An air lock device for sealing a casing located inside a well, the air lock device including a body having a bore and configured to be attached with each end to the casing; a moving element located inside the bore; and a blocking element connected to the moving element, the blocking element preventing a fluid to pass through the bore of the body. The moving element forms an inner chamber with the body in which the blocking element is trapped after the blocking element is punctured by the moving element.