On the assessment of the diversity of coefficients of oil recovery from developed objects

Abstract

Based on the geological and commercial material collected and systematized by the offshore fields of Azerbaijan, the article discusses the reasons for the varying degrees of use of their reserves. For this purpose, the identification of deposits was carried out accord- ing to the natural regime, as a complex factor affecting oil recovery. Oil recovery models have been obtained for offshore reservoirs, draining mainly in two types of mechanisms: mixed and solution gas drives. Based on these regression equations and geological-economical analysis, a comparative analysis of the factors influencing oil recovery was carried out. Study of the different nature of the implementation of reserves of deposits characterized by different natural mechanisms so as to determine the degree to which the geological and technological parameters at various stages of development influence oil recovery. Objects: Offshore deposits of the Republic, characterized mainly by the solution gas and mixed drives. Application of the methods of mathematical statistics (Student’s and Fisher’s criteria) for the comparative analysis of the parameters of the mined deposits, confined to different natural conditions, allowing the revelation of the degree to which they are different and various patterns of the use of the reserves. In order to determine the influence of various factors on oil recovery, we used the method of correlation-regression analysis. It was found that a wide range of changes in oil recovery factors is associated with the internal structure of the deposits, with varying degrees of activity of the energy of the reservoirs and the fluids saturating them. It is known that each of the geological and technolog- ical parameters to one degree or another affects oil recovery, this influence is complex and subject to certain changes in the process of reservoir mining. In order to study the influence of parameters on oil recovery, we developed matrices of averaged values of a number of parameters of offshore deposits draining by mixed and solution gas drives. Using multivariate correlation-regression analysis and appropriate software, we obtained models for each of the above types of the mechanisms. A comparative analysis of those models, as well as geological and field studies of the parameters included in the obtained regression equations, make it possible to correct the oil production process in a timely manner, and can also be used in designing projects for the additional mining of those objects.