Abstract
This article is dedicated to the study of the degree of development of the system approach in literary sources. The work highlights the issue that the system approach and its individual elements are not sufficiently and fully utilised in activities related to the development of oil reservoirs. The essence of the system approach is identified, stating that it is a method based on considering individual processes and objects in the development of an oil field as interacting and closely interrelated elements. The object of the study is the system approach and the methodology of assessment in its use. Methodology: research of scientific-methodological literature, methods of inductive-deductive reasoning, analysis, synthesis, abstraction, and theoretical generalization. In accordance with the reviewed sources, the following conclusions are drawn: the development and operation of a specific field are carried out according to the type of two-circuit system controlled by enterprise workers and a research institute; it is determined that the most promising approach would be the use of 3D hydrodynamic models, which allow for the consideration of data on vertical exchange processes or filtration flows; the proposed EPS concept minimises inaccuracies in the field of oil and gas science and has a positive impact on the stability and hierarchy of knowledge of subsurface formations, the formation of 3D models based on this, and the accuracy of calculating reserves.