METHOD OF DEVELOPMENT OF INHOMOGENEOUS OIL RESERVOIR (OPTIONS) Russian patent published in 2018 - IPC E21B43/22 C09K8/42 

FIELD: oil and gas industry.

SUBSTANCE: invention refers to the oil industry, in particular to the methods for extracting oil from the inhomogeneous oil reservoir using the method of controlling the reservoir coverage by means of water flooding and redistribution of the filtration flows. According to the first option, the initial injectivity of the injection well is predetermined at the initial injection pressure, where the injectivity of the injection well is from 200 up to 400 m³/day, the aqueous dispersion of the filler and of the alkaline reagent before increasing the injection pressure by 5–30% from the initial injection pressure at the following content of the components, wt%: filler – 0.01–1.0, alkaline reagent – 0.01–3.0, water with mineralization from 0.15 up to 300 g/dm³ – the rest, the wood flour or dolomite flour are used as the filler, the 10 % aqueous solution of sodium hydroxide or trisodium phosphate are used as the alkaline reagent, the composition containing the alkaline reagent and water is then finished until the injection pressure is increased by 10–50 % from the initial injection pressure not exceeding the maximum allowable pressure on the production casing or on the productive strata, at the following component ratio, wt%: alkaline reagent – 0.1–5.0, water with mineralization from 0.15 up to 300 g/dm³ – the rest, the 10 % aqueous solution of sodium hydroxide or trisodium phosphate are used as the alkaline solution, and it is squeezed into the reservoir using water in the volume of 10–15 m³, wherein injection of the mentioned aqueous dispersion of the filler and alkaline reagent and of the composition containing the alkaline reactant and water into the formation is carried out in the volume ratio of (1–5):(4–1). According to the second option, the initial injectivity of the injection well is predetermined at the initial injection pressure, when the injection well is injected from 400 up to 800 m³/day, the aqueous dispersion of the filler and alkaline reagent is pumped in two rims, the first rim of the aqueous dispersion of the filler and the alkaline reagent is pumped until the injection pressure is increased by 10–30 % from the initial injection pressure at the following component content, wt%: filler – 0.1–1.5, alkaline reagent – 0.1–5.0, water with mineralization from 0.15 up to 300 g/dm³ – the rest, the wood or dolomite flour are used as the filler, the 10 % aqueous solution of sodium hydroxide or trisodium phosphate are used as the alkaline reagent, then the second rim of the aqueous dispersion of the filler and the alkaline reagent is injected until the injection pressure is increased by 15–50 % from the initial injection pressure, which does not exceed the maximum permissible pressure on the production column or on the productive strata, at the following components content, wt%: filler – 0.05–1.2, alkaline reagent – 0.05–3.5, water with mineralization from 0.15 up to 300 g/dm³ – the rest, the wood or dolomite flour are used as the filler, 10 % aqueous solution of sodium hydroxide or trisodium phosphate are used as the alkaline reagent, after pumping of the second rim, it is squeezed in the form of water in the volume of 15–20 m³, while injection into the reservoir of the mentioned rims is carried out in the volume ratio (1–4):(3–1).

EFFECT: technical result is the increased efficiency by means of reducing the water flooding and increasing the reservoir coverage.

2 cl, 4 tbl