Breakup of gas bubbles during solution-gas-drive in porous media using experiments and simulations

Solution-gas-drive is one of the main recovery mechanisms for oil reservoirs. This mechanism is initiated after the reservoir pressure drops below the bubble point, and gas molecules start to nucleate inside the pores. Our experiments on microfluidic chips show that growing bubbles undergo breakup (Rayleigh-Plateau) instability if some amount of pressure gradient is sustained between both ends of the porous medium. In this regime, we observe that exsolved gas bubbles are swept out of the system by the flowing liquids due to the pressure gradient. To understand the conditions leading to this breakup instability, we built a three-dimensional direct numerical simulation model of the multiphase flow in a representative T-junction geometry, where we observe bubbles breaking up experimentally. Using this numerical model we performed a parameter sweep that includes pressure gradient, length scale of the geometry along with various material properties including surface tension, contact angle, viscosity, and density. As a result of this effort, we built a phase diagram using two dimensionless numbers including the relevant parameters to evaluate if a given set of conditions would result in bubble breakup.