Patent ID: 9255447
Filing Date: 2016-02-09
CPC Classification: E21B

Claim Text:
1. A method of forming a supported bore comprising the steps of: locating a first drill bit on a first expandable tubular member; drilling a first supported bore to a first depth with the first drill bit to form the first supported bore with the first expandable tubular member; then expanding a portion of the first expandable tubular member to a larger diameter; inserting a second drill bit mounted on a second tubular member within the first tubular member, the second drill bit being located on a steerable tool mounted on the second tubular member in order to provide the second drill bit and tubular member with directional drilling capability, the steerable tool being a mechanical device adjustable to effect changes in bore direction; drilling through a wall portion of the first tubular member above the first drill bit and drilling a second supported bore to a second depth with the second drill bit to form the second supported bore with the second tubular member; and cementing the second tubular member and the second drill bit and the steerable tool in place within the second supported bore.