The A-2 Lock-Set Retrievable Casing Packer is a full bore double-grip retrievable packer with an integral unloader. Opposed, non-transferring dovetail slips prevent movement of the packer in either direction due to pressure differentials, while allowing landing of the tubing in tension, compression or neutral. The lock segments serve as a releasable lock ring to maintain pack-off once the packer is set and locks the unloader in the closed position until the tool is released. The split lock and control segments allow the tools to be both set and released with right-hand rotation. The Packer holds pressure from above or below while allowing the tubing to be landed in tension, compression or in a neutral condition. The setting and releasing are controlled by right-hand tubing rotation