Methods of releasing a well tool set in a wellbore are provided. In various embodiments, a well tool, such as a packer, is released from sealing and gripping engagement within a wellbore using alternate methods. A dual-string packer is described in which the packer may be released by severing a mandrel of the packer, displacing a piston of the packer, or by displacing a retaining device in a flow passage of the packer.