Characterization of Darai Limestone Composition and Porosity Using Data-Constrained Modeling and Comparison with Xenon K-Edge Subtraction Imaging

Abstract

Data-constrained modeling is a method that enables three-dimensional distribution of mineral phases and porosity in a sample to be modeled based on micro-computed tomography scans acquired at different X-ray energies. Here we describe an alternative method for measuring porosity, synchrotron K-edge subtraction using xenon gas as a contrast agent. Results from both methods applied to the same Darai limestone sample are compared. Reasonable agreement between the two methods and with other porosity measurements is obtained. The possibility of a combination of data-constrained modeling and K-edge subtraction methods for more accurate sample characterization is discussed.

Quantitative multi-scale analysis of mineral distributions and fractal pore structures for a heterogeneous Junger Basin shale

“…Consequently, the fine length-scale information below image pixel size is preserved. So nano-scale fractures or pores in the sample can be quantitatively detected from X-ray micro-CT data as the partial volume fraction distributions [13][14][15][16]. Quantitative investigation of fractal structures of pore cluster has been analysised in this study.…”

“…Due to the existence of the X-ray CT data noise which is typically at a few percent, there is no strict formula for such energy parameter value selection so long as they are at or below such noise level. The above values are selected to obtain the 3D compositional maps closest to the known measurements [14,24]. The optimal solution is obtained by adjusting the volume fraction variables v (m) n for each material composition m, using a combination of matrix and liner search, subject to the constraints:…”