Abstract: Methods of actuating a well tool can include releasing chemical energy from at least one portion of a reactive material, thermally expanding a substance in response to the released chemical energy, and applying pressure to a piston as a result of thermally expanding the substance, thereby actuating the well tool, with these steps being repeated for each of multiple actuations of the well tool. A well tool actuator can include a substance contained in a chamber, one or more portions of a reactive material from which chemical energy is released, and a piston to which pressure is applied due to thermal expansion of the substance in response to each release of chemical energy. A well tool actuator which can be actuated multiple times may include multiple portions of a gas generating reactive material, and a piston to which pressure is applied due to generation of the gas.

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: Methods of actuating a well tool can include releasing chemical energy from at least one portion of a reactive material, thermally expanding a substance in response to the released chemical energy, and applying pressure to a piston as a result of thermally expanding the substance, thereby actuating the well tool, with these steps being repeated for each of multiple actuations of the well tool. A well tool actuator can include a substance contained in a chamber, one or more portions of a reactive material from which chemical energy is released, and a piston to which pressure is applied due to thermal expansion of the substance in response to each release of chemical energy. A well tool actuator which can be actuated multiple times may include multiple portions of a gas generating reactive material, and a piston to which pressure is applied due to generation of the gas.

Abstract: A method of severing at least a first object comprises: positioning a severing device adjacent to the first object, wherein the first object is a wireline or a tubular, and wherein the severing device comprises: a first reactant, and a second reactant; initiating a reaction, or allowing a reaction to occur, between the first reactant and the second reactant, wherein the reaction is an exothermic reaction, and wherein heat evolved from the reaction has a temperature greater than or equal to the melting point of the first object; and directing at least a portion of the heat from the outside of the first object through the first object.

Abstract: Methods of actuating a well tool can include releasing chemical energy from at least one portion of a reactive material, thermally expanding a substance in response to the released chemical energy, and applying pressure to a piston as a result of thermally expanding the substance, thereby actuating the well tool, with these steps being repeated for each of multiple actuations of the well tool. A well tool actuator can include a substance contained in a chamber, one or more portions of a reactive material from which chemical energy is released, and a piston to which pressure is applied due to thermal expansion of the substance in response to each release of chemical energy. A well tool actuator which can be actuated multiple times may include multiple portions of a gas generating reactive material, and a piston to which pressure is applied due to generation of the gas.

Abstract: Methods of actuating a well tool can include releasing chemical energy from at least one portion of a reactive material, thermally expanding a substance in response to the released chemical energy, and applying pressure to a piston as a result of thermally expanding the substance, thereby actuating the well tool, with these steps being repeated for each of multiple actuations of the well tool. A well tool actuator can include a substance contained in a chamber, one or more portions of a reactive material from which chemical energy is released, and a piston to which pressure is applied due to thermal expansion of the substance in response to each release of chemical energy. A well tool actuator which can be actuated multiple times may include multiple portions of a gas generating reactive material, and a piston to which pressure is applied due to generation of the gas.

Abstract: Methods of actuating a well tool can include releasing chemical energy from at least one portion of a reactive material, thermally expanding a substance in response to the released chemical energy, and applying pressure to a piston as a result of thermally expanding the substance, thereby actuating the well tool, with these steps being repeated for each of multiple actuations of the well tool. A well tool actuator can include a substance contained in a chamber, one or more portions of a reactive material from which chemical energy is released, and a piston to which pressure is applied due to thermal expansion of the substance in response to each release of chemical energy. A well tool actuator which can be actuated multiple times may include multiple portions of a gas generating reactive material, and a piston to which pressure is applied due to generation of the gas.

Abstract: Methods of actuating a well tool can include releasing chemical energy from at least one portion of a reactive material, thermally expanding a substance in response to the released chemical energy, and applying pressure to a piston as a result of thermally expanding the substance, thereby actuating the well tool, with these steps being repeated for each of multiple actuations of the well tool. A well tool actuator can include a substance contained in a chamber, one or more portions of a reactive material from which chemical energy is released, and a piston to which pressure is applied due to thermal expansion of the substance in response to each release of chemical energy. A well tool actuator which can be actuated multiple times may include multiple portions of a gas generating reactive material, and a piston to which pressure is applied due to generation of the gas.

Abstract: According to an embodiment, a method of severing at least a first object comprises: positioning a severing device adjacent to the first object, wherein the first object is a wireline or a tubular, and wherein the severing device comprises: a first reactant, and a second reactant; initiating a reaction, or allowing a reaction to occur, between the first reactant and the second reactant, wherein the reaction is an exothermic reaction, and wherein heat evolved from the reaction has a temperature greater than or equal to the melting point of the first object; and directing at least a portion of the heat from the outside of the first object through the first object.

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: 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 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: 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: 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 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 method of actuating a well tool utilizing first and second pressure sources includes the steps of: placing an actuator chamber in communication with the first pressure 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: Methods of actuating a well tool can include releasing chemical energy from at least one portion of a reactive material, thermally expanding a substance in response to the released chemical energy, and applying pressure to a piston as a result of thermally expanding the substance, thereby actuating the well tool, with these steps being repeated for each of multiple actuations of the well tool. A well tool actuator can include a substance contained in a chamber, one or more portions of a reactive material from which chemical energy is released, and a piston to which pressure is applied due to thermal expansion of the substance in response to each release of chemical energy. A well tool actuator which can be actuated multiple times may include multiple portions of a gas generating reactive material, and a piston to which pressure is applied due to generation of the gas.

Abstract: Methods of actuating a well tool can include releasing chemical energy from at least one portion of a reactive material, thermally expanding a substance in response to the released chemical energy, and applying pressure to a piston as a result of thermally expanding the substance, thereby actuating the well tool, with these steps being repeated for each of multiple actuations of the well tool. A well tool actuator can include a substance contained in a chamber, one or more portions of a reactive material from which chemical energy is released, and a piston to which pressure is applied due to thermal expansion of the substance in response to each release of chemical energy. A well tool actuator which can be actuated multiple times may include multiple portions of a gas generating reactive material, and a piston to which pressure is applied due to generation of the gas.

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 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.