Definition(s)
Subsea Test Tree
Assembly of valves positioned above the tubing hanger running tool located inside the subsea BOP and equivalent to the lower workover riser package. NOTE It is used to secure the well and provides a disconnect point for the C/WO riser. The subsea test tree can be configured for operation on horizontal or vertical trees.
Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards