(under subclass 369) Process including a significant step of changing the below ground pressure by either (a) varying the pressure in the central conduit or pump inlet, as by a vacuum pump, or (b) varying formation pressure in a geopressurized zone so that recoverable gas is evolved from the formation fluid.
(1) Note. Inasmuch as any process for reproducing fluid from a formation will in all likelihood cause incidental changes in below ground pressure, the broad recitation of producing the formation or of pumping it is, in itself, not sufficient for classification in this subclass.
