Different methods of permeability calculation in digital twins of tight sandstones

Abstract

The development of tight hydrocarbon resources has a significant impact on the future of the energy market. Digital Rock Physics (DRP) is technically recognized as an effective method for characterizing reservoir rock properties. However, there is uncertainty about what result the user-defined chain of Digital Image Processing (DIP) and Pore-Scale Simulation (PSS) will produce when applying DRP. The uncertainty surrounding this technology faces even a greater deal in tight formations where a considerable portion of pores are sub-resolved and cannot explicitly be seen in the reconstructed micro-scale x-ray Computed Tomography (μxCT) images.Regarding the μxCT images of Achimovskiy formation, which is classified as a tight sandstone resource, the addressed uncertainty has been evaluated based on various scenarios of well-known DIP and PSS approaches. The results show that image processing and segmentation impact on the absolute permeability values stronger than calculation methods. Furthermore, the cross-plot analysis shows that simple image processing and segmentation indicate the same trend as precise image processing and segmentation. The generated results for the studied formation show that if the experimental open porosity of a core sample is higher than 5%, μxCT images could feasibly resolve the system of connected pores.