Improving vessel efficiency featured image credit: Woodside Energy Ltd
This collaborative research project has focused on scheduling the support vessels that service Woodside-operated offshore facilities. The vessels are used for delivering supplies and for assisting with oil off-takes to oil tankers.
The most cost-efficient vessel routes are influenced by various constraints, including time windows – most facilities are only open during daylight hours – along with vessel speeds, vessel cargo capacities and the capability of each vessel to assist with oil off-takes, as not every vessel in the fleet is equipped for this operation.
Despite an industry-wide push into ‘big data’ computer technology over the past few years, the mathematical models in this project were so large that state-of-the-art optimisation software packages struggled to find good solutions, and in some cases couldn’t even begin processing the model.
New solution algorithms were consequently devised by the Curtin team and this work has been accepted to appear in the Journal of Industrial and Management Optimisation.
“One outcome of the project was providing Woodside with strong evidence for a business case to reduce the support fleet from four to three vessels – this is a significant saving since the cost of running an additional vessel is considerable,” says Curtin’s Associate Professor Ryan Loxton, who led the project.
“Another outcome was modelling the implications of changing the vessel schedule from a ‘taxi-style’ service whereby vessels would service facilities on demand, to a regular fixed schedule that is easier to deliver in practice.”
The Curtin team’s current focus is on developing more powerful optimisation algorithms that will allow for ‘on the fly’ dynamic optimisation of day-to-day and week-to-week vessel schedules.
“Major challenges include the current dynamic and uncertain operating environment, and the computational demands required. The standard solution algorithms are too slow for the problems that we encounter,” says Curtin’s Dr Elham Mardaneh, who worked on the project.
Although the models were highly customised to suit Woodside’s offshore operations, Mardaneh says that there is also considerable potential to adapt the technology to make optimal routing decisions in other industries such as mining.
“Mine sites also involve difficult vehicle routing problems, such as how to route haul trucks among different locations in the most optimal manner.”
– Blair Price