US 6,644,411 B2Granted

Tubing hanger with flapper valve

AssigneeKvaerner Oilfield Products

InventorsDewey Craig Compton, Edwin R. Knerr

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Abstract

A tubing hanger including a tubing hanger body having a tubing string which is adapted to be supported in the bore of the wellhead housing wherein the apparatus comprises a flapper valve disposed in or below the tubing hanger, wherein the valve further comprises a flapper valve having a flapper valve closure member substantially in the form of a concave spherical segment defining an annular valve seat concentric with the tubing for the flapper valve; a flapper plate disposed in the valve chamber for rotatable movement from a valve position in which the flapper plate is removed from the annular valve seat to a valve position in which the flapper plate extends transversely across the flow passage for the flapper valve and forms a sealing engagement with the annular valve seat and the sealing surface is substantially in the form of a convex spherical segment, wherein the convex spherical segment is disposed intermediate between the first and second planar surfaces.

Claims14

Dependent claims

Apparatus for use in a subsea wellhead including a wellhead housing having a wellhead bore therethrough and at least one casing hanger supported within the wellhead bore for suspending at least one casing string within the well head bore, wherein said apparatus comprises:

a. a tubing hanger including a tubing hanger body having an annulus defined between production bore and said casing string therethrough;
b. a flapper valve disposed in said annulus of said tubing hanger adapted for opening and closing the annulus, said flapper valve having a flapper valve closure member with a first segment defining an annular valve seat in said annulus within said tubing hanger;
c. a flapper plate disposed in said valve chamber is adapted for rotatable movement from a valve open position in which said flapper plate is removed from said annular valve seat to a valve closed position in which said flapper plate extends transversely across said annulus and forms a sealing engagement with said annular valve sear thereby preventing flow through said annulus;
d. a sealing surface substantially in the form of a first segment disposed intermediate between a first planar surface and a second planar surface;
and
e. means responsive to pressurized fluid for hydraulically moving the valve plate from a closed position to an open position.

3 more elements

Dependencies are inferred from the claim text.