Downhole environments expose seals to temperatures ranging from below 0°C in deepwater to over 200°C in HPHT (high-pressure/high-temperature) wells. Thermal expansion, degradation of polymer chains, and glass transition effects dramatically influence seal performance. Material selection is therefore the first critical engineering decision https://globalsealstech.com/product-category/oil-gas-seals/downhole-completion-tools-seals/