Patent ID: 7621339

Claim:
A pump, positionable in a fluid column substantially separated into an undesired fluid portion and a desired fluid portion, for selectively lifting the desired fluid to a surface and injecting the undesired fluid into an injection zone, the pump comprising: a housing having a top wall, and a bottom wall defining a cylinder; a plunger positioned within the cylinder reciprocable through an induction stroke and a production stroke; a piston moveably positioned between the plunger and the top wall separating a desired fluid chamber from an undesired fluid chamber; a desired fluid intake assembly providing one-way fluid flow from the fluid column to the desired fluid chamber; a desired fluid exhaust providing one-way fluid flow from the desired fluid chamber to the surface; an undesired fluid intake providing one-way fluid flow from the fluid column to the undesired fluid chamber; and an undesired fluid discharge providing one-way fluid flow from the undesired fluid chamber toward the injection zone; wherein on the induction stroke the desired fluid is drawn into the desired fluid chamber and the undesired fluid is drawn into the undesired fluid chamber, and on the production stroke the desired fluid is produced to the surface and the undesired fluid is injected into the injection zone if the injection zone pressure is overcome.