US Patent 6920925 Wellhead isolation tool

A wellhead isolation tool and a wellhead assembly incorporating such a tool are provided. The wellhead assembly has an annular assembly coupled to a well. The annular assembly may include a casing head coupled to the well and a tubing head mounted over the casing head. The wellhead isolation tool is suspended in the annular assembly. The wellhead isolation tool has a first end portion extending above the annular assembly and a second end portion below the first end portion within the annular assembly. A production casing suspended in the annular assembly and is aligned with the wellhead isolation tool.