METHOD FOR PROCESSING THE BOTTOM-HOLE ZONE OF A PRODUCTIVE LAYER SATURATED WITH HYDROCARBONS WITH RESIDUAL HIGHLY MINERALISED PORE WATER Russian patent published in 2021 - IPC E21B43/27 E21B43/22 

FIELD: petroleum industry.

SUBSTANCE: invention relates to the petroleum industry, in particular, to intensification of the inflow of hydrocarbons by means of acidic treatment of a productive layer during development and operation of boreholes drilled on structurally complex horizons buried under conditions of low temperatures and containing halite salts in the mineral composition of rocks and residual highly mineralised water with a content of chloride salts of more than 150 g/l in the void of fluid-conducting collectors. The method for processing the bottom-hole zone of a productive layer saturated with hydrocarbons with residual highly mineralised pore water includes injection of an acid composition into the layer, technological sustaining after injection, and commissioning of the borehole. Prior to acidic treatment, a desalting agent - fresh water with an added surface-active agent - is injected into the bottom-hole zone in a concentration of 0.1 to 2 wt.% calculated as 3 to 5 pore volumes of the productive layer per 1 m of the effective petroleum-saturated thickness penetrated by perforation. The acid composition with the added surface-active agent in an amount of 0.1 to 2 wt.% is then injected into the bottom-hole zone of the layer. The productive layer is sustained for 8 to 16 hours after acidic treatment. The reaction products are extracted from the borehole, and then the borehole is killed by a saline solution with a surface-active agent, commercial petroleum, or a hydrocarbon-based liquid.

EFFECT: deep cleaning of the bottom-hole zone of the productive layer without deposition, increase in the efficiency of acidic treatment, increase in the flow rate of the borehole.

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