Optimum Design Of Offshore Gas Pipelines Crossing Active Seismic Faults In The Mediterranean Sea
Proceedings Publication Date
The need for hydrocarbon extraction and transportation between countries has created the requirement for the construction and operation of reliable onshore and offshore pipelines worldwide. For this reason, more offshore pipelines are expected to be constructed in the future, especially in the Mediterranean region where the pipeline network is relatively small. Since offshore pipelines usually cross extensive areas, they may experience various geohazards that threaten the integrity of the pipeline, especially in the Mediterranean Sea which is one of the most seismic regions in the world. The present study focuses on the potential impact of seismic faults to offshore gas pipelines. After a literature review of offshore pipelines worldwide, the study is involved with the potential geohazards with an emphasis on the active seismic faults of the wider Mediterranean region. Afterwards, the finite-element software ABAQUS is utilized in order to simulate (a) the rupture of normal and reverse faults through sedimentary layers and the subsequent permanent ground deformations on the seafloor, and (b) the distress of the pipeline when it is subjected to the aforementioned ground deformations. Factors, such as the properties of the fault, the geometrical and mechanical properties of the ruptured sedimentary formations, the pipeline characteristics and the hydrostatic pressure are analysed. Finally, the study makes an effort to evaluate the results in order to assess the magnitude of the problem and to briefly propose some mitigation measures, as well as suggestions for further research.