Transport in Porous Media最新文献

We present a history matching (HM) workflow applied to the International FluidFlower benchmark study dataset, which features high-resolution images of CO(_2) storage in a meter-scale, geologically complex reservoir. The dataset provides dense spatial and temporal observations of fluid displacement, offering a rare opportunity to validate and enhance HM techniques for geological carbon storage (GCS). The combination of detailed experimental data and direct visual observation of flow behavior at this scale is novel and valuable. This study explores the potential and limitations of using experimental data to calibrate standard models for GCS simulation. By leveraging high-resolution images and resulting interpretations of fluid phase distributions, we adjust uncertain parameters and reduce the mismatch between simulation results and observed data. Simulations are performed using the open-source OPM Flow simulator, while the open-source Everest decision-making tool is employed to conduct the HM. After the HM process, the final simulation results show good agreement with the experimental CO(_2) storage data. This suggests that the system can be effectively described using standard flow equations, conventional saturation functions, and typical PVT properties for CO(_2)–brine mixtures. Our results demonstrate that the Wasserstein distance is a particularly effective metric for matching multi-phase, multi-component flow data. The entire workflow is implemented in a Python package named pofff (Python OPM Flow FluidFlower), which organizes all functionality through a single input file. This design ensures reproducibility and facilitates future extensions of the study.

Foam injection in porous media is a promising technique for enhanced recovery and other industrial applications, but its modeling is complicated by instabilities in the computed foam apparent viscosity. This study investigates oscillations observed during foam displacement simulations. Mesh refinement demonstrates that increasing discretization reduces the amplitude of global oscillations in the average apparent viscosity; however, sharp local peaks persist at shock fronts and may intensify over time. These instabilities are not solely numerical artifacts but are linked to the mathematical structure of the foam model, particularly the presence of steep saturation fronts. We show that numerical diffusion, unavoidable in simulation frameworks, can amplify such effects. To address this issue, we introduce a filtering technique that reconstructs the water saturation profile in the vicinity of the shock without affecting convergence. The method effectively suppresses viscosity oscillations while maintaining physical accuracy near discontinuities.

This study investigates the thermosolutal convection of a power-law fluid with variable gravity in a vertical through flow that is heated and salted from below. Linear instability analysis investigates the growth of small disturbances in a system. After non-dimensionalizing the governing equations, they are linearized around a base state. The normal mode method applied for solving the perturbation equations. It gives the exponential form to solve stability criteria. The complete study was analyzed by using linear stability analysis; the influence of variable gravity is studied. This theoretical study investigates double-diffusive convection within a porous media filled by power-law fluid. It mainly examines how gravity and concentration gradients influence on thermal solutal convection behavior. The focus is on vertical through flow and its role in the onset and effect of instability.

Predicting the macroscopic properties of thin fiber-based porous materials from their microscopic morphology remains challenging because of the structural heterogeneity of these materials. In this study, computational fluid dynamics simulations were performed to compute volume air flow based on tomographic image data of uncompressed and compressed paper sheets. To reduce computational demands, a pore network model was employed, allowing volume air flow to be approximated with less computational effort. To improve prediction accuracy, geometric descriptors of the pore space, such as porosity, surface area, median pore radius, and geodesic tortuosity, were combined with predictions of the pore network model. This integrated approach significantly improves the predictive power of the pore network model and indicates which aspects of the pore space morphology are not accurately represented within the pore network model. In particular, we illustrate that a high correlation among descriptors does not necessarily imply redundancy in a combined prediction.

This study revisits and extends the analytical model presented by Maas (J Hydrol 347:223–228, 2007), which describes simultaneous downward infiltration of fresh water and upward seepage of fresh or saline groundwater beneath an elongated island. Under steady-state conditions and using the sharp interface approximation, the interface between the two types of water forms a semi-elliptical shape. Notably, the unusual y-linearity of the flow potential provides an analytical advantage, enabling a direct and elegant extension from a one-phase to a two-phase system. For transient conditions, Maas (J Hydrol 347:223–228, 2007) employed a successive steady-state approach based on elliptical shapes. We demonstrate that this approach is physically inconsistent, as the tip of the lens must possess a finite derivative to allow for movement. Instead, we introduce an interface motion equation to track this front dynamically. Additionally, we identify potentially unstable configurations during outward lens migration, where denser salt water temporarily overlays fresh water near the lens tip. To address this, we incorporate diffusion, moving beyond the sharp interface assumption. Finally, we assess the applicability of Maas’s elliptical approximation for interface motion and find it remains robust as long as the approximation that lens thickness is negligible compared to its width is used with caution. These findings broaden the analytical understanding of fresh water lens dynamics in island aquifers and refine the conditions under which simplified models remain valid.

