New approach to crude oil classification problem

Abstract

Formulation of the problem. The problem of crude oil classification has existed since the beginning of oil production. Presently, there is a lot of available information about chemical composition and physical-chemical properties of crude oil found in various petroleum- bearing regions around the world, however, the problem with oil typification still exists and there is no uniform classification. Primarily, this is connected with significant differences in chemical composition of oil and absence of a proven set of key criteria that such classification can be based on.
The available classifications can be relatively divided into three categories: chemical, genetic and process. However, there is no classification that would approach oil regarding its production problems. When choosing a recovery technique and development strategy for a particular oil deposit, one has to refer to several classifications simultaneously and, in some cases, one classification may contradict another.
The aim of the investigation. To develop a new industrial crude oil classification.
Methods. In order to determine the key factors affecting physical and chemical properties of oil, 150 oil reservoirs of Dnieper-Donets basin containing oil with various composition have been studied using well operation and testing data.
Results. Obtained results have confirmed the relationship between the three key oil content components - asphaltenes and waxes, sulfur and resins, which affect specific physical-chemical properties of oil. None of the existing classifications account for this relationship, nor they take into consideration quantitative correlation of such components.
Scientific novelty and practical significance. Based on the relationship determined between the main components, a new oil production classification have been developed allowing to choose sustainable field development strategy and production methods as early as at the initial exploration stage, extend time between workovers in wells by mitigating production problems, minimizing geological risks related to bringing wells back on production after scheduled repair or workover operations, and increasing cost efficiency of oil and gas deposits development.