Patent ID: 7121346

Claim:
A wellhead assembly for use on a well with a blowout preventer stack having a bore therethrough, comprising: a wellhead housing, said wellhead housing adapted to suspend at least one casing string therein, and seal an annulus between said wellhead housing and said at least one casing string; a spool tree sealingly secured to an upper end of said wellhead housing, said spool tree having a bore therethrough adapted to receive a tubing hanger therein and seal thereabout; a tubing hanger sealingly secured within said spool tree at a prearranged angular orientation, said tubing hanger having at least one tubing bore therethrough, said tubing hanger having a tubing string suspended therefrom; an intervention spool sealingly secured to the upper end of said spool tree, said intervention spool having a bore therethrough adapted to receive a valve assembly having a plurality of valves arranged therein, said valves having a bore concentric with said tubing hanger, said valve assembly valves being operable, with the blowout preventer stack in place, by a plurality of valve actuators positioned on the exterior of said intervention spool; and, a blowout preventer stack positioned above and sealingly secured to said intervention spool, said blowout stack having a bore substantially equal to the bore of said intervention spool.