Experimental and Numerical Pore Scale Study of Residual Gas Saturation in Water/Gas Imbibition Phenomena

Document Type: Research Article


1 Chemical Engineering Department, Amirkabr University of Technology, P.O. Box 158754413 Tehran, I.R. IRAN

2 IOR Research Institute, National Iranian Oil Company, P.O. Box 1969813771 Tehran, I.R. IRAN


Residual gas saturation is one of the most important parameter in determining recovery factor of water-drive gas reservoir. Visual observation of processes occurring at the pore level in micromodels can give an insight to fluid displacements at the larger scale and also help the interpretation of production performance at reservoir scale. In this study experimental tests in a glass micromodel were used to determine the influence of the capillary number and pore morphology on the residual gas saturation in gas–liquid two-phase flow. The saturation of the phases was determined through recorded images in the micromodel. 2D modeling and simulation of this process is presented in this study and simulation results are verified by comparing to experimental results where sufficient agreement was confirmed.  The simulation results indicate that pore morphology and capillary number have significant influence on the competition between frontal displacement and snap-off.  Frontal displacement leads to high recovery and snap off causes gas entrapment. It is concluded that increasing the pore and throat sizes, increasing the coordination number and increasing angularity (decreasing half angle) result in reducing the residual gas amount. The results also indicate that residual gas saturation is not only a function of petrophysical property and pore morphology, but also it depends on flow rate and the experimental procedure. Residual gas saturation does not change significantly when Nc is less than 10-7.


Main Subjects

[1] Geffen T., Parrish D., Haynes G., Morse R., Efficiency of Gas Displacement from Porous Media by Liquid Flooding, Journal of Petroleum Technology, 4: 29-38 (1952).
[2] Land C., Comparison of calculated with experimental imbibition relative permeability, Old SPE Journal, 11: 419-425 (1971).
[3] Kleppe J., Delaplace P., Lenormand R., Hamon G., Chaput E., Representation of Capillary Pressure Hysteresis in Reservoir Simulation, SPE 38899, "Proceedings of the SPE Annual Meeting", San Antonio, Texas, (1997).
[4] Suzanne K., Hamon G., Billiotte J., Trocme V., Distribution of Trapped Gas Saturation in Heterogeneous Sandstone Reservoirs, " Proceedings of the Annual Symposium of the Society of Core Analysts", Abu Dhabi, (2001).
[5] Chierici GL and Ciucci GM, Water Drive Gas Reservoirs: Uncertainty in Reserves Evaluation from Past History, Journal of Petroleum Technology, 19 (2): 237-44 (1967).
[6] Hamon G., Suzanne K., Billiotte J., Trocme V., Field-Wide Variations of Trapped Gas Saturation in Heterogeneous Sandstone Reservoirs, "In SPE Annual Technical Conference and Exhibition", Louisiana, (2001(.
[7] Delclaud J., Laboratory Measurements of the Residual Gas Saturation, In: "Advances in Core Evaluation II: Reservoir Appraisal: Reviewed Proceedings of the Second Society of Core Analysts European Core Analysis Symposium", 2: 431-451 (1991).
[9] Crowell D. C., Dean G., Loomis A., "Efficiency of Gas Displacement from a Water-Drive Reservoir", US Dept. of the Interior,Bureau of Mines, 6735 (1966).
[10] Bull Ø., Bratteli F., Ringen J. K. , Melhuus K., Bye A.L., Iversen J. E. , The Quest for the True Residual Gas Saturation–an Experimental Approach, "International Symposium of the Society of Core Analysts", Texas, USA, p. 1-12, (2011).
[11] Lenormand R., Liquids in Porous Media, Journal of Physics: Condensed Matter, 2: SA79 (1999).
[12] Blunt M. J., Scher H., Pore-level Modeling of Wetting, Physical Review E, 52: 6387 (1995).
[13] Mogensen K., Stenby E. H., A Dynamic Two-Phase Pore-Scale Model of Imbibition, Transport in Porous Media, 32: 299-327 (1998).
[14] Hughes R.G. Blunt M.J., Pore Scale Modeling of Rate Effects in Imbibition, Transport in Porous Media, 40: 295-322, (2000).
[15] Hekmatzadeh M., Dadvar M., Emadi M., Pore Network Modeling for Prediction of Residual Gas Saturation in Water Invasion Process, J. of Porous Media, 17: 503-520 (2014).
[16] Jamshidi S., Bozorgmehry R., Pishvaie M., An Irregular Lattice Pore Network Model Construction Algorithm, Iran. J. Chem. Chem. Eng. (IJCCE), 29(1): 61-70, (2010).
[17] Coxeter H. S. M., "Introduction to Geometry", John Wiley & Sons, 36-38 (1961).
[19] Al-Gharbi M. S., Blunt M.J., Dynamic Network Modeling of Two-Phase Drainage in Porous Media, Physical Review E, 71: 016308 (2005).
[20] Bernadiner M. G., A Capillary Microstructure of the Wetting Front, Transport in Porous media, 30: 251-265 (1998).
[21] Lenormand R., Zarcone C., Sarr A., Mechanisms of the Displacement of One Fluid by Another in a Network of Capillary Ducts, J. Fluid Mech, 135: 337-353 (1983).
[22] Vizika O. and Payatakes A., Parametric Experimental Study of Forced Imbibition in Porous Media, Physico Chem. Hydro Dyn, 11: 187-204 (1989).
[23] Oren P.E., Bakke S., Arntzen O.J., Extending Predictive Capabilities to Network Models, SPE Journal, 3: 324-336 (1998).
[24] Patzek T., Verification of a Complete Pore Network Simulator of Drainage and Imbibition, SPE Journal, 6: 144-156 (2001).
[25] Ransohoff T., Radke C., Laminar Flow of a Wetting Liquid Along the Corners of a Predominantly Gas-Occupied Noncircular Pore, J. Colloid Interface Sci., 121: 392-401, (1988).
[26] Zhou D., Blunt M. J., Orr F. M., Hydrocarbon Drainage Along Corners of Noncircular Capillaries , J. Colloid Interface Sci., 187(1): 11-21..0. (1997).
[27] Chatzis I., Morrow N., Measurement and Conditions for Entrapment and Mobilization of Residual, US DOE Final Report, DOE/BETC/3251-12 (1981