METHOD FOR GEOCHEMICAL MONITORING OF WELL OPERATION AFTER HYDRAULIC FRACTURING Russian patent published in 2021 - IPC E21B49/08 E21B47/10 

FIELD: oil industry.

SUBSTANCE: invention relates to the field of oil field development, particularly to laboratory methods for determining the properties of the extracted oil, which makes it possible to find the dependencies of the oil composition on the age of the underlying rocks, and when analyzing the properties of the extracted oil from a well with hydraulic fracturing, determining foreign impurities that are not typical of this formation and determining the proportion of these impurities. Thus, if the upper or underlying layers are affected, it is possible to determine the proportion of oil supply to the well products, the implementation of the claimed method is ensured by applying the algorithm developed by the applicant within the framework of the developed technology. The method consists in the fact that representative samples of wellhead oil samples are taken from wells working for one specific reservoir in such a way as to cover the research both by area and by section of the studied area; further, the unique component composition of oil is determined in these samples, making it possible to identify the difference between layers of different ages in the concentration of elements, in the presence/absence of any element, while the determination of the concentration of elements is carried out on the basis of measurements of their mass spectra in an inductively coupled plasma mass spectrometer equipped with a gas cell; then the data obtained is processed by constructing a cloud of values, where the ordinal number of the sample is indicated on the X axis, and the concentration of the element is indicated on the Y axis; if differences in the composition of oils of different age formations are established, wellhead oil samples are examined at wells, with the work carried out on hydraulic fracturing and comparing with the composition of representative samples taken from a particular reservoir, it is determined where the oil comes from and the quantitative, qualitative composition of mixtures and the proportion of their intake into the producing well are calculated, while calculations are performed using methods for mathematical statistics, through which the actual calculation of the shares of each reservoir is performed.

EFFECT: representative samples of wellhead oil samples are taken from wells working for one specific reservoir in such a way as to cover the research both by area and by section of the studied area; further, the unique component composition of oil is determined in these samples.

1 cl, 11 dwg