Abstract: Devices that can be used to recover hydrocarbon production from closed-in oil wells capable of building up wellhead pressure and/or to sustain marginal oil production in oil wells are disclosed. Production in oil and natural gas producing wells in mature fields that have the ability to build up wellhead pressure and where the depletion of reservoir pressure has caused low or zero productivity may be automated. The devices include at least two bellows that facilitate their operation. The bellows may close the well to build up pressure in the wellhead and open the well to flow line pressure.

Abstract: The phase of this process is done by the functionality of the perforated lower stem, which due to the fact that its internal conduit is able to connect the lower bellow in an alternated way, first to the tubing and after, to the casing. This is possible due to the fact that it is assisted by: a) a window that communicates the casing with the tubing when the lower bellow is open, and b) sealing packing installed in the lower stem to isolate the casing pressure, in order that the lower bellow can register only the tubing pressure when it is in closing position.

Abstract: The phase of this process is done by the functionality of the perforated lower stem, which due to the fact that its internal conduit is able to connect the lower bellow in an alternated way, first to the tubing and after, to the casing. This is possible due to the fact that it is assisted by: a) a window that communicates the casing with the tubing when the lower bellow is open, and b) sealing packing installed in the lower stem to isolate the casing pressure, in order that the lower bellow can register only the tubing pressure when it is in closing position.