METHOD OF SELECTIVE ISOLATION OF HIGH-PERMEABILITY FORMATION INTERVALS IN WELL Russian patent published in 2002 - IPC

FIELD: oil and gas production, particularly, isolation of high-permeability intervals in producing wells. SUBSTANCE: method includes successive injection of aqueous solution of flocculant with addition of mud powder and viscoelastic composition into bottom-hole formation zone. Prior to injection of aqueous solution of flocculant with addition of mud powder injected into bottom-hole formation zone is 0.1-1.0% of aqueous solution of polyacrylamide. Flocculant is used in the form of water-soluble polymer of acryl series. EFFECT: higher efficiency of selective isolation of formation with materials nonuniform in permeability due to prevention of supporting composition from getting into low-permeability intervals. 2 cl