製作期間 短縮과 建造費 節減을 위한 中型級 FPSO Topside 單層 再配置 設計에 관한 硏究

Abstract

Low oil price has driven cost-saving solutions for offshore structures such as standardization of topside equipment, relief of over-specification, weight reduction, and so on. From a perspective of EPCI contractor, it is also quite important to mitigate delay risk mainly caused by design changes and deliverable delay as well as the fabrication cost reduction. This study focuses on the EPCI contractor’s concern by rearranging the topside equipment traditionally placed on two or three decks on a single deck. The rearrangement of topside modules has been made for KNARR FPSO built in Samsung Heavy Industries for Teekay in 2014. The floating production vessel is 256 meters long and 48 meters wide. The ship has a production capacity of 63,000 barrels a day, and a storage capacity of 800,000 barrels. Accommodation is for 100 people. SHI provided the design dossier and has worked together by regularly reviewing and advising on the revised arrangements. This drives the innovative design toward a more feasible and applicable design. The single process deck was extended by 2 meters to both sides and the poop deck located in stern was also extended sternward by 6 meters. The gap between modules were bridged and the perimeter track of a module deck secured for maintenance can be overlapped. The equipment placed on two module decks has been rearranged on the enlarged single deck. Nonetheless, a few partial higher decks are unavoidable to place some equipment to be higher than other connected equipment like heat exchanger, tote tanks and so on. The single level topside design is expected to enable a simpler construction and allow shipyards to compress the fabrication schedule. Especially, long-lead equipment has postponed assembling a module on land until all equipment are delivered and it has led to delays of topside integration and even to sail-away. The single level design may mitigate the potential delay drastically. The lately delivered equipment can be separately integrated on FPSO moored to the quayside. The lowered center of gravity is also beneficial to the weight saving of topside module structures. The total pipe spool and cable length can be cut down and complicated fabrication process can be simplified. Other related bulk materials such as Passive Fire Protection, outfitting structures such as stair towers, vertical ladder, hatches and handrails, etc. can be also saved as well as escape route for safe evacuation to muster stations can be secured simply. And this arrangement is also advantageous from the maintenance perspective since two Pedestal cranes can cover the most process area. Detailed material handling plans and Risk assessment has been prepared to verify the new topside design.