Core Insights - Daqing Oilfield has achieved a significant breakthrough in enhanced oil recovery (EOR) technology, with the successful implementation of polymer flooding in the Xinnan development area, resulting in an oil increase of over 50,000 tons [1][4]. Group 1: Technology and Development - The Xinnan development area has been focusing on finding new production growth points as the recoverable reserves from Class I oil layers decrease due to ongoing industrial development [3]. - Class III oil layers, which are crucial for potential reserves, have been challenging to develop due to severe heterogeneity and lack of mature EOR technology solutions [3]. - In August 2018, Daqing Oilfield initiated a field trial for polymer flooding in the upper return of the I1-2 layer, aiming to explore suitable injection systems and development technologies for Class III oil layers [3]. Group 2: Implementation and Results - The technical team established a classification development principle for well groups, allowing for personalized injection plans based on the development and connectivity of oil layers, leading to efficient polymer injection [3]. - The trial area achieved a cumulative utilization thickness ratio of 94.59%, significantly exceeding the expected target, demonstrating effective oil layer utilization [3]. - The successful trial not only validated the feasibility of EOR technology for Class III oil layers but also provided a replicable and scalable technical model for the entire oilfield [4].