Drilling flange and independent screwed wellhead with metal-to-metal seal and method of use
AssigneeStinger Wellhead Protection, Inc.
InventorsBob McGuire, L. Murray Dallas
Life of this patent
Estimating the term…
Abstract
A drilling flange and an independent screwed wellhead provides a metal-to-metal seal that supplements the traditional elastomeric O-rings for providing a fluid seal between the drilling flange and the wellhead. The metal-to-metal seal may be achieved using a metal ring gasket or two contacting metal surfaces that are machined to required tolerances and are configured to be forced together when the drilling flange is mounted to the wellhead. The metal-to-metal seal ensures a fluid seal between the flange body and the wellhead in the event that the O-rings malfunction or are destroyed by fire.
Claims20
An independent screwed wellhead, comprising a top end for mating engagement with a bottom end of a flange mounted thereto, the top end of the independent screwed wellhead comprising a machined socket for receiving a pin end of the bottom end of the flange, the machined socket comprising a frusto-conical surface offset from an axial plane of the independent screwed wellhead by 4°-10° that mates with a complementary frusto-conical surface machined on the pin end of the flange to provide a high-pressure metal-to-metal seal between the flange and the independent screwed wellhead when the pin end of the flange is received in the machined socket of the independent screwed wellhead.
An independent screwed wellhead, comprising a top end for mating engagement with a bottom end of a flange mounted thereto, the top end comprising a socket with a machined frusto-conical metal contact surface that mates with a complementary machined frusto-conical metal contact surface of the bottom end of the flange received in the socket when the flange is mounted to the independent screwed wellhead, the machined frusto-conical metal contact surface in the socket providing a metal-to-metal seal with the bottom end of the flange when the machined frusto-conical metal contact surface on the bottom end of the flange is forced into the socket by a lockdown nut rotatably supported by a shoulder on an outer sidewall above the bottom end of the flange, the lockdown nut engaging a thread on the top end of the independent screwed wellhead.
An independent screwed wellhead, comprising a top end for mating engagement with a bottom end of a flange mounted thereto, the top end comprising a machined socket with a frusto-conical metal contact surface that mates with a complementary frusto-conical metal contact surface machined on a pin at the bottom end of the flange, the pin end being received in the machined socket when the flange is mounted to the independent screwed wellhead, the frusto-conical metal contact surface in the machined socket providing a metal-to-metal seal with the pin at the bottom end of the flange when the complementary frusto-conical metal contact surface is forced into the machined socket by a lockdown nut rotatably supported by a shoulder on an outer sidewall above the bottom end of the flange, the lockdown nut engaging a thread on the top end of the independent screwed wellhead.
Dependencies are inferred from the claim text.