Posture Monitoring Technology And Data Fusion Of FPSO Offshore Platform

The offshore platform is one of the important infrastructures in marine operations, as well as the necessary tool and equipment for offshore oil and gas exploitation in the ocean. Offshore platform suffers some security risks because it has long been affected by the complex and uncertain marine environment. The impact of the complex ocean environment factors such as wind, wave and current leads to the complexity of the offshore platform motion. In order to ensure the safety of the offshore platform in work and life and provide early warning, the platform and its surrounding marine environment should be monitored effectively for a long time.Based on the background of the FPSO single-point mooring offshore platform, combined with the characteristics of the marine environment and the offshore platform structure, the paper studies the monitoring technique of the FPSO. The sensors such as angle sensor, INS, acceleration sensor and GPS sensor that are installed in the FPSO hull and mooring system can monitor the attitude and position of the FPSO single-point offshore platform. The integrated on-site monitoring system displays the attitude of FPSO in real time. GPS sensors play an important role in the FPSO monitoring system and mainly monitor the position and attitude information of the FPSO. Based on the structural characteristics of the FPSO offshore platform and the actual demand for using the GPS to monitor the FPSO hull’s attitude, the scheme using multiple GPS sensors and the equations which are used to calculate the attitude of the FPSO hull are designed. The use of multiple GPS sensors to calculate the attitude provides an effective way for the follow-up data fusion. The GPS critical technologies in the process of calculating are also described in detail.Aiming at the sensor measurement data error of the single point mooring attitude sensors in FPSO during monitoring, this paper proposes a method of information fusion based on multi-sensor redundant monitoring. The method creates the multi-body dynamic motion equation of the FPSO single-point mooring system and builds containment relationships among the redundancy data which is based on monitoring data of multi-sensors installed on FPSO hull and mooring system. This method using nonlinear least square method can effectively correct the monitoring data error and improve the accuracy of the data constraints.FPSO on-site monitoring system realized monitoring the FPSO soft yoke single-point mooring system in long-term for the first time in our country and also provides valuable information for the motion analysis and structural design of FPSO. The data which is obtained by the on-site monitoring system can reflect the motion attitude and the mooring force more truly than the model calculations and pool experiments. Error calibration for monitoring data can provide accurate data for the data analysis of the FPSO offshore platform in the future work.