Apr. 2002 Vol. 223 No. 4  European Technology Round Up
Netherlands
Fin protection system gaining acceptance by drilling contractors

The riser fin configuration can be seen around a 21-in. by 75-ft clip riser joint.

After introduction of the Lankhorst / Mouldings riser fin system for protection of drilling risers and auxiliary lines at OTC 2001, several drilling contractors have shown considerable interest. Global Santa Fe and Stena Drilling Ltd. decided to equip their bare slick joints with fins. These fins will enable them to decrease the riser running and retrieving time. They will also enlarge the processing window of weather conditions under which riser manipulations can take place, without doing harm to the riser or rig.

Global Santa will install two systems on their new-built clip risers for the SF 184 & 185 rigs. These fins are a larger version, with a 54-in. O.D. and 10-ft length. In early January 2002, the assembly around a mock-up took place (photo).

Stena Drilling decided to install the system on its Stena Tay and Stena Dee semi-submersibles to evaluate the concept’s benefits. A few modifications were carried out to facilitate horizontal storage of the riser on deck at any place preferred.

Pride International’s subsea engineering manager, Tony Hogg (who initially developed the riser fin concept with his Petrodrill team and Lankhorst), said he is considering installation of the new design on two ultra-deepwater drillships – Pride Angola and Pride Africa. 

Mock-up of the riser fin system was assembled recently at Kværner Oilfield Products in Houston.

Amethyst class rigs Petrodrill 4 and Petrodrill 5, currently being built in Pascagoula, are most likely going to be equipped with the original design, as was done with the Pride Brazil and Pride Carlos Walter semi-subs.