A packer refers to an elastic sealing element, which seals the annular space between various sizes of tubing string and the wellbore and between the tubing string, and isolates the production layer to control the production (injection) fluid and protect the casing Downhole tools. In the same way, it can be concluded that the Injection Packers are used to prevent the rebound of the injection after injection, so as to achieve the effect of airtight separation.
In large-scale oil production projects, the role of the packer is more obvious. It plays a role of stratification. The packer is designed with oil production channels. When setting, the piston sleeve moves up and the oil production channel is opened; after setting, the upper pressure Acting on the balance piston, the rubber cylinder is pushed upward to prevent the unsealing pin from shearing force; when unsealing, the unsealing pin is cut by the friction between the rubber cylinder and the casing, the piston sleeve goes down, and the oil production channel is closed.
The water blocking construction process of the oil well packer is reduced, the snubbing and no blowout operation can be conveniently realized, and it can bear high pressure in both directions and has a long service life. The cup packer commonly used in oil fields is self-sealing. The outer diameter of the cup is larger than the inner diameter of the casing, and the seal of the packer is achieved by the interference fit of the cup and the casing. The resistance is large when going down the well, and the cup is easy to wear and scratch, thus losing the sealing performance. With the in-depth understanding of oil layers, it is imperative to tap the potential of thick oil layers. At the same time, higher requirements are put forward for downhole packers.