications of the fluid flow control device will be readily apparent to those of skill in the art.

According to a second aspect of the present invention there is provided a downhole apparatus comprising:

• • a fluid flow control device for a downhole apparatus, the device comprising:
    • a body portion comprising a first fluid flow port and a second fluid flow port;
    • a fluid flow path from the first fluid flow port to the second fluid flow port; and
    • a valve member located in the fluid flow path and configured to be movable from a first, closed position in which the fluid flow path is blocked by the valve member, and a second, open position in which the fluid flow path is open;
    • wherein the valve member is configured to be movable from the first, closed position to the second, open position in response to a valve pressure cycle comprising:
      • application of a positive differential pressure from the first flow port to the second flow port; and
      • removal of the positive differential pressure.

The downhole apparatus may be an inflow control device, or a packer, a downhole valve, a downhole sliding sleeve, or any suitable downhole apparatus.

The downhole apparatus may comprise a string or tubing and an annulus between the string/tubing and the outer casing or well bore. The first fluid flow port may be fluidly connected to an inner portion of the string or tubing and the second fluid flow port may be fluidly connected to the annulus. The second fluid flow port may be fluidly connected to an inner portion of the string or tubing and the first fluid flow port may be fluidly connected to the annulus.

The string or tubing may be a production string or production tubing.

According to a third aspect of the present invention there is provided a method of operating a fluid flow control device, the method comprising the steps of:

• • (i) providing a fluid flow control device for a downhole apparatus, the device comprising:
    • a body portion comprising a first fluid flow port and a second fluid flow port;
    • a fluid flow path from the first fluid flow port to the second fluid flow port; and
    • a valve member located in the fluid flow path and configured to be movable from a first, closed position in which the fluid flow path is blocked by the valve member, and a second, open position in which the fluid flow path is open;
    • wherein the valve member is configured to be movable from the first, closed position to the second, open position in response to a valve pressure cycle comprising:
    • application of a positive differential pressure from the first flow port to the second flow port; and
    • removal of the positive differential pressure;
  • (ii) arranging the first fluid flow port to receive fluid from a source of fluid;
  • (iii) arranging the second fluid flow port to receive fluid from another source of fluid; and
  • (iv) applying the valve pressure cycle to the valve member to move the valve member from the first, closed position to the second, open position.

According to a fourth aspect of the present invention there is provided a method of controlling the flow of fluid from a first region of a downhole apparatus to a second region, the method comprising the steps of:

• • (i) providing a downhole apparatus comprising a fluid flow control device for a downhole apparatus, the device comprising:
    • a body portion comprising a first fluid flow port and a second fluid flow port;
    • a fluid flow path from the first fluid flow port to the second fluid flow port; and
    • a valve member located in the fluid flow path and configured to be movable from a first, closed position in which the fluid flow path is blocked by the valve member, and a second, open position in which the fluid flow path is open;
    • wherein the valve member is configured to be movable from the first, closed position to the second, open position in response to a valve pressure cycle comprising:
    • application of a positive differential pressure from the first flow port to the second flow port; and
    • removal of the positive differential pressure;
  • (ii) arranging the first fluid flow port to receive fluid from a first region of the downhole apparatus;
  • (iii) arranging the second fluid flow port to receive fluid from a second region of the downhole apparatus; and
  • (iv) applying the valve pressure cycle to the valve member to move the valve member from the first, closed position to the second, open position.

The first region may be an inner portion of a string, such as a production string, and the second region may be an annulus between the string, such as a production string, and the outer casing or well bore, or the second region may be an inner portion of a string, such as a production string, and the first region may be an annulus between the string, such as a production string, and the outer casing or well bore.

Embodiments of the first to the fourth aspects of the invention may include one or more features of any one or more of the other aspects of the present invention or their embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described, by way of example, with reference to the drawings, in which:

FIG. 1a shows a fluid flow control device in accordance with an embodiment of the invention, in which the device is closed, with the trigger mechanism and valve members in their first positions;

FIG. 1b shows the device of FIG. 1a when the trigger is in the intermediate position and the valve members are in their first positions;

FIG. 1c shows the device of FIG. 1b when the trigger is in the second position and the valve members are in their first positions;

FIG. 1d shows the device of FIG. 1c when the trigger is in the second position and the valve members are in their intermediate positions; and

FIG. 1e shows the device of FIG. 1d when the trigger is in the second position and the valve members are in their second positions, such that the device is then open;

FIGS. 2a and 2b show a retainer of the trigger in detail; and

FIG. 3 shows a downhole apparatus comprising the fluid flow control device of FIG. 1a.

