In this study, we propose a dynamic fractal dimension modeling (DFDM) framework that integrates image analysis, wavelet-based fractal methods, and structural fractal geometry to quantify the evolution of pore complexity. Unlike conventional static fractal approaches, our method captures time-dependent scaling laws and captures the spatiotemporal evolution of pore networks. The results demonstrate that dynamic fractal dimensions provide a robust descriptor of multi-scale heterogeneity, effectively bridging pore-scale processes with reservoir-scale behavior. This framework not only advances the theoretical understanding of fractal pore dynamics but also establishes a predictive tool with potential applications in unconventional hydrocarbon recovery, geological CO2 sequestration, and multi-phase flow in porous media.
Predicting nonlinear flow in stress-sensitive porous media is critical for CO2 displacement and storage performance. We develop a wavelet-based nonlinear partial differential equation (PDE) that explicitly captures localized pressure evolution and stress-permeability coupling beyond conventional Darcy flow. From this framework, three closure indicators are derived: the curvature \(\:\kappa\:\left(t\right)\), the scaling exponent \(\:n\left(t\right)\), and the inertial ratio \(\:R\left(t\right)\), which define a unified nonlinear criterion for regime transitions. Systematic displacement experiments reveal that these indicators robustly delineate three distinct flow regimes: nonlinear mixed-phase formation, quasi-Darcy displacement, and post-breakthrough inertial channelization. The measured transitions (\(\:{t}_{1}\),\(\:{t}_{2}\)) agree closely with theoretical predictions, confirming the robustness of the nonlinear PDE model. This integrated framework provides mechanistic insight into multi-phase transport under stress sensitivity and delivers quantitative tools for regime identification. The results offer direct guidance for optimizing injection strategies, predicting breakthrough, and mitigating channelization risks in CO2-EOR and geological carbon storage.
Understanding CO2 transport in fractal porous media requires models capable of capturing multi-scale structural variability and temporal correlations inherent to complex geological formations. In this work, we develop a mechanistic stochastic framework based on wavelet-assisted damped fractional Brownian motion (WA-DFBM) to describe CO2 migration and diffusion across fractal pore structures. The method integrates multi-resolution wavelet decomposition with the long-range dependence and damping characteristics of fractional Brownian motion, enabling simultaneous representation of microscopic heterogeneity, temporal memory, and dissipative effects. The resulting WA-DFBM framework reproduces key transport signatures observed in porous media, including anomalous diffusion, non-stationary fluctuations, and scale-dependent variance evolution. Comparison with conventional Brownian-based models demonstrates that WA-DFBM provides enhanced capability for representing multi-scale pore heterogeneity and dynamic variability. This approach offers improved mechanistic insight into CO2 transport behavior in fractal porous media and establishes a generalized modeling framework applicable to a wide range of subsurface flow and transport problems.
In this study, we propose a dynamic fractal dimension modeling (DFDM) framework that integrates image analysis, wavelet-based fractal methods, and structural fractal geometry to quantify the evolution of pore complexity. Unlike conventional static fractal approaches, our method captures time-dependent scaling laws and captures the spatiotemporal evolution of pore networks. The results demonstrate that dynamic fractal dimensions provide a robust descriptor of multi-scale heterogeneity, effectively bridging pore-scale processes with reservoir-scale behavior. This framework not only advances the theoretical understanding of fractal pore dynamics but also establishes a predictive tool with potential applications in unconventional hydrocarbon recovery, geological CO2 sequestration, and multi-phase flow in porous media.
Accurately modeling CO2 diffusion in low-permeability heterogeneous reservoirs is critical for optimizing enhanced oil recovery and carbon sequestration strategies. We present a novel stochastic time series model that integrates damping effects, fractional Brownian motion, and wavelet transforms to simulate CO2 migration and diffusion behavior in complex porous media. Compared to traditional approaches, our model captures multi-scale heterogeneity and dynamic fluctuations more effectively, offering improved predictive accuracy at microscopic spatial and temporal scales. This approach provides a refined understanding of CO2 transport mechanisms in tight reservoirs and supports the design of more efficient CO2-EOR and CCUS operations.