Centre for Offshore Foundation Systems

Pipeline geotechnics

 

As near-shore opportunities decrease in number, offshore hydrocarbon developments are extending into deeper waters located further from shore, creating new challenges for the industry.

The pipelines and risers that link the production facility to the wells and the offloading point, that in some cases provide an export route to shore, represent an increasingly important part of development infrastructure.

Our Centre has devoted increasing attention to the geotechnical behaviour of pipelines, partly through major research projects including the SAFEBUCK JIP, the CSIRO Cluster Collaboration and the MERIWA JIP on submarine slide – pipeline interaction.

Our focus

We are developing new analysis techniques for predicting the as-laid embedment of pipelines and the resulting pipe-soil interaction forces that can be mobilised when the pipeline is subjected to axial or lateral loading.

One focus of our work is the challenge of maintaining pipeline stability on unstable seabeds in times of severe cyclonic loading, which is particularly relevant to the Australian environment.

We have developed new computational models for various aspects of fluid-soil-pipe interaction, and UWA’s O-tube experimental facility provides a state-of-the-art capability to study on-bottom stability.

Another focus of our pipeline research is to support the development of modern design methods for the mitigation of thermal and pressure-induced loading, through reliable control of lateral buckling and axial walking, and the assessment of catenary riser–seabed interaction.

We have developed sophisticated centrifuge modelling techniques to simulate the lay process of seabed pipelines and the subsequent in-service behaviour, including thermal operating cycles and dynamic motion of riser-seabed interaction.

Furthermore, we regularly conduct experimental studies for pipeline designers to assist the establishment of site-specific pipe-soil interaction parameters for the design of pipelines worldwide.

We have also devised a novel capability to simulate the interaction between ship anchors and buried pipelines, and have conducted several studies to assist the design of pipeline protection systems where shipping creates a hazard.