Abstract: A computer-implemented method, medium, and system for determining contributing inflow control devices (ICDs) using transient pressure data from a permanent downhole monitoring system (PDHMS) in a wellbore is disclosed. One example computer-implemented method includes receiving transient pressure data from a PDHMS in the wellbore. Multiple ICDs are installed in the wellbore and include multiple contributing ICDs that contribute to fluid flow in the wellbore. Curve fitting of multiple composite exponential signals is performed to match the transient pressure data. A total number of the multiple contributing ICDs is determined based on a result of performing the curve fitting. A respective normalized distance between each pair of adjacent ICDs of the multiple contributing ICDs is determined. A depth of a last ICD in the multiple contributing ICDs is determined. A list of all contributing ICDs is generated based on the determination of the depth of the last ICD.

Abstract: A technique facilitates multiple actuations of a toe valve system positioned along a tubing string. According to an embodiment, the toe valve system comprises a piston sleeve slidably disposed in an outer housing which has at least one port therethrough. The toe valve system also may comprise a shifting sleeve shiftable between positions with respect to the at least one port. The piston sleeve may initially be held in a position closing off the at least one port to prevent flow between the interior and exterior of the tubing string. The piston sleeve is held in this closed position via a liquid trapped in a piston chamber which is located between the piston sleeve and the outer housing. The liquid, e.g. oil, is retained in the piston chamber by a release member, e.g. a rupture disc, until sufficient pressure is applied within the toe valve system and against the piston sleeve so as to actuate the release member and to thus allow outflow of liquid from the piston chamber.

Abstract: An isolation valve includes a ball valve element, an actuation section to rotate the ball valve element, and a trigger section that actuates the actuation section in response to a pressure differential. The actuation section includes an actuation mandrel, a piston housing that at least partially encases the actuation mandrel, a collet piston, and a holding collet. The piston housing and the actuation mandrel define a hydraulic chamber, and the collet piston separates the hydraulic chamber into an upper hydraulic chamber and a lower hydraulic chamber. The holding collet supports the collet piston during a stroke of the actuation mandrel that is triggered by the trigger section. The collet piston is configured to assume a rest position on the actuation mandrel before and during the stroke of the actuation mandrel, and the collet piston is configured to disengage from the actuation mandrel after the stroke of the actuation mandrel.

Abstract: The present invention discloses a method for controlling a toe-end sliding sleeve in a horizontal well based on efficient decoding communication. The method comprises the following steps: forming a pressure wave signal by adjusting and controlling a pressure value in a wellbore according to a first preset encoding manner; acquiring a pressure value change signal in the wellbore, determining a reference time by using an STA/LTA method, and predicting pressure value to acquire a predicted pressure value signal curve; identifying a toe-end sliding sleeve control command in the acquired pressure wave signal by using a first preset decoding manner based on the fitness between the acquired pressure value signal curve and the predicted pressure value signal curve; and driving the toe-end sliding sleeve to perform actions according to the toe-end sliding sleeve control command.

Abstract: An actuator assembly of a downhole tool may include a high pressure chamber and a low pressure chamber. A pressure applied from the surface to the tool may enter both chambers. The low pressure chamber may include an inlet that restricts the flow of pressure and prevents the pressure within the low pressure chamber from increasing quickly. The high pressure chamber may also include an inlet that restricts the flow of pressure to prevent the pressure within the high pressure chamber from increasing quickly. The inlet of the high pressure chamber may also include a check valve that prevents pressure from bleeding off from the high pressure chamber through the check valve. The pressure within the high pressure chamber may actuate a piston to actuate the tool in response to the pressure applied from the surface falling within a predetermined pressure and time range.

Abstract: A hydraulic line balance manifold includes a housing having first and second open ports for fluidly coupling an upper open line to a downhole tool, first and second close ports for fluidly coupling an upper close line to the downhole tool, and bypass channel for fluidly coupling the second open port with the second close port according to pressure within the upper open line and the upper close line. A sensor piston having first and second positions relative to the housing is slidably disposed within the housing, the second open port fluidly uncoupled from the second close port through the bypass channel when the sensor piston is in the first position, second open port fluidly coupled to the second close port through the bypass channel when the piston is in the second position for reducing fluid resistance to mechanical operation of the slave valve in a mechanical override intervention operation.

