Purpose. Determination of the required concentration of polymer solution, providing the maximum well insulation effect, depending on the filtration characteristics of the medium. Methodology. The research was conducted by experimental method using the methodology of planning the experiment. The theory of rational planning was used by varying two variables on five levels. Media permeability and polymer solution concentration were used as variables. Methods of mathematical statistics were used in processing the results. Findings. Experimental studies made it possible to build a model expressing the dependence of the residual resistance factor on the permeability of the medium and the concentration of the polymer solution. By further statistical processing the connection between permeability and necessary concentration of polymer solution was obtained. Originality. The experimental studies have substantiated the possibility of evaluating the influence of medium permeability and concentration of polymer solution on the residual resistance factor and determined its dependence on the concentration of polymer solution and medium permeability. The main point of polymer solutions application is justification and choice of the reagent concentration. The concentration should be selected in such a way that it provides the maximum value of the residual resistance factor and the viscosity of the solution necessary to level out permeability heterogeneity of the environment to some extent. To achieve this, a relationship has been obtained that allows determining the concentration of the polymer solution at a given permeability of the environment that provides the maximum residual resistance factor. Practical value. The conducted experimental studies allow developing the ideas about the regularities of water manifestations. The results of the research allow selecting purposefully both the formulations of composite systems and the technology of their application to improve the efficiency of oil production and to limit water inflows in specific geological and physical conditions.

No abstract

No abstract

The submitted paper studies published data and summarizes contemporary views concerning classification of tight oil reserves and evaluation of their quality. In recent years there has been an increase in the production of tight oil reserves, which are difficult to extract because of their anomalous properties, as well as because of difficult geological conditions, which makes it important and necessary to study the qualitative properties of tight oil. The paper offers results of the analysis and systematization of indicators of the properties of oil samples collected at various Kazakhstani fields and their classification prepared using fuzzy cluster analysis algorithm. Three groups of signs were considered as classification attributes of various types of tight oil reserves: 1) signs characterizing the composition, this is the content of sulfur, chlorides; 2) properties, this group includes oil density and viscosity, 3) mode of occurrence, i.e. in-situ permeability. Preliminary analysis was completed to determine current status of the issue of tight oil reserves classification and quality evaluation. A review of classification results of tight oil reserves demonstrated the need to break down the entire data set (assemblage) into uniform groups using a series of classification attributes, for which fuzzy cluster analysis is the most appropriate solution. A parameter characterizing oil quality was offered, too. Three clusters have been obtained, each of which characterizes the difficulty of extraction, linguistic rules of conformity of a lot of oil characteristics and total quality factor have been formulated.

No abstract