Stranded GOM Drill Barge Refloated
Inland Salvage Inc. (ISI) recently demonstrated its diversified capabilities with the offshore deployment ISI salvage and emergency response equipment and personnel in the successful fuel removal, partial dismantlement and refloat of a stranded 2,500 ton posted drill barge. The drill barge suffered side shell damage and loss of watertight integrity due to contact with a support barge in rough seas. As a result, she was unable to discharge ballast and refloat after completing work-over operations in Caillou Island Field, Timbalier Bay, Louisiana. The drill barge's location in a corridor between barrier islands exposed the site to periodic heavy seas and swells.
The barge's Owner called upon third-party divers initially but were unable to make the required repairs, and advised the Owners to seek professional salvage assistance. ISI was immediately contracted and salvage crews and equipment were dispatched to the site within 24 hours.
The arrival of tropical storm Debby, with deteriorating sea conditions, required that refloat efforts be put on hold and immediate actions be taken to prevent further damage to the vessel during the storm. Side shell shoring was achieved by way of vertical toggles along the damaged exterior section of the hull. The side shell toggles arrested the breathing of shell plating (moving in and out with oncoming seas) and stopped the spread of damage into other compartments. Then steel plates were installed over longitudinal splits in the side shell and bolted into position. The steel plate and bolting arrangement stiffened damaged side shell sections to resist the working of interior framing. All emergency salvage repairs were in place and ISI was able to evacuate crews before onslaught of the storm.
The underwater efforts on the part of ISI salvage divers using underwater burning, underwater welding, and patch installation was heavily backed up and supported by a topside crew of welding and fabrication personnel. These topside personnel insured diver requested prefabbed components would be ready to hit the water as needed.
With the passing of the storm, the salvage crews returned and found the emergency response salvage repairs intact and had effectively prevented the spread of hull damage. ISI conducted thorough pipeline and side scan surveys of the surrounding area of the casualty. The surveys revealed live pipelines passed under the barge leading to surrounding wellheads. Extensive surveys of surrounding pipelines strongly reduced the ability of anchoring or spud type mooring systems and restricted the use of ISI's heavy lift salvage barges. ISI opted to mobilize a 175 series lift boat with a 115 ton crane to the site to use as a work platform.
ISI's on-site Salvage Master, Mr. Peter Drummond, working closely with ISI Project Management and Argonautics Marine Engineering, developed a modified plan involving the removal of 170 tons of drill equipment and drill floor structure along with the discharge of 375 tons of liquid ballast and cargo. A specialty team of shipbreakers was mobilized to assist divers and crew in removal of topside structure. Airlifting removal of residual mud build up in hull was restricted to damaged area. The remaining mud would provide ballast without the complications associated with free surface water. All participants were aware of the limited window of opportunity and the consequences if a storm caught the barge partially afloat in the narrow confines of the pipeline and wellhead field. All structure removal work was complete and permission was received to proceed with the modified refloat plan.
Within 18 hours of the notice to proceed, the vessel was refloated, moved away from wellhead, stabilized, and was ready to begin its journey to the shipyard for repairs. Towing vessels and crews, familiar with the area, skillfully maneuvered the rig's hull through the very confined and shallow field. The towing company's captains kept in constant radio contact with the salvage master, providing updates to the salvage crew on tow conditions. The cooperation between the towboats and the Salvage Master enabled the underway movement of ballast and pumping to reflect the stability adjustments as the tow progressed. ISI worked closely with the USCG / MSU Houma during the evolution and provided real-time updates from beginning to end.