Analysis of wall thickness calculation for rigid pipeline by using carbon steel for offshore: article

Previously, Pandora field used 16 Inch outer diameter of grade X52 Carbon Steel for 26 km of Natural Gas pipeline. These topics are to propose a new design of gas pipeline as backup for future use for Pandora field by chose the best where offers the best trade-off in strength, weight, cost, weldability, durability and its usage records. Also, to increase the productivity and design life of the pipeline. Basically, this research project is to analyse which material grade of carbon steel is better based on previous case study by using the same field. Either stay with the grade X52 Carbon Steel or propose other material grade of carbon steel that compatible with the field environment, pipe and design parameters. The proposed offshore pipeline has to withstand the loads that will be applied to the pipeline from installation to hydro testing until operating. During installation, the pipe will subject to bending, torsion, tension and external pressure but when it goes to operation it will be loaded with internal pressure from the content, external pressure from the sea, thermal stress from the temperature changes as deeper the sea higher the temperature. This final year project presents an analysis of pipeline on existing field by calculating new wall thickness and choose best material grade selection using Mathcad software. The required wall thickness is discussed by checking the wall thickness against few design criteria such as pressure containment due to hoop stress, buckle initiation, buckle propagation and collapse pressure based on preferred standard such as API 5L Specification and ASME B31.8. Last but not least, all objectives are achieved successfully.