PACKER Russian patent published in 2011 - IPC E21B33/12 

FIELD: oil and gas production.

SUBSTANCE: packer consists of upper and lower subs, and of hollow mandrel with sleeve sealer. On the mandrel there is installed a differential transfer bushing with two internal bridges; a middle chamber is formed between these bridges and the mandrel. A piston with a seat for a drawdown ball is installed in the mandrel. The packer consists of a back valve in the low sub containing a case, a spring loaded lock element and a valve bushing, interacting with the piston and fixed on the case by means of a shear pin. Through orifices made in the wall of the mandrel and communicating a cavity of the mandrel with a middle chamber are overlapped with one more back valve. Pressure arising in the packer and diameters of packer elements interacting with a differential bushing are correlated with mathematic dependencies.

EFFECT: reliable operation, expanded functionality and reduced operational expenditures.

2 dwg