Patent ID: 7975771
Filing Date: 2011-07-12
Classification: E21B

Abstract:
1. A method of drilling a subsea well, comprising: (a) providing a landing shoulder within an outer string of a casing, securing an upper end of the outer string of casing to an outer wellhead housing above the landing shoulder, and lowering the outer string of casing into a wellbore; (b) attaching a drill bit to a lower end of an inner string of casing, lowering the inner string of casing and the drill bit through the outer string of casing into the wellbore; (c) rotating the inner string of casing and the drill bit to deepen the wellbore; (d) attaching a casing hanger to an upper end of the inner string of casing and landing the casing hanger on the landing shoulder after the drill hit has reached a selected depth; (e) cementing the inner string of casing in the wellbore after the casing hanger has landed on the landing shoulder; and (f) attaching a tieback member to an inner wellhead housing and lowering the tieback member into sealing engagement with the casing hanger and landing the inner wellhead housing in the outer wellhead housing.