It refers to the downhole tool connected to the downhole string and used to seal the annular space between the tubing and the casing of the oil and gas well or the open hole wall.
When it is necessary to seal the annular space between the tubing and the casing of the oil and gas well or the open hole wall, connect the packer on the downhole string, and after going down to the design depth, the packer on the packer will be expanded and the oil trapping sleeve annular space is driven by hydraulic drive. Different forms of packers have different ways of initiating and unsealing.
After the hydraulic expansion packer is lowered to the design depth, the pressure is applied from the tubing, and the high-pressure liquid acts on the inner cavity of the rubber cylinder through the pressure transfer pores inside the packer. When the oil pressure is released and the pressure of the oil jacket is balanced, the rubber cartridge shrinks back to its original state by its own resilience force to achieve unsealing.
After the compression packer is lowered to the design depth, the pressure is applied from the oil pipe, and the high-pressure liquid acts on the piston mechanism through the pressure transfer pores inside the packer. When the oil pressure is released and the pressure of the oil jacket is balanced, the rubber cartridge returns to its original state by its own resilience to achieve unsealing.