Patent ID: 7967077

Claim:
A packer for establishing a sealing and gripping engagement with a surface disposed in a wellbore, comprising: a packer mandrel; a seal assembly slidably disposed about the packer mandrel, the seal assembly having a running position and a radially expanded sealing position; a slip assembly slidably disposed about the packer mandrel, the slip assembly having a running position and a radially expanded gripping position; a piston slidably disposed about the packer mandrel and defining a chamber therewith, the chamber at a pressure lower than a pressure in the wellbore, the piston operably associated with the seal assembly and the slip assembly; and a collet assembly disposed about the packer mandrel and releasably coupled to the piston, wherein, the piston is positioned between the seal assembly and the collet assembly such that the collet assembly initially restrains movement of the piston toward the seal assembly resisting a force generated by a pressure difference between the pressure in the wellbore and the pressure in the chamber until radially inward shifting of at least a portion of the collet assembly decouples the collet assembly from the piston allowing the pressure in the wellbore to shift the piston longitudinally relative to the packer mandrel toward the seal assembly which operates the seal assembly from the running position to the radially expanded sealing position and operates the slip assembly from the running position to the radially expanded gripping position, thereby setting the packer.