Abstract: A downhole anchor mechanism (110) which can be set on at least two successive standard diameters of casing (232). The tool body has a recess into which a split cone (70) is located. The increased thickness of the split cone (70) provides for a greater thickness of slip (90), giving increased radial travel of the slips 90 when moved axially over the split cone (70). The cone (70) and slips (90) are profiled to provide two ramps/slopes for increased structural integrity and a greater ramp angle to reduce the axial travel of the slips to achieve the increased radial travel. The downhole anchor mechanism (110) provides anchoring of a work string on two standard diameters of casing in a single trip in a wellbore.

Abstract: A downhole system for completing a well includes a well tubular metal structure including an inside having an inside pressure, an opening and an axial extension, and a sliding sleeve movable along the axial extension between a first position in which the sliding sleeve seals off the opening and a second position in which fluid communication between the borehole and the inside of the well tubular metal structure is allowed. The sliding sleeve has a first sealing element arranged on one side of the opening and a second sealing element arranged on the other side of the opening in the first position A pressure reducing mechanism is arranged in relation to the first sealing element for reducing a pressure exerted on the first sealing element while moving the sliding sleeve from the first position to the second position.

Abstract: A system for actuating a balance line safety valve comprising: a balance line safety apparatus comprising: a balance chamber disposed in a well; a relief valve in fluid communication with the balance chamber; a check valve in fluid communication with the balance chamber; and a balance line in fluid communication with the relief valve and the check valve, a piston disposed in a well, wherein a back side of the piston is in fluid communication with the balance chamber; and a control line in fluid communication with a top of the piston.

Abstract: Hydraulic fluid is from a hydraulic pump to a tool connected to respective first and second ends of a wellbore linear actuator. The actuator has a double acting cylinder with a cylinder head, a cylinder cap opposite the cylinder head, a piston head, and a piston rod. The piston head separates the cylinder into a first chamber and a second chamber, and the piston rod extends out of the second chamber through the cylinder cap. The double acting cylinder has first and second ends, and the double acting cylinder further includes a feed fluid passage between the first and second ends. The feed fluid passage includes a first fluid line through the piston head and the piston rod, the first chamber, and a second fluid line through the cylinder head.

Abstract: A downhole valve (18) comprises a housing and first and second sleeve assemblies (70 and 76) mounted within the housing (24) and defining an axial pocket (80) therebetween, wherein the first and second sleeve assemblies are arranged to be moved axially relative to each other. A valve member (32) is mounted within the axial pocket and is rotatable about a rotation axis in response to relative axial movement of the first and second sleeve assemblies from a closed position in which fluid flow through the downhole valve is restricted towards an open position in which fluid flow through the downhole valve is increased or permitted. An interface arrangement (94) axially extends from the second sleeve assembly and engages the valve member via an interface mechanism for converting relative axial movement of the first and second sleeve assemblies to rotation of the valve member.

Abstract: A modular force multiplier converts a pull-up force applied to a work string from the surface into a multiplied opposite linear force that can be used to operate downhole tools to perform tasks requiring the application of linear force.

Abstract: A downhole component includes a unitary body having a first end portion, a second end portion and an intermediate portion extending therebetween. The intermediate portion defines an outer surface and an inner surface forming a flow path. An annular chamber has a first end section spaced from a second end section by a gap. The annular chamber is formed in the unitary body spaced from the first end portion, the second end portion, the outer surface, and the inner surface.

Abstract: In one aspect, there is disclosed an apparatus for indexing a device about an indexing axis, the apparatus comprising an indexing drive mechanism comprising a drive portion configured in driving engagement with a driven member for indexing the device about the indexing axis. The driven member is arranged in operable association with an assembly comprising at least one resilient element arranged so as to be capable of transitioning to/from a state of bias such that exposure of the device to any undesirable physical forces is reduced to at least some extent.

Abstract: A rotating ball valve assembly includes a rotatable ball element. The rotatable ball element includes a first side portion, a second side portion, and a central passage. One of the first and second side portions includes first and second outwardly projecting pin elements. A sliding sleeve assembly includes a sliding sleeve member having a first guide track with a first force reducing profile associated with the first outwardly projecting pin element and a second guide track having a second force reducing profile associated with the second outwardly projecting pin element. The sliding sleeve member is shiftable relative to the first and second tubular members to selectively pivot the rotatable ball element between an open orientation and a closed orientation.

Abstract: A downhole system including a valve including a housing having a longitudinal axis, a flowbore within the housing for fluid flow along the longitudinal axis, an annulus within the housing, the annulus concentrically surrounding the flowbore and fluidically separated from the flowbore, a piston arrangement within the housing, the piston arrangement including a piston movable from a first position to a second position, and an electronic trigger system including an electronic trigger, a first fluid chamber, and a second fluid chamber. Activation of the electronic trigger communicates the first fluid chamber with the second fluid chamber to move the piston from the first position corresponding to a closed condition of the valve blocking flow within the annulus to the second position corresponding to an open condition of the valve permitting flow within the annulus past the piston.

