Abstract: A switch responsive to a pressure differential, including a pressure response mechanism for providing a pressure response in response to the pressure differential and a device actuator arranged to interact with the pressure response mechanism and to utilize the pressure response of the pressure response mechanism to actuate a device. The device actuator actuates the device to an operative state when the pressure differential is below a lower pressure differential threshold, and may actuate the device to a non-operative state when the pressure differential is above an upper pressure differential threshold.

Abstract: Methods and apparatus are disclosed for generating fluid pulses in a fluid column, such as within a well. Various described example fluid pulse generators each have a valve structure including a plurality of rollers rotatable around axes that are oriented perpendicular or otherwise angled with respect to the flow direction, the rollers being arranged to collectively at least partially obstruct the cross-sectional area of the fluid conduit. The rotational positions of the rollers may be varied to change the degree of obstruction in the conduit, thereby to generate pressure pulses in the fluid column detectable at a location remote from the fluid pulse generator; these pressure pulses can be used to encode a signal received at the fluid pulse generator.

Abstract: Methods and apparatus are disclosed for generating fluid pulses in a fluid column, such as within a well. Various described example fluid pulse generators each have a valve structure including a plurality of rollers rotatable around axes that are oriented perpendicular or otherwise angled with respect to the flow direction, the rollers being arranged to collectively at least partially obstruct the cross-sectional area of the fluid conduit. The rotational positions of the rollers may be varied to change the degree of obstruction in the conduit, thereby to generate pressure pulses in the fluid column detectable at a location remote from the fluid pulse generator; these pressure pulses can be used to encode a signal received at the fluid pulse generator.

Abstract: A switch responsive to a pressure differential, including a pressure response mechanism for providing a pressure response in response to the pressure differential and a device actuator arranged to interact with the pressure response mechanism and to utilize the pressure response of the pressure response mechanism to actuate a device. The device actuator actuates the device to an operative state when the pressure differential is below a lower pressure differential threshold, and may actuate the device to a non-operative state when the pressure differential is above an upper pressure differential threshold.

Abstract: In at least some embodiments, a downhole tool includes a tool body defining a tool centerline, and a recessed ring guide intermediate to ends of the tool body. The downhole tool also includes an expander ring having an asymmetric wall thickness and rotatable around the recessed ring guide between a reduced tool profile orientation and an expanded tool profile orientation. The downhole tool also includes an actuator configured to rotate the expander ring between the reduced profile orientation and the expanded profile orientation.

Abstract: In at least some embodiments, a downhole tool includes a tool body defining a tool centerline, and a recessed ring guide intermediate to ends of the tool body. The downhole tool also includes an expander ring having an asymmetric wall thickness and rotatable around the recessed ring guide between a reduced tool profile orientation and an expanded tool profile orientation. The downhole tool also includes an actuator configured to rotate the expander ring between the reduced profile orientation and the expanded profile orientation.