The invention discloses a
blowout preventer remote automatic
grease injection
system based on PID control and a control method, and relates to the technical field of
grease injection, and the control method comprises the following steps: an initialization stage: automatically matching the specification of a
choke tube according to the
diameter of a cable, and preheating sealing
grease to a set temperature; in the
dynamic control stage,
wellhead pressure and grease
injection pressure are monitored in real time, pressure errors are calculated, the flow of a grease
injection pump is adjusted according to a PID
algorithm, and when the cable lowering speed suddenly changes, pressure fluctuation is inhibited in advance through a differential link; and according to the safety redundancy mechanism, when the main
PID controller fails, the standby
PID controller is automatically switched, and emergency locking is triggered when the
wellhead pressure exceeds the limit. The flow of a grease
injection pump is adjusted in real time through an incremental PID
algorithm and a self-adaptive adjustment method, the grease injection amount is accurately controlled, pressure fluctuation is reduced, sudden change of the cable lowering speed is predicted through a differential link, the response precision is improved, stable operation of the
system is ensured through a redundant controller and an emergency locking function, PID output is corrected through a dynamic temperature-
viscosity model, and the reliability of the
system is improved. The
system service life is prolonged.