Scantling Design And Strength Research On Triangular Multi-purpose Tension Leg Platform

In China, the offshore shallow waters growing oil and gas resources are overexploitationand even exhausted while the exploitation of deep-water oil and gas resources are faced withtechnical problems. In addition, with the rise of the development of marginal oil and gasfields, the development program used in these oil and gas field is becoming an urgent problemin the oil and gas industry in China. Therefore, the design，manufacturing and research ofoffshore platforms for deepwater oil and gas fields and marginal oilfield exploration, mininghas became a research focus for the theorists and engineering experts, especially the designand construction of the tension leg platform technology has caused high attention of theauthorities and it has been listed as the plan of the second "National863Program". It isforeseeable in the near future that the tension leg platform will become the main technicalequipment of China’s deep-sea and marginal oil and gas resource development.At the sea area of more than260meters deep of the South China Sea, several small oilfields have been found. But they failed to use conventional technology for commercialdevelopment. In order to find the most affordable engineering solutions to solve the technicalproblems of the independent development of the South China Sea deepwater marginal smalloilfields, a Chinese company, on the basis of completion of several related technologyresearches, through independent innovation, completed the concept design study preliminaryresults data of a very unique triangular multi-purpose tension leg platform.This paper, based on the main dimensions and general arrangement of the triangularmulti-purpose tension leg platform initially completed, will further complete the followingtwo aspects:First: According to the conceptual design, overall layout scheme and scale, using theAmerican Bureau of Shipping (ABS) and the American Petroleum Engineering Institute (API)specification, this paper will complete the scantling design of the structure of the triangularmulti-purpose tension leg platform, including the contents of the four areas, the lowerpontoon, the middle pontoon, topside and column. After the completion of the scantlingdesign, I will draw the scantling plan, typical section plan, and preliminary estimate theweight and the center of gravity.Second: Based on the completion of scantling plan and typical section plan, using finite element analysis software MSC.Patran&Nastran，I will complete finite element modeling ofthe triangular multi-purpose tension leg platform, at the same time, using the hydrodynamiccalculation software Hydrostar calculated wave load of the platform. Then, according to theenvironmental conditions of the platform based on the conceptual design, the boundaryconditions and load will be applied to the finite element model to analysis the platformstructural strength response situation in these environmental conditions. Finally, summarizingthe results of the platform strength calculation and completing the analysis of the overallstrength of the triangular multi-purpose tension leg platform.