CASING PIPE AIR-TIGHTNESS CONTROL DEVICE Russian patent published in 2006 - IPC E21B33/00 E21B33/12 

FIELD: oil production, particularly sealing or packing boreholes or wells.

SUBSTANCE: device comprises two packers having the same structure and pressure relief valve installed in-between. The relief valve is adapted for excessive pressure discharge into annuity between the device and casing pipe. Spring-loaded disc valve is installed over upper packer. The disc valve is used for flow string pressure-testing. Overflow valve for liquid drainage from tubing string is installed over the disc valve. The overflow valve is provided with shutoff member, which may be dropped inside the device before device lifting from well. Check valve is arranged in lower part of the device.

EFFECT: possibility of rising pipe pressure-testing and increased packer and separate packer components air-tightness.

2 cl, 2 dwg