Offshore Ice Resistant Liquid Natural Gas Export Terminal Concept

Abstract

Abstract Cost and delivery of long distance natural gas pipelines to a distant LNG (liquid natural gas) liquefaction facility at a warm water port location has become excessive and environmental restraints have been increasing. An alternative to this type of facility is now being considered: an offshore ice resistant LNG Port accommodating a new class of LNG transport vessels. Improvements in LNG processes have reduced the footprint of the facility by 2/3 and lowered the cost by 20% giving an advantage to an offshore ice resistant port facility that can be used for offloading LNG which will eliminate the long distance natural gas pipeline. The presentation is based on original analysis. The benefits for deep water Arctic Marine Port are undeniable. It is possible to provide safe harbor and configure the port to fit the requirements of the endeavor. For Arctic offshore LNG liquefaction operations, this port can be designed to provide safe harbor and be relocated if needed to another site. A system of ship-like rectangular GBS (Gravity Base Structure) type structures can be constructed to create a safe area where there would be no ice movement and would provide shelter from large wind storms. The structures could be constructed in the Pacific Rim and towed to the site of the new port. They would then be ballasted into position. For the Beaufort Sea, the port could be positioned offshore west of BP's Northstar Island in approximately 60ft. of water. The ice movement is benign and units can be readily designed to resist the ice loads. Life expectancy would be greater than 20 years. The concept is extremely adaptable to the location and type of deployment. The Ice Resistant LNG Port System would be designed to accommodate the shallow waters of the near shore Arctic seas. In addition, the individual units could be configured to serve multi-functions in the exploration and development of offshore hydrocarbon fields. These units could be configured to provide shallow water drilling GBSs and or storage for offshore operations or both. Advances in ice class LNG transport vessels developed for the Russian Arctic allows the discharge and transport of LNG by sea, thus eliminating long distance natural gas pipelines. The new LNG carriers being designed for the use at the Yamal project are capable of breaking through ice 2.1 meters thick and newer designs will be capable of breaking 2.5 meters ice unassisted. These new vessels are to enter service in 2016 and haul the LNG to the Pacific-rim countries. The vessels are 299 meters long and draft 12 meters.