Foam dynamics in the presence of oil during multiphase flow in porous rock

Foam injection is a promising method to increase oil recovery in mature oil fields because it can overcome the limitations of conventional gas injection by significantly reducing the mobility and improve sweep efficiency. It is economic because later gas breakthrough leads to less gas production and reduced costs related to gas recycling and re-injection. Reservoir simulation models describe foam behaviour with parameters that are difficult to measure in core-flooding experiments. For example, foam mobility depends on gas bubble density, which changes through bubble generation and coalescence events on the pore scale. A further complication is that foam mechanisms and film stability generally are different in the presence of oil, as shown in experiments. Thus, reservoir simulators rely heavily on fitting foam parameters to core-scale floods before their use. In this project, we will develop and use mathematical methods to investigate multiphase foam flow on the pore scale with a detailed description of the mechanisms for foam film stability and rupture. The project will conduct new pore-scale micromodel experiments to validate and calibrate the modelling approach. We will use the developed methods on segmented 3D rock images to understand and quantify the effect of oil on foam flow in porous rock. Efforts to model foam with oil present on pore scale are missing in the scientific literature, yet it is an essential part to improve our understanding of foam and make reservoir simulations with foam reliable. From pore-scale simulations, we will determine foam stability and texture, foam generation and coalescence rates, trapped gas fractions, limiting capillary pressure for foam coalescence, relative permeability curves, and hysteresis effects, to investigate foam mobility reduction with and without oil present. The outcome will be a better understanding of foam dynamics in porous rock, which allows a more accurate foam representation in reservoir simulations.