Packer seals form the primary barrier in completion strings. Compression, inflatable, and swellable types use HNBR, FKM, FFKM, or TFE/P compounds qualified to API 11D1, ISO 14310, and NORSOK M-710 standards. They hold differential pressures from 5,000 to 25,000 psi across temperatures ranging from -40°C to 350°C in HPHT wells https://globalsealstech.com/product-category/oil-gas-seals/downhole-completion-tools-seals/