RELIABILITY ASSESSMENT OF FREE SPANNING OFFSHORE PIPELINE

Pipeline from offshore petroleum fields must have frequently prone to many threats such as corrosion, free spanning, extreme weathers and etc. This study will be only concentrated on free spanning of offshore pipeline. The presence of free span along the length of pipeline may result in excessive displacement and bending or vibration of the pipeline section. The research will begin with data gathering of pipeline from Malaysian Water Operation. All data related to the pipelines are gathered. This study is divided into three major parts which are the study of the length of pipeline span, bending moment capacity of pipeline and also the stress analysis in the pipeline. These are the three elements which can cause failure to the pipelines. Thus, an assessment analysis of free spanning pipeline is crucial in order to ensure the reliability of these pipelines. All equations are developed by using the data obtained f. Then, Limit State Function is developed for this research. From the limit state function, probability of failure of pipelines according to each category can be obtained. Software’s were used to conduct the study. Software’s that were used are BestFit, to get the distribution of the data and VaP to get the probability of the pipeline to fail. At the end of the research, all three failure modes is compared to get the best reliable mode according to the probability of failure for each mode.