Definition(s)
HPHT environments
HPHT environments are intended to mean that one or more of the following well conditions exist: a) the completion of the well requires completion equipment or well control equipment assigned a temperature rating greater than 350 °F or a pressure rating greater than 15,000 psig; b) the maximum anticipated surface pressure or shut-in tubing pressure is greater than 15,000 psig on the seafloor for a well with a subsea wellhead or at the surface for a well with a surface wellhead; or c) the flowing temperature is greater than 350 °F on the seafloor for a well with a subsea wellhead or on the surface for a well with a surface wellhead.
Source: API TR 1PER15K-1, Protocol for Verification and Validation of High-pressure High-temperature Equipment, First Edition, March 2013. Global Standards