Abstract

Understanding fluid behavior within subsurface formations necessitates a comprehensive examination of the pore space and the associated pore-scale processes. Digital rock physics (DRP), a rapidly developing discipline at the interface of geosciences and computer sciences, offers a promising approach to unravel the complexities of pore-scale physics and the resulting fluid flow in the sub-surface. In contrast to traditional laboratory studies, which are often time-consuming, expensive, and limited in capturing the true intricacies of pore networks, DRP can be employed to analyze and predict effective porosity and permeability, two critical sub-surface parameters that governs fluid flow. The present study provides a scale dependent comparative analysis of estimating permeability using numerical and empirical methods such as, the Lattice Boltzmann simulation method (LBM), the Kozeny-Carman empirical relation, and laboratory measurements. The findings of the study reveal that the permeability values derived from the Kozeny-Carman equation are higher compared to those obtained from LBM simulations. This disparity can be attributed to the simplifications and assumptions inherent in the Kozeny-Carman model, given its macroscopic nature. The equation assumes a simplified representation of pore geometry and assumes uniform flow through interconnected channels, neglecting the intricate flow behavior at the pore scale. The scale-dependent comparative analysis highlights the disparities in permeability estimation between the Kozeny-Carman equation and LBM simulations. The present study is a preliminary investigation carried out on rock samples that exhibit similarities to Lithuanian reservoirs. Its primary aim is to establish a foundational basis for future research concerning the storage of CO2 and hydrogen within Lithuanian reservoirs.