DESCRIPTION OF PREFERRED EMBODIMENTS

With reference to FIGS. 1a to 3, a fluid flow control device 1 for a downhole apparatus 100 is shown.

The downhole apparatus may include, or may be an inflow control device, packer, downhole valve, downhole sleeve, or the like.

The fluid flow control device 1 comprises a body portion 2 comprising a first fluid flow port 4 and a second fluid flow port 6, and there is a fluid flow path 8 from the first fluid flow port 4 to the second fluid flow port 6. The fluid flow device 1 comprises two valve members 10 (which in this embodiment are pistons) located in the fluid flow path 8 and each of the valve members 10 are configured to be movable from a first, closed position 12 in which the fluid flow path 8 is blocked by the valve members 10, and a second, open position 14 in which the fluid flow path 8 is open.

The valve member 10 is configured to be movable from the first, closed position 12 to the second, open position 14 in response to a valve pressure cycle comprising:

• • application of a positive differential pressure from the first flow port 4 to the second flow port 6; and
  • removal of the positive differential pressure.

In the embodiments shown here, the fluid flow control device 1 comprises a trigger mechanism 32 operable to convert each of the valve members 10 from a secured state 34, in which the valve member 10 cannot be moved, and an unsecured state 36, in which the valve member 10 can be unlocked and moved. As will be described in more detail below, in the embodiment shown here, the trigger mechanism 32 functions and moves in a similar manner to the valve members 10, and the trigger mechanism 32 ensures that the valves 10 can only be hydraulically actuated once the trigger mechanism 32 has undergone its trigger pressure cycle. In this way, two pressure cycles (a trigger pressure cycle and the valve pressure cycle) are required to open the fluid flow control device 1 to permit fluid to flow therethrough from the second fluid flow port 6 to the first fluid flow port 4. This mitigates the risk of the device 1 being opened accidently in response to a single pressure cycle. However, in some applications the trigger mechanism 32 is not required. Therefore, in some embodiments of the invention, the fluid flow control device 1 does not include the trigger mechanism 32, and the, or each valve member 10 is in the unsecured state 36, ready to be opened in response to the valve pressure cycle. In the embodiments without a trigger mechanism 32, the valve members 10 are typically still locked in place, as described above, prior to the application of positive pressure, although in some embodiments it may not be required to include a lock for the valves 10.

It will be understood that depending on the design of the fluid flow control device 1, the magnitude of the positive pressure required can be determined according to user preference, and considering the downhole application of the fluid flow control device 1.

The fluid flow control device 1 is configurable between a first, closed state 1a in which fluid cannot flow between the first and second fluid flow ports 4, 6, and a second, open state 1b in which fluid can flow therebetween. In this embodiment, in the open state 1b, fluid can flow from the second fluid flow port 6 to the first fluid flow port 4.

In other embodiments, it may be desirable to have bidirectional fluid flow (the fluid flow control device 1 could be configured to permit fluid to flow from the second flow port 6 to the first flow port 4, and/or from the first flow port 4 to the second flow port 6, when the device 1 is in the second, open state 1b).

In the embodiments illustrated and described here, the fluid flow control device 1 is configured to prevent or restrict fluid flow from the first fluid flow port 4 to the second fluid flow port 6 when the device 1 is in the second, open state 1b.

In the embodiments shown here, the fluid flow control device 1 has one first fluid flow port 4 and one second fluid flow port 6, but in other embodiments there could be a plurality of first fluid flow ports 4 and/or a plurality of second fluid flow ports 6.

The first fluid flow port 4 is located at a first end 2a of the body portion 2 and the second fluid flow port 6 is located at an opposite second end 2b of the body portion 2. The body portion 2 is an elongate cylindrical member comprising a longitudinal axis 2x. The fluid flow path 8 is generally along the longitudinal axis 2x, with the fluid flow path 8 splitting to go through the two valve members 10 before coming together towards the first end 2a. The body portion 2 is fluid impermeable such that any fluid flow through the body portion 2 occurs between the flow ports 4, 6. The first and second fluid flow ports 4, 6, are openings in the body portion 2. It will be understood that in some embodiments, it may be desirable for the body portion 2 or the fluid flow ports 4, 6, to have connectors, such as threaded parts or flanges, for connecting to a further component. The skilled person will readily appreciate how the device 1 can be fluidly connected within a downhole apparatus, such as an inflow control device or a packer, or other tool.

