METHOD INCREASING OUTPUT OF OIL FIELD Russian patent published in 2004 - IPC

FIELD: oil industry. SUBSTANCE: invention is related to development of oil field nonuniform by permeability and oil saturation. Method increasing output of oil field includes injection of biological polymer, gel-forming composition containing aqueous solution of starch and exopolysacharide produced by strain Azotobacter vinelandii ( Lipman ) ФЧ-1,BKПM B-5933 in the form of culture fluid into formation through injection well and uninterrupted injection of aqueous solution of above-mentioned exopolysacharide. Before injection of gel- forming composition share of porous space falling at sections of formation with abnormally high permeability and value of ratio of permeability of channels with abnormally high permeability to average permeability is found. Volume of injected composition is established by formula ′Ω = Vfηε/ψ and volume of aqueous solution of biopolymer is found by formula ′Ω₁ = Vη(0,2-0,4)/Ф, where ′Ω is volume of injected biopolymer gel- forming composition, cu m; ′Ω₁ is volume of aqueous solution of biopolymer, cu m; V is volume of drainage zone falling at one well, cu m; f is share of porous space falling at sections of formation with abnormally high permeability; ε is value of relation of permeability of channels with abnormally high permeability to average permeability of formation; η - is coverage of interlayer with flooding; ψ is value of drop of hydraulic conduction of porous medium after formation of biopolymer gel in it found from equation , where Ф is ratio of fluidity of biopolymer solution to water fluidity chosen from equation Ф = 1+28,6C_exo1-7C2exo1