Abstract: In the context of the carbon peaking and carbon neutrality and the transformation of energy consumption structures in oil and gas fields, the integrated development and intelligent regulation of fossil fuels alongside renewable energy sources such as wind, solar, and geothermal energy have emerged as a new model for the future energy system. The construction of multi-energy complementary energy systems (MECES) in oil and gas fields contributes to cost reduction, efficiency enhancement, and low-carbon transformation. This paper proceeds from the general to the specific. Firstly, it expounds on the connotation and key technological progress of MECES in general scenarios. Then, it focuses on the technical framework and practical paths of the optimization technology of MECES at oil and gas fields, deeply analyzes the consumption characteristics of major energy-consuming equipment in oil and gas production systems. Based on the particularity of oil and gas production scenarios, it systematically summarizes the key technological progress of MECES at oil and gas production well sites from four dimensions: source-load prediction, capacity optimization, collaborative scheduling, and energy efficiency assessment, and sorts out the typical application models of domestic and international oil companies. Finally, it points out the core challenges and research prospects faced by the application of the current MECES optimization technology in oil and gas fields, hoping to provide systematic theoretical references and practical guidance for the green transformation of the oil and gas industry.