DEVICE FOR WELL RESERVOIR TREATMENT IN WELL Russian patent published in 2006 - IPC E21B33/12 

FIELD: oil and gas production industry, particularly devices to isolate reservoirs in well during segregated injection of different reagents in reservoirs.

SUBSTANCE: device comprises packer including through body and elastic collar, isolation means including shaft with radial channels and inner cylindrical groove, slide with radial channels grouped in two rows and divided with transversal solid partition. The slide is installed in shaft and adapted to receive bush with ball seat to support ball to be dropped into the device before second reservoir treatment. Upper row of radial channels is in front of radial channels of the shaft. The shaft, the slide and the bush are connected with each other by differential shear members. Before the second reservoir treatment upper and lower rows of radial slide channels are communicated with each other by the inner cylindrical groove to establish hydraulic communication between flow string interior and packer body interior. The device is also provided with additional packer spaced a distance exceeding upper reservoir thickness from main packer. Additional packer comprises cylinder located from additional packer top and additional elastic collar installed on hollow base connected to isolation means by clutch and cylinder fixed to flow string. Piston is fixedly secured to hollow base top. Piston is slidably installed in the cylinder so that the piston may be axially displaced in upward direction to define cavity along with the cylinder. The cavity is communicated with flow string interior. The cylinder may cooperate with additional elastic collar.

EFFECT: elimination of additional casing pipe cutoff over upper reservoir.

3 dwg