Abstract: A fluid sampler operable for taking at least one fluid sample in a subterranean well and associated methods. A fluid sampling method includes the steps of disposing a fluid sampler at a first target location in the well, receiving the fluid sample into at least a first sample chamber of the fluid sampler, pressurizing the fluid sample in the first sample chamber using a pressure source of the fluid sampler, retrieving the fluid sampler to a surface location, isolating the fluid sample in the first sample chamber from the pressure source of the fluid sampler and supercharging the fluid sample in the first sample chamber using a pressure source on the surface.

Abstract: A well tool with combined actuation of multiple valves. A well tool includes at least two valves and an actuator which actuates each of the valves, one valve being positioned longitudinally between the other valve and the actuator, and the other valve being operable in response to displacement of an operating device by the actuator. Another well tool includes a valve with a closure which displaces when the valve is operated, a volume of a chamber which increases and a volume of another chamber which decreases when the closure displaces, and a pressure differential between the chambers being substantially zero when the closure displaces. Another well tool includes at least two valve closures which are the only displaceable components of the well tool exposed to a first internal flow passage portion when one closure prevents fluid communication between the first and a second internal flow passage portions.

Abstract: Thermal expansion matching for an acoustic telemetry system. An acoustic telemetry system includes at least one electromagnetically active element and a biasing device which reduces a compressive force in the element in response to increased temperature. A method of utilizing an acoustic telemetry system in an elevated temperature environment includes the steps of: applying a compressive force to at least one electromagnetically active element of the telemetry system; and reducing the compressive force as the temperature of the environment increases.

Abstract: Well tools including valves operable by low electrical input. One well tool includes a valve which controls fluid communication between pressure regions in a well, the valve including a rotatable member which is biased to rotate, and a brake or clutch which prevents rotation of the member. Another valve includes a barrier which separates reactants, with the valve being operable in response to the barrier being opened and the reactants thereby reacting with each other. Yet another valve includes a barrier which separates the pressure regions, and a control circuit which heats the barrier to a weakened state. Another valve includes a member displaceable between open and closed positions, a restraining device which resists displacement of the member, and a control device which degrades or deactivates the restraining device and thereby permits the member to displace between its open and closed positions, in response to receipt of a predetermined signal.

Abstract: A method of actuating a well tool utilizing first and second pressure sources includes the steps of: placing an source, thereby displacing a piston from a first position to a second position; and then placing another chamber in communication with the second pressure source, thereby displacing the piston to a third position. A multi-position actuator includes an operating member which displaces to operate a well tool, a first position of the operating member corresponding to a pressure source being in communication with a chamber and another pressure source being in communication with another chamber, a second position of the operating member corresponding to the same pressure source being in communication with both of the chambers, and a third position of the operating member corresponding to the pressure sources being connected to the chambers oppositely to that of the first position.

Abstract: An actuator control system includes a housing assembly having at least one line therein for controlling operation of an actuator, and a modular controller attached externally to the housing assembly and interconnected to the line. A method of constructing an actuator control system includes the steps of: assembling a modular controller, the modular controller including a control valve therein for controlling operation of an actuator via a hydraulic line; testing the modular controller, including functionally testing the control valve; and then attaching the modular controller to a housing assembly having the line formed therein. Another actuator control system includes a housing assembly having at least one line therein for controlling operation of an actuator, and a modular controller attached separately to the housing assembly and interconnected to the line via a manifold of the modular controller, the manifold including a concave interface surface which receives the housing assembly therein.

Abstract: A hydraulic control and actuation system for downhole tools. In a described embodiment, a hydraulic control and actuation system includes an internal chamber serving as a low pressure region and a well annulus serving as an energy source. A valve assembly provides selective fluid communication between alternating opposite sides of a piston and each of the energy source and low pressure region. Displacement of the piston operates a well tool. Operation of the valve assembly is controlled via telemetry between a remote location and an electronic circuit of the system.

Abstract: A safety valve system includes a safety valve having an actuator and a line connected to the actuator. The safety valve is operable by opening the line in the well, with the line being free of any connection to a surface control system. Another safety valve system includes multiple safety valves. An actuator of each safety valve is connected to an actuator of another safety valve via a line. A biasing force in each of the actuators is operative to close the respective one of the safety valves in response to opening of the line. The biasing force is produced at least in part by hydrostatic pressure in a well.

Abstract: A safety valve system includes a safety valve having an actuator and a line connected to the actuator. The safety valve is operable by opening the line in the well, with the line being free of any connection to a surface control system. Another safety valve system includes multiple safety valves. An actuator of each safety valve is connected to an actuator of another safety valve via a line. A biasing force in each of the actuators is operative to close the respective one of the safety valves in response to opening of the line. The biasing force is produced at least in part by hydrostatic pressure in a well.

