Completion/workover (C/WO) riser systems
C/WO riser systems are used for the initial installation of the subsea completion equipment and during major well workovers. These systems typically require the use of a mobile offshore drilling vessel equipped with fullwellbore-diameter pressure control equipment. The two basic components of these systems are the C/WO riser and the WOCS, as described below.
The completion and workover risers may in fact be a common system [typically known just as the completion/workover (C/WO) riser], with specific items added or removed to suit the task being performed.
Source: API RP 17A, Design and Operation of Subsea Production Systems—General Requirements and Recommendations, Fourth Edition, Reaffirmed 2011. Global Standards
Completion/Workover Riser (C/WO riser)
Temporary riser used for completion or workover operations.
Source: API RP 17G, Recommended Practice for Completion/Workover Risers, Second Edition, July 2006 (Reaffirmed April 2011). Global Standards