US Patent 7647990 Method for drilling with a wellbore liner

A method for drilling with a liner includes: providing a liner string including an upper portion extending towards surface and a lower portion; drilling to a depth with the liner string; disconnecting the upper portion from the lower portion; pulling the upper portion from the well; and leaving the lower portion in the well to line the wellbore. A drilling assembly for drilling a borehole with a borehole liner includes: an upper liner string; a lower liner string including an upper end and a lower end; a releasable connector connecting the lower liner string to the upper liner string; and a drilling assembly connectable at the lower end of the lower liner string.