Gate-to-Gate Life Cycle Assessment of CO2 Utilisation in Enhanced Oil Recovery: Sustainability and Environmental Impacts in Dukhan Field, Qatar

This study presents a gate-to-gate Life Cycle Assessment (LCA) evaluating the sustainability and environmental impacts of utilising CO2 for Enhanced Oil Recovery (EOR) in Dukhan Field. The assessment employs a detailed model that encompasses CO2 capturing, transportation, injection, and oil production processes. Utilising Gabi software, the study assesses CO2 emissions across different stages of the EOR process and evaluates the environmental efficiency using two functional units: '1 kg of CO2 captured' and '1 kg of oil produced'. Results indicate that Post-Combustion Capture (PCC) contributes the highest emissions, accounting for 76% of the total Global Warming Potential (GWP), while transportation pipelines and separators contribute only 2% and 4%, respectively. By Year 21, emissions drop by over 98%, with a corresponding GWP reduction from 4.73 billion kgCO2e in Year 1 to 94.97 million kgCO2e. Emission rates for CO2 capture and oil production also decrease significantly, reaching 0.01 kgCO2e per kg of CO2 captured and 0.03 kgCO2e per kg of oil produced. These findings highlight the transformative potential of closed-loop CO2 management, where recycling reduces reliance on external CO2 sources and enhances the sustainability of EOR operations. This study provides actionable insights for optimising CO2-EOR systems, contributing to both economic and environmental sustainability goals.