Swellable packers represent a newer technology. Elastomers are formulated to swell in water or oil after days or weeks of exposure. No mechanical setting is required, making them ideal for open-hole completions and multilateral wells where traditional setting tools cannot reach. Swelling can increase volume by 100–500% https://globalsealstech.com/product-category/oil-gas-seals/downhole-completion-tools-seals/