We revisit the classical problem of fully developed Darcy–Brinkman flow through a tube with elliptic cross section. Building upon the exact velocity field originally derived by Narasimhacharyulu and Pattabhiramacharyulu (Proc. Indian Acad. Sci. Sect. A 87:79–83, 1978), we find, for the first time, an exact series expression for the Poiseuille number in this regime. Our results match the earlier Ritz-based approximations and are in close agreement with the finite-element solutions presented here.

We present a pore network approach for the simulation and study of biofilm growth inside porous structures under various limiting conditions. The proposed pore-scale model allows us to resolve the interrelationship between growth and diffusive transport based on the solution of coupled ordinary differential equations. Special focus of this study is on diffusion as well as on metabolically limited conditions, which is realized with different second Damköhler numbers. Instead of relying on idealized geometries, the pore network structures are generated using the effective transport properties of thin sintered particles and fibrous felt porous layers derived from high-resolution X-ray micro-CT scans. The great differences in pore sizes and porosities of the regarded structures result in significantly different effective diffusivities. In addition to that, competitive substrate consumption and inhibition is achieved using the experiment-based kinetic model for S. oneidensis from Tang et al. (Tang et al., Biotechnol. Bioeng. 96:125–133, 2007). The primary nutrients are lactate and oxygen. Acetate is both, a by-product and a potential substrate, theoretically enabling dynamic shifts in substrate utilization. With the chosen parameters and conditions, the second Damköhler number can be varied with a significant impact on biomass distribution inside of the two selected pore networks, especially in dependence on oxygen availability in single pores. The simulation results show that biofilm growth is limited by the transport of dissolved oxygen. Interestingly, significantly more biomass per m³ is produced in the sintered structure because of the generally higher pore utilization degree.

Graphical Abstract

Multiphase flow simulation in porous media is a challenging task with significant industrial implications. Pore Network Modeling (PNM) is an effective method that provides accurate results within a reasonable computational timeframe. However, as the complexity of these systems increases, particularly when simulating whole-core-sized pore networks (Digital Plugs) with millions of elements, there is a growing demand to improve the computational efficiency of PNM. The primary computational bottleneck is the pressure field update process, which involves solving a linear system of balance equations. To address this issue, our research focuses on evaluating the performance of a recently developed multiscale preconditioner for solving this system. We compare its performance against a state-of-the-art algebraic multigrid (AMG) method. Networks where the multiscale preconditioner outperforms AMG are identified, and a multilevel strategy is implemented to extend the capabilities of the method to networks with up to 200 million pore bodies. This shows the multiscale method is a promising alternative to accelerate multiphase simulations in Pore Network Modeling.

Calcium carbonate scaling poses a significant challenge in oil and gas production, hindering recovery and impacting economic viability. This study utilizes microfluidic "reservoir-on-chip" platforms to visualize, quantify, and characterize CaCO₃ precipitation in hydrophobic and hydrophilic porous media to elucidate scaling mechanisms. Traditional methods face limitations in observing the intricacies of scale formation at the pore scale. Microfluidic platforms, however, offer real-time, high-resolution visualization of flow dynamics and scale deposition, enabling the study of key parameters like temperature, solution concentration, and surface wettability. This research investigates the impact of these parameters on CaCO₃ scaling, with a particular focus on wettability's influence on the nucleation process. By elucidating the interplay of different factors, this study aims to provide insights into mitigating and controlling scale formation in oil and gas production. Our findings demonstrate that the covered area by precipitates increased with increasing temperature and concentration for both hydrophobic and hydrophilic surfaces, with more substantial coverage observed on hydrophilic surfaces. Scanning electron microscopy and X-ray diffraction analysis confirmed the presence of calcite, vaterite, and aragonite polymorphs. Furthermore, the findings hold implications for advancing carbon capture, utilization, and storage (CCUS) technologies, particularly mineral carbonation, by providing a deeper understanding of carbonate formation dynamics at the pore scale.

Graphical abstract