The Dynamical Analysis And Design Of Keypoint Of SPAR In The Deep South China Sea

As one of the floating production system, SPAR is widely used in marine engineering. It is well suited to exploiting oil and gas resources. The dynamic performance and fatigue life of SPAR are hotspots in marine engineering. The development of SPAR in China is still in the initial stage due to the limitation of technical level and environment condition. Deep South China Sea is rich in oil and gas resources, but the marine environment is too complex. Researching the dynamic performance and fatigue life of SPAR in Deep South China Sea is meaningful and important to the development of technology and exploitation of resources of our country.Based on the long term marine environment of Deep South China Sea, this paper gets the parameters of wind, wave and current in different sea conditions. As the actual marine environment parameters, they are suitable for SPAR to use them as loads. This paper designs an integrated Truss SPAR with referring to DNV offshore position mooring standard and API standard. Frequency and time domain analysis is researched after modeling the Truss SPAR. The sequence of frequency domain analysis describes the exercise performance while the sequence of time domain analysis describes the safety performance of SPAR. With the sequence of mooring system in time domain, the fairlead is designed and modeled referring to the standard of DNV and API. Then this paper calculates the fatigue life of fairlead with the sequence of strength analysis based on the critical plane-energy method.This paper gets marine environment parameters in work condition and extreme condition of Deep South China Sea. Results of frequency domain analysis show that Truss SPAR performs well in freedom of heave and yaw. Peak frequencies of other freedoms also avoid the common value of wave in South China Sea. Results of time domain analysis show the force in mooring line and the displacement of SPAR are both in the specified range of API standard. Fatigue life of SPAR is274.29as calculated in paper, which satisfies the design requirements of ABS. By and large the Truss SPAR performance well and is highly safe in Deep South China Sea.