Safety device for a fluid production well, associated installation and method

Safety device (10) for a fluid production well, comprising a valve (58) used to seal a passage, and which can move between an open position of the passage (52) and a closed position of the passage (52); and connecting biasing means (92) for permanently biasing the valve (58) towards the closed position thereof. The device comprises holding means (42) for holding the valve (58) in its open position against permanent biasing means (92), and actuating means (42, 44) which are configured to actuate the holding means (42), on reception of a maintenance signal, to generate : * a first displacement of the movement element (98) from the active valve biasing position to an intermediate valve biasing position, in which the valve (58) remains in its open position; and * a subsequent second return displacement of the movement element (58) from the intermediate valve biasing position to the active valve biasing position.