Patent ID: 7650936

Claim:
An independent screwed wellhead and a drilling flange comprising, in combination: an annular wellhead body with a bottom end adapted to be secured to a surface casing of a well, the annular wellhead body including a passageway with a top end having an upper abutment surface and a lateral contact surface; an annular drilling flange having a top flange, an axial passageway at least as large as the passageway of the annular wellhead body, a sidewall having an outer surface with an annular shoulder near a bottom end of the outer surface and a lateral contact surface below the annular shoulder that mates with the lateral contact surface of the annular wellhead body to provide a metal-to-metal fluid seal between the annular wellhead body and the annular flange body; and a lockdown nut rotatably supported by the annular shoulder, the lockdown nut engaging a pin thread on the top end of the annular wellhead body to secure the annular drilling flange to the annular wellhead body.