METHOD FOR EVALUATING THE IMPACT OF A SOLUTION ON A ROCK IN ORDER TO INCREASE OIL RECOVERY Russian patent published in 2022 - IPC E21B49/02 G01N33/24 

FIELD: petroleum geology.

SUBSTANCE: invention relates to the field of petroleum geology and can be used when working in fields with hard-to-recover oil reserves. A method is proposed for selecting a process solution for enhanced oil recovery, based on the study of the core material of an oil field, characterized in that the most characteristic interlayers of the geological section are selected according to the core of the wells, from which samples of 30x30 mm in size are cut; the initial samples are photographed on a digital camera for a general description of the main details of the structure and material composition; examining samples on an X-ray tomograph to obtain 2D sections and 3D images; then the samples are placed on the stage of a scanning electron microscope, the surfaces are scanned, and “reference points” are selected and photographed - places where cracks or pores are thickened. Next, the samples are placed in a solution with an imitation of the real process in the well and kept in it for 20 days, then they are taken out, dried and sequentially studied in an X-ray tomograph and an electron microscope. Under an electron microscope, areas of "reference points" are examined with obtaining microphotographs and the chemical composition of neoplasms is determined by the microprobe method. Next, X-ray tomography data is processed with the construction of fracture maps before and after the experiment, and the number of cracks in different opening ranges is determined. Electron microscopy data is processed by comparing images of "reference point" areas. Tables of the chemical composition of neoplasms are compiled. A general conclusion is drawn up based on the results of the experiments, and a conclusion is made about the choice of working fluid for a given oil-bearing formation

EFFECT: increasing the information content of the study of pores and cracks in rock samples by providing an opportunity to evaluate the entire size range of voids and their change under the influence of external influences by the technological solution to ensure the optimal choice of the technical solution for reservoir treatment in order to increase oil recovery.

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