Abstract: A releasable packer device and a method for selectively releasing a packer assembly from a set position in a wellbore. A packer assembly is described that incorporates a split body lock ring that is in ratcheting engagement with a central mandrel to secure the packer elements in a set position. In addition, there is a mechanical means for releasing the body lock ring from its locking position to an unlocked position. The body lock ring is released by radially expanding the ring by urging an axially-movable release sub with a releasing portion into contact with the body lock ring to unseat the ratcheting mechanism that retains the packer assembly in its set position.