Hydraulic Full-Bore Packer for cross-flow prevention of PGPM1 for casing strings 245 mm is
applied to ensure reliable isolation of gas-, oil- and water-bearing formations at any depth.
The packer PGPM1 consists of the following main units: body with mounted sealing rubberized fabric unit fixed by steel crimping cups, unit protecting packer from early actuation,
valve unit body, valve unit and bottom sub.
The packer works as follows: during the cementing process the cementing plug is passing
through the packer interior cavity and cuts off hollow shear pins with a sealing ring thus
opening liquid access to the packer valve unit. After receiving the “bump” signal and pressure relief the valve is switched and 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
to the under-hose cavity. The overpressure build-up to 6-8 MPa at the packer setting depth
leads to inflation of the sealing element which is pressed to the borehole walls hermetically.
After the pressure relief the valve system switches and cuts off the liquid in the under-hose
cavity keeping its volume under the hose.