Analysis of proppant particles porosity based on microCT image processing

Abstract

The proppant is a granular material with a typical size of 0.2 to 1.2 mm. It is used to prevent the closure of fractures in the reservoir created by hydraulic fracturing procedure, which is actively used in the oil and gas industry. Some types of proppant are manufactured from porous technical ceramics. Presence of internal voids can dramatically decrease the proppant grain mechanical strength and consequently proppant pack conductivity under natural stress. For a detailed study of proppant particles’ internal porosity structure and its relation to the pack’s strength, we applied X-ray microtomography (microCT), which allows to observe this structure non-destructively.In the work, we presented our approaches for digital analysis of reconstructed 3D microCT images for studying the internal voids and the homogeneity of their distribution inside the proppant. We used an automatic thresholding for primary segmentation of pores and particles. We apply 3D marker-controlled watershed to separate individual proppant particles. We propose features for characterization of radial and layered porosity distribution for each particle and homogeneity evaluation. The correctness of our method was tested on synthetic models. Current results indicate probable dependence of proppant strength properties on its internal porosity, but not on the homogeneity of porosity distribution.