In the conditions of oil and gas complex enterprises, the main issues in the discussion of development strategies are reliable and high-quality power supply to the most critical consumers in a market economy. This is facilitated by the constant challenges that individual companies encounter when they face issues of improving the energy efficiency of specific production processes, developing and implementing measures aimed at reducing costs while maintaining the volume of products, reducing the downtime of individual equipment, finding and eliminating the root causes of process disturbances. At this stage, the specialists responsible for reliability need to have not only modern competencies, but also the ability to justify and make decisions in a limited time. Thus, the analysis and monitoring of the occurrence of process disturbances at enterprises of the oil and gas complex with subsequent risk assessment becomes particularly important and relevant, and the role of specialists with such competencies increases many times, as problems arise with the hierarchy and classification of risks corresponding to real operating conditions. This article provides an overview of methods for investigating process disturbances, provides the main results of assessing the risks of process disturbances for power grids of different voltage levels, provides a quantitative assessment of risks depending on the identified root causes. Recommendations are given on the identified problems, including the analysis of individual indicators of reliability of power supply to industrial enterprises. The proposed solutions for the application of a matrix approach to assessing the risks of process disturbances in the power supply system of oil and gas complex enterprises will reduce the existing accident rate by analyzing the main causes of process disturbances and, as a result, increase the energy intensity of the manufactured product. Additionally, the adaptation of this method within the framework of the operation of such enterprises will allow managing the reliability of power supply systems.