The mining services group will execute heavy mechanical and electrical maintenance, specialist rope access and scaffold services for Alcoa. The five-year contract is worth A$90 million (US$61 million).
According to SRG, site mobilisation is well advanced, meaning it can begin contract services in February.
SRG Global managing director David Macgeorge called it "a very significant contract award" for its asset services division, showcasing its "ability to deliver multi-disciplinary integrated solutions for tier-one customers".
"We look forward to building a long-term partnership with Alcoa to deliver value-engineered maintenance and access services that drives value for their operations," he said.
The refinery, located 22 kilometres south of Perth, receives bauxite ore from Alcoa's Huntly mine in Western Australia.