In the process of oil extraction, a special tube is inserted into a drilled well, through which oil is pumped at high pressure. During the oil extraction, the pipe walls can be damaged by moving ground particles, corrosion, etc, which results in leakages of oil / gas. In order to eliminate leaks, special valves (packers) are used to block the flow of oil/gas that rises from the ground. Currently available packers differ in diameter and length, they also can be mechanical or hydraulic. However, all of them are single-use, because when installing the packer in the pipe, special clips penetrate into the walls causing irreparable damage. Then a special solution is pumped through the packer, covering all the defects and holes and thus firmly sticking the packer to the pipe walls. After the use, the packer is partly removed from the well (fasteners remain in the pipe) and it is no longer suitable for further use. Sometimes, the packer is not pulled out, and in this case a new hole is drilled to supply oil through the installed packer. There are also multiple use packers without anchor, they can move along the pipe without causing damage. However, all existing packers are rather big and special lifting devices are needed to install a packer in the well. The packer designed by the Russian company is reusable. The technology allows making it hydraulic or hydromechanical. The packer is fixed in the tube through a patented method of fastening without anchors. It can be easily removed from the well and placed there again without any damage to the walls of the pipe or its construction. The device size may range, on customer request, from 146 to 295 mm, depending on the size of casing string. Maximum working pressure is 100 atmospheres. The increase in pressure is possible on demand up to 300-400 atmospheres. The packer reacts to pressure drops directed downwards and upwards. Small size (30-260 kg of weight and 650-1200 mm in length) allows installing and dismantling without lifting mechanisms. The packer is easy in production, it does not require special equipment or supplies, The production does not require re-equipment of similar manufacture. The prime cost of the proposed packer is less than of analogues, due to small size and simplicity of construction.