“Open Innovation” has proved to be a successful concept that can facilitate technological development of industries. Though the Open Innovation Model and the challenges of its implementation have been widely researched, there is a lack of studies that deal with the openness towards external innovation in major oil and gas companies. The objective of this research was to study major oil and gas companies’ openness towards external sources of innovation. The authors focused on the role of R&D investments in the R&D internationalization and the establishment of venture funds, the links between regional specificities, innovation portfolio diversity and the perception of external innovation. To do this, the authors examined the practices of 18 major oil and gas, oil service companies. The data was gathered from open digital sources and analyzed with the use of desk research, qualitative and quantitative methods, including regression and correlation analysis. The study confirmed that major oil and gas companies with higher R&D investments and diverse innovation portfolios were more likely to be open to external innovation; regional specificities had a great impact on R&D networks as companies in North America and Western Europe had higher R&D internationalization ratio than in Russia and China. It was concluded that venture funding was an inclusive tool for expanding innovation funnel suitable for smaller companies with low R&D expenditures.