Foam formation analysis during drainage of a surfactant solution*

Foam is widely used in oil recovery operations to maximize oil production, and solve problems caused by either a thief zone or gravity override. Foam, that can be pre-formed and injected in the reservoir or produced in-situ through the pore space, fills the high permeability areas known as thief zones and divert the displacing fluid into the direction of trapped oil, reducing the relative permeability of gas and leading to a more stable flood front. The presence of liquid lamellae between gas bubbles in the foam also reduces the gas mobility, by the increase of the gas apparent viscosity. The flow mobility is a function of the pore geometry and foam properties. However, the dynamics of foam in a porous media is not fully understood due to its complexity. The goal of this research is to study foam formation during drainage of a two-dimensional porous media glass model by visualizing the pore scale displacement flow of a surfactant solution by injected gas. A microfluidic setup composed of glass micromodel, syringe pump, pressure transducer, and a microscope is used to study the evolution of the phase distribution and foam characteristics as a function of pore space geometry and flow conditions through image processing.