The study evaluates the energy and environmental performance of Ecuador's upstream oil facilities between 2015 and 2020, focusing on major extraction blocks. By analyzing data on oil, gas, and water production, fossil fuel consumption, and electricity usage, key performance indicators were developed to assess efficiency and environmental impact. The findings revealed disparities in energy efficiency, with Block 43-ITT being the most efficient at 7.82 kWh per barrel, while Block 57-LB was the least efficient at 31.41 kWh per barrel. The study emphasizes that maturing oil fields require more energy and emit more greenhouse gases, underlining the necessity for sustainable energy practices. EP Petroecuador’s initiatives, such as substituting fuel and integrating renewable electricity, led to a reduction of approximately 540 kTons of CO2 emissions by replacing 163.32 million gallons of diesel with low-carbon fuels and renewable electricity. These findings serve as a baseline for optimizing energy use and reducing emissions, offering valuable insights for policymakers and industry leaders to adopt data-driven strategies that enhance energy efficiency and minimize environmental impact in Ecuador's oil sector.