Abstract: A subsea pressure control system includes an inlet flowline, a pressure sensing device coupled into the inlet flowline and in fluid communication with the inlet flowline, a controller coupled to the pressure sensing device, an actuator coupled to the controller, and a valve coupled to the actuator and a fluid outlet. The controller may be responsive to the pressure sensing device, the actuator may be responsive to the controller, and the valve may be responsive to the actuator to regulate a measured pressure of the pressure sensing device at or below a setpoint pressure. Another subsea pressure control system includes a controller responsive to a setpoint pressure in a flowline, and a valve responsive to a signal from the controller, wherein the signal is based on the setpoint pressure and actuates the valve from a closed position to an open position.

Abstract: Sensor and communications systems are disclosed for communicating measurements from subsea equipment, such as at an offshore well, to the surface. A sensor for a physical parameter, such as pressure or temperature at a blowout preventer, capping stack, or conduit in communication with the same, is electrically connected to a subsea acoustic transponder. An acoustic communications device, for example an acoustic transducer and transceiver electronics deployed on a remotely-operated vehicle, interrogates the acoustic transponder with an acoustic signal, in response to which the acoustic transponder transmits an acoustic signal encoded with the measurement. The acquired measurement data are then communicated to a redundant network at the surface. The sensor and acoustic transponder systems can be installed after an event at the subsea equipment, such as blowout of the well.