The first and second fluid flow ports 4, 6 are openings configured to permit bi-directional fluid flow therethrough, although the fluid flow control device 1 only allows fluid flow in a single direction through the fluid flow path 8.

Turning now to the operation of the valves 10, with the trigger mechanism 32 being described further below, each valve member 10 is configured to be movable from the first, closed position 12 to an intermediate closed position 13, in which the valve member 10 continues to block the fluid flow path 8. Each valve member 10 is movable from the intermediate closed position 13 to the second, open position 14.

The body portion 2 includes stop members 16 configured to stop each valve member 10 at the intermediate closed position 13. The stop members 16 are flanges.

Each valve member 10 is a fluid impermeable piston, and is an elongate longitudinal member. Each valve member 10 includes a piston head configured to receive the positive pressure from the first fluid flow port 4.

In this embodiment, the positive pressure of the valve pressure cycle acts on the piston head 10a to move the valve member 10.

The body portion 2 includes housings 18 for receiving a portion of the valve member 10 therein. Each housing 18 is a cylinder for receiving the piston valve member 10 therein. The stop members 16 are located at a wall of the housing 18. The valve members 10 are slidably engageable with their housing 18.

A first end 18a of the housing 18 is fluidly connected to the first fluid flow port 4 and a second end 18b of the housing 18 is fluidly connected to the second fluid flow port 6. The housing 18 defines a portion of the fluid flow path 8 when the valve members 10 are in the second, open position 14.

Each valve member 10 is configured to be movable in a first direction 20 in response to the application of positive differential pressure. The valve members are configured to be movable in a second direction 22 in response to the removal of the positive differential pressure.

The first direction 20 and the second direction 22 are straight directions, and are opposite directions. The first direction 20 is towards the second fluid flow port 6 and the second direction 22 is towards the first fluid flow port 4.

Each valve member 10 is movable in the first direction 20 from the first, closed position 12 to the intermediate closed position 13, and movable in the second direction 22 from the intermediate closed position 13 to the second, open position 14.

In the embodiments illustrated and described here, each of the valve members 10 are configurable between a first, locked state 24, in which the valve member 10 cannot be moved to the second, open state 14, and a second, unlocked state 26, in which the valve member 10 can be moved to the second, open state 14. The valve members 10 are configurable from the first, locked state 24 to the second, unlocked state 26 in response to application of the positive differential pressure from the first flow port 4 to the second flow port 6.

Each valve member 10 includes a locking mechanism 28 for locking the valve member 10 in the first, locked state 24. The locking mechanism 28 an irreversible locking mechanism 28 formed of shear pins (an example of a locking member).

In this embodiment, the valve members are configured as one-way valves. Specifically, when the valve members have moved to the second, open position 14, any attempt to flow fluid from the first fluid flow port 4 to the second fluid flow port 6 will result in the valve members 10 moving to the intermediate position 13. It will be readily apparent that other ways of implementing one-way functionality exist.

The valve members 10 are hydraulically actuatable from the first, closed position 12 to the intermediate closed position 13 and from the intermediate closed position 13 to the second, open position 14.

Each valve member has a first end 10b in fluid communication with the first flow port 4 and a second end 10c in fluid communication with the second fluid flow port 6. The first and second ends 10b, 10c, are fluidly isolated when the valve member 10 is in the first, closed position 12, and are fluidly isolated when the valve member 10 is in the intermediate closed position 13.

The fluid flow control device 1 is configured to apply a biasing force to the valve member 10 towards the second, open position 14. Each valve member 10 includes a valve biasing mechanism 30 configured to bias the valve member 10 towards the second, open position 14. The valve biasing mechanism 30 is configured to move the valve member 10 to the second, open position 14 during the step of removing the positive differential pressure of the valve pressure cycle. The valve biasing mechanism 30 includes one or more helical spring members 30a located at and around the wall of the valve member 10. The biasing mechanism 30 has a spring support 30b for fixing the spring 30a relative to the valve member 10. Each spring 30a is fixedly connected to the spring support 30b and to the valve member 10. The valve biasing mechanism 30 applies the biasing force to the head 10a of the valve member 10.

