Abstract: Disclosed is a well packer which is set by pressure applied through a tubing string which supports the packer within a surrounding well conduit. Once set, the packer is retrievable by either longitudinal or rotary movement of the supporting tubing string. Setting pressure drives opposed cone assemblies longitudinally toward each other to cause slip segments to move radially outwardly into anchoring engagement with the surrounding well conduit. The lowermost cone assembly is constructed in the form of a split ring and is equipped with friction teeth along its internal surface to retain the packer in its set position. A helical retrieving component secures the packer assembly to the central mandrel of the packer. Righthand rotation of the tubing string causes the outer body of the packer to unthread from the helical retrieving component secured to the mandrel which in turn unsets the packer.