Abstract: Disclosed is a subsurface safety valve with a magnetic booster feature. One disclosed safety valve includes a housing, a flow tube reciprocably disposed between an upper position and a lower position within the housing, a first magnetic element coupled to the housing, and a second magnetic element coupled to the flow tube and configured such that interaction of the first and second magnetic elements induces at least one of a first force on the flow tube when the flow tube is in the upper position and a second force on the flow tube when the flow tube is in the lower position.

Abstract: Method and systems for opening and closing a subsurface valve are disclosed. A rod piston forms a first piston chamber, a second piston chamber and a third piston chamber within a housing. The first piston chamber is fluidically coupled to a high tubing pressure and the second piston chamber is fluidically coupled to a surface control line and a first compartment of a storage chamber. The third piston chamber is coupled to a second compartment of the storage chamber. A flow tube couples the rod piston to a flapper. The rod piston is moved between a first position and a second position in response to a change in a pressure in at least one of the first piston chamber, the second piston chamber and the third piston chamber. The movement of the rod piston between the first position and the second position at least one of opens and closes the flapper.

Abstract: A system for use with a well can include multiple hydraulic actuators in the well, each of the actuators being connected to a common hydraulic line, and multiple pressure control devices, each pressure control device preventing flow from the hydraulic line to a respective one of the actuators unless a pressure differential across the pressure control device exceeds a predetermined level. A method of controlling operation of multiple hydraulic actuators in a well can include applying pressure to at least one of the actuators, thereby increasing pressure in a common hydraulic line connected to each of the actuators, preventing communication of the increased pressure in the common hydraulic line to additional actuators, and permitting flow from the common hydraulic line to each of the actuators, in response to a pressure differential across the pressure control devices exceeding a predetermined level.

Abstract: Methods and systems operate multiple downhole tools in wells based on hydraulic pressures supplied in control lines. The methods and systems pair each of the tools with a manifold enabling selective actuation of each of the tools from a remote location. Some embodiments include between three and twelve manifold and tool pairs configured for control independent from one another with four of the control lines.

Abstract: Design and control of well systems with multiple tubing strings is described. An example system models multiple tubing strings in wellbores as segments, with multiple control points selectively located among the segments. Each segment is modeled as one or more equations that describe characteristics of a fluid resource associated with the segment. The system can predict flow of fluids and energy in a wellbore by solving physical conservation equations subject to specified conditions. The system models multiple control points, and solves the equations to convergence to satisfy injection and production targets and specified constraints. Results may be used to improve production of the resource. The system can apply a variety of strategies to model wells via multiple control points, including conservation of mass and energy models, a global phase-component partitioning model, a conductive heat transfer model, a pseudo-pressure model, a non-Darcy flow model, a phase separation model, and so forth.

Abstract: This Application addresses maintaining a hydrostatic pressure exerted on a wall of a wellbore in different intervals of the wellbore. This is done by flowing a liquid through at least a pressure regulator in each interval, and wherein each pressure regulators regulates the amount of pressure exerted by the liquid on the wall of the wellbore. The amount of pressure may be maintained for a specific period of time. The wellbore is part of a soft subterranean formation.

Abstract: An actuator assembly for effective interventionless activation of a valve in wells of multilateral architecture. The assembly may be pressure actuated from an oilfield surface even in certain circumstances where another valve in another leg of the well has been opened in a manner compromising pressure control of the well. Due to the multi-stage nature of the actuator, pressure based activation remains viable as a result of supplemental and/or fail-safe modes of actuation, for example, where such pressure control becomes compromised.

Abstract: A production system for producing hydrocarbons from a subterranean reservoir includes a wellhead including a housing and a head. The housing has a central axis, an upper end, a lower end, and an inner surface. The inner surface defines a passage extending axially through the housing. In addition, the inner surface of the housing includes an annular recess positioned between the upper end and the lower end. The housing also includes a first production port extending radially through the housing. Further, the system includes a casing hanger disposed within the housing. The casing hanger has an upper end, a lower end, an outer surface, and a through bore extending from the upper end to the lower end. The casing hanger also includes a plurality of circumferentially-spaced ports extending radially through the casing hanger from the through bore to the annular recess of the housing.

