An efficient way to increase oil production in heavy oil reservoirs is by the In Situ Combustion (ISC) process implementation. Part of the oil in place is oxidized, generating heat that increases mobility by reducing oil viscosity. The increase in oil production is associated with displacement mechanisms such as flue gas flooding, steam drive, viscosity reduction by oil swelling and temperature increase, among others. However, not all reservoirs are suitable for an ISC process. Therefore, prior to the implementation of an ISC project, the reservoir properties and reactive characteristics of oil should be evaluated.
The isoconversional principle is a technique to obtain information about oil oxidation characteristics, using the kinetic of the oil oxidation/combustion reactions. The isoconversional methods obtain the kinetic from different Ramped Temperature Oxidation (RTO) tests, usually three to five; this technique provides direct information of the effective activation energy. In addition, the technique can be used as a screening tool to identify good candidates to an ISC process and allow recognition of the number of dominant reactions to model the process in numerical simulators.
This paper presents the results obtained after applying the isoconversional principle in a Colombian heavy oil. Furthermore, a reaction scheme to model the process in a commercial numerical simulator is proposed. The reaction scheme was validated by matching the experimental results in a numerical thermal simulator.