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 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: 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 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: A single line control module for well tool actuation. A well tool control system includes an actuator, a control module for controlling pressure applied to the actuator, and a single line extending between the control module and a remote location, elevated pressure being applied to the line and exhausted from the line at the remote location to operate the actuator. Another well tool control system includes an actuator having first and second chambers, a line for applying elevated pressure to the actuator to operate the actuator, and a control module including an accumulator, and a valve. The valve has a first position in which the line is connected to the first chamber and the accumulator is connected to the second chamber, and a second position in which the line is connected to the second chamber and the accumulator is connected to the first chamber.

Abstract: A pulse width modulated downhole flow control. A downhole flow control system includes a flow control device with a flow restrictor which variably restricts flow through the flow control device. An actuator varies a vibratory motion of the restrictor to thereby variably control an average flow rate of fluid through the flow control device. A method of controlling flow in a well includes the steps of: installing a flow control device in the well, the flow control device including a flow restrictor which variably restricts flow through the flow control device; and displacing the restrictor to thereby pulse a flow rate of fluid through the flow control device.

Abstract: Methods of monitoring various downhole conditions are described, including a system for determining and/or identifying the flow of fluid in a well, determining sand production in a well, identifying localized events in a well, determining the apparent flow velocity of fluid flowing through a downhole conduit, and/or monitoring the strain in downhole tubulars. These determinations may be made by monitoring signals received from one or more sensors located in a well and analysing the signals, such as their frequency and timing.

Abstract: A head member having a piston provided thereon is connected to an elongate tube such as a micro-tube. The micro-tube contains one or more optical fibres, preferably suspended therein by a protective fluid such as a scavenging gel. The head member is preferably inserted into an already-deployed downhole tubular and fluid is pumped down that already deployed tubular behind the piston such that the head member and attached micro-tube and optical fiber(s) are pumped downhole. A sealing means such as a resin material may be pumped downhole in the annulus between the outer circumference of the micro-tube and the inner circumference of the already-deployed tubular downhole in low viscosity form and which may be adapted to cure or harden after a passage of time and/or under application of heat.

Abstract: A direct proportional control system for remotely controlling actuation of a tool. A well control system includes an actuator for a downhole well tool, the actuator including an actuator member which displaces to operate the well tool. A control system member is positioned at a remote location. A displacement of the control system member is proportional to a displacement of the actuator member.

Abstract: A downhole electrical power generator. A downhole electrical power generating system includes a flow restricting device which variably restricts flow through an opening, the restricting device vibrating in response to flow through the opening and the restricting device thereby alternately increasing and decreasing flow through the opening; and an electricity generating device which generates electricity in response to vibration of the restricting device.

Abstract: A fiber optic conduit for use in a hostile environment includes a hydrogen barrier shell that is disposed outwardly from an inner axial tube. The hydrogen barrier shell comprises a material that is capable of reducing hydrogen permeation through the fiber optic conduit and a thickness of at least approximately one-thousandth of an inch. The inner axial tube is operable to receive one or more optical fibers. The conduit further includes an outer axial tube that is disposed outwardly from the hydrogen barrier shell and is operable to form a hydrostatic pressure boundary for the fiber optic conduit.

Abstract: A deep water subsea tree completion having a distributed temperature sensing system. In a described embodiment, a method of installing an optical fiber in a well includes the steps of: conveying an optical fiber section into the well; and monitoring a light transmission quality of the optical fiber section while the section is being conveyed into the well.