Patent ID: 8627883

Claim:
An apparatus for controlling fluid flow in a wellbore penetrating subsurface strata, comprising: a tubular manifold for conducting fluid through a portion thereof when disposed in the wellbore; a shaft supported for reciprocal axial movement within the manifold; a pair of opposing valve seats supported within the manifold in substantial alignment with the shaft; a pair of opposing valve closure elements carried by the shaft for reciprocal axial movement therewith between positions preventing fluid flow across one of the valve seats; a fluid inlet passageway; a pair of fluid outlet passageways; the opposing pair of valve seats defining channels for fluid flow from the fluid inlet passageway to the respective pair of fluid outlet passageways; wherein movement by the shaft of one of the valve closure elements to a position preventing fluid flow across one of the valve seats also moves the other valve closure element to a position permitting fluid flow across the other valve seat; a magnetic element carried by the shaft for reciprocal axial movement therewith between a pair of stator elements; a pair of springs each carried on opposing sides of the magnetic element such that one of the springs is compressed by and applies an axial force to the shaft under the movement of the shaft from a neutral position; and a compound magnet carried by the manifold about the magnetic element for applying an axial force to the magnetic element that together with the axial force of the one spring and fluid pressure within the manifold control movement of the shaft and the valve closure elements, the compound magnet comprising an electromagnet and a permanent magnet in which the electromagnet may be selectively energized to initiate movement of the shaft, and the permanent magnet is employed to hold the magnetic element proximate either of the stator elements when no current is applied to the electromagnet.