Duplex cone expander for expanding a tubular upward and downward from preexpanded section

摘要

A method for expanding a casing (101) includes: placing a casing within the wellbore wherein the casing has a smaller outside diameter than a finil inside diameter of the casing; placing an expandable assembly mandrel (214) within the casing, the expandable mandrel suspended from a drill string (225); converting the expandable mandrel to a first expansion diameter while the expandable mandrel is within the casing wherein the first expansion diameter is about the final inside diameter plus twice the thickness of the final casing; forcing the expanded mandrel through a lower bell portion of the casing; converting the expandable mandrel to a second expansion diameter, wherein the second expansion diameter is about the final inside diameter; and forcing the expanded mandrel through an upper portion of the casing.