Abstract: A position sensor for well tools. A position sensor includes an indicator portion including a carrier supporting a resistive element and at least one contact, and a support device for supporting the carrier. Another position sensor includes an indicator portion including a slider for displacing at least one contact relative to a resistive element, the slider being displaceable between first and second limits, and an end load mechanism including a biasing device which exerts a biasing force on the slider as the slider approaches at least the first limit. Another position sensor includes an indicator portion including a resistive element and at least one contact which contacts and displaces across the resistive element, a change in position of the contact relative to the resistive element being indicated by a resistance change as the contact displaces across the resistive element.

Abstract: A valve for use in a tubular string in a subterranean well includes a sleeve having first and second opposite ends, the sleeve being displaceable between open and closed positions to thereby selectively permit and prevent flow through a sidewall of a housing assembly, and a first and second pistons at the respective first and second ends of the sleeve. Pressure differentials applied to the first and second pistons are operative to displace the sleeve between its open and closed positions.

Abstract: A metal to metal seal for downhole tools. A sealing device includes a metal seal. A nonmetal seal may be used to bias the metal seal in a radial direction in response to a pressure differential applied to the sealing device. A well tool includes a housing assembly, a closure member and the sealing device. Both of the metal and nonmetal seals contact a selected one of the housing assembly and closure member when the closure member blocks flow through the housing assembly. A method of sealing between the housing assembly and closure member includes the step of displacing the closure member to relieve the pressure differential, the metal seal continuing to seal against the pressure differential until the nonmetal seal no longer seals between the housing assembly and the closure member.

Abstract: Casing valves for selective well stimulation and control. A well system includes at least one valve interconnected in a casing string operable via at least one line external to the casing string to selectively control fluid flow between an exterior and interior of the casing string, and the casing string, valve and line being cemented in a wellbore. A method of selectively stimulating a subterranean formation includes: positioning a casing string in a wellbore, the casing string including spaced apart valves operable via a line to selectively control fluid flow between an interior and exterior of the casing string; and for each of multiple intervals of the formation in sequence, stimulating the interval by opening a corresponding one of the valves, closing the remainder of the valves, and flowing a stimulation fluid from the casing string into the interval.

Abstract: A position sensor for well tools. A position sensor includes an indicator portion including a carrier supporting a resistive element and at least one contact, and a support device for supporting the carrier. Another position sensor includes an indicator portion including a slider for displacing at least one contact relative to a resistive element, the slider being displaceable between first and second limits, and an end load mechanism including a biasing device which exerts a biasing force on the slider as the slider approaches at least the first limit. Another position sensor includes an indicator portion including a resistive element and at least one contact which contacts and displaces across the resistive element, a change in position of the contact relative to the resistive element being indicated by a resistance change as the contact displaces across the resistive element.

Abstract: A position sensor for well tools. A position sensor includes an indicator portion including a carrier supporting a resistive element and at least one contact, and a support device for supporting the carrier. Another position sensor includes an indicator portion including a slider for displacing at least one contact relative to a resistive element, the slider being displaceable between first and second limits, and an end load mechanism including a biasing device which exerts a biasing force on the slider as the slider approaches at least the first limit. Another position sensor includes an indicator portion including a resistive element and at least one contact which contacts and displaces across the resistive element, a change in position of the contact relative to the resistive element being indicated by a resistance change as the contact displaces across the resistive element.

Abstract: A well system includes a valve interconnected in a casing string and selectively configurable between first and second configurations via a line external to the casing string, the valve in the first configuration being operable to selectively permit and prevent fluid flow between the casing string exterior and interior, and in the second configuration to selectively filter and prevent fluid flow between the casing string exterior and interior. A method of selectively stimulating a formation includes: positioning a casing string in a wellbore intersecting the formation, the casing string including a valve operable via an external line to selectively permit and prevent fluid flow between the casing string interior and exterior; and stimulating an interval set of the formation by opening the valve, flowing a stimulation fluid from the casing string into the interval set, and then configuring the valve to filter formation fluid which flows into the casing string.

