The article considers the features of the business model for managing oilfield service processes in big oil and gas companies using the example of PJSC Oil Company «Rosneft». The purpose of the article is to study current business models in oil and gas industry, identify their advantages and disadvantages, and develop recommendations for improving sourcing procedures in accordance with the dynamics and changes in the external environment of companies' functioning. The research applies a variety of scientific methods which include analysis, synthesis and systematization of conceptual and practical aspects of sourcing in the context of the Russian oil and gas industry. The authors provide a critical analysis of theoretical aspects related to the concepts of sourcing, outsourcing and insourcing, which have been in the focus of Russian economic science since the mid-2000s. Special attention is paid to the insourcing model, which is available and used by large companies in capital-intensive industries with long-term investment and production cycles, such as oil and gas. The signs of production and management inefficiency of insourcing are formalized. In terms of transaction costs, a comparison is made between the efficiency and effectiveness of outsourcing and vertical integration. Taking into account the peculiarities and distinctive features of modern business environment, its uncertainty and new challenges for oil and gas producing companies, the authors conclude that strategic outsourcing is most in demand. The results obtained in the study can be used in practice of oil and gas companies, as well as by government bodies in the process of developing a regulatory policy in the relevant area.