Abstract: A telemetry system and method configured to communicate a wellbore parameter such as fluid composition, temperature, and pressure. In one embodiment, a plurality of tracers is stored downhole, and each of the tracers represents a different value of the wellbore parameter. After measuring the wellbore parameter, the measured value is correlated to one or more of the plurality of tracers that is equivalent to the measured value of the downhole parameter. The one or more tracers representing the measured value are then released from their respective containers to travel upstream. A sensor located upstream may detect the one or more tracers, which are then correlated back to obtain the measured value of the wellbore parameter. In another embodiment, ratiometric amounts of the tracers may be used to represent additional values of the wellbore parameter.

Abstract: An actuator apparatus for actuating a downhole well tool according to which a housing extends in the well and a tool to be actuated is disposed in the housing. A drive member is connected to the tool for operating the tool, and an actuator system is disposed in the housing and is normally connected to the drive member for driving the drive member and operating the tool. In the event the actuator system fails, an additional actuator system is disposed in the housing and is adapted to be connected to the drive member for also driving the drive member and operating the tool.