EAAI Journal 2025 Journal Article
Improved U-net with weighted loss function and its application in the prediction of remaining oil distribution
- Kang Zhou
- Ke Su
- Zhibin An
- Yingjie Chen
- Jian Hou
Research on predicting the remaining oil distribution using artificial neural networks has been thoroughly conducted. However, conventional methods often perform poorly in regions exhibiting drastic changes in oil saturation. To address this limitation, the paper adopts U-net as the prediction model and improves the loss function by dynamically adjusting the loss weights of each pixel based on the extent of changes within the remaining oil distribution map. Furthermore, an exponential relationship between the weight of the loss function and the variance of oil saturation is established, and thus the loss function is modified to be saturation-variance-dependent. The findings demonstrate that modifying the weighted loss function enhances U-net's learning capability in regions with drastic changes in oil saturation, thereby effectively improving prediction performance in these challenging areas. Moreover, the optimal prediction performance of U-net is achieved when the base value of the exponential weighted function is set to 2. The proportion of predictions with R2 greater than 0. 95 is 72 % using U-net with the weighted loss function, marking a 48 % increase compared to the U-net without modifications. The study provides a promising method for prediction of remaining oil distribution, and can also serve as a valuable reference for application of the U-net in image prediction with drastic local changes.