Tubing hanger and wellhead housing with mating tubing annulus passages

摘要

A subsea wellhead assembly has a tubing annulus path that extends partly through the tubing hanger and partly through the wellhead housing. A tubing hanger tubing annulus passage extends through part of the tubing hanger from a lower port on the lower end of the tubing hanger to an upper port on the exterior surface of the tubing hanger below the tubing hanger seal. A wellhead housing tubing annulus passage within the sidewall of the wellhead housing has a lower end at the bore below the tubing hanger seal and an upper end at the bore above the tubing hanger seal. A valve is mounted to the wellhead housing and accessible by an ROV from the exterior for opening and closing the inner wellhead housing tubing annulus passage.