用深度学习模拟昂贵的矿石扫描,低成本高效分割岩心薄片图像。
Deep mineralogical segmentation of thin section images based on QEMSCAN maps
- 基于U-Net架构,用偏光显微图像训练模型模拟QEMSCAN的矿物分布图。
- 对已见岩相预测准确率R²超0.97,未见岩相也达0.88,边界识别精准。
- 适合地质勘探、石油储层评估人员快速获取矿物分布,节省成本与时间。
岩石薄片的矿物学解析对油气储层评价至关重要,但人工分析主观且耗时。虽然QEMSCAN技术可实现自动化矿物映射,却存在成本高、耗时长的问题。本文提出一种卷积神经网络模型,用于碳酸盐岩薄片图像的自动矿物分割,以低成本、通用化和高效方式模拟QEMSCAN结果。采用U-Net语义分割架构,以平面和交叉偏振显微图像为输入,对应QEMSCAN图为标签进行训练,该方法尚未广泛探索。模型需区分方解石、白云石、镁质黏土矿物、石英、孔隙及其余矿物合并为“其他”类。通过在训练中见过与未见过的岩相上验证,评估其泛化能力。由于图像与地图分辨率不同,采用图像配准实现空间对齐。研究发现,分割质量高度依赖分辨率差异和可学习岩性纹理多样性,但在固态纹理边界识别和矿物分布估计方面表现优异,对已见岩相的预测分布与真实分布呈近乎线性关系,决定系数R²超过0.97;对未见岩相也达到0.88。
原文摘要 · Abstract (English)
Interpreting the mineralogical aspects of rock thin sections is an important task for oil and gas reservoirs evaluation. However, human analysis tend to be subjective and laborious. Technologies like QEMSCAN(R) are designed to automate the mineralogical mapping process, but also suffer from limitations like high monetary costs and time-consuming analysis. This work proposes a Convolutional Neural Network model for automatic mineralogical segmentation of thin section images of carbonate rocks. The model is able to mimic the QEMSCAN mapping itself in a low-cost, generalized and efficient manner. For this, the U-Net semantic segmentation architecture is trained on plane and cross polarized thin section images using the corresponding QEMSCAN maps as target, which is an approach not widely explored. The model was instructed to differentiate occurrences of Calcite, Dolomite, Mg-Clay Minerals, Quartz, Pores and the remaining mineral phases as an unique class named "Others", while it was validated on rock facies both seen and unseen during training, in order to address its generalization capability. Since the images and maps are provided in different resolutions, image registration was applied to align then spatially. The study reveals that the quality of the segmentation is very much dependent on these resolution differences and on the variety of learnable rock textures. However, it shows promising results, especially with regard to the proper delineation of minerals boundaries on solid textures and precise estimation of the minerals distributions, describing a nearly linear relationship between expected and predicted distributions, with coefficient of determination (R^2) superior to 0.97 for seen facies and 0.88 for unseen.
Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。