Improving Pore Network Imaging & Characterization of Microporous Carbonate Rocks Using Multi-Scale Imaging Techniques

Abstract

Epoxy-pore casting is widely used to characterize geological samples. In this study, we present a robust pore imaging approach that applies Confocal Laser Scanning Microscopy (CLSM) to obtain high resolution 3D images of etched epoxy-pore casts of highly heterogeneous carbonates. In our approach, we have increased the depth of investigation for carbonates 20-fold, from 10 μm reported by (Fredrich, 1999; Shah et al., 2013) to 200 μm. In addition, high resolution 2D images from scanning electron microscopy (SEM) have been correlated with the 3D models from CLSM to develop a multi-scale imaging approach that covers a range of scales, from millimeters in 3D to micrometers in 2D. The developed approach was implemented to identify various pore types, e.g., the inter-crystalline and intra-granular microporosity, and the inter-boundary sheet pores in the limestone and dolomite samples.