Large Diameter Drilling (LDD) and Barge Master have combined their expertise to complete a world first: drilling operations from a diving support and construction vessel in water depths in excess of 270 metres.
By integrating LDD’s reverse circulation LD2500 drill rig with a motion compensation platform (BM-T700) LDD have successfully completed the installation of seven anchor mooring piles for a Catenary Anchor Leg Mooring (CALM) Buoy – with the technique employed, whilst unique and bespoke, having the potential for industry-wide application.
The Project (Limetree Bay Installation) was executed in the Caribbean Sea, circa 2km off the coast of St. Croix, USVI, for Imodco Terminals, a subsidiary of SBM Offshore.
The project was exceptionally challenging; operational and environmental constraints limited the use of more conventional methods. The LDD devised solution mounted the LD2500 to a cantilever beam which was subsequently affixed to the T700 motion compensation platform. Typically, reverse circulation drilling takes place off a jack-up barge or from the pile top itself, however substantial water depths (ranging between 80-275m), challenging sea-bed conditions (sea-bed slopes up to 17 degrees) as well as the physical attributes of the anchor pile design made this impossible. An innovative and robust solution was required. LDD’s selected solution combined the proven technology of the motion compensated platform and the LD2500 drilling system to achieve a successful project outcome.