Abstract: Casing valves for selective well stimulation and control. A well system includes at least one valve interconnected in a casing string operable via at least one line external to the casing string to selectively control fluid flow between an exterior and interior of the casing string, and the casing string, valve and line being cemented in a wellbore. A method of selectively stimulating a subterranean formation includes: positioning a casing string in a wellbore, the casing string including spaced apart valves operable via a line to selectively control fluid flow between an interior and exterior of the casing string; and for each of multiple intervals of the formation in sequence, stimulating the interval by opening a corresponding one of the valves, closing the remainder of the valves, and flowing a stimulation fluid from the casing string into the interval.

Abstract: Casing valves for selective well stimulation and control. A well system includes at least one valve interconnected in a casing string operable via at least one line external to the casing string to selectively control fluid flow between an exterior and interior of the casing string, and the casing string, valve and line being cemented in a wellbore. A method of selectively stimulating a subterranean formation includes: positioning a casing string in a wellbore, the casing string including spaced apart valves operable via a line to selectively control fluid flow between an interior and exterior of the casing string; and for each of multiple intervals of the formation in sequence, stimulating the interval by opening a corresponding one of the valves, closing the remainder of the valves, and flowing a stimulation fluid from the casing string into the interval.

Abstract: A method for positional control of an actuator includes applying pressure to both an input line and an output line connected to the actuator and then releasing a predetermined volume of fluid from the output line, thereby displacing a piston of the actuator a corresponding predetermined distance. A system for positional control of an actuator includes the actuator included in a well tool positioned in a well; the input line connected to the actuator and extending to a remote location; the output line connected to the actuator and extending to the remote location; and a fluid volume measurement device connected to the output line at the remote location. The fluid volume measurement device is operative to meter the predetermined volume of fluid from the output line.

Abstract: A downhole ram pump. A downhole pump system includes a flow restricting device which variably restricts fluid flow through an opening, the restricting device vibrating in response to the fluid flow, thereby alternately increasing and decreasing the fluid flow through the opening; and a pump device which generates a pressure differential in response to vibration of the restricting device. Another downhole pump system includes a flow restricting device which vibrates in response to fluid flow through an opening, thereby alternately increasing and decreasing the fluid flow through the opening, a pressure differential across the restricting device variably biasing the restricting device to increasingly restrict the fluid flow through the opening, and the pressure differential alternately increasing and decreasing in response to respective alternate increasing and decreasing flow through the opening; and a pump device which generates differential pressure in response to vibration of the restricting device.

Abstract: A method of actuating a well tool includes the steps of: increasing pressure in a fluid line of a fluid metering device; closing a pilot-operated valve in response to the pressure increasing step; and discharging a predetermined volume of fluid from the metering device in response to the pressure increasing and valve closing steps. A fluid metering device for a well tool includes a piston separating chambers; and a pilot-operated valve which selectively prevents fluid communication between the chambers in response to at least a predetermined pressure being applied to a fluid line of the metering device, and which permits fluid communication through the valve between the chambers in response to pressure in the fluid line being less than the predetermined pressure. A greater pressure may be applied to the fluid line to thereby bypass the metering device and allow fluid to discharge from the line.

Abstract: A well tool having a magnetically coupled position sensor. In operation of a well tool, relative displacement is produced between members of the well tool. A magnetically coupled position sensor includes one magnet assembly attached to a member for displacement therewith and another magnet assembly movably attached to the other member and magnetically coupled to the first magnet assembly for displacement therewith. The position sensor further includes a magnetically permeable material which increases a magnetic flux density between the magnet assemblies. The magnetically permeable material may be positioned between magnets of the magnet assemblies and/or spaced apart therefrom.

