APPLICATION OF DISPLACEMENT CHARACTERISTICS FOR FORECASTED PRODUCTION INDICATORS EXPRESS-EVALUATION

Abstract

Background Recently, in the oil and gas production complex, there has been a steady trend towards a deterioration in the structure of oil and gas reserves, which, in turn, imposes special conditions and requirements when performing predictive calculations of production levels. This is especially true for deposits with carbonate reservoirs of a complex type with high heterogeneity, in particular fractured-pore cavernous limestones and dolomites. Let’s consider carbonate reservoirs of field N as an example. According to the current project document, the field provides for the formation of a system for the development of facilities with waterflooding of reservoirs and the use of water and water-gas mixture as their working agents. The efficiency of the process of oil displacement by a working agent according to field data is expressed by the so-called oil displacement characteristics by water, which are the dependences of oil recovery on the volume of water that has penetrated into the reservoir. The displacement characteristic for an oil deposit more fully characterizes the efficiency of the development of an oil deposit than, for example, the oil recovery coefficient. The displacement characteristic reflects the history of the reservoir, clearly showing the effectiveness of the displacement process at any time of development, and is a convenient form for studying the nature and characteristics of the development and flooding of an oil reservoir. The displacement characteristic describes not only the final oil recovery in the reservoir, but also the dynamics of the oil recovery intensity coefficient from the water cut of the product during the development of heterogeneous formations in the mode of oil displacement by water. Aims and Objectives Obtaining an analytical displacement characteristic that takes into account the experience of developing analogous deposits and actual operating data, as well as further adaptation to the displacement characteristic obtained from the results of hydrodynamic modeling, in which all the involved displacement mechanisms are most fully represented. Results The performed analysis of the features of the geological structure of the field, analogous fields and the results of hydrodynamic modeling made it possible to construct a displacement characteristic that takes into account all the geological features of the field and the introduction of water and gas effects. The obtained displacement characteristic allows you to quickly perform calculations of predicted production indicators without the use of lengthy calculations on hydrodynamic models.