Masoud Mohammadi - Master Science of Hydrocarbon Reservoir Engineering from Science and Research Branch of Islamic Azad University, Tehran, Iran. He is now with the engineering department of the National Iranian Gas Company (NIGC) – Fars Province Gas Company
Riyaz Kharrat - Petroleum Department of Petroleum University of Technology, Iran. He is now with the Department of PetroleumEngineering, Montanuniversität Leoben University, Parkstraße ۲۷, ۸۷۰۰ Leoben, Austria
Arash Yousefy - Oil and Gas Engineering Department, DIATI, Polytechnic University of Turin, Turin, Italy. He is now with ITT SpA asProject Engineer

Heavy oil in complicated reservoir has the potentialto be an energy source for the next generations, since a long timeago Light oil reservoirs have been depleted more easily than theheavy oil reservoirs. In situ combustion process can be reckonedas one of the most practical approaches in enhanced oil recoveryand development of these types of reservoirs. For this purpose, air(usually hot air) is injected in the reservoir to achieve ignition andcombustion front maintenance. Then it will push heated oils andfront advancement toward producer wells. In this paper, asimulation model of Kumar’s combustion tube was applied, tunedand validated using experimental data presented by Kumar.Further investigation of heterogeneity effects on Top-Down In-situcombustion process was done through modification of a basicmodel to heterogeneous models including Areal and Vertical types.Also, various parameters such as average temperature of thesystem, cumulative oil and water production, diffusion and fluidsaturation were investigated. Results revealed the significant roleof permeability variation on ISC process. Both of Vertical andAreal types of heterogeneity can effect ISC process. Simulationresults demonstrate that the vertical heterogeneity has a minoreffect on front’s shape, cumulative oil and water and gassaturation distribution; however, the front advancement andvelocity influenced by vertical heterogeneity considerably. Incontrast to vertical type, the Areal heterogeneity can effect on anextensive range of parameters such as front’s shape and velocity,gas distribution, cumulative fluid. The simulation results confirmednegative effect of Areal heterogeneity on In-situ combustionprocess. In other words, the results indicate that the orientation ofwells and layers play an important role in the ISC process.

In-situ Combustion, Heterogeneity, Combustion Front, Combustion Tube, Average Temperature