Abstract: Methods and apparatus are presented for a hybrid downhole force generator (DFG) using a stroke amplifier driven by hydrostatic pressure for a low-force, long-stroke portion of setting a downhole tool and a DFG powered shaft for a high-force, short-stroke portion of setting the tool. The stroke amplifier has a piston slidable in a housing, movable in response to hydrostatic pressure. The DFG powered shaft is connected to the piston via one-way slips which allow relative motion of the piston and shaft in one direction. The amplifier housing is connected to the DFG housing. In use, the DFG shaft is powered by a power supply, such as an electric motor, etc. The shaft is powered to shear a shearing mechanism, freeing the piston to move in response to the hydrostatic pressure.

Abstract: A downhole valve for use in a well has a closure device that is biased closed to seal against flow through the central bore of the valve. A plurality of pistons are each coupled to a respective hydraulic control line into the valve. Each piston is adapted to reside in an actuated position, supporting the closure open, when at least a specified hydraulic pressure is supplied through its control line, and to reside in an unactuated position, not supporting the closure open, when at least the specified hydraulic pressure is not present in its control line. The valve has a chamber containing a hydraulic fluid hydraulically coupling the pistons to support any piston not receiving the specified hydraulic pressure in an unactuated position. In certain aspects, when the piston is in the unactuated position, it seals against communication of fluid with its respective control line using a static-type seal.

Abstract: Certain aspects and embodiments of the present invention are directed to a subsurface safety valve that can be disposed in a wellbore that is through a fluid-producing formation. The subsurface safety valve can include a closure mechanism, a sleeve, and a control line. The closure mechanism can be positioned in a passageway defined by a tubing string. The closure mechanism can be configured to prevent a flow of fluid to a portion of the passageway that is closer to a surface of the wellbore than the closure mechanism. The sleeve can be positioned in the passageway adjacent to the closure mechanism. The control line can communicate pressure to a piston from a pressure source within an inner diameter of the tubing string, causing the piston to apply a force to the sleeve. The sleeve can open the closure mechanism in response to the force being applied to the sleeve.

Abstract: An integral multistage safety valve is designed to provide a second level of protection should a first stage fail. The valve may be used in oil and/or gas wells. The interior portion of the multiphase safety valve is designed so as to reduce turbulence and pressure loss through the valve when the valve is in an open position. The valves may be independently operable, or operable with a single control line. The multi-stage valve reduces the number of body joints required to construct two identical valves thereby reducing cost and potential leak paths and increasing reliability of the system.

Abstract: A downhole control system for actuating hydraulically controlled devices positioned in a well. The system includes a first set of N hydraulically controlled devices positioned in the well and a second set of at least one hydraulically controlled device positioned in the well. A common control line is ported to a first side of each of the hydraulically controlled devices in the first set. N control lines are each ported to a second side of one of the hydraulically controlled devices in the first set. A first control line of the N control lines is ported to a first side of a first hydraulically controlled device of the second set and a second control line of the N control lines is ported to a second side of the first hydraulically controlled device of the second set, such that N+1 control lines are operable to actuate N+1 hydraulically controlled devices.

Abstract: Disclosed are sand control screens and completion assemblies that receive, retain, and protect control lines during installation and operation thereof. One disclosed completion assembly includes a base pipe, at least one screen jacket positioned around the base pipe and operable to prevent an influx of particulate matter of a predetermined size therethrough, a control line housing arranged uphole from the at least one screen jacket and having a fiber optic splicing block disposed therein, the at least one fiber optic splicing block being communicably coupled to a control line that extends uphole from the control line housing, and one or more hydraulic conduits arranged longitudinally between the at least one screen jacket and the base pipe and extending from the control line housing.

Abstract: A downhole hydraulic control system includes a hydraulic control module positioned in a well. First and second hydraulically controlled devices are positioned in the well. The first hydraulically controlled device has a first actuator and the second hydraulically controlled device has a second actuator. First and second hydraulic control lines extend uphole of the hydraulic control module in the well. In a first configuration of the hydraulic control module, pressure variations in the first and second hydraulic control lines are operable to independently shift the first and second actuators in respective first directions. In a second configuration of the hydraulic control module, pressure variations in the first and second hydraulic control lines are operable to shift the first and second actuators in respective second directions.

Abstract: A control system for use in a subterranean well comprises at least one power generation device positioned within the subterranean well, the at least one power generation device adapted to supply electrical power to at least one apparatus positioned within the subterranean well and at least one control line positioned in the subterranean well. The at least one control line connects each power generation device to surface and is adapted to supply a hydraulic pressure applied from surface to the at least one power generation device from which the at least one power generation device generates the electrical power to be supplied to the at least one apparatus.

