Pore to Core Scale Characterization of Hydraulic Flow Units Using Petrophysical and Digital Rock Analyses

This article illustrates an integrated method for characterizing hydraulic flow units in subsurface reservoirs using multiscale images and petrophysical data analysis from well cores. This method is applied to 35 meters of cores drilled from a Late Jurassic Upper Jubayla Formation outcrop in Saudi Arabia, which is analogous to the lower section of the Arab-D reservoir. Scanning electron microscope (SEM) imagery, thin-section petrography, and X-ray computed tomography (CT) images of whole cores and core plugs are used to visualize and characterize these carbonate rocks across multiple length scales. Core plug porosity and permeability data are used for petrophysical characterization and deriving hydraulic flow units (HFU). The multimodal pore types associated with the HFUs and their connectivity using thin section and SEM image analysis, combined with mercury injection porosimetry are used. Whole-core CT textures and heterogeneity logs are correlated with HFU and digital image analysis of core plugs. Whole-core CT data prove to be a highly valuable tool for bridging the scale gap between well data and reservoir models. This methodology can be applied to datasets from a large number of wells, especially when combined with machine learning tools, allowing improved characterization of complex carbonate reservoirs. Herein, an integrated approach is used for the characterization of hydraulic flow units in complex carbonate reservoirs by leveraging multiscale pore space imaging techniques. The method is demonstrated using cores from a Late Jurassic Upper Jubayla Formation outcrop in Saudi Arabia, which is analogous to the prolific Arab-D reservoir.image (c) 2023 WILEY-VCH GmbH

Automated summary

This article presents an integrated method for characterizing hydraulic flow units in subsurface reservoirs using multiscale images and petrophysical data analysis. It demonstrates the application of this method to carbonate rocks in a Late Jurassic formation in Saudi Arabia. The approach combines various imaging techniques and petrophysical analysis to accurately characterize the flow units and improve reservoir characterization. The findings show that whole-core CT data is a valuable tool for bridging the scale gap between well data and reservoir models.