METHOD FOR ISOLATION WORK PERFORMING IN WELL Russian patent published in 2006 - IPC E21B33/13 

FIELD: oil and gas well operation, particularly methods or devices for cementing, for plugging holes, crevices, or the like.

SUBSTANCE: method involves injecting plugging composition in reservoir; washing out excessive plugging composition from string space by reverse back-pressure flushing thereof. Gel-forming compositions filterable in reservoir are serially supplied in reservoir along with following restrengthening thereof with hardening composition, namely synthetic resin or cement solution, which can be absorbed or nonabsorbed by reservoir. Back-pressure during excessive reservoir-absorbable plugging composition removal is 0.6-0.9 of final plugging composition pressure during forcing it into reservoir. Back-pressure during excessive reservoir-nonabsorbable plugging composition removal is 0.9-1.0 of final plugging composition pressure during forcing it into reservoir. Pressure of plugging composition hardening in isolation zone is 0.1-0.5 of final plugging composition pressure during forcing it into reservoir.

EFFECT: increased isolation work quality.

4 ex