INSTALLATION METHOD OF CEMENT BRIDGE IN WELL Russian patent published in 2012 - IPC E21B33/16 

FIELD: oil and gas industry.

SUBSTANCE: installation method of cement bridge in the well involves lowering to the well perforation interval of tubing string (TS) equipped with special connection pipe, pumping of visco-elastic separating agent portions, flushing of separating plugs, tubing string lifting and anticipation of cement solution hardening. Prior to pumping of visco-elastic separating agent there performed is simultaneous locking of perforation interval with gel, which is 45-55 m higher than perforation interval; the first separating plug is forced; the first portion of visco-elastic separating agent, cement grouting, the second portion of visco-elastic separating agent is pumped with further flushing with the second separating plug. As visco-elastic separating agent there used is water suspension of PBMG gel powder with density of 1100 kg/m³ and static shear stress (SSS_10s/10min)=134/215 dPa.

EFFECT: avoiding the displacement of cement bridge downwards from planned installation interval owing to locking the gel perforation interval and improving the strength and quality of bridge owing to eliminating the dilution of cement grouting with well fluid during formation of cement stone.

1 tbl, 6 dwg