Patent ID: 6823943
Filing Date: 2004-11-30
Classification: E21B

Abstract:
A method of providing well bore protection between the bore of an oil or gas well and the formations outside the well bore by inserting a liner into the bore of a casing string in said oil or gas well to a position extending below the lower end of said casing string comprisingproviding a circumference of the outer perimeter of said liner which is greater than the circumference of the inner diameter of said casing string, collapsing said liner to a shape such that the maximum non-axial dimension of said liner is less than the internal diameter of the casing string through which it is being inserted, and in which all portions of the outer diameter of said liner can be engaged by either a first blowout preventer ram seal from a first direction or a second blowout preventer ram seal from the opposite direction.