Abstract: A casing apparatus is provided to install a hard, pressure-resistant seal along a wall of a well in situ. The casing apparatus includes a moving device and a deformable tubular sleeve having a first end and a second end and. The moveable element is radially inflatable and movable inside the deformable tubular sleeve along a longitudinal axis of the deformable tubular sleeve. When the moving device is radially inflatable to an inflated condition and is moved from the first end to the second end, the moving device deforms the deformable tubular sleeve radially against the wall and progressively from the first end to the second end. A force of deforming the tubular sleeve applied by the inflated moving device is adjustable by changing the inflated condition of the moving device during the deformation process.