Miscible, porous media displacements with density stratification

Area of Science:

• * Fluid dynamics and porous media physics.
• * Computational modeling of multiphase flow.

Background:

• * Miscible displacements in porous media are crucial for enhanced oil recovery and carbon sequestration.
• * Understanding the interplay of viscous and gravitational forces is key to optimizing these processes.

Purpose of the Study:

• * To investigate the impact of gravity override on miscible displacements in homogeneous and heterogeneous porous media using 3D numerical simulations.
• * To analyze the influence of viscous and gravitational effects on displacement dynamics via the vorticity variable.

Main Methods:

• * High-accuracy, three-dimensional numerical simulations were employed.
• * The quarter five-spot configuration was used to model fluid flow.
• * Vorticity variables were utilized to describe viscous and gravitational influences.

Main Results:

• * Density differences establish a gravity layer, enhancing the effective Peclet number in homogeneous media.
• * In heterogeneous media, viscous and permeability vorticity field coupling suppresses the gravity layer effect.
• * Reduced coupling (viscous wavelength >> permeability wavelength) enhances gravity override effectiveness.
• * Significant buoyancy forces can cause gravity layer pinch-off, decelerating displacement.

Conclusions:

• * Gravity override is significantly influenced by porous medium heterogeneity and vorticity field coupling.
• * The findings provide insights into optimizing fluid displacement strategies in complex geological formations.
• * Understanding these dynamics is critical for predicting and controlling subsurface fluid flow behavior.