Many downhole well systems use downhole flow control valves and other devices which are hydraulically actuated by double acting hydraulic pistons. For example, a downhole control valve may employ a double acting hydraulic piston to operate a moving sleeve which, in turn, controls the inflow or outflow of fluid with respect to the surrounding borehole and formation. Actuating fluid is supplied from a surface pressure source and routed downhole through two hydraulic control lines coupled with hydraulic control chambers on opposed sides of the actuating piston. One hydraulic line provides high-pressure fluid to a hydraulic control chamber on one side of the piston while the other hydraulic line evacuates an equivalent volume of low-pressure exhaust fluid from the hydraulic control chamber on the other side of the piston. However, if the flow of hydraulic actuating fluid into or out of either chamber is blocked, the system becomes hydraulically locked, e.g. the control valve cannot be actuated to a different flow position.
In general, a system and methodology provide improved control over a variety of hydraulically actuated devices, such as flow control valves. A hydraulic control module is placed in hydraulic communication with an actuator of a hydraulically actuated device. The hydraulic control module comprises features which prevent hydraulic locking of the system. Additionally, the control module may comprise metering features to enable metered flow of actuating fluid. The features may include valves, mini-indexers, flowline configurations, or other features which maintain the ability to shift the hydraulically actuated device and/or provide metering of the actuating fluid. For example, the control module may provide feature configurations which enable mechanical intervention and/or hydraulic override capability.
However, many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.
Certain embodiments of the disclosure will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying figures illustrate the various implementations described herein and are not meant to limit the scope of various technologies described herein, and:
In the following description, numerous details are set forth to provide an understanding of some embodiments of the present disclosure. However, it will be understood by those of ordinary skill in the art that the system and/or methodology may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
The present disclosure generally relates to a system and methodology which provide improved control over a variety of hydraulically actuated devices, e.g. flow control valves. The technique utilizes a control module coupled with the hydraulically actuated device. By way of example, the control module may have various features for metering hydraulic fluid, providing hydraulic override, and/or enabling mechanical intervention without incurring hydraulic lock. In some embodiments, the hydraulic fluid is metered via a mini-indexer combined with cooperating valving. The metering system of the control module enables control without the use of a conventional J-slot indexer in a flow control valve, thus simplifying the control structure by avoiding the complex indexer and pin structure used with a hydraulic housing in a conventional J-slot indexer.
According to an embodiment, a hydraulic control module is placed in hydraulic communication with an actuator of a hydraulically actuated device. The hydraulic control module is coupled with at least one hydraulic control line, e.g. a pair of hydraulic control lines, and comprises features which prevent hydraulic locking of the system. The features may include cooperating valves, mini-indexers, flowline configurations, and/or other features which maintain the ability to meter flow and to shift the hydraulically actuated device. For example, the control module may provide feature configurations which enable mechanical intervention and/or hydraulic override capability.
Referring generally to
As explained in greater detail below, the control module 28 comprises various features for metering the flow of hydraulic actuating fluid and/or for preventing hydraulic lock. For example, the control module 28 may comprise various features which enable mechanical intervention and/or hydraulic override. Such features ensure the continued ability to mechanically and/or hydraulically shift the hydraulically actuated device 26 to a desired operational position, e.g. a closed position.
In one type of embodiment, the hydraulically actuated device 26 may be in the form of a flow control valve shiftable between positions enabling flow between an exterior and interior of well string 22. In these types of applications, well string 22 may be in the form of a sand screen assembly completion deployed into a horizontal or otherwise deviated section of wellbore 24. Flow control valve 26 may be actuated via control module 28 to allow or block the inflow of well fluids into the interior of the well string/sand screen assembly 22.
Various types of hydraulically actuated device 26 comprise an actuator piston 32, e.g. a double acting hydraulic actuator piston, which is selectively shifted via control module 28. When hydraulically actuated device 26 is a form of a flow control valve, for example, the actuator piston 32 may be coupled with a sleeve 34 shifted between an open flow position and a closed flow position with respect to a flow passage 36, e.g. a port or ports, extending between an exterior and interior of the well string 22. The control module 28 ensures a desired metering of flow to the actuator piston 32 while maintaining the ability for mechanical intervention and/or hydraulic override so as to shift the actuator piston 32 to a desired operational position.
