Continuous growth in prices for primary energy sources and environmental restrictions on pollutant emissions justify investments in industrial facilities to minimize specific energy consumption. In addition, oil-producing and refining enterprises were built in previous decades, when energy efficiency problems were not so urgent, so little attention was paid to the development and application of tools for improvement. In this regard, at present, the application and development of methods for increasing energy efficiency is certainly relevant, especially for oil processing and stabilization units (OPSUs) at fields, through which all oil produced in a country passes. Our goal is to achieve heat integration of OPSUs with a capacity of 4 million tons of processed raw materials per year. In this study, for the heat integration of the OPSU, pinch-analysis methods with the construction of grid diagrams are used for a retrofitting project for increasing the energy efficiency of the heat exchange network (HEN) of an OPSU. The heat and economic analysis of the synthesized HEN were performed using Pinch 2.02 software. This paper presents a retrofitting-based energy-efficiency project for the OPSU HEN. A method for evolving the synthesized HEN by breaking heat load paths is applied to increase the economic efficiency of the retrofit project. The stability of the OPSU operation in the optimal mode is shown with the observed change in the bank interest rate. The implementation of the synthesized HEN will reduce specific energy consumption by 77%, decreasing CO₂ emissions released into the atmosphere by 30 thousand tons per year.