Scanning electron microscopy is the key to constructing a digital mineral model of a rock

Introduction. The digitalization of the oil industry includes “Digital Core Analysis” — a technology for creating accurate digital twins of rocks. This enhances the informativeness of research and the efficiency of project decisions.

The aim of this work is to develop a method for constructing a digital mineralogical model of core samples using computed tomography and scanning electron microscopy combined with an energy-dispersive spectrometer attachment.

Methods. Rock samples were studied using scanning electron microscopy combined with energy-dispersive spectroscopy, computed tomography, X-ray diffraction analysis, X-ray fluorescence spectroscopy, and petrographic examination of thin sections.

Results. Based on the proposed approach, a method for constructing a digital core model has been developed. The method allows for the reconstruction of a digital three-dimensional mineral model of the core. This is  achieved by using two-dimensional elemental distribution maps obtained from a standard scanning electron microscope with integrated energy-dispersive spectroscopy, applying the proposed algorithm for recalculation into mineral composition, and a three-dimensional model of the rock skeleton (matrix) obtained by computed tomography. Based on the obtained model, quantitative calculations of mineral composition can be performed. Verification of the obtained results is carried out through mineralogical studies.

Conclusion. The successful verification of the proposed method with traditional mineralogical studies indicates that the proposed method is a reliable tool for obtaining a digital core model based on standard equipment, without the need for expensive complexes with unique sok ware. 

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