METHOD FOR DETERMINATION OF DOWNHOLE FLUID INFLOWS AT MULTI-STAGE HYDRAULIC FRACTURING OF FORMATION Russian patent published in 2019 - IPC E21B43/267 E21B47/11 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil industry and can be used to control development of productive formation. Method comprises obtaining a fluorescent marker in form of polymer microspheres with preparation of resin dispersion and luminescent substances, combining the obtained marker with a carrier medium fed into the well, inserting a marker with the said carrier medium into the well, sampling from the well and analyzing them with determining the codes and concentrations of the markers in the well fluid samples using fluorometry, determination of the fluid based on the results of said analyzes of downhole fluid inflows. According to the invention, obtaining said marker is carried out using a luminescent substance that fluoresces after exposure to UV radiation or visible radiation with wavelength of 320 to 760 nm in the wavelength range of 350–780 nm, both in-form and in form of binary mixtures of said luminescent substances in their ratio from 0.01:0.99 to 0.99:0.01, by radical copolymerisation of styrene with divinylbenzene or dispersed polycondensation of melamine-formaldehyde or carbamide-formaldehyde resin, or hydrolytic polycondensation of tetraethoxysilane, introduced in form of 20–30 % aqueous suspension thereof, with amount in mixture of 0.1–5.0 % of weight of the cured resin, to obtain dispersion containing 40–60 wt% of dry residue, as bearing medium is used aluminosilicate proppant, where said marker is arranged in hydrophilic or hydrophobic polymer coating based on epoxy resin, said introduction is carried out in a horizontal well, said determination of codes and concentration of markers in well fluid samples is carried out using flow cytofluorometry, according to obtained results, calculating tributaries of corresponding stages of hydraulic fracturing.

EFFECT: technical result consists in improvement of reliability of results of determination of downhole fluid inflows at multi-stage hydraulic fracturing of formation.

3 cl, 4 ex