Packer

A packer is a standard component of the completion hardware of oil or gas wells used to provide a seal between the outside of the production tubing and the inside of the casing, liner, or wellbore wall.

It is a tool used to form an annular seal between two concentric strings of pipe or between the pipe and the wall of the open hole. A packer is usually set just above the producing zone to isolate the producing interval from the casing annulus or from producing zones elsewhere in the wellbore. Separates fluid types, protects against pressures and corrosion.

Based on their primary use, packers can be divided into two main categories: production packers and service packers. Production packers are those that remain in the well during well production. Service packers are used temporarily during well service activities such as cement squeezing, acidizing, fracturing and well testing.