Application of Nonparametric Criteria in Solving the Basic Tasks of Optimizing Oil Recovery Processes

The purpose of this study is a comprehensive assessment of the possibility of introducing nonparametric criteria into the modeling process of nonlinear oil production systems and solving basic problems of oil field development, allowing for the nonequilibrium of the initial information. The relevance of this work is due to the need to develop and improve the scientific and methodological foundations for the development of residual oil reserves concentrated in difficult mining and geological conditions and, in most cases, confined to long-term deposits. The object of the study is the deposits of carbonate reservoirs of the Tournaisian stage of the lower section of the carboniferous system, in particular, attributed to the Kizelovsky, Cherepetsky, Upinsky and Malevsky horizons, information on which was obtained during the generalization of data on the operation of more than 600 wells for various purposes. When analyzing the geological structure, changes in the porosity and permeability of reservoir rocks were considered in detail, taking into account their classification by structural and genetic type and the direction of filtration of the composition during laboratory experiments, after which a significant influence of this characteristic on the effectiveness of pumping acid-containing systems into the reservoir was established. According to sixteen parameters reflecting the conditions of occurrence of objects, thickness and filtration-capacitance properties of reservoir rocks, as well as physico-chemical parameters of extracted fluids, a discriminant analysis was carried out, the results of which do not allow making managerial decisions due to the presence of an uncertainty zone and the adjacent location of objects relative to the centroids of known clusters in the axes of canonical discriminant functions. To solve this problem, an alternative algorithm is proposed, which is based on the calculation of the modified Kruskal-Wallis criterion, differentiated by objects and depending on one criterion or another for the effectiveness of hydrochloric acid treatments. The implementation of this approach has made it possible to increase the quantitative and qualitative results of repeated analysis of geological and field data using discriminant functions and to identify hidden patterns in small and generalized groups of objects as a whole. It is concluded that further development of this area is necessary, including for the possibility of modeling nonlinear processes taking into account their dynamics of change over time.