Viscous stabilization of 2D drainage displacements with trapping

Area of Science:

• Geosciences
• Fluid Dynamics
• Porous Media Physics

Background:

• Understanding fluid displacement in porous media is crucial for various applications, including oil recovery and carbon sequestration.
• Viscous forces play a significant role in stabilizing invasion fronts during fluid displacement.
• Existing theories on viscous stabilization have been developed primarily for connected flow paths.

Purpose of the Study:

• To investigate the mechanisms of viscous stabilization during drainage displacement in two-dimensional porous media.
• To examine the influence of loopless displacement patterns on the capillary pressure distribution at the invasion front.
• To assess the compatibility of existing viscous stabilization theories with drainage processes dominated by loopless flow.

Main Methods:

• Utilizing a network simulator to model two-dimensional porous media.
• Analyzing the invasion front dynamics during drainage displacement.
• Calculating the capillary pressure difference as a function of height separation along the invasion front in horizontal displacement.

Main Results:

• A near-linear relationship was observed between capillary pressure difference and height separation along the horizontal invasion front.
• Numerical results support models that consider loopless displacement patterns, where nonwetting fluid flows in separate strands.
• Existing theories for viscous stabilization were found to be incompatible with drainage displacement when loopless strands dominate.

Conclusions:

• Drainage displacement in porous media can exhibit loopless flow patterns, deviating from traditional strand-like flow.
• The near-linear relationship of capillary pressure suggests specific stabilization mechanisms at play in loopless drainage.
• Current theories of viscous stabilization require revision to accurately describe drainage displacement dominated by loopless fluid pathways.