Patent ID: 6871708

Claim:
A subsea wellhead assembly, comprising: an outer wellhead housing; an inner wellhead housing; at least one casing hanger landed in the inner wellhead housing and sealed by a packoff; a passage extending downward through a sidewall of the inner wellhead housing from an upper opening on an exterior of the inner wellhead housing to a lower opening in an interior of the inner wellhead housing, the upper opening being above the outer wellhead housing, the lower opening being below the packoff; and a passageway extending downward through the sidewall of the inner wellhead housing from an upper opening on an exterior of the inner wellhead housing to a lower opening in the interior of the inner wellhead housing, the upper opening of the passageway being above the outer wellhead housing, the lower opening of the passageway being below the packoff, wherein a portion of the passageway passes through the casing hanger, the lower opening of the passageway being located on an exterior portion of the casing hanger.