Offshore Pipeline Seabed Interaction

Offshore pipelines are increasingly being required to operate at high temperature and pressure, and the associated increment of axial stress caused by expansion is a major concern for design. It is essential to have an in-depth understanding of pipe-soil interaction phenomenon to control creeping and  buckling failures.

Research Conducted on offshore pipeline seabed interaction

The research objectives are to interpret the axial interaction behaviour of offshore pipelines to be laid on the seabeds of the North Western Shelf of Australia. A special sophisticated 2D actuator setup (Monash Advanced Pipe System or MAPS) was purpose built to simulate the pipe walking on a model clay seabed. Element pipe testing was conducted for both drained and undrained pipe displacement rates. The results led to the characterisation  of the governing parameters on the axial pipe-soil interaction behaviour. The problem was also studied by means of extensive numerical studies using ABAQUS FEM. Further, a cyclic simple shear device capable to incur the low vertical stress conditions is developed and employed in the investigation. Figures  1 to 3 show the MAPS testing setup.

Figure 1: Image of actuators from the MAPS setup.
Figure 1: Image of actuators from the MAPS setup.

Figure 2: MAPS testing setup

Figure 2: MAPS testing setup.

Figure 3: Initial pipe embedment.

Figure 3: Initial pipe embedment.

Numerical Modelling

The following videos shows pipeline seabed soil interaction simulation using ABAQUS (Figure 1).

Figure 4: Pipeline seabed soil interaction simulation using ABAQUS

Figure 4: Pipeline seabed soil interaction simulation using ABAQUS.

Simple Shear Device

Figure 5: Simple shear device

Figure 5: Simple shear device.

Publications

More details and the outcome of these experiments can be found in the following literature:

  • Senthilkumar, M., Kodikara, J. and Rajeev, P (2013). Pipe-clay seabed interaction of offshore pipelines under axial movements using PIV, International Society of Offshore and Polar Engineers, Alaska, USA.
  • Senthilkumar, M., Kodikara, J. and Rajeev, P (2013). Axial interaction behaviour of offshore pipelines, GéoMontréal 2013, Montreal, Canada.
  • Senthilkumar, M., Rajeev. P., Kodikara (2012). Axial interaction behavior of offshore pipelines using elastic analysis, 12th Australian and New Zealand conference, Melbourne, Australia.
  • Senthilkumar, M., Kodikara, J. and Rajeev, P. (2011). Numerical Modelling of Undrained Vertical Load-Deformation Behaviour of Seabed Pipelines, 13th International Conference of the International Association for Computer Methods and Advances in Geomechanics, Melbourne, Australia.
  • Senthilkumar, M., Rajeev. P., Kodikara, J. and Thusynathan, N. I. (2011). Laboratory Modelling of Pipe clay Seabed Interaction in Axial Direction, International Society of Offshore and Polar Engineers, Mauii, Hawaii.
  • Senthilkumar, M., Kodikara, J. and Rajeev, P. (2011) Numerical Modelling of Vertical load-displacement behaviour of Offshore Pipeline Using Coupled Analysis, Pan Am CGS Geotechnical Conference, Toronto, Canada. Senthilkumar, M., Rajeev, P. and Kodikara, J. (2010).Offshore Pipe Clay-Seabed Interaction in Axial Direction, Cluster workshop , Perth,    Australia.
  • Senthilkumar, M., Rajeev, P. and Kodikara, J. (2010). Consolidation around offshore pipe embedment using coupled analysis, 1st summer conference, Monash University, Melbourne, Australia.

Other burried pipeline and offshore pipeline research conducted at Monash University