Patent ID: 6142224
Filing Date: 2000-11-07
Classification: E21B,F04B

Abstract:
An apparatus for selectively lifting produced fluid, including produced hydrocarbons and a portion of produced water, to a ground surface and injecting, without lifting to the ground surface, the remaining produced water, subsurface, in a subterranean well comprising:a casing having two spaced intervals and extending from the ground surface downwardly within the subterranean well such that a first of said two spaced intervals communicates with a producing zone and a second of said two spaced intervals communicates with an injection zone;a pump assembly, disposed in said casing, having an upper plunger, a middle plunger, and a lower plunger, said upper plunger coupled to said middle plunger and said middle plunger coupled to said lower plunger, said pump assembly reciprocable through an upstroke and a downstroke;a first valve disposed on said upper plunger and a second valve disposed on said middle plunger, said first valve and said second valve responsive to the upstroke and the downstroke of said pump assembly;a packer disposed within said casing between said first of said two spaced intervals and said second of said two spaced intervals, wherein said casing and said packer are configured to permit the produced fluid to collect above said packer whereby the produced hydrocarbons and produced water segregate by gravity;an inlet disposed between said lower plunger and said packer, said inlet responsive to said upstroke of said pump assembly to permit unidirectional flow of the produced water segregated by gravity into said pump assembly below said lower plunger to form a column of produced water;an outlet in fluid flow communication with said inlet and said pump assembly, said outlet responsive to said downstroke of said pump assembly to permit unidirectional flow of said column of produced water into said casing below said packer; andwherein said upper plunger has a surface area larger than a surface area of said lower plunger, thereby allowing said column of produced water to be injected into said casing at a magnified injection pressure.