Pressure cycle operated perforating firing head

摘要

Pressure cycle operated apparatus and methods. A method of actuating a firing head includes the steps of : reciprocably displacing an actuator piston of the firing head, the displacing step including the piston being alternately pressure balanced and unbalanced; and igniting a combustible material in response to the piston displacing step. A method of generating electricity includes: reciprocably displacing a piston, the displacing step including the piston being alternately pressure balanced and unbalanced; and generating electricity in response to the piston displacing step. A firing head includes an actuator piston separating at least two chambers; a check valve which permits one-way flow between the chambers; a flow restrictor which restricts flow between the chambers; a biasing device which biases the piston toward one of the chambers; and a firing pin releasing device which releases a firing pin in response to displacement of the piston.