Melbourne service firms supply seals for downhole tools in liner hanger systems, using PEEK thermoplastic anti-extrusion with HNBR energizers surviving 250°C cement kicks. Seals feature wave spring preloads compensating 0.3mm radial growth in 7" liners. Victorian precision grinders achieve ±0.0005" flatness preventing micro-leak paths. In Otway CCS pilots, they isolate injection zones... https://globalsealstech.com/product-category/oil-gas-seals/downhole-completion-tools-seals/