In the context of digitalization and digital transformation of the oil industry, the introduction of high-tech technologies leads to the need for companies to intensify R&D. Thus, in recent years, the R&D costs of industry leaders have been growing, and the share of R&D costs in the total assets of companies is also growing. The purpose of the study is to identify/refute and substantiate the relationship between R&D costs and financial performance of companies in the oil industry in the digital transformation context. As part of the study, we analyzed the financial statements of the largest oil producing companies with more than 60% of the market, such as Rosneft (34.8% of the crude oil production market in Russia), Gazprom Neft (7% of the market share), Tatneft (5.3% of the market share), Lukoil (14.6% of the market share). For each company, the dependencies of R&D costs and revenue, profit and profitability indicators for the period 2010–2022 were analyzed. A correlation and regression analysis were carried out, which revealed certain patterns. It was found that the maximum effect of the introduction of R&D has an impact on the net profit of the company in 2–3 years, while the effect of the introduction is traced after 1 year, in the fourth or fifth year the effect is not observed. The conclusion is made about the relationship between R&D costs and key financial indicators of companies, such as revenue, net profit and profitability. The resulting relationship will allow us to obtain forecast values for revenue, net profit, and profitability, considering the time lag.