Hydrate blockages are one of the biggest challenges in deep water production operations. Although a great effort is made to prevent hydrates from forming, once in place they can be extremely difficult to remediate.
This presentation will review a case study where subsea construction work on the gas export system from the Boomvang Spar led to the formation of over 3 miles of hydrates in a 4-mile long 18" gas export pipeline. Discussion will focus on lessons learned as well as solutions implemented to remediate the hydrate plug, with emphasis on a hydraulic workover unit that was positioned on the spar to drill through the entire length of hydrates in the riser and flowline system. Challenges such as riser integrity, tubular design, fluid selection, torque/drag concerns, and BHA locating will all be addressed.