PR sand control packer is a kind of rely on packer rubber tube outer diameter and differential pressure of the casing of the Canon and realize seal, under the packer in the process, the rubber tube always cling to the inner wall of the casing., and can only carry a top-down pressure difference, the greater the pressure difference, the better the sealing, it belongs to a kind of one-way pressure type packer, apply to the differential pressure small shallow Wells, the pressure can be balanced or tubing anchor well, can also be used to wash Wells reservoir pollution prevention and so on in the process.