Patent ID: 8322417

Claim:
A method for facilitating production of a fluid product from a subterranean system in which heat is introduced to a formation, comprising: with a steam assisted gravity drained production well including a conduit, recovering the fluid product from the formation; and with a temperature activated valve disposed in hydraulic communication with the production well, controlling fluid flow from the formation to the production well, the valve including: a power source operative to provide magnetic lines of flux; a movable actuator member which controls fluid flow through an opening as a function of actuator position; and an intermediate member; wherein, a first potential pathway for the magnetic lines of flux traverses the actuator member and a second potential pathway for the magnetic lines of flux traverses the intermediate member, and wherein magnetic permeability of the intermediate member at a first temperature is less than at a second temperature, such that more magnetic flux is directed to the actuator member at the first temperature, and thus greater magnetic attractive force causes the actuator member to move in a first direction at the first temperature; and wherein the intermediate member includes a material having a Curie temperature close to a steam temperature of injected steam in the steam assisted gravity drained production well and including the further step of closing the valve at the Curie temperature of the material.