Abstract: A system for communicating between a first unit and a second unit without a physical connection, the system including a magnetic element for creating a magnetic field, a sensor operatively arranged to detect changes in the magnetic field, and a driver operatively arranged to alter the magnetic field detected by the sensor in accordance with a first signal, the first signal operatively arranged to transmit data independent of an amplitude of the first signal, the sensor generating a second signal in response to changes in the magnetic field, the second signal representative of the first signal.

Abstract: An apparatus for measuring a parameter includes: an optical crystal having an optical axis and configured to be disposed at a selected location; an optical signal source in optical communication with a surface of the crystal and configured to transmit an optical signal having an initial polarization to the surface, the surface configured to reflect at least a portion of the signal as a reflected signal; a detector configured to receive the reflected signal; and a processor configured to determine a polarization of the reflected signal and estimate the parameter at the location based on the polarization of the reflected signal.

Abstract: Systems and methods for electrically isolating selected ones of a set of downhole tools that are connected to a common electrical cable. In one embodiment, a system includes surface equipment, a plurality of downhole tools and a common electrical cable. The downhole tools are connected to the cable by coupling switches. Each switch has a closed position in which the downhole tool is electrically coupled to the cable and an open position in which the downhole tool is electrically decoupled from the cable. The coupling switches are remotely actuated by placing an actuating device in proximity to the switches, thereby alternately coupling the corresponding downhole tools to the common cable or isolating the tools from the cable.

Abstract: A system for communicating between a first unit and a second unit without a physical connection, the system including a magnetic element for creating a magnetic field, a sensor operatively arranged to detect changes in the magnetic field, and a driver operatively arranged to alter the magnetic field detected by the sensor in accordance with a first signal, the first signal operatively arranged to transmit data independent of an amplitude of the first signal, the sensor generating a second signal in response to changes in the magnetic field, the second signal representative of the first signal.

Abstract: A system and method for performing a wellbore operation is disclosed. A first memory device for storing data is provided at a downhole location, the first memory device having a first data retention time. A second memory device is provided at the downhole location, and controller is used to store data at the first memory device and to transfer the data to the second memory device at a selected time interval less than the first data retention time.