Downhole temperatures increase approximately 1°F per 70 feet of depth with geothermal gradients varying by region. Standard wells operate at 150°F-250°F, while HPHT wells exceed 350°F-500°F. Thermal wells and geothermal applications approach 600°F. High temperatures degrade elastomers through oxidation, reversion, and crosslink breakdown causing hardening and loss of sealing force. HN... https://globalsealstech.com/product-category/oil-gas-seals/downhole-completion-tools-seals/