Abstract: A phase change fluid spring (450) for actuating a downhole tool (50) in a wellbore. The phase change fluid spring (450) includes a housing (114) defining a fluid chamber (120) and a phase change fluid disposed within the fluid chamber (120). The phase change fluid is in a first phase and at a first pressure at the surface. The phase change fluid is in a second phase and at a second pressure in the wellbore, the second pressure being greater than the first pressure. The phase change fluid is operable to store and release energy downhole to actuate the downhole tool (50).

Abstract: Thermal expansion matching for an acoustic telemetry system. An acoustic telemetry system includes at least one electromagnetically active element and a biasing device which reduces a compressive force in the element in response to increased temperature. A method of utilizing an acoustic telemetry system in an elevated temperature environment includes the steps of: applying a compressive force to at least one electromagnetically active element of the telemetry system; and reducing the compressive force as the temperature of the environment increases.

Abstract: A shear coupled acoustic telemetry system. An acoustic telemetry system includes a tubular string having a pressure-bearing wall and an acoustic telemetry assembly positioned external to the wall and operative to communicate an acoustic signal between the assembly and the wall. The assembly may be shear coupled to the wall. The assembly may include a pressure-bearing housing positioned external to the wall.

Abstract: Thermal expansion matching for an acoustic telemetry system. An acoustic telemetry system includes at least one electromagnetically active element and a biasing device which reduces a compressive force in the element in response to increased temperature. A method of utilizing an acoustic telemetry system in an elevated temperature environment includes the steps of: applying a compressive force to at least one electromagnetically active element of the telemetry system; and reducing the compressive force as the temperature of the environment increases.

Abstract: A rotary control valve and associated actuator control system. An actuator control system comprises a rotary control valve including a generally planar face seal, and an actuator operatively connected to the rotary control valve. Another actuator control system comprises a control valve including multiple faces having multiple ports formed therein. Fluid communication is selectively permitted and prevented between the ports in response to relative displacement between the faces. A differential area is configured to apply a biasing force which maintains sealing engagement between the faces, and which increases in response to an increase in pressure applied to the control valve.

Abstract: A fluid sampler operable for taking at least one fluid sample in a subterranean well and associated methods. A fluid sampling method includes the steps of disposing a fluid sampler at a first target location in the well, receiving the fluid sample into at least a first sample chamber of the fluid sampler, pressurizing the fluid sample in the first sample chamber using a pressure source of the fluid sampler, retrieving the fluid sampler to a surface location, isolating the fluid sample in the first sample chamber from the pressure source of the fluid sampler and supercharging the fluid sample in the first sample chamber using a pressure source on the surface.

Abstract: A multi-sensor wireless telemetry system. A telemetry system includes multiple sensor assemblies, each sensor assembly including at least one sensor and a sensor data transmitter, and a transceiver which receives sensor data from each of the transmitters. An acoustic telemetry system includes multiple transmitters, and a transceiver. The transmitters transmit to the transceiver using one acoustic signal mode, and the transceiver transmits to a remote location using a different acoustic signal mode.

Abstract: A shear coupled acoustic telemetry system. An acoustic telemetry system includes a tubular string having a pressure-bearing wall and an acoustic telemetry assembly positioned external to the wall and operative to communicate an acoustic signal between the assembly and the wall. The assembly may be shear coupled to the wall. The assembly may include a pressure-bearing housing positioned external to the wall.

Abstract: Thermal expansion matching for an acoustic telemetry system. An acoustic telemetry system includes at least one electromagnetically active element and a biasing device which reduces a compressive force in the element in response to increased temperature. A method of utilizing an acoustic telemetry system in an elevated temperature environment includes the steps of: applying a compressive force to at least one electromagnetically active element of the telemetry system; and reducing the compressive force as the temperature of the environment increases.

Abstract: In a subterranean well completion a bi-directional signal transmission system includes an in-line acoustic transceiver mounted in a tubing string extending through the wellbore, the transceiver being disposed beneath a hanger structure engaging the tubing string. Via the tubing string the transceiver receives acoustic signals from well parameter sensing apparatus further downhole and converts the received acoustic signals to non-acoustic signals. The resulting non-acoustic signals are then transmitted upwardly through the hanger structure, to a signal receiving location, via cabling. In this manner, the hanger structure does not adversely affect the strength of either upwardly or downwardly transmitted signals traversing it. Alternatively, the acoustic well parameter signals received by the transceiver are converted to electromagnetic signals which pass through the earth, are picked up by a receiver external to the well completion, and then relayed to the receiving location.

Abstract: A hydraulic control and actuation system for downhole tools. In a described embodiment, a hydraulic control and actuation system includes an internal chamber serving as a low pressure region and a well annulus serving as an energy source. A valve assembly provides selective fluid communication between alternating opposite sides of a piston and each of the energy source and low pressure region. Displacement of the piston operates a well tool. Operation of the valve assembly is controlled via telemetry between a remote location and an electronic circuit of the system.