SUBSEA PIPELINE DESIGN AND THERMAL EXPANSION AND STRESS ANALYSIS FOR SUBSEA TIE-IN SPOOL

• Main Author: Revo Refaldiano, Don
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/49261
• Institution: Institut Teknologi Bandung

Subsea pipeline is one of the few structure with supporting function of products transportation in oil and gas industries. Regarding the condition of the place, subsea pipeline is affected the more by its environment rather than onshore pipeline, for example there are effects from wave and current force. As the environment affection is rising, the operational affection will rise so the product can be transported in an extreme condition. The engineering process for subsea pipeline need to be conducted for operational condition, hydrotest condition, and installation condition.. The engineering of pipe property in this Undergraduate Thesis are including the design of wall thickness regarding DNV-OS-F101, the design of on-bottom stability regarding DNV-RP-F109, and the design of free span regarding DNV-RP-F105. Next, subsea pipeline will be designed and analyzed for thermal expansion in expansion spool regarding ASME B31.8 Ch VIII, then will be analyzed with the help of CAESAR II 2019 software for stress analysis. The result of wall thickness design regarding DNV-OS-F101 in this Undergraduate Thesis is subsea pipeline being modeled needs 7.1 mm (0.2790 in) thick of steel pipe. From the on-bottom stability design regarding DNV-RP-F109, can be concluded that the subsea pipeline needs concrete coating of 34 mm (1.3390 in) thickness for 0.2 total diameter trenching, while for no trenching it needs 45 mm (1.7720 in). From the free span analysis regarding DNV-RP-F105, can be conluded that subsea pipeline with 0.2 total diameter trenching needs 9 m of free span, while no trenching gives the same number, which is 9 m. From the thermal expansion analysis regarding ASME B31.8, can be conluded that subsea pipeline will expand about 23.44 mm in hydrotest condition and 11.26 mm in operational condition. Regarding the subsea pipeline modelling with CAESAR II 2019 software and ASME B31.8 Ch VIII, subsea pipeline needs to be in L shape to maximize the efficiency and effecitivity of the expansion spool to hold off the stress. The maximum result of thermal expansion from modelling of pipeline system is about 21.12 mm, which is similar to the one from thermal expansion analysis hydrotest condition, this confirm that the result is valid.