Metal seal for wellheads
AssigneeStream-Flo Industries Ltd.
InventorsKeith D. Farquharson, Tinale Guo, Heinrich Lang, Tony M. Lam, Kevin Paul Scheider
Life of this patent
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Abstract
A reusable metal seal for a wellhead provides a metal-to-metal seal and includes upper and lower tapered sealing flanks which may be deflected by tapered wall surfaces on the wellhead engaging the taper sealing flanks, and the seal may have a plurality of annular relief grooves.
Claims22
A seal for a wellhead for providing a metal-to-metal seal between a casing head and a tubing head, the casing head and tubing head each having a tapered wall surface adapted for engagement with the seal, comprising:
- an annular seal member having an upper and a lower end and an inner wall surface and an outer wall surface;
- an upper tapered sealing flank disposed on the outer wall surface of the seal member and adjacent the upper end of the annular seal member;
- a lower tapered sealing flank disposed on the outer wall surface of the seal member and adjacent the lower end of the annular seal member;
- the upper and lower tapered sealing flanks having a first diameter before engagement with the tapered wall surfaces of the casing head and the tubing head;
- the upper and lower tapered sealing flanks having a second diameter after engagement with the tapered wall surfaces of the casing head and the tubing head, with the second diameter being smaller than the first diameter;
- and
- after the seal member is removed from engagement with the tapered wall surfaces of the tubing head and the casing head, the upper and lower tapered sealing flanks have a third diameter, the third diameter being substantially the same as the first diameter.
A method for providing in a wellhead a metal-to-metal seal between a casing head and a tubing head, the casing head and tubing head each having a tapered wall surface for engagement with the seal, comprising:
- installing a seal having an annular seal member having, an upper and a lower end and an inner wall surface and an outer wall surface, an upper tapered sealing flank disposed on the outer wall surface of the seal member and adjacent the upper end of the annular seal member, a lower tapered sealing flank disposed on the outer wall surface of the seal member and adjacent the lower end of the annular seal member;
- providing relative movement between the casing head and the tubing head to cause the tapered wall surfaces of the casing head and tubing head to engage the upper and lower tapered sealing flanks of the seal, and the upper and lower tapered sealing flanks have a first diameter before engagement with the tapered wall surfaces of the casing head and the tubing head;
- and
- the upper and lower tapered sealing flanks to have a second diameter after engagement with the tapered wall surfaces of the casing head and the tubing head, with the second diameter being smaller than the first diameter.
Dependencies are inferred from the claim text.