Referring generally to
Valve 40 has a mechanical override position 54 which allows actuator piston 32 to be mechanically shifted. When in the override position 54, actuator piston 32 is readily shifted by allowing the actuator fluid to simply flow through valve 40 from open chamber 50 to close chamber 52 during manual closure of hydraulically actuated device 26 or vice versa during manual opening of the device 26. In a variety of applications, the valve 40 may normally be biased to the mechanical override position 54. However, pressure applied via either of the hydraulic lines 30 pilots the valve 40 to switch the valve 40 to a different hydraulic flow position.
For example, if piloting pressure is applied via the appropriate hydraulic control line 30 to close line 44, the valve 40 is shifted to a flow position which allows hydraulic actuating fluid to flow through valve 40 and into close chamber 52 via actuator close line 48. Actuating fluid within open chamber 50 is then bled out through actuator open line 46, through valve 40, and out through the other hydraulic control line 30. If, on the other hand, piloting pressure is applied via the appropriate hydraulic control line 30 to open line 42, the valve 40 is shifted to a flow position which allows hydraulic actuating fluid to flow through valve 40 and into open chamber 50 via actuator open line 46. Actuating fluid within close chamber 52 is then bled out through actuator close line 48, through valve 40, and out through the other hydraulic control line 30.
Depending on the application, the piloting pressure used to shift the valve 40 may be at a substantially lower level than the pressure used to shift actuator piston 32 of hydraulically actuated device 26. This enables valve 40 to operate before a substantial differential pressure is established with respect to the valve 40. In other words, valve 40 is able to function with a low equalization pressure across the ports of valve 40 in fluid communication with hydraulic lines 42, 44.
Referring generally to
In this example, the valve 58 may normally be positioned in the mechanical override position 54, as illustrated. When a piloting pressure is applied in hydraulic control line 30, the piloting pressure is directed to valve 58 via hydraulic line 60 of hydraulic circuit 38. The piloting pressure causes valve 58 to shift to a flow position 62 which allows hydraulic actuating fluid to flow along hydraulic line 64, through mini-indexer 56, through valve 58, and into one of open chamber 50 or close chamber 52 to shift actuator piston 32 in the desired direction. By applying an increased indexer pressure on hydraulic control line 30 via a pressure pulse or pulses, the mini-indexer 56 may be cycled to the desired flow position.
In the position illustrated in
Referring generally to
In this example, the hydraulic circuit 38 comprises a hydraulic pressure line 70 coupled with mini-indexer 56 which has, for example, two indexer flow positions. Pressure pulses at a suitable pressure level may be applied via hydraulic control line 30 and hydraulic pressure line 70 to shift the mini-indexer 56 to the desired flow position. The hydraulic circuit 38 also comprises two position valve 58 which may normally be biased to the mechanical override position 54. However, sufficient pressure in hydraulic control line 30 effectively applies a pressure against valve 58 via hydraulic line 72 so as to shift the valve 58 to flow position 62.
The hydraulic circuit 38 enables hydraulic override so as to quickly move actuator piston 32 back to a default position, e.g. an original position. For example, when mini-indexer 56 is in the flow position illustrated in
By applying the appropriate pressure pulse or pulses to mini-indexer 56, the mini-indexer 56 may be shifted to the other flow position which enables shifting of actuator piston 32 in an opening direction, as illustrated in
Depending on the parameters of a given operation, the embodiment of control module 28 illustrated in
Referring generally to
The return hydraulic control line 30 is in fluid communication with mini-indexer 56 via hydraulic line 76. Additionally, the return hydraulic control line 30 is in fluid communication with actuator close line 48 via hydraulic line 78. A two position valve 80 is disposed along hydraulic line 78 and may be shifted between a flow position and a no-flow position with respect to fluid in hydraulic line 78. Furthermore, valve 58 is operatively coupled between hydraulic line 72 and an opposed hydraulic line 82 extending between valve 58 and return hydraulic control line 30. Application of pressure in hydraulic line 72 and/or hydraulic line 82 may be used to shift the valve 58 between flow positions. The two position valve 80, on the other hand, is shifted between the no-flow and flow positions via appropriate hydraulic pressure applied in hydraulic line 84 and/or hydraulic line 86. Hydraulic line 84 is coupled between valve 80 and hydraulic line 76, while hydraulic line 86 is coupled between valve 80 and actuator close line 48.
