A system of valves placed on the subsea wellhead designed to control the flow into or out of the completed well. NOTE The subsea tree may provide numerous additional functions [e.g. chemical injection points, well intervention means, pressure relief means (annulus vent), etc.].
Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards
Assembly of valves attached to the uppermost connection of the subsea wellhead and used to control well production.
Source: API Standard 2RD, Dynamic Risers for Floating Production Systems, Second Edition, September 2013. Global Standards
Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards