STUDYING THE DEGREE OF FLOODING BY GEOPHYSICAL METHODS OF THE UZEN DEPOSIT

The geological study of the productive horizons of the Uzenskoye field and the degree of their flooding due to oil and gas production is considered. To assess the waterlogging of reservoir layers, the most reliable method of geophysical methods is identified. A number of wells have been studied to determine the calculated parameters of terrigenous deposits based on the results of the well geophysical survey (GIS) data. This paper presents the analysis and development of new methods for assessing reservoir saturation and flooding with residual oil. The studied part of the section is Lower Cretaceous and Jurassic deposits associated with the industrial oil and gas potential of the Uzenskoye field. A significant decrease in the temperature of productive formations led to a decrease in the quality of reservoirs of productive formations. In recent years, the composition of the fluids saturating rocks has changed dramatically. As a result, the estimate of the saturation coefficient of productive layers was distorted. The purpose of this work is to study the degree of waterlogging of deposits and to develop the most reliable methodology for assessing the waterlogging of reservoir formations using geophysical methods. In order to reliably determine the coefficient of current oil and gas saturation, it is necessary to determine the clay and porosity coefficients most correctly. When determining the loam content of productive columnar rocks, it is necessary to take into account that in the reservoir layers the gamma logging curves are distorted under the influence of polymictism. For the potential curve of spontaneous polarization (PS) of rocks in the productive reservoir of the deposit, there are displacements and changes in the amplitude of the PS curves relative to the clay line due to the filtration processes of the injected waters. Distorting factors that reduce the accuracy of the determination of clay by the PS method include the presence of a filtering component of the main zone, a deep penetration zone, a coloration and glazing zone of the borehole walls, and the use of various reagents in the washing liquid. The distribution of polymictic and clay components, as well as the processes of desalination of layered liquids, are expressed to varying degrees on the PS and GC curves. The calculated clay is close to the basic definitions.