When mini-indexer 56 is in the flow position illustrated in
By applying the appropriate pressure pulse or pulses to mini-indexer 56, the mini-indexer 56 is shifted to the other flow position which enables shifting of actuator piston 32 and an opening direction, as illustrated in
However, when a hydraulic override is desired, pressure on the return hydraulic control line 30 may be increased to shift the valve 58 to the override position 54, as illustrated in
Referring generally to
The hydraulic circuit 38 of control module 28 comprises metering system 66 having a metering piston assembly 88 with a spring biased metering piston 90 coupled to a collet 92. Additionally, hydraulic circuit 38 comprises a two-way valve 94 which has an open flow position and a no-flow position. In the illustrated example, the two-way valve 94 is biased to the open flow position illustrated in
When the open hydraulic control line 30 is pressurized to an actuation pressure, the pressure applied through hydraulic lines 96, 100 shifts the two-way valve 94 to the no-flow position. This pressure builds up against a face of the collet 92 until a breaking pressure is reached and the metering piston 90 begins to move in a rightward direction until reaching a hard stop. The movement of metering piston 90 forces a predetermined quantity of actuating fluid through the open actuator line 46 and into the corresponding chamber, e.g. open chamber 50. The hydraulic actuating fluid on the opposite side of actuator piston 32 is vented through the close hydraulic control line 30. In some embodiments described herein, the actuator piston 32 also may be coupled with a collet which breaks and releases after a predetermined pressure, e.g. 2000 psi, acting against actuator piston 32 is reached.
When the pressure applied through open hydraulic control line 30 is reduced to initiate a drain cycle, the valve 94 returns to the open flow position. This allows actuating fluid to flow through hydraulic line 96, valve 94, hydraulic line 98, and into metering piston assembly 88 on the right side of metering piston 90. As the metering piston 90 is returned to its original default position, the metering piston assembly 88 is again filled with the predetermined quantity of actuating fluid. The predetermined quantity of fluid is used to shift actuator piston 32 to the next incremental position upon once again raising the pressure in open hydraulic control line 30 to an actuation pressure able to shift metering piston 90 in a rightward direction until reaching the hard stop. Furthermore, the hydraulic override system comprises close hydraulic control line 30 acting in concert with valve 94. Pressure in the close hydraulic control line 30 shifts valve 94 to a flow position which enables venting of actuating fluid while pressure in the close hydraulic control line 30 moves piston 32 continually to the default position, e.g. closed position, without incurring hydraulic lock.
Referring generally to
Furthermore, the valve 104 may be coupled with actuator line 46 via hydraulic line 106 at a position between metering piston assembly 88 and actuator piston 32. The valve 104 also is coupled with close hydraulic control line 30 via hydraulic line 108, as illustrated. The two-way valve 104 may be actuated between a flow position and either of two no-flow positions via appropriately pressurized fluid. The appropriately pressurized fluid may be supplied via a hydraulic line 110 coupled between valve 104 and open hydraulic control line 30 and/or via a hydraulic line 112 coupled between valve 104 and hydraulic line 108, as illustrated.
A relief valve 114 may be coupled across metering piston assembly 88 between open hydraulic control line 30 and hydraulic line 106 via a hydraulic circuit 116. The relief valve 114 provides redundancy in case valve 104 fails to function as intended. If, for example, the two-way, three position valve 104 becomes stuck in a closed position while in a drain cycle, the actuator piston 32 may be shifted via pressure applied in the close hydraulic control line 30 while hydraulic actuating fluid is vented through relief valve 114. If valve 104 is not stuck, the increased pressure in close hydraulic control line 30 shifts the valve 104 to a no-flow position via the increased pressure routed through hydraulic line 112.
When the open hydraulic control line 30 is pressurized to an actuation pressure, the pressure applied through hydraulic lines 110 shifts the valve 104 to one of the no-flow positions. This pressure builds up against a face of the collet 92 until a breaking pressure is reached and the metering piston 90 begins to move in a rightward direction until reaching a hard stop. The movement of metering piston 90 forces a predetermined quantity of actuating fluid into the corresponding chamber, e.g. open chamber 50. The hydraulic actuating fluid on the opposite side of actuator piston 32 is vented through the close hydraulic control line 30.