Abstract: The present invention provides a method for producing hydrocarbon gas from a wellbore and a control valve assembly for said wellbore. The wellbore comprises a wellhead, a production zone, a production tubing, and a velocity string installed inside the production tubing. The method comprises allowing gas to flow from the production zone through the velocity string, said gas forming a primary gas stream, and controlling the flow of gas from the annulus between the outer wall of the velocity string and the inner wall of the production tubing to the primary gas stream by means of the control valve wherein a controlled mass flow of said gas is combined with the primary gas stream.

Abstract: Disclosed herein is a hydraulic system. The system includes a chemical injection line and a plurality of tools in operable communication with the chemical injection line that are independently responsive to changes in pressure or flow through the chemical injection line and that are configured to control flow of wellbore fluids.

Abstract: A downhole valve for fluid energized packers includes a valve sub and a packer. The valve sub further includes a control tube and a rotatable ball, the control tube having at least one closable aperture fluidly coupled to the packer when open, and the rotatable ball rotatable about an axle having at least one flow path closable by a rotation of the ball. The rotatable ball rotates about an axle coupled to a shift sleeve coupled to the lower end of the control tube. The rotatable ball includes a rotation pin extending from its outer surface and a rotation pin sleeve is adapted to rotate the ball in response to a movement of the ball toward or away from the rotation pin sleeve.

Abstract: A method of traversing a travel joint with a line can include, after the travel joint has been installed in a well, activating a connector which provides sealed fluid communication between sections of the line on respective opposite sides of the travel joint. A travel joint system for use with a subterranean well can include a travel joint comprising a releasing device which permits relative displacement between sections of the travel joint, and a connector which provides fluid communication between sections of a line.

Abstract: A system for use with a well having multiple zones can include multiple well screens which filter fluid flowing between a tubing string and respective ones of the zones, at least one optical waveguide which senses at least one property of the fluid as it flows between the tubing string and at least one of the zones, multiple flow control devices which variably restrict flow of the fluid through respective ones of the well screens, and multiple pressure sensors which sense pressure of the fluid which flows through respective ones of the well screens. A tubing string for use in a subterranean well can include at least one well screen, at least one flow control device which selectively prevents and permits substantially unrestricted flow through the well screen, and at least one other flow control device which is remotely operable, and which variably restricts flow through the well screen.

Abstract: A system for servicing a subterranean formation comprising a wellbore completion string comprising a first master activatable stimulation assembly, a first slave activatable stimulation assembly, wherein the first slave activatable stimulation assembly activates responsive to activation of the first master stimulation assembly; a second master activatable stimulation assembly, and a second slave activatable stimulation assembly, wherein the second slave activatable stimulation assembly activates responsive to activation of the second master stimulation assembly.

Abstract: A valving system includes, a plurality of flow control valves, and a plurality of chemical control valves in operable communication with a plurality of the plurality of flow control valves such that each of the plurality of chemical control valves is actuated between closed and open positions when the flow control valve it is in operable communication with is actuated between closed or open positions.

Abstract: A method of controlling pressure in a wellbore can include determining a desired well pressure setpoint, adding an offset to the setpoint in response to an actual well pressure deviating from the setpoint by a predetermined amount, and adjusting a flow control device, thereby influencing the actual well pressure toward the setpoint plus the offset. A well system can include a flow control device which variably restricts flow from a wellbore, and a control system which determines a desired well pressure setpoint, compares the setpoint to an actual well pressure, and adds an offset to the setpoint in response to a predetermined amount of deviation between the setpoint and the actual well pressure, whereby the control system adjusts the flow control device, and thereby influences the actual well pressure toward the setpoint plus the offset.

Abstract: The disclosure relates to purging a RCD including a bearing of contaminants with a fluid circuit, the fluid circuit having at least one housing adjacent to the RCD, a first plurality of valves within the bearing, a second plurality of valves within the housing, at least one inlet port located on the RCD, each inlet port being connected to the housing, at least one outlet port located on the RCD, each outlet port being connected to the housing, and a purge outlet in fluid communication with the fluid circuit.

