The increasing demand for oil and gas, currently estimated at 135 million barrels of oil equivalent per day, keeps pushing the boundaries of offshore engineering into ever deep waters. For instance, in the Gulf of Mexico, exploration and production activities are performed in water depths exceeding 3000 meters. Such remote locations and challenging environments call for new procedures and solutions in the design and installation of offshore pipelines.
In this paper, numerical modelling and analysis of offshore pipelines is reviewed and discussed. Finite element techniques to assist in pipeline design are introduced, and applied to pipeline routing optimization. Special emphasis is devoted to out of straightness and on bottom stress analysis. Contact algorithms allowing the simulation of pipe laying on an uneven seabed (using bathymetry) are reviewed, and recent developments in modelling of pipe-soil interaction are highlighted. The importance of free span detection and evaluation is stressed. In addition, it is shown how finite element analysis can contribute to the prediction and mitigation of both upheaval and lateral buckling of subsea pipes. At the end of this paper, pipeline walking on an inclined seabed is simulated, and the importance of seabed friction on the walking rate is demonstrated.