After the actuator piston 32 is shifted one-stroke, the drain cycle begins. During the drain cycle, the pressure applied through open hydraulic control line 30 is reduced, e.g. reduced to less than 500 psi, and the valve 104 returns to the open flow position. This allows actuating fluid to flow through hydraulic line 106 and into metering piston assembly 88 on the right side of metering piston 90. As the metering piston 90 is returned to its original default position by spring bias or other suitable technique, the metering piston assembly 88 is again filled with the predetermined quantity of actuating fluid. This predetermined quantity of actuating fluid may be used to again shift actuator piston 32 to the next incremental position when pressure in open hydraulic control line 30 is raised to an actuation pressure, thus shifting metering piston 90 in a rightward direction until reaching the hard stop. It should be noted that a hydraulic override arrangement is provided when pressure in the close hydraulic control line 30 shifts valve 104 to a no-flow position and is thus able to move piston 32 continually to the default position, e.g. closed position, without incurring hydraulic lock. During movement of actuator piston 32, actuating fluid is vented through hydraulic circuit 116.
Referring generally to
When the open hydraulic control line 30 is pressurized below a predetermined level, e.g. below 10 psi, the piloted check valve 118 is in an open flow position. In this low pressure, open flow condition, actuating fluid is able to fill the rear or rightward side of the metering piston assembly 88. Subsequently, pressure is increased in open hydraulic control line 30 which shifts piloted check valve 118 to a closed position. Upon applying additional pressure, the metering piston 90 is shifted and the predetermined quantity of actuating fluid is delivered to actuating piston 32, e.g. to open chamber 50, to incrementally shift the actuating piston 32 in, for example, the open direction.
When the pressure in open hydraulic control line 30 is reduced to a bleed pressure, the piloted check valve 118 again shifts to an open position. While valve 118 is the open position actuating fluid is drawn into the rightward side of the metering piston assembly 88 as the spring biased metering piston 90 is returned to its original default position. Increasing the pressure in the open hydraulic control line 30 provides a subsequent incremental movement of actuator piston 32. This process may be repeated for the desired number of incremental movements.
However, the actuator piston 32 may be continuously moved to the closed position by applying sufficient pressure in the close hydraulic control line 30. Pressurizing the close hydraulic control line 30 shifts the piloted check valve 118 to an open flow position via pressure applied through hydraulic connector line 124. This establishes a hydraulic override and allows return fluid to freely flow through hydraulic line 122, piloted check valve 118, and hydraulic line 120 as the pressurized hydraulic fluid in close hydraulic control line 30 moves the actuator piston 32 to the fully closed position. As with the embodiments illustrated in
Referring generally to
In the embodiment illustrated, the cooperating valve 128 also supplies hydraulic actuating fluid to a metering module assembly 134 comprising metering system 66 in the form of metering valve 68 in fluid communication with a first pilot operated valve 136 and a second pilot operated valve 138. In this example, the second pilot operated valve 138 is in communication with valve 128 via a hydraulic line 140. It should be noted the first pilot operated valve 136 and the second pilot operated valve 138 may be shifted via pressure supplied by pilot lines 142, 144, respectively, coupled with the hydraulic pressure line 140. The second pilot operated valve 138 also is fluidly coupled with metering valve 68 via hydraulic line 146 on one side of metering valve piston 74 and via hydraulic line 148 on the other side of metering valve piston 74. Additionally, the second pilot operated valve 138 is in fluid communication with first pilot operated valve 136 via hydraulic line 150. The first pilot operated valve 136 also is in fluid communication with return 126 via a return hydraulic line 152 which may have a check valve 154.
