Tubing retrievable variable setting differential pressure actuated well safety valve

Abstract

A tubing retrievable differential pressure operated well safety valve which closes at a predetermined rate of flow which may be changed from the well surface. A housing is adapted to be threadedly connected to well tubing. A spring forces a flow tube and choke bean downwardly to normally hold the valve open, but when the producing rate increases to a preset value the bean and flow tube moves upwardly overcoming the spring allowing the valve to close. A releasable connection is provided between the choke bean and the flow tube for connecting the choke bean to and releasing the choke bean from the flow tube by longitudinal movement of the bean relative to the flow tube. The connection may include a collet interconnecting the beam and the flow tube in which the collet includes an enlargement for engaging a recess in the bean. The flow tube includes a backup shoulder for locking the enlargement in the recess and also includes an opening for allowing the collet to become released from the bean. Spring means between the flow tube and the collet yieldably urge the collet enlargement on to the shoulder. A chamber between the flow tube and the housing is connected by a fluid passageway from the bore having a restriction and a piston on the flow tube is positioned in the chamber and is retarded by restricted flow of fluid from the chamber.

Dependencies are inferred from the claim text.