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As human society gradually increasing demand for energy and to reduce land-based oil and gas reserves, abundant marine resources, oil and gas exploration and development has gradually become the focus. Offshore oil exploration and development is inseparable from offshore platforms, but poor service environment offshore platforms, marine development projects at home and abroad, had many incidents of a catastrophic accident offshore platforms, not only to the marine environment caused tremendous pollution, it also brings incalculable economic losses and adverse social impact. Effective assessment and forecasting platform security and reliability, is to ensure the safe operation of platform structure, the maximum effective measures to avoid the accident. In this paper, the finite element software ANSYS, Chengdao oilfield offshore jacket platform for the object, the platform structure static analysis, transient dynamic response analysis, ultimate strength and fatigue reliability analysis, comprehensively and objectively reflect the safety of the structure , availability and durability, reasonable arrangements for the CHENGDAO oilfield production provides an important platform for decision making. Include the following: (a). Adopt PY, QZ, TZ curve considering the nonlinear characteristics of the soil, summed PY, TZ, QZ method for determining the curve, and a spring element to simulate the nonlinear soil around the pile of soil, the establishment considering the structure - pile - soil interaction platform finite element model; considering the pile - soil interaction, the platform enhanced structural flexibility, stiffness decreases. (2). Static analysis of the platform to ensure the platform structure in extreme wave conditions strength and stiffness requirements are met; research results show that the platform in 50 years of extreme wave conditions, and so the value of the maximum displacement effects force values ??were within the allowable range of values, with a larger static safety reserves. (3). The platform modal analysis and transient dynamic response analysis; modal analysis results show that the natural frequency of the platform effectively avoid the natural frequency of the waves, and the waves can be very good to avoid resonance; through transient Response analysis platform for various conditions of displacement, velocity, acceleration, and stress-time curve, as a platform to provide a more effective safety assessment of reliable information. (4). Were calculated defect-platform ultimate strength and the presence of seawater corrosion, component damage and loss, soil erosion and other damage to the foundation platform for the ultimate bearing capacity, the final calculation of the platform's strength reserve coefficient; research results show that the kinds of types of corrosion damage ultimate load capacity of the platform the greatest impact on the platform to pay special attention during service work platform corrosion. (5). Marine engineering structural fatigue life assessment of the basic methods of research, from the energy point of view of structural dynamics analysis platform, based on the application of the above method of spectral analysis of the platform for structural fatigue life estimate the overall platform; analysis The results showed that the fatigue life of CB273 platform to meet the design requirements.
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