Hydraulic Full-Bore Packer for cross-flow prevention of PGP-type is applied to ensure
reliable isolation of gas-, oil- and water-bearing formations.
The packer consists of two main units: sealing hose and valve unit. PGP, PGP1 and PGP6
are equipped with valve system with spring.
The packer works as follows: when the cementing plug is passing through the packer, it cuts
off the female pin thus opening liquid access to the valve unit. This is how the preparation
for actuation is done. After receiving the “bump” signal and pressure relief the preparation
of valve system to the packer setting process is carried out and, followed by the pressure
build-up in the string, the liquid passes from the casing string to the under-hose cavity.
After the pressure relief in packers PGP, PGP1 and PGP6 the valve system switches and
cuts off the liquid in the under-hose cavity keeping its volume under the hose.