Patent ID: 7093652
Filing Date: 2006-08-22
Classification: E21B,F04B

Abstract:
1. A plunger for use in a gas/fluid lift system in downhole tubulars in a wells producing fluids and/or gases under variable well pressures, comprising: a first body and a second body slidingly engageable within the tubulars and capable of movement up and down said tubulars, said first and second body each having a top end and a bottom end and an inner core within each said body for internal sealing; a connector disposed between said first and second bodies and joining said bodies, said connector having first and second ends, said first end attached to the bottom end of the first body and said second end attached to the top end of the second body; a flexible jacket having an outer side and inner side, formed by a plurality of segments mounted about each said core, each of said segments having a convex outer surface and an inner surface, first and second sides, and top and bottom ends, wherein the inner surface of each segment has a plurality of fingers thereon that protrudes inward toward the core; a tortuous flow path for well fluids and/or gases between each said core and the inner side of each said jacket; each said jacket having an inner side providing an internal seal, and an outer side being radially expandable to provide an external seal against the interior of said tubulars, wherein each of said internal and external seals retards a flow of well fluids and/or gases which thereby increases a pressure below the plunger to thereby move the plunger and well fluids to a well surface when the well pressure inside the tubulars above the plunger is reduced.