Abstract: An apparatus for use in a subterranean well includes a valve, a transducer and a circuit. The valve is adapted to propagate acoustic energy in response to a well fluid flow contacting the valve. The transducer is acoustically coupled to the valve and isolated from the flow to furnish an indication of the acoustic energy. The circuit is adapted to furnish signals to transmit stimuli indicative of the characteristic to a surface of the well based on the indication furnished by the transducer.

Abstract: A method for use with equipment located downhole in a subterranean well includes providing a model describing behavior of the equipment and measuring a state of the equipment downhole. An indication is received of the state at a surface of the well, and the model is modified based on the indication. The system includes a communication link, a circuit and a machine. The communication link is adapted to furnish an indication of a state of the equipment to the surface of the well. The circuit is located downhole and is adapted to detect the state and produce the indication. The machine is adapted to provide a model describing behavior of the equipment and modify the model based on the indication.

Abstract: A safety system for use with an apparatus lowered into a well includes a power supply and a controller that monitors at least a predefined condition of the apparatus. A switch blocks power from the apparatus until the predefined condition is present. A test system includes a test device that generates a signal having a predetermined characteristic (a certain frequency, for example). A controller detects the signal and enables performance of a test operation when the signal of the predetermined frequency is present.

Abstract: A system for use in a subterranean well includes a production tubing and a valve. The production tubing has a port to receive well fluid from a formation. The valve is mounted to the production tubing and includes a sealed housing, a motor, a valve cover, an actuator drive and a sensor. The motor is located inside the housing, and the actuator drive is actuated by the motor to move the valve cover over the port to selectively control the communication of the well fluid between the formation and the passageway of the tubing. The sealed housing may permit the well fluid to accumulate inside the housing over time. The sensor is located inside the housing and provides an indication of the amount of well fluid that has accumulated inside the housing. This information may be useful for such exemplary purposes as predicting when the valve will fail and for evaluating the condition of the valve.