Well drilling slime pump overpressure automatic protective device

The utility model relates to a well drilling slime pump overpressure automatic protective device and belongs to the technical field of petroleum engineering well drilling slime pump pressure control devices. A gas relay and a gas releasing valve are successively installed on a gas pipeline connected between a gas source and a clutch. The gas relay is connected with a driller operation table through the gas pipeline, an electromagnetic valve is installed between the gas source and the gas relay, a contacting point type pressure gage is installed on a slime pump outlet pipeline, and the pressure gage and the electromagnetic valve are respectively connected with a voltage transformation relay through wires. The well drilling slime pump overpressure automatic protective device has the advantages that pumping pressure electrical signals sent by the contacting point type pressure gage are used for controlling the opening and the closing of the electromagnetic valve to control running and stopping of a slime pump, a