METHOD OF DETERMINING CURRENT WATER SATURATION OF A PRODUCTIVE FORMATION Russian patent published in 2020 - IPC E21B49/00 G06F30/20 

FIELD: measurement.

SUBSTANCE: invention relates to methods of determining current water saturation of productive formation. According to the method permeability of the formation is defined, and taking into account permeability, a digital filtration model of the deposit is created, from which change in time of current water saturation of the formation is calculated during operation. Continuous pumping of water into at least one injection well is performed. At least once at a time selected from a time interval within which the value of the current water saturation calculated by the digital model ranges from 0.45 to 0.7 relative units, water marked with indicator is pumped into at least one injection well. At each repeated injection of indicator-labeled water, an indicator different from that used during previous injection is used in each injection well, and indicators different from those used for other injection wells are used for each injection well. Then from the production well mouth samples of formation fluid are taken to determine concentration of all injected indicators and time of receipt of maximum concentration of each indicator from each production well. Calculating the normalized value of arrival time of the maximum concentration of each indicator by multiplying the time elapsed from the moment of water-marked water marking to the time of receipt of the maximum concentration of the indicator by the value of the formation permeability. Graph of dependence of current water saturation on standard time of receipt of maximum concentration of indicator from production well is plotted and value of current water saturation is determined by plotted curve.

EFFECT: technical result consists in providing the possibility of determining the value of current water saturation of the formation covered by flooding from one injection well from several injection wells in general and in each production well of the section.

1 cl, 2 dwg