In this embodiment, the fluid flow control device 1 includes a single fluid flow path 8, which splits into each valve member 10, before coming back together. However, in other embodiments there could be a plurality of fluid flow paths 8 between the first and second fluid flow ports 4, 6, and in some examples each valve member 10 may have an independent fluid flow path 8 to the other valve members 10. The, or each fluid flow path 8 has an associated valve member 10, to ensure that the fluid flow control device 1 can be configured from the closed state 1a to the open state 1b.

Each of the valve members 10 are configured to permit fluid to flow from the second fluid flow port 6 to the first fluid flow port 4 when the valve member 10 is in the second, open position 14.

When each of the valve members 10 are in the second, open position 14, the valve member 10 is configured to prevent or reduce the flow of fluid from the first fluid flow port 4 to the second fluid flow port 6, as each of the valve members 10 are configured to return from the second, open position 14 to the first closed position 12 and then to the intermediate position 13 when positive pressure is applied from the first fluid flow port 4 to the second fluid flow port 6. In this embodiment, re-application of the positive pressure differential from the first to second flow port 4, 6, closes each valve member 10, which initially reduces any possible fluid flow for a short time, and then as the valve member 10 continues to move in the first direction 20, the valve member 10 will prevent fluid flow.

The properties and operation of the trigger mechanism 32 will now be described in detail.

The trigger mechanism 32 is a hydraulically actuatable trigger mechanism 32.

In this embodiment, the trigger mechanism 32 comprises a single trigger member 38 operable to secure and to unsecure the two valve members 10. The trigger mechanism 32 could comprise any suitable number of trigger members 38. For example, although in this embodiment one trigger member 38 is associated with two valve members 10, each valve member 10 could have its own trigger member 38. It is also possible to have a single trigger member 38 secure/unsecure more valve members 10 than shown here.

The trigger member 38 is a fluid impermeable piston, and is an elongate longitudinal member. The trigger member 38 has a piston head 40 configured to receive positive pressure from the first fluid flow port 4.

The trigger member 38 is movable from a first position 42 to a second position 44. The trigger mechanism 32 is configured to unsecure the valve member 10 by moving the trigger member 38 from the first position 42 to the second position 44. The trigger member 38 is movable from the first position 42 to an intermediate position 43, and from the intermediate position 43 to the second position 44. The trigger member 38 is movable along a first trigger direction 46 when moving from the first position 42 to the intermediate position 43, and the trigger member 38 is movable along a second trigger direction 48 when moving from the intermediate position 43 to the second position 44. The first trigger direction 46 is in the same direction as the first direction 20 of the valve member 10, and the second trigger direction 48 is in the same direction as the second direction 22 of the valve member 10.

The body portion 2 includes a stop member 50, which is a flange configured to stop the trigger member 38 at the intermediate trigger position 43. The body portion 2 includes a trigger housing 52 for receiving a portion of the trigger member 38 therein. The trigger housing 52 is a cylinder. The stop member 50 is located at a wall of the trigger housing 52. The trigger member 38 is slidably engageable with the trigger housing 52.

The trigger mechanism 32 comprises a securing mechanism 54 for securing the valve member 10. The trigger member 38 is configured to operate the securing mechanism 54, which happens when moving the trigger member 38 from the first position 42 to the second position 44.

Moving the trigger member to the second position 44 operates the securing mechanism 54 to unsecure the valve member 10.

The securing mechanism 54 is configured to prevent movement of each of the valve members 10, particularly along the longitudinal axis 2x of the body portion 2, until the valves 10 are unsecured.

The securing mechanism 54 includes two securing members 56 (which are ball members), each of the securing members 56 being configured to engage with and secure one of the valve members 10 in the first, closed position 12 when the trigger member 38 is in the first position 42. Each of the securing members 56 are engageable with a securing member receiving portion 58 of the valve member 10. The receiving portion 58 is a recess in the valve member piston 10. Although a ball and recess securing mechanism 54 has been described here, it will be understood that other securing mechanisms 54 are possible.

In the embodiments illustrated and described here, each securing member 56 is also engageable with the trigger member 38. Therefore, each securing member 56 is configured to engage with and secure one of the valve members 10 and to engage with or be in abutment with the trigger member 38 when the trigger member 38 is in the first position 42.

