Multi-Layer Water Swelling Packer

摘要

A packer for downhole use responds to water containing fluids by swelling from its core. The core is preferably covered with an outer layer that preferably has a lower rate of diffusion and swelling than the core that it surrounds. Because of this arrangement, the packer can be delivered to the desired location before it is set by swelling of the core. The outer layer can also be responsive to water containing fluids by dissolving slowly to allow time to properly position the packer before the core swells to a sealing relationship with the surrounding tubular or the wellbore wall.