Numerical Simulation Of Two Dimensional Foam Flow Characteristics In Porous Media Based On Stochastic Population Balance Model

Foam has found wide applications in Enhanced Oil Recovery(EOR)and has shown promising potentials on fulfilling efficient Carbon Dioxide(CO2)geological storage as well.Whereas the present foam modeling works are still in an immature stage.Previous studies based on transient foam models were too complex to be applied easily in practical situations.To address this lacuna,a simple but robust stochastic bubble population balance model,which involves only two variable parameters,is employed in this paper to study the transient foam flow characteristics in a porous media.Firstly,the entrance effect of foam liquid in homogeneous porous media was studied.Then,the seepage characteristics of foam in a heterogeneous porous media consisted of two parallel layers with different permeability is studied,and compared the results of numerical simulation and experimental results.The calculation results show that:(1)Due to the injection of gas and surfactant solution at the entrance center,the seepage process of the foam in the porous media shows obvious entrance effect;The Kg of foam formation rate increases,which indicates that the greater the formation rate of foam,the smaller the entrance effect.The maximum bubble density parameter n? only has an impact on the seepage pressure,but has a little effect on the distribution of water saturation.(2)When the foam flows in heterogeneous porous media,the foam propagates firstly in high permeability layer,then penetrates through the layer barrier and finally floods through the lower permeability layer as well.It is deduced the pressure distribution incorporating bubble population dominates the foam flow behavior in the heterogeneous porous media.Good qualitative agreements between the numerical and experimental results confirm that the stochastic population balance model could adequately describe foam flow mechanism in the heterogeneous porous media.(3)Based on the study of the parameters of the stochastic bubble population balance model: the value of Kg mainly affects the formation rate of bubble,the bigger the Kg,the faster the formation of the bubble structure;the maximum foam density n? mainly affects the maximum apparent viscosity of foam,when n? is greater,the apparent viscosity of foam is stronger,the displacement efficiency is higher.