Abstract: A hydraulically balanced multiple drop well completion has a plurality of hydraulic control lines each of which communicates hydraulic inputs and a plurality of hydraulically operated tools numbering greater than or equal to the number of hydraulic control lines. Each of the hydraulic control lines is connected to at least one of the hydraulically operated tools to communicate hydraulic inputs to actuate the hydraulically operated tools. Each of the hydraulically operated tools discharges hydraulic fluid to one of the hydraulic control lines other than the hydraulic control line from which it receives the controlling hydraulic input.

Abstract: The present invention relates to an emulsion, consisting of an oil phase and an aqueous phase and comprising as emulsion components (?1) 15 to 40% by weight of at least one water-immiscible organic solvent as solvent of the oil phase, (?2) 15 to 40% by weight of water as solvent of the aqueous phase, (?3) 10 to 40% by weight of at least one surfactant, (?4) 10 to 40% by weight of an alkoxylated fatty alcohol and (?5) 0 to 25% by weight of at least one other additive, wherein the quantities by weight of the components (?1) to (?5) are each relative to the total weight of the emulsion, and together add up to 100% by weight. The invention further relates to a method for producing an emulsion, to the emulsion which can be obtained from said method, to the use of an emulsion, to a method for cleaning the surfaces of well holes, drilling devices or drillings, to a method for producing a well bore, and to a method for producing an oil or a gas.

Abstract: A control valve includes a housing, an inlet port at the housing, a device port at the housing, a valve port at the housing, and a spool disposed at the housing, the spool initially connecting the inlet port to the device port and subsequently to a pressure event connecting the inlet port to the valve port. An actuation system includes a plurality of control valves, each valve being addressable and conditionable to communicate with one of a device and another control valve, and a plurality of devices each in operable communication with one of the plurality of control valves.

Abstract: A charging unit, system and method are provided. The system includes an activation unit and a charging unit. The activation unit includes a pump unit, a pressure circuit with an unloader valve to selectively permit fluid to pass from the pump unit to the wellsite component, and an accumulator bank operatively connectable to the pressure circuit to store the fluid under pressure for passage to the wellsite component whereby the wellsite component is selectively activated. The charging unit includes a charging circuit operatively connectable to the pressure circuit to selectively receive the fluid from the pump unit, a charging accumulator operatively connectable to the charging circuit to store the fluid under pressure, and a pressure reducing valve operatively connectable to the charging circuit to selectively pass the fluid from the charging accumulator to the accumulator bank whereby an activation pressure of the fluid provided to the wellsite component is maintained.

Abstract: A side pocket mandrel has openings to receive a plurality of valves such that the flow of fluid from outside the string and into the tubular such as in gas lift will flow through the valves in series. The side pocket mandrel that has a single valve pocket can also be used in tandem with another similar side pocket mandrel to get the same dual barrier configuration to meet requirements of many jurisdictions of such a valve arrangement for tubular wall openings.

Abstract: A downhole fluid flow control system having dynamic response to local well conditions. The system includes a tubing string operably positionable in a wellbore. Annular barriers are positioned between the tubing string and the wellbore to isolate first and second zones. A fluid flow control device is positioned within each zone. A flow tube that is operably associated with the fluid flow control device of the first zone is operable to establish communication between the second zone and the fluid flow control device in the first zone such that a differential pressure between the first zone and the second zone is operable to actuate the fluid flow control device of the first zone from a first operating configuration to a second operating configuration.

Abstract: A biased actuator includes, a reservoir, at least one piston in operable communication with the reservoir, at least one metal seal and a biasing system in operable communication with both the reservoir and the at least one piston. The at least one metal seal is disposed about the at least one piston and is sealed to both the piston and the reservoir.

Abstract: A downhole control system can include a pair of drive lines passing through a wellbore member such as a tubing hanger, and a plurality of hydraulic switches, each in communication with the drive lines. Each hydraulic switch can have a unique pressure band, wherein the switch only responds when the pressure in the drive lines is within the unique pressure band. Once the pressure in the drive lines is within the pressure band, the switch can open or close in response to a pressure differential in the drive lines.

Abstract: A hydraulic control system for a sub-surface safety valve has control lines in hydraulic communication with the valve. A first control line communicates hydraulic pressure to actuate the valve, while the other control line communicates hydraulic pressure to compensate for hydrostatic pressure associated with the first control line. A regulator regulates hydraulic communication between the two control lines. The regulator prevents fluid communication from the first to the balance control line as long as integrity of the second line is maintained. When the second line fails, the safety valve can fail in the open position. In this case, the regulator permits hydraulic pressure to bleed from the first line to the second line. This allows the safety valve to then fail in a closed condition and allows the second line to potentially be recharged if its integrity is regained.