Method and system for multi-energy computer tomographic cuttings analysis

A method for estimating selected physical properties of a rock sample, which comprises the steps of:

• (a) positioning rock fragments of the same drilling interval in spaced positions in a casting container,
• (b) introducing flowable polymer into the casting container to encapsulate the rock fragments,
• (c) hardening the polymer to form a rock fragments-embedded carrier,
• (d) removing the rock fragments-embedded carrier from the casting container,
• (e) performing a multi-energy X-ray CT scan of the rock fragments-embedded carrier with at least 3 reference objects,
• (f) creating digital images of the rock fragments from the multi-energy X-ray CT scan, wherein each of the rock fragments scanned at two or more different energy levels returns a CT value for each voxel thereof,
• (g) estimating the bulk density, RhoB, and effective atomic number, Zeff, for each of the rock fragments as data pairs based on the digital images of the rock fragments, comprising averaging the voxels for each entire rock fragment per different energy scan and processing the average values for each rock fragment to provide the data pairs,
• (h) categorizing the bulk density, RhoB, and effective atomic number, Zeff, data pairs into a single set for a single rock fragments-embedded carrier or separate subsets if more than one rock fragments-embedded carrier of differing intervals is scanned in step (e),
• (i) selecting at least one rock fragment from the set or subsets as applicable for further digital analysis,
• (j) extracting the at least one selected rock fragment from the carrier,
• (k) creating 2D digital images of the selected rock fragment using an SEM,
• (l) estimating at least one of porosity, organic matter content, and mineralogy from the images created in step (k),
• (m) selecting a subarea of the images created in step (k), which can comprise at least one of relatively high porosity and high organic matter or other features of interest,
• (n) imaging the selected subarea of step (m) with a FIB-SEM,
• (o) creating 3D digital images from the imaging in step (n),
• (p) segmenting the 3D digital images of step (o) to identify voxels as pore, rock or organic matter, and
• (q) estimating rock properties from the segmented images.