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

摘要

A method is provided for providing a casing in a wellbore including placing a casing within the wellbore wherein the casing has a smaller outside diameter than a final inside diameter of the casing, placing an expandable mandrel within the casing, the expandable mandrel suspended from a drill string, 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 portion of the casing while the expandable mandrel is of the first expansion diameter; 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 while the expandable mandrel is of the second expansion diameter.