METHOD FOR OIL RESERVOIR DEVELOPMENT Russian patent published in 2021 - IPC E21B43/22 C09K8/588 

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry, in particular to methods for increasing oil recovery from oil reservoirs that are inhomogeneous in permeability. The method of developing an oil reservoir involves injecting solutions of sodium silicate, polyacrylamide and filler into the reservoir through an injection well and extracting oil through production wells. Prior to injection, aqueous solutions of sodium silicate, polyacrylamide with a molecular weight of 5 million Da to 12 million Da and a degree of hydrolysis of 5% to 20%, or cellulose ether with a degree of substitution for carboxymethyl groups of at least 0.9 with a concentration of 0.0005 to 0.3 wt.% and filler are mixed. Moreover, as sodium silicate, an aqueous solution of high-modulus sodium polysilicate with a silicate modulus of 4.2-6.2 with a concentration of 0.05 to 3.0 wt.% is used. As a filler, powdered cellulose with a concentration of 0.01 to 1.5 wt.% is used. The injection capacity - Cap._inj. is determined, the volume of injection of the specified mixture - V_Mixture is calculated and the concentration of powdered cellulose - C_pow.c. is selected based on the injection capacity. At Cap._inj. of 150-200 m³/day, V_Mixture is 100-200 m³, C_pow.c. is 0.01-0.25 wt.%, at Cap._inj. of 200-300 m³/day, V_Mixture is 200-350 m³, C_pow.c. is 0.25-0.6 wt.%, at Cap._inj. of 300-600 m³/day, V_Mixture is 350-500 m³, C_pow.c. is 0.6-1.5 wt.%. The specified mixture is injected into the reservoir until the specific injection capacity is reduced by 10-60 %, and after the injection of the specified mixture, water with a mineralization of 0.5 g/dm³ to 260 g/dm³ in the volume of 15 m³ is pumped into the formation and flooding is resumed.

EFFECT: increased efficiency of the method of developing a heterogeneous reservoir.

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