Abstract: Pressure balanced downhole connections. A well system includes a well tool, a conduit assembly connected to the well tool, the conduit assembly including a conduit and a line positioned within the conduit, the line being connected to the well tool for operation of the well tool, and a device for equalizing pressure between an interior and an exterior of the conduit, the device being positioned downhole. A method of isolating a line in a subterranean well from well fluids in the well includes the steps of: connecting a conduit assembly to a device for equalizing pressure between an interior and an exterior of the conduit assembly, the conduit assembly including a line installed within a conduit; and positioning the conduit assembly and pressure equalizing device in the well.

Abstract: A well tool having a magnetically coupled position sensor. In operation of a well tool, relative displacement is produced between members of the well tool. A magnetically coupled position sensor includes one magnet assembly attached to a member for displacement therewith and another magnet assembly movably attached to the other member and magnetically coupled to the first magnet assembly for displacement therewith. The position sensor further includes a magnetically permeable material which increases a magnetic flux density between the magnet assemblies. In another position sensor, one magnet assembly includes a magnet having a pole axis, the other magnet assembly includes another magnet having another pole axis, and the pole axes are aligned with each other.

Abstract: Bypassing damaged lines in a well. A subterranean well system includes a circuit extending in the well to a well tool. A set of multiple redundant lines is provided at a location along the circuit. Each of the set of lines is capable of providing conductivity between portions of the circuit. A method of providing conductivity across a damaged portion of a circuit in a subterranean well includes the steps of: damaging at least one line of a set of redundant lines extending along a tubular string; and isolating the damaged at least one line from an undamaged portion of the circuit.

Abstract: A metal to metal seal for downhole tools. A sealing device includes a metal seal. A nonmetal seal may be used to bias the metal seal in a radial direction in response to a pressure differential applied to the sealing device. A well tool includes a housing assembly, a closure member and the sealing device. Both of the metal and nonmetal seals contact a selected one of the housing assembly and closure member when the closure member blocks flow through the housing assembly. A method of sealing between the housing assembly and closure member includes the step of displacing the closure member to relieve the pressure differential, the metal seal continuing to seal against the pressure differential until the nonmetal seal no longer seals between the housing assembly and the closure member.

Abstract: An energized composite metal to metal seal. A sealing device includes a metal seal with a metal sealing surface facing radially outward, and another metal sealing surface facing radially inward; and a nonmetal seal including a nonmetal sealing surface positioned proximate one metal sealing surface and facing radially outward, and another nonmetal sealing surface positioned proximate the other metal sealing surface and facing radially inward. A method of sealing between a housing assembly and a closure member includes applying a pressure differential across the sealing device while the sealing device seals between the housing assembly and the closure member, and the pressure differential increasing contact pressure in a metal to metal seal between the housing assembly and a metal sealing surface on the metal seal, and increasing contact pressure in a metal to metal seal between the closure member and another metal sealing surface on the metal seal.

Abstract: Purging of fiber optic conduits in subterranean wells. A downhole optical sensing system includes an optical line, at least two tubular conduits, one conduit being positioned within the other conduit, and the optical line being positioned within at least one of the conduits, and a purging medium flowed in one direction through one conduit, and flowed in an opposite direction between the conduits. A method of purging a downhole optical sensing system includes the steps of: installing at least two conduits and an optical line in a well as part of the sensing system, one conduit being positioned within the other conduit, and the optical line being positioned within at least one of the conduits; and flowing a purging medium through the conduits in the well, so that the purging medium flows in one direction through one conduit and in an opposite direction between the conduits.

Abstract: A well system includes a valve interconnected in a casing string and selectively configurable between first and second configurations via a line external to the casing string, the valve in the first configuration being operable to selectively permit and prevent fluid flow between the casing string exterior and interior, and in the second configuration to selectively filter and prevent fluid flow between the casing string exterior and interior. A method of selectively stimulating a formation includes: positioning a casing string in a wellbore intersecting the formation, the casing string including a valve operable via an external line to selectively permit and prevent fluid flow between the casing string interior and exterior; and stimulating an interval set of the formation by opening the valve, flowing a stimulation fluid from the casing string into the interval set, and then configuring the valve to filter formation fluid which flows into the casing string.