Human capital management is one of the most important management subsystems of a modern oil and gas complex enterprise. To systematically monitor it, identify the dynamics of indicators, adjust goals and results at a modern oil and gas enterprise, a comprehensive methodology for assessing human capital should be used as part of the management control function. Despite the fact that oil and gas industry enterprises invest heavily in the development of their personnel and in maintaining their health, their management systems lack control subsystems that allow them to collect and process feedback data from investments in human capital. In most cases, the oil and gas industry enterprises use the calculation of labor indicators, which are scattered and do not give an overall picture, which do not allow tracking the overall dynamics. In order to solve this problem, an attempt has been made to develop a unified methodology for assessing human capital, designed to integrate indicators of development and accumulation of human capital, quickly find bottlenecks, develop corrective actions to optimize the situation, and present a more visual picture to external stakeholders through social reports of oil and gas industry enterprises. The use of the proposed methodology for assessing human capital, integrating it into the reporting of an oil and gas enterprise, will contribute to optimizing the management system of the enterprise as a whole. Each stage of human capital assessment is considered in detail on the example of a large oil and gas industry enterprise Gazprom Pererabotka LLC, the methodology was tested by calculating indicators according to the proposed methodology.