Underbalanced well drilling and production

摘要

The invention provides a drilling rig and method comprising coupling a surface blow out preventer (12) to a wellhead using casing; providing a remotely operable subsurface latch (72) to sever the connection between said wellhead and said surface blow out preventer (12); and producing hydrocarbons from a subsea well in an underbalanced condition using a rotating head (10) mounted on the surface blow out preventer (12).