Some aspects of offshore pipeline design against upheaval buckling

ABSTRACT: Pipelines are often used to transport hydrocarbon in onshore and offshore environments. In offshore, proper trenching and back-filling are difficult. Therefore, an offshore pipeline might experience both lateral and upheaval buckling during operation at high temperature and high pressure (HT/HP), depending upon the soil resistance. The initial imperfection is another factor that governs the initiation and type of buckling. The existing theoretical solutions have some limitations in modelling initial imperfection and soil resistances. Finite element (FE) simulation is performed for varying initial imperfection and nonlinear soil resistances to investigate the structural response of the pipeline. The effects of burial depth, pipe diameter and wall thickness on operating temperature are studied. The post-peak degradation of uplift resistance plays a significant role in post-buckling behaviour.