Coarsening of Foam in Two Model Fractures with Different Roughness
Abstract
Summary In this paper, we study foam coarsening in fractures. To this end, we have built two 1-meter-long model fractures, similar in some ways to microfluidic porous media. The two fractures are made of glass plates and have different roughness and hydraulic aperture. We characterize the roughness and represent the aperture distribution of the fracture as a network of pore bodies and throats. We use a fast-speed camera to visualize foam behavior inside the fractures. We show how foam evolves during coarsening in both model fractures. We also estimate the height of lamellae at the end of our coarsening experiments. Based on this information, we discuss whether coarsening stops because bubble pressures are equalized or slows nearly to a stop because bubbles lose contact through lamellae, at the end of the coarsening experiments.