Riser Flexible Joints

Effective Date: 7/14/2004

U.S. Department of the Interior
Minerals Management Service
Gulf of Mexico OCS Region

Safety Alert No. 222
July 14, 2004

Contact: Elizabeth Komiskey
(504) 736-2418


Riser Flexible Joints

Recently a small oil spill occurred in the Gulf of Mexico as a result of a leak from a steel catenary export riser.   Through visual inspection by divers it was determined that the flexible joint on the riser was the source of the spill.  After shutting in the pipeline and removing the flexible joint, a preliminary inspection found damage on the flexible joint in the elastomeric seal area near the rotating ball.  As a precaution, the operator inspected a second flexible joint on another steel catenary export riser on the same facility even though a leak had not been detected.  The results of that inspection indicated similar damages to the elastomeric seal area near the rotating ball. 

It is not known if these two cases are isolated nor what caused the damage to the flexible joints.  Given the potential for failures in similar riser designs, MMS recommends that lessees, operators, right-of-way holders, contractors, and others in the offshore oil and gas industry who have installed, operate, and are responsible for the maintenance of flexible joints on any steel catenary risers perform an inspection of all  flexible joints as soon as possible to ensure that these flexible joints do not have similar problems. If inspections identify problems and failure is considered imminent, lessees, operators, or other responsible parties should immediately initiate repair procedures.

MMS may update this Safety Alert if additional information about the cause of the damage to the flexible joint becomes available