Patent ID: 8186457
Filing Date: 2012-05-29
Classification: E21B

Abstract:
1. A method of drilling a well with a drilling rig having a blowout preventer (BOP), comprising: (a) drilling the well to a selected first depth using drill pipe; (b) then running a first length of casing into the well with a drill bit assembly attached, the first length being less than a distance from the first depth to the BOP; (c) attaching drill pipe to the first length of casing and while the drill pipe extends through the BOP, drilling the well from the first depth to a second depth with the drill bit assembly attached to the first length of casing; (d) when at a selected second depth, pulling the drill pipe from the well and adding more joints of casing to the first length of casing to increase the first length to a second length of casing with a lower end of the second length of casing approximately at the second depth and an upper end of the second length of casing at the rig; and (e) cementing the second length of casing in the well.