Zhang Yuhang, Zhang Guanlong, Zhao Weiwei, Zhou Jian, Li Kaiyuan, Cheng Zhong
School of Earth Sciences and Engineering, Xi'an Shiyou University, Xi'an, 710065, China.
Shaanxi Key Laboratory of Petroleum Accumulation Geology, Xi'an Shiyou University, Xi'an, 710065, China.
Sci Rep. 2024 Sep 6;14(1):20860. doi: 10.1038/s41598-024-71504-1.
In this study, the Xgboost method is employed for TOC estimation in mixed carbonate and siliciclastic shale from the Hashan area, Junggar Basin. The results show that this approach is effective for TOC estimation in this area although the model performance is not very excellent with a correlation coefficient of 0.54 between measured TOC and predicted TOC values, likely due to a small samples dataset. Therefore, the PCA method is applied to debase dimension of well log data from five dimensional to two-dimensional data, which enhances the correlation coefficient between the predicted and measured TOC from 0.54 to 0.68. Based on the model, the isopleth maps of TOC distributions in Fengcheng Formation were redrawn showing two shale oil exploration targets, which likely correspond to two depositional centers of this strata. All the same, the model in this work provides reliable data for shale oil evaluation in the study area and a good example under similar geological setting.
在本研究中，采用Xgboost方法对准噶尔盆地哈山地区混合碳酸盐岩和硅质碎屑页岩中的有机碳含量（TOC）进行估算。结果表明，尽管该模型性能并非十分优异，实测TOC与预测TOC值之间的相关系数为0.54，可能是由于样本数据集较小，但该方法在该地区进行TOC估算仍是有效的。因此，应用主成分分析（PCA）方法将测井数据从五维降为二维，这使得预测TOC与实测TOC之间的相关系数从0.54提高到0.68。基于该模型，重新绘制了风城组TOC分布等值线图，显示出两个页岩油勘探目标，这可能对应于该地层的两个沉积中心。同样，本研究中的模型为研究区页岩油评价提供了可靠数据，并为类似地质背景下的研究提供了良好范例。
