A PhD student at The University of Western Australia is working to reduce risks and costs for industry by understanding how the dynamic subsea environment impacts infrastructure design.
Lili Qu moved from China to Australia to study in offshore engineering at UWA and is now in the fourth year of her PhD.
Ms Qu works in the Transforming energy Infrastructure through Digital Engineering (TIDE) research hub, which was established under the Australian Research Council in 2021 to combine expertise in mathematics, statistics and machine learning with world-leading research in oceanography, hydrodynamics and geotechnics.
Her research examines how scour, the removal of sediment around structures caused by the movement of water, impacts the behaviour of critical infrastructure in subsea environments.
“Scour can be a big problem for infrastructure such as pipelines, foundations or other subsea energy systems,” Ms Qu said.
"When a structure is set on a mobile surface, such as sand, flow around the structure may cause the individual particles to be washed away.
“In an extreme case, this can lead to settlement or tilt of the structure – impacting its ability to function as designed.
“I am trying to predict and prevent scour so we can help the industry apply cost effective and reliable countermeasures, or to better design structures in the first instance.”
Ms Qu examines data provided by TIDE industry partners’, representing offshore installations on the North West Shelf of Western Australia, where strong currents are variable and difficult to predict.
She uses this information for experiments using the Large O-Tube, a closed-loop flume with a base of seabed soil, at UWA’s Coastal and Offshore Research Lab at the Shenton Park Field Station.
“I use the facility to gain insight into various flow conditions and assess their impact on scour around subsea structures,” Ms Qu said.
“I then try to find countermeasures to mitigate scour or reduce the scour process.”
The changing topography of the seabed is captured by digital imaging methods including binocular infra-red scanning.
Ms Qu has explored different shapes and configurations of subsea structure, to understand how this may increase their long-term stability.
“Once we figure out how to reduce scour at one location, it’s possible to translate the findings to other locations with different flow intensity – widening the impact of the research.”
Her project overlaps with activities undertaken in OceanWorks, which is part of Woodside FutureLab Network at UWA.
Combined with the extensive TIDE partner network, Ms Qu works closely with industry and her supervisors, Professor Phil Watson, Professor Scott Draper and Dr Hongwei An, to deliver her findings, receive feedback, and create potential to increase industry confidence when designing and maintaining subsea structures.