Patent attributes
A steam operated flow control device and method is disclosed. In one mode, the flow control device enables steam to be injected into a subterranean formation region containing hydrocarbons. In another mode, the flow control device enables the hydrocarbons to be produced from the subterranean formation to the surface. The flow control device includes a piston disposed between a housing and a mandrel having aligned ports, which slides between a first position where one set of ports align with the ports in the housing and the mandrel and a second position where another set of smaller ports align with the ports in the housing and mandrel. The piston is operated by a bellows having a chamber which contains a fluid. The fluid responds to temperature and/or pressure variations.