Metal-to-metal annulus packoff for a subsea wellhead system
AssigneeFMC Corporation
InventorShiva P. Singeetham
Life of this patent
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Abstract
An all-metal, well annulus packoff assembly for establishing a high pressure, corrosion resistant metal-to-metal seal between a wellhead housing and a casing hanger, including an annular metallic seal element having a generally upstanding U-shaped cross section that is adapted for non-rotational sequential setting against the hanger and the housing.
Claims10
An annular packoff for establishing a metal-to-metal seal in the annulus between a wellhead housing and a casing hanger, the packoff comprising an assembly including:
- a) an annular metallic seal element adapted for non-rotational sequential setting against said casing hanger and said wellhead housing, said seal element including an annular base, an inner tubular portion extending axially from said base, an outer annular lip portion likewise extending axially from said base, at least one annular sealing ridge on said tubular portion for metal-to-metal contact with a casing hanger, and at least one annular sealing ridge on said lip portion for metal-to-metal contact with a wellhead housing;
- b) an energizing mandrel for sequentially energizing the seal element into metal-to-metal sealing engagement first with said casing hanger and then with said wellhead housing in response to axial movement of said mandrel with respect to said hanger and said housing;
- c) means releasably connecting the seal element to the energizing mandrel;
- d) an annular locking mandrel;
- e) means for slidably connecting the locking mandrel to the energizing mandrel;
- and
- f) means for releasably locking the energizing mandrel to the casing hanger in response to axial movement of the locking mandrel with respect to said energizing mandrel.
An annular packoff for establishing a metal-to-metal seal in the annulus between a wellhead housing and a casing hanger, said packoff comprising an assembly including:
- a) an annular metallic seal element adapted for non-rotational sequential setting against said casing hanger and said wellhead housing, said seal element having an inner frusto-conical surface with at least one annular sealing ridge for sealingly contacting a frusto-conical sealing surface of said casing hanger;
- b) an annular energizing mandrel for sequentially energizing the seal element into metal-to-metal sealing engagement first with said casing hanger and then with said wellhead housing in response to axial movement of said energizing mandrel with respect to said hanger and said housing, said energizing mandrel including a lower end portion with an inner cylindrical surface and an outer frusto-conical surface, said mandrel frusto-conical surface having an angular taper greater than that of said casing hanger frusto-conical surface;
- c) means releasably connecting the seal element to the energizing mandrel;
- d) an annular locking mandrel;
- e) means for slidably connecting the locking mandrel to the energizing mandrel;
- and
- f) means for releasably locking the energizing mandrel to the casing hanger in response to axial movement of the locking mandrel with respect to said energizing mandrel.
Dependencies are inferred from the claim text.