Each securing member 56 is disengaged from, and unsecures the associated valve member 10 when the trigger member 38 is in the second position 44. It will be understood that there are numerous ways in which the valves 10 can be unsecured/secured.

The trigger member 38 is configured to move each of the securing members 56 from a first, engaged position 60, in which the securing member 56 engages and secures the valve member 10, and a second, disengaged position 62, in which the securing member 56 is disengaged from and unsecures the valve member 10. The trigger member 38 moves the securing member 56 from the first, engaged position 60 to the second, disengaged position 62 when the trigger member 38 moves from the first position 42 to the second position 44 via the intermediate position 43.

The trigger member 38 comprises a guide 64 configured to move the securing member 56 from the first, engaged position 60 to the second, disengaged position 62 when the trigger member 38 moves from the first position 42 to the second position 44. The guide 64 is a variable depth portion in a wall of the trigger member 38, which in this embodiment is a recess for accommodating a part of the securing member 56 therein.

The securing member 56 is configured to move from the first, engaged position 60 to the second, disengaged position 62 along an axis that is substantially perpendicular to the longitudinal axis 2x of the body portion 2. The trigger member 38 is configured to be movable from a first, locked state 66, to a second, unlocked state 68 in response to a trigger pressure cycle. In the embodiments illustrated and described here, the trigger pressure cycle comprises application of a positive differential pressure from the first flow port 4 to the second flow port 6 (to unlock the trigger member 38, which happens by moving the trigger member 38 from the first position 42 to the intermediate position 43), and removal of the positive differential pressure (to move the trigger member 38 from the intermediate position 43 to the second position 44).

The trigger member 38 is movable from the first trigger position 42 to the intermediate position 43 and then to the second trigger position 44 in response to the trigger pressure cycle comprising:

• • application of a positive differential pressure from the first flow port 4 to the second flow port 6; and
  • removal of the positive differential pressure.

In the embodiments that include a trigger mechanism 32, the fluid flow control device 1 is configured to secure each of the valve members 10, and to then unsecure the valve members 10 in response to the trigger pressure cycle. When each of the valve members 10 have been unsecured by the application of the trigger pressure cycle, the valve member 10 is configured to be movable from the first, closed position 12 to the second, open position 14 in response to the valve pressure cycle.

In embodiments without a trigger mechanism 32, the valve pressure cycle opens the fluid flow path 8. In embodiments with the trigger mechanism 32, the trigger pressure cycle, followed by the valve pressure cycle opens the fluid flow path 8.

It will be understood that in embodiments where the trigger mechanism 32 is not required, the trigger mechanism 32 could be removed, or simply permanently held in the second position 44 (e.g. by a lock).

The trigger mechanism 32 comprises a trigger locking mechanism 70 for locking the trigger member 38 in the first, locked state 66. The trigger locking mechanism 70 is an irreversible locking mechanism 70 formed of shear pins (an example of a locking member).

The trigger member 38 comprises a first end 38a in fluid communication with the first flow port 4 and a second end 38b in fluid communication with the second fluid flow port 6. The first and second ends 38a, 38b are fluidly isolated when the trigger member 38 is in the first position 42, intermediate position 43 and the second position 44. No fluid passes between the fluid flow ports 4, 6, through the trigger mechanism 32 or trigger member 38.

The valve pressure cycle and the trigger pressure cycle can be applied using any suitable downhole fluids. For example, hydraulic fluid could be provided to the first fluid flow port 4, and the fluid in the annulus provided to the second fluid flow port 6. Fluid present in the annulus could be fluid from a reservoir or formation, or any other fluid found in, or commonly used in the annulus.

The fluid flow control device 1 is configured to apply a biasing force to the trigger member 38 towards the second position 44. The trigger member 38 includes a trigger biasing mechanism 72. The trigger biasing mechanism 72 is configured to bias the trigger member 38 towards the second position 44. The trigger biasing mechanism 72 is configured to move the trigger member 38 to the second position 44 during the step of removing the positive differential pressure of the trigger pressure cycle. The trigger biasing mechanism 72 includes a helical spring member 72a located at and around the wall of the trigger member 38. The trigger biasing mechanism 72 includes a spring support 72b for fixing the spring 72a relative to the trigger member 38. The spring 72a is fixedly connected to the spring support 72b and to the trigger member 38. The trigger biasing mechanism 72 applies the biasing force to the head 40 of the trigger member 38 and the wall thereof.

