Patent attributes
The present inventions relate to improved apparatus and methods for radially expanding tubulars, such as tubing, casing and sand-control screen assemblies in a subterranean oil or gas well, and more specifically, to a variable diameter expansion tool for expanding downhole tubulars to varying diameters. In general, the inventions provide apparatus and methods for radially expanding a tubular, such as pipe, tubing, screen or screen assembly, deployed in a subterranean well by moving an expansion tool axially through the well. An automatically infinitely variable-diameter expansion cone tool is provided. A variable-diameter cone is provided, movable between an expanded position and a retracted position. The cone is enlarged to its expanded position and advanced through expandable components until a restriction is reached. At the restriction, the variable-diameter cone automatically retracts enough to allow the tool to continue advancing through the wellbore. When the restriction is past, the variable-diameter cone enlarges again to its expanded position.