Multi-Scale, Multi-Modal Imaging for Upscaling Rock Properties

Abstract

Recent advances in imaging technologies have allowed us to interrogate materials at progressively higher resolution. As we have begun to investigate geomaterials at resolutions on the single nanometer scale, our observations have upended several long-lived paradigms of geoscience. This has proved particularly true in shale reservoirs. Although it is fascinating to continue to look more deeply into these reservoirs, we are also faced with two daunting challenges. The first, involves the processing of extremely large volumes of image data. Individual images can be larger than 100 gigabytes in size, too large for many of the existing tools for image analysis to open and segment. The second, involves the upscaling of our observations from the nanometer scale of the pore space to the vertical thickness of the formation (hundreds of meters) and the basin scale (hundreds of kilometers). Upscaling our observations over twelve orders of magnitude is required in order to identify sweet spots in shale reservoirs from seismic data. We link analysis of registered 2D and 3D images at multiple scales and from varying imaging tools (nano- and Micro-CT, SEM/EDS/CL and FIB/SEM, reflected, transmitted, and fluorescent light microscopy, laser Raman microscopy, acoustic microscopy) with physical property measurements made in the laboratory on the identical sample material. In this way the influence of organic matter content, type, and thermal maturity, porosity, primary and authigenic mineralogy, and sedimentary heterogeneity on acoustic, strength, and flow properties of shale formations can be documented. Registering whole core CT with images from other tools, and with laboratory measurements allow upscaling of laboratory measurements and images, with in situ measurements of physical properties made in the wellbore by logging tools. Recent successes in applying this methodology include obtaining good agreement in image analysis estimates of porosity and TOC with core plug measurements, identification of organic matter type and maturity through linked SEM/transmitted/reflected/fluorescent light and laser Raman imaging, and documentation of the influence of TOC/porosity/detrital and authigenic mineralogy on acoustic properties at a lamina and core plug scale.

AAPG Datapages/Search and Discovery Article #90323 ©2018 AAPG Annual Convention and Exhibition, Salt Lake City, Utah, May 20-23, 2018