During operation, low-pressure fluid supplied via hydraulic control line 30 flows through mini-indexer 56 and corresponding valve 128 to metering module assembly 134. The low-pressure fluid flows through hydraulic line 140, through second pilot operated valve 138, through hydraulic line 148, and into metering valve 68. The low-pressure fluid moves the metering valve piston 74 to a retracted state as it fills the corresponding piston chamber within metering valve 68 on the side of actuator piston 32, as illustrated in
Once metering valve 68 is filled via the inflow of low-pressure hydraulic actuating fluid, the pressure on hydraulic control line 30 is increased. The increased pressure is experienced by pilot lines 142, 144 and causes both first pilot operated valve 136 and second pilot operated valve 138 to shift against spring bias to their shifted positions, as illustrated in
The high-pressure fluid forces metering valve piston 74 to shift until reaching a stop within the metering valve 68. During the forced movement of metering valve piston 74, actuating fluid is directed through a hydraulic line 156 and into a corresponding chamber, e.g. the open chamber 50, adjacent actuator piston 32. The predetermined volume of hydraulic actuating fluid forced into chamber 50 causes actuator piston 32 to move the desired increment.
When pressure on hydraulic control line 30 is reduced to the low-pressure level, the metering module assembly 134 returns to the configuration illustrated in
If a hydraulic override is desired to quickly shift actuator piston 32 back to a default position, e.g. a closed position, valve 128 may be appropriately actuated. For example, valve 128 may be actuated to direct hydraulic actuating fluid supplied via control line 30 to flow through a hydraulic close line 158 to an opposite side of actuator piston 32. As the actuator piston 32 is forced to the default/closed position, actuating fluid from the other side of piston 32 is vented through hydraulic line 156, metering valve 68, hydraulic line 148, second pilot operated valve 138, hydraulic line 140, valve 128, and hydraulic return line 130 to return 126. This assembly of components again comprises a hydraulic override arrangement which enables rapid movement of actuator piston 32 to a default position without incurring hydraulic lock.
Various types of mini-indexers 56 and corresponding valves 128 may be used in this type of control arrangement. For example, the mini-indexer 56 may be coupled with a two position, four-way valve 128, and the mini-indexer 56 may be actuated to a desired position according to hydraulic pressure pulses. For example, the mini-indexer may be indexed between two positions, e.g. switched between open and close lines, based on a predetermined number of pressure pulses, e.g. two pulses, four pulses, eight pulses, or another suitable number of pulses.
The mini-indexer 56 also may be constructed to effectively introduce asymmetry into the actuation cycles, i.e. the actuation cycles may utilize unequal numbers of pressure cycles to switch from open to closed configurations as compared to the switch from closed to open configurations. In this type of embodiment, the mini-indexer 56 may be actuated based on an odd number of pressure pulses, e.g. three pulses, five pulses, seven pulses, or other suitable number of pulses. If, for example, the mini-indexer 56 is actuated based on three pulses, the corresponding valve 128 may remain open during two pressure pulses and stay closed for one pressure pulse.
In this type of embodiment, each pressure pulse in an open direction can be used to ultimately move the actuator piston 32 to the next incremental choke position while a quick close can be achieved using a single pressure pulse supplied to the mini-indexer 56 over a sufficient duration. Accordingly, various types of mini-indexers 56 and corresponding valves 128 may be used in cooperation with metering module assembly 134 to achieve desired metering and control over the operation of hydraulically actuated device 26 while maintaining the ability for a rapid hydraulic override. The mini-indexer 56, valve 128, and metering module assembly 134 can be used to substantially reduce the number pressure cycles that would otherwise be used for controlled actuation of the flow control valve or other hydraulically actuated device 26.
Depending on parameters of a given application, the control module 28 may be constructed in a variety of configurations and may comprise various features. Examples of such features include various types of indexers, multi-position valves, pilot operated valves, metering valves, and hydraulic circuitry arrangements. Depending on the parameters of a given operation, the control module 28 may be coupled with a single hydraulic control line 30 or a plurality of hydraulic control lines 30, e.g. two hydraulic control lines.
Similarly, the control module 28 may be used to control actuation of many types of devices. In a variety of well operations, e.g. production operations, the control module 28 may be used to control a corresponding flow control valve used to control fluid flow with respect to a downhole completion, e.g. to control the inflow of well fluids into sand screen assemblies. Some applications utilize multiple control models 28 with multiple corresponding flow control valves or other hydraulically controlled devices. The control module 28 also may be used in non-well related applications to similarly control a specific hydraulically controlled device or devices.
Although a few embodiments of the disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims.