Increasing global demand for oil and reduce production of light oil has led to more attention to heavy oils resource. Solution gas drive is one of the most effective methods is considered in terms of cost in heavy oil production. The objective of this research was to develop a numerical model for bubble growth and then a dynamic model for simulation of Solution gas drive mechanism. The bubble growth is one of the most important steps in solution gas drive process. In bubble growth model, both hydrodynamic and diffusion forces are considered. The Navier-Stokes equation and the mass conservation equation have been used for considering the hydrodynamic and diffusion forces in this modeling, respectively.The assumptions used in the proposed model can be mentioned as gas- liquid equilibrium at the interface, instantaneous nucleation, Henry equilibrium relationship, constant density of the liquid, spherical gas bubble, and constant time depended pressure drop condition. Newton's method was used for linearization of equations. The major difference of this model with other models is that in the present model, real gas behavior is considered for gas treatment. In order to study the validation of the model, the model results are compared to the Pooladi-Darvish and Firoozabadi’s laboratory data and also with the Scriven’s model. The comparison shows that this model has good compatibility with the experimental data. In the next step, the effect of various parameters such as viscosity, diffusion coefficient, surface tension, initial bubble radius, depletion rate are studied on the bubble growth. The results show that in early times, the effect of hydrodynamic forces are more important than that of diffusion forces, so that it prevents the bubble growth, but finally, the growth is controlled by diffusion forces. Also, the results show that nucleation can occur before reaching to the minimum point on the P-V curve. And even after nucleation, reservoir pressure reduction will continue. In order to dynamic modeling of solution gas drive process, a dynamic model is proposed. There are three adjustable parameters in proposed model which is adjusted according to results of depletion tests. All of adjustable parameters have a physical meaning and are only function of the rock – fluid system and are independed of the experimental condition, specially the depletion rate. In the proposed model,A first order equation which is depended on gas saturation is used which is adjusted according to results of depletion rates. To account for the effect of viscous forces on gas mobility, relative permeability functions were introduced that not only depend on gas saturation, but also on local oil phase velocity and viscosity. Results showed that the average relative errors between experimental results and proposed model according to power law and exponential distribution of microbubbles are 4.5% and 6%, respectively. Also,Results was showed that this model has a good constancy with experimental results. Keywords: Solution gas drive, heavy oil, primary production, dynamic modeling, bubble growth.