The fluid flow control device 1 is configured to prevent the trigger member 38 moving from the second position 44 to the first position 42 when the valve pressure cycle is applied. As shown in FIGS. 2a and 2b, the trigger mechanism 32 comprises a retainer 74 configured to prevent the trigger member 38 moving from the second position 44 to the first position 42 in the first trigger direction 46. The retainer 74 is configured to engage with and retain the trigger member 38 when the trigger 38 moves to the second position 44. The retainer 74 includes protruding members 74a for engaging with corresponding retaining member receiving portions 38c of the trigger member 38. In other embodiments the trigger member 38 could include protruding member(s) for engaging with corresponding retaining member receiving portions of the retainer 74, or there could be a combination of male and female members on the trigger 38 and male and female members on the retainer 74.

The trigger member 38 and the retainer 74 each comprise complimentary abutment members 76 arranged to be in abutment when the trigger member 38 is in the second position 44. In this embodiment, the abutment members 76 prevent the trigger member 38 moving from the second position 44 to the first position 42. This prevention of movement of the trigger member 38 means that once the trigger mechanism 32 has served its function, it does not move needlessly up and down the trigger housing 52 when valve pressure cycle(s) are applied.

The retainer 74 is slidably engageable with the trigger member 38, and the protruding members 74a snap into place when the trigger member 38 moves into the second position 44 for the first time.

The fluid flow control device 1 is configured for fluidly connecting production tubing to the annulus between the production tubing and the outer casing or the well bore. Other applications of the fluid flow control device 1 will be readily apparent to those of skill in the art.

The downhole apparatus will typically comprise a string or tubing and an annulus between the string/tubing and the outer casing or well bore, as is known in the art of oil and gas wells. The first fluid flow port 4 can be fluidly connected to an inner portion of the string or tubing and the second fluid flow port 6 can be fluidly connected to the annulus. However, in some embodiments, it may be desirable to do the reverse, in which the second fluid flow port 6 is fluidly connected to an inner portion of the string or tubing and the first fluid flow port 4 is fluidly connected to the annulus.

The string or tubing will typically be a production string or production tubing.

An example of how the fluid flow control device 1 can be used will now be provided.

In this example, the first fluid flow port 4 is fluidly connected to the inside of production tubing, and the second fluid flow port 6 is fluidly connected to the annulus (this is shown in FIG. 3, and will be described in more detail below). The fluid in the annulus is reservoir fluid, containing hydrocarbons, gas, water, sand, etc as is known in the art. This provides pressure to the second fluid flow port 6.

With the device 1 in situ, and with reference to FIG. 1a, and when the time comes to wish to transition the device 1 to an open state 1b, the trigger pressure cycle is applied.

First, a positive differential pressure is applied from the first fluid flow port 4 to the second fluid flow port 6 by applying fluid from the production tubing. The differential pressure from the production tubing to the annulus should be sufficient to move the trigger member 38 from the first position 42 (FIG. 1a) to the intermediate position 43 (FIG. 1b) to break the shear pins of the trigger locking mechanism 70. The magnitude of the positive differential pressure required will vary depending on the physical and geometric properties of the device 1.

Next, with the shear pins broken and the trigger member 38 in the intermediate position 43 (FIG. 1b), the positive differential pressure of the trigger pressure cycle is removed, which moves the trigger member 38 to the second position 44 (FIG. 1c) from the intermediate position 43, because the trigger biasing mechanism 72 acts to push the trigger member 38 in the second direction 48. Removal of the positive pressure is typically called a “bleed out” phase. This can be achieved by opening a valve in the production string, or in any manner known to those of skill in this field, and for brevity this will not be described in detail. It will be understood that in some applications, a negative pressure would be suitable, it is simply required that the positive differential pressure is neutralised or removed to enable the trigger biasing mechanism 72 to take over and move the trigger member 38. This step results in the valve members 10 being moved from the secured state 34 (FIGS. 1a and 1b) to the unsecured state 36 (FIG. 1c).

With the valve members 10 in the unsecured state 36, the operator will now execute the valve pressure cycle. First, a positive differential pressure is applied from the first fluid flow port 4 to the second fluid flow port 6 using hydraulic fluid in the production tubing. Again, the magnitude of the positive pressure differential will vary depending on the properties and geometry of the device 1. This step of applying positive differential pressure to the valve members 10 breaks the shear pins of the valve locking mechanism 28 and moves the valve members 10 from the first position 12 (FIG. 1c (and also FIGS. 1a and 1b)) to the intermediate position 13 (FIG. 1d). At this point, the fluid flow control device 1 is still in the closed state 1a.

