METHOD FOR EXTRACTION OF HARD-TO-RECOVER OILS Russian patent published in 2022 - IPC E21B43/263 E21B28/00 

FIELD: oil industry.

SUBSTANCE: invention relates to the oil industry, preferably to the development of deposits with difficult-to-recover oils, including deposits at late stages of development and productive formations with low capacity. According to the invention, a series of mini-hydraulic fracturing is carried out, with the formation of cracks of azimuth-oriented perforations in the production column of the well, by exploding high explosive charges lowered into the perforation interval of the well filled with working fluid under pressure above that in the reservoir, with carrying out an explosion, without stopping the injection of working fluid into the well, while preventing an increase in pressure at the wellhead above the critical value. The geometric and physicomechanical characteristics of the productive formation obtained as a result of mini-hydraulic fracturing are measured, on the basis of which a wave effect is carried out on the formation by generating waves with a frequency corresponding to the minimum attenuation decrement.

EFFECT: use of the proposed method makes it possible to significantly increase oil recovery from hard-to-recover oil deposits, increase the flow rate of low-flow wells, extend their operational mileage and reanimate wells after conservation, including those liquidated due to lack of flow.

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