WALL THICKNESS CALCULATION AND ON-BOTTOM STABILITY ANALYSIS OF HDPE SUBSEA TAILING PIPELINE

• Main Author: SEPTIAN ADRIANTO (NIM : 13106062); Dosen Pembimbing : Prof. Dr. Ir. IGN Wiratmaja Puja, NICKO
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/16687
• Institution: Institut Teknologi Bandung

Subsea pipeline design shall refer to the condition of loading due to hydrostatic and hydrodynamic forces. This can be achieved by performing pipe wall thickness <br /> <br /> <br /> calculations and by doing subsea pipeline on-bottom stability analysis appropriately. <br /> <br /> <br /> Pipe required wall thickness must resist loads due to the condition of slurry flow internal operating pressure and external hydrostatic forces that arise due to differences <br /> <br /> <br /> in ocean depths. The hydrodynamic forces due to ocean waves and currents cause an additional requirement, namely the on-bottom stability analysis. <br /> <br /> <br /> In this final project, pipeline has been designed according to ASME B31.11, API 15LE, and DNV RP-E305. Batu Hijau tailing pipeline system, HDPE 48 ", which is 3-km-long from the transition point up to terminus point (125 m below sea level), is used as case study. The design process is done by considering internal pressure load at various operating conditions, external loads due to hydrostatic pressure, and subsea on bottom stability analysis. Stability analysis involves the hydrodynamic forces due to pipe lift, drag force, and inertia force. Linear Airy wave theory is used as the basis for modeling the water particle kinematics due to waves and underwater currents. <br /> <br /> <br /> Data analysis showed that the dimension ratio, DR, requirement is 7.3 (pipe wall thickness = 167 mm) for nominal outside pipe diameter 48 in (1220 mm). The onbottom <br /> <br /> <br /> stability analysis then carried out at three different location of points, where the minimum weight ballast obtained are 8464.37 kg , 5924.81 kg, and 5073.49 kg based <br /> <br /> <br /> on depth and sea conditions at point 2 (9.98 m), point 6 (40.29 m), and point 11 (129.14 m), respectively.