Fiber optic sensing for offshore engineering applications

• Main Author: Sjamsudin, Wendy Wijaya
• Other Authors: Yang Yaowen
• Format: Final Year Project
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Civil engineering
• Online Access: http://hdl.handle.net/10356/74804
• Institution: Nanyang Technological University

A floating production storage and offloading (FPSO) unit is a floating ship used by the offshore oil and gas industries for the production and processing of hydrocarbons as well as for storing oil. It is compulsory to monitor the degradation of structural health of FPSO caused by waves and still water and by the harsh environment in which the FPSO is operational. In offshore monitoring, there are two main factors affecting the strain changes which are temperature and loadings. Hence, it is crucial to differentiate the data from these two different sources. Temperature is an important issue, especially when the structure is operating in harsh condition. Inconsistent temperature causes fluctuations to the data recorded by the sensors. Therefore, in this report, temperature compensation tests are done to study the behavior of the FPSO materials in different temperature conditions. Beside temperature, sensors used in offshore monitoring must be able to read the degradation of structural health due to loadings. Continuous loadings over a long period of time might cause fatigues and localized structural damages. Hence, loading tests are done to evaluate the strain changes due to varying weights. After temperature compensation and loading tests are done, the next major problem is to monitor strain on a continuous basis. This is to approximately calculate the structural damage and life predictions of FPSO. Therefore, FPSO modelling and simulation are done to analyze the effectiveness of using sensors in offshore monitoring. The model tests are done in two loading conditions which are full loading and ballast draft condition to consider both sagging and hogging moment respectively. ANSYS simulation are then used to check the accuracy of the model test results.