Next, the positive differential pressure of the valve pressure cycle is removed in any suitable manner, which allows the valve biasing mechanism 30 to take over and move the valve members 10 from the intermediate position 13 to the second position 14 (FIG. 1e). Once this happens, the fluid flow path 8 is now unblocked and open, and fluid in the annulus can now flow from the second flow port 6 through the valve housings 18, past each of the valve members 10, and through the first fluid flow port 4. There is therefore a branching of the fluid flow path 8 at the housings 18 before joining together again and exiting the first fluid flow port 4. At this step, fluid from the reservoir to which the annulus is connected can flow through the first fluid flow port 4 up the production string. This demonstrates use of the device 1 within an inflow control device, with the other components of the inflow control device omitted for brevity.

If a trigger mechanism 32 is not present, then the example method above skips the trigger pressure cycle and makes use of a single valve pressure cycle to open the device 1.

In some uses of the device 1, fluid in the annulus will be used to apply the positive pressure differential to the first fluid flow port 4, with fluid in the inside of the string/tubing connected to the second fluid flow port 6. In this example, when the device 1 is opened, fluid flow will be from the inside of the string to the annulus.

In other example uses of the invention, fluid flow can be from any region of the downhole apparatus to any other region, or within one region of a packer to another region thereof. The device 1 is generally applicable to applications requiring one or more, or two or more pressure cycles, and for regulating fluid flow from one region to another, with the examples above in relation to the production string and annulus, and reference to reservoirs, provided for illustrative purposes.

FIG. 3 shows the fluid flow control device 1 integrated within a downhole apparatus 100. The downhole apparatus 100 includes an in flow control device 100a at a section of production tubing 112, with the annulus 111 between the production tubing 112 and the outer casing/wellbore.

The downhole apparatus 100 includes a base pipe 101, which acts as a conduit isolating fluids in the annulus 111 from fluids within the production tubing 112. An end cap 102 allows access to the in flow control device 100a and the fluid flow control device 1. A pressure housing 103 provides further isolation between tubing 112 and annulus 111 fluids.

An isolation housing 104 prevents or mitigates the ingress of debris, and an adapter housing 105 retains a screen section 106. The screen section 106 allows fluid flow into the inflow control device 100a, through the fluid flow path 8′, through the second fluid flow port 6 of the fluid flow device, and through a tubing port 110. As will be apparent, the tubing 112 has several tubing ports 110 arranged circumferentially around the tubing 112, each of which can lead to a first fluid flow port 4 of a fluid flow control device 1.

Still with reference to FIG. 3, a bottom cap 107 retains the screen section 106 and seals the base pipe 101.

An internal portion 108 of the fluid flow path 8′typically includes restrictor components if necessary, which can be used to restrict the flow of fluid from the screen section 106 to the tubing 112.

The fluid flow control device 1 is located at zone 109, and can be arranged in any suitable manner.

As will be understood, when the fluid flow control device 1 has been configured to be in the open state 1b, fluid can then flow from the annulus 111 to the tubing 112.

Modifications and improvements may be made to the foregoing embodiments without departing from the scope of the present invention.

For example, the body portion 2 could be a cuboidal member, or any suitable shape.

The fluid flow control device 1 could comprise one valve member 10, or two or more valve members, each movable between a first closed position and a second open position. The fluid flow control device 1 could comprise any suitable number of valve members, each of which may open or close a different part of the fluid flow path 8, or there may be several independent fluid flow paths 8 as required.

The trigger mechanism 32 could comprise one or more, or a plurality of trigger members 38.

Although shear pins have been used to lock the valves 10 and trigger member 38, other locking mechanisms 28, 70 could be used.

In some embodiments, the body portion 2, valves 10 and/or the fluid flow path 8 could be a different shape or geometry to that shown here. For example, an irregular shape, e.g. a lozenge, or oval shape, or the like, may provide further space saving. The cylindrical and elongate shapes depicted here are for illustrative purposes only, to demonstrate a working embodiment. It will be understood that the fluid flow ports 4, 6, can be any suitable shape, and may have an irregular shape and need not be circular in cross-section.