The 8K Double Grip Packer is the most versatile of the mechanically set retrievable packers and may be used in any production application. The packer is suited for treating, testing, injecting, pumping wells, and flowing wells, deep or shallow. The packer can be left in tension or compression, depending on well conditions and the required application. A large internal by-pass reduces swabbing when running and retrieving. The by-pass closes when the packer is set and opens prior to releasing the upper slips when retrieving to allow pressure equalization. The J-slot design allows easy setting and releasing.