The rise and dissolutions of CO2 or CH4 particles (bubbles or drops) from deep ocean is important for understanding the fate of the release of these components from marine sediments. In this paper is presented a complete fluid-dynamic and dissolution model that accounts also the effect of the presence of gas hydrates at the interface of the particles. The rise velocity is a result of the effect of the particle deformation on the drag coefficient. The proposed model for evaluating the particle rise velocity has not be developed specifically for the case of CO2 and CH4 release here analyzed, but it is general for liquid-liquid or gas-liquid systems. The comparison of the model with experimental data reported in the literature shows a good agreement.