METHOD OF QUALITATIVE AND QUANTITATIVE ESTIMATION OF DOWNHOLE GAS INFLOWS IN MULTISTAGE HYDRAULIC FRACTURING IN A MULTIPHASE FLOW SYSTEM Russian patent published in 2021 - IPC E21B47/11 

FIELD: petroleum industry.

SUBSTANCE: invention relates to the petroleum and gas industry and can be used to control development of a productive formation. The method includes obtaining a fluorescent marker in form of polymer microspheres while preparing a dispersion of a resin and luminescent substances, combining the obtained marker with a carrier medium supplied to the well. Inserting a marker with said carrier medium into the well. Taking samples from the well and analysing said samples determining the codes and the number of markers in samples constituting a polymer membrane using flow cytofluorometry and determining downhole gas inflows based on the results of said analyses. The marker is obtained using a luminescent substance fluorescing upon exposure to UV emission or visible emission with a wavelength of 320 to 760 nm in the wavelength range of 350 to 780 nm, both independent and in form of binary mixtures of said luminescent substances at the ratio thereof from 0.01:0.99 to 0.99:0.01, by means of radical copolymerisation of styrene with divinylbenzene, or dispersion polycondensation of melamine formaldehyde resin or urea-formaldehyde resin, or hydrolytic polycondensation of tetraethoxysilane introduced as a 10 to 20% water suspension thereof at an amount in the mixture of 0.1 to 5.0% by weight of the hardened resin, producing a dispersion containing 40 to 60 wt.% dry residue. An aluminosilicate proppant and/or quartz sand is used as a carrier medium, wherein said marker is placed in a polymer coating based on epoxy resin. The markers are introduced into a horizontal well, the codes and concentrations of markers in the samples are determined using flow cytofluorometry based on the results whereof the inflows for the corresponding hydraulic fracturing stages are calculated. The size of the polymer microspheres is 0.2 to 50.0 mcm, and the luminescent substance is selected from the group consisting of selenide, sulfide, zinc or cadmium telluride.

EFFECT: proposed invention allows to obtain reliable results of determining downhole gas inflows at multiphase flow of the formation fluid.

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