Research on intelligent identification method of shale lithology based on deep coupling of logging curves
-
摘要: 【目的】四川盆地渝西区块五峰组-龙马溪组是国内典型的页岩气储层,其层间强非均质性,导致采集的测井曲线信息存在大量冗余且曲线间耦合关系复杂,岩相测井识别难度高、精度低,亟需技术方法创新。【方法】本文在岩相划分与分析的基础上,联合主成分分析法与随机森林算法构建了一种岩相智能识别方法。【结果】研究结果表明:①利用主成分分析法对测井曲线进行优化,可以使测井曲线深程度耦合,削减测井信息冗余及曲线间复杂耦合关系等因素对岩相识别的影响,得到了更加科学有效的数据信息;②向原始数据添加不改变其岩相的微量变化,可以达到数据增强的效果,在一定程度上解决随机森林算法由于数据集比较小或者不平衡时,模型的泛化能力和稳定性差的问题;③联合主成分分析法与随机森林算法构建的岩相智能识别方法运用识别精准达83%以上,适用性强,准确率高。【结论】该方法不仅在一定程度上克服了研究区岩相识别困难的问题,也极大提高了岩相识别效率,对促进研究区页岩气经济高效具有重要意义。Abstract: 【Objective】The Wufeng-Longmaxi formations in the Yuxi Block of the Sichuan Basin are typical shale gas reservoirs in China. The strong interbedded heterogeneity of these formations leads to a significant amount of redundancy in the collected logging curve information and complex coupling relationships between curves, resulting in the difficulty and low accuracy of lithofacies identification using traditional methods, which urgently needs technical innovation. 【Methods】In this study, based on lithofacies classification and analysis, an intelligent lithofacies identification method combining Principal Component Analysis (PCA) and Random Forest algorithm was developed. 【Results】The research findings are as follows: Firstly, by optimizing the logging curves using PCA, the deep coupling of logging curves can be achieved, thereby reducing the impact of factors such as redundancy of logging information and complex coupling relationships between curves on lithofacies identification, resulting in more scientifically effective data information. Secondly, by adding minor variations to the original data without altering its lithofacies, data augmentation can be achieved, addressing to some extent the problem of poor generalization ability and stability of the model caused by small or imbalanced datasets when using the Random Forest algorithm. Finally, the intelligent lithofacies identification method constructed by combining PCA and Random Forest algorithm achieved an identification accuracy of over 83%, demonstrating its high precision and strong applicability. 【Conclusion】This method not only overcomes the difficulties in lithofacies identification in the study area to a certain extent but also greatly improves the efficiency of lithofacies identification, which is of great significance for promoting the economic and efficient development of shale gas in the study area.
点击查看大图
计量
- 文章访问数: 215
- PDF下载量: 37
- 被引次数: 0