Structural Optimization for the Ice-Resistance Platform in Bohai Bay

Bohai Bay is a major offshore oil and gas production area in China, a number of oil and gas fields are located there. The offshore facilities in this area are subject to ice loads in the winter, and the ice loads on the platform are one of the major concerns in the structural design in this area. The loads include ice impact, ice-induced-vibration and floating ice influence to the offshore operations. Compared to the loads combination of wind, wave and current, the ice load may be the governing loading condition in the structural design. The ice induced vibration to the production facilities and the living quarters may also seriously affect safety and the health of the operating personnel. This paper briefly introduces the development history of the ice-resistance platform design in Bohai Bay, and based on previous experience, the ice loads calculation method, the structure configuration of primary steel, the appurtenance arrangement and the conical structure at ice abrasive zones are discussed to optimize the ice-resistance capability. The material selection and different vibration mitigation methods are also discussed in this paper. Although significant progress has been made on the ice-resistance platform design, the problems still remain such as the floating ice accumulation around well slots. Further study on ice-induced vibration is necessary. This paper summarizes the main issues and challenges in the ice-resistance platforms and proposes the key points for future development. This paper also provides helpful references to the design and optimization of the offshore platform in an ice active environment.