Updated screening criteria for enhanced oil recovery methods and their application to the T oilfield in eastern Mongolia

Enhanced oil recovery (EOR) plays a vital role in maximizing oil production from depleting reservoirs. As EOR technologies advance, updating screening criteria is essential to evaluate and recommend suitable EOR methods for target reservoirs. This study aims to establish updated screening criteria to identify the most effective EOR methods based on specific reservoir characteristics. A structured selection approach facilitates the evaluation of advanced EOR technologies to ensure the suitability for particular reservoirs while optimizing recovery processes and improving overall efficiency. To demonstrate this approach in practice, we present a case study using field data collected from the T oilfield in Mongolia. The estimated recovery factor based on primary and secondary recovery is in the range of 10% to 17%. Therefore, the field development plan considers the application of EOR to the T oilfield. An integrated methodology that combines EOR screening with score assignment is applied to provide a comprehensive evaluation of potential EOR technologies. The results show that the miscible carbon dioxide (CO₂) injection, miscible hydrocarbon (HC) injection, and immiscible nitrogen (N₂) injection methods have the highest scores without any violation of criteria. This approach ensures a thorough selection process by considering various technical factors relevant to reservoir characteristics and aligning with the study’s objective. The case study demonstrates the effectiveness of the proposed screening criteria in real-world scenarios and offers valuable insights for operators selecting EOR methods under similar conditions.