Structuring the Investment Project Portfolio of an Oil and Gas Company with an Account of the Carbon Tax

This paper proposes an economic-mathematical framework for selecting efficient corporate investment projects under investment constraints, incorporating the impact of a transboundary carbon tax. The approach is based on solving a knapsack problem and it was tested using real-world data from PAO Lukoil, with varying carbon tax rates over the forecast period 2025–2030. The results confirm that the introduction of carbon regulation increases the share of zero-carbon projects in the investment portfolio while reducing the company’s projected profits.