Abb Vetco Gray Incorporated

Peter A Scott

Stephen Paul Fenton

David Stewart Christie

Walter J Lacey

Robert O Lilley

A subsea wellhead assembly has a tubular housing having a sidewall, an axial bore, and a housing lateral passage extending from the bore through the sidewall. A blocking sleeve fits around the housing to block the housing lateral passage while drilling through the housing. A tubing hanger is secured to a string of tubing and landed in the housing. The tubing hanger has a vertical passage which communicates with the tubing and a tubing lateral passage which extends from the vertical passage and registers with the housing lateral passage. A lower annulus port is in the sidewall of the housing below the lower seal and leads to a tubing annulus. An upper annulus port is in the sidewall of the housing above the upper seal and leads to the bore of the housing. A tree block having a central opening for receiving the housing is lowered over the housing after removal of the blocking sleeve. The tree block has a tree production passage which registers with the housing lateral passage for directing flow of production fluid from the well. A production valve is mounted to the tree block for opening and closing the tree production passage. A bypass passage in the tree block connects the upper and lower annulus ports to communicate the bore above the tubing hanger with the tubing annulus.

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Aberdeen, United Kingdom

Peter A Scott