In carbonate rocks, pore diameters range in size over at least nine orders of magnitude, from submicrometer-scale voids to km-scale caves. This study is focused on micropores, which are defined as pore bodies with diameter ≤ 10 micrometers. Corresponding pore throats are generally ≤ 1 micrometer in diameter. To visualize and quantify microporosity, geologists commonly use pore casts, transmitted-light petrography, and scanning electron microscopy. Shortfalls exist in all of these techniques. Laser scanning confocal microscopy, a relatively new approach, provides a step change in our ability to image and quantify microporosity in carbonate rocks.Laser scanning confocal microscopy provides high-resolution (0.2-micrometers/pixel) images of micropores. Such pores are generally obscure or invisible using conventional petrography. In practice, confocal microscopy is applied to polished rock chips or thin sections that have been vacuum-pressure impregnated with epoxy. The laser light source interacts with fluorescent dye within the epoxy. Emitted fluorescent light, recorded using point-by-point illumination, indicates the physical location of pores. A pinhole, placed in front of the detector, eliminates out-of-focus light. Because each measurement is a single point, confocal microscopes scan along grids of parallel lines to provide optical images of planes at specified depths within the sample.Confocal microscopy is used to generate 2D and 3D images of pore bodies and throats. Results can be compared to laboratory-measured petrophysical properties, such as pore-throat diameters from mercury injection capillary pressure (MICP) data. Now, for the first time, we can compute pore-body to pore-throat size ratios without pore casts. These ratios are important, because they can be related to mercury recovery factors from imbibition MICP experiments.

中文翻译：

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使用共聚焦显微镜进行微孔定量

在碳酸盐岩中，孔径的大小至少有 9 个数量级，从亚微米级空隙到千米级洞穴。本研究的重点是微孔，其定义为直径≤ 10 微米的孔体。对应的孔喉直径一般≤1微米。为了可视化和量化微孔隙度，地质学家通常使用孔隙模型、透射光岩相学和扫描电子显微镜。所有这些技术都存在不足。激光扫描共聚焦显微镜是一种相对较新的方法，它为我们对碳酸盐岩中的微孔进行成像和量化的能力提供了一个阶跃变化。激光扫描共聚焦显微镜提供了微孔的高分辨率（0.2 微米/像素）图像。使用传统的岩相学，这种孔隙通常是模糊的或不可见的。在实践中，共聚焦显微镜应用于抛光的岩石碎片或用环氧树脂真空压力浸渍的薄片。激光光源与环氧树脂内的荧光染料相互作用。使用逐点照明记录的发射荧光指示毛孔的物理位置。位于探测器前面的针孔可消除散焦光。因为每次测量都是一个点，所以共聚焦显微镜沿着平行线的网格进行扫描，以提供样品内指定深度平面的光学图像。共聚焦显微镜用于生成孔体和喉道的 2D 和 3D 图像。结果可以与实验室测量的岩石物理特性进行比较，例如来自压汞毛细管压力 (MICP) 数据的孔喉直径。现在，第一次，我们可以在没有孔隙铸型的情况下计算孔体与孔喉的尺寸比。这些比率很重要，因为它们可能与渗吸 MICP 实验的汞回收率有关。