An increase in downhole pressure that occurs when a string is lowered in the well or when circulation is initiated.

Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards



Vessel motion along the for/aft axis.

Source: API RP 16Q, Recommended Practice for Design, Selection, Operation and Maintenance of Marine Drilling Riser Systems, First Edition, November 1993 (Reaffirmed August 2001). Global Standards



Vessel motion along the fore/aft axis.

Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards

Source: ISO 13624-1:2009, Petroleum and natural gas industries – Drilling and production equipment – Part 1:Design and operation of marine drilling riser equipment. Global Standards



  1. pressure change produced by conditions such as pump or compressor startup or shutdown, valve openings or closures, and line leaks.
  2. pulsating flow in centrifugal compressors caused by operating under low flow conditions.

Source: IADC UBO / MPD Glossary, December 2011. Global Standards

Comments are closed.