Simulation of In-Situ Combustion Process in Balol Pilot

Abstract

Abstract The In-situ Combustion (ISC) process has been successfully applied in the Southern part of Balol field for the last 21 years. This sector has oil of 300 cp viscosity and 15° API. The Pilot was initiated in 1990 followed by semi-commercialization in 1992 and commercialization in 1997. It has been instrumental in enhancing the oil recovery from 13% to 50%. The ISC process in the pilot stage has been modeled on the thermal simulator. At first, the 1-D Combustion tube experiment has been successfully modeled and history matched with single equation incorporating the oxidation of heavy oil. The reaction kinetics from Combustion tube model with suitable modification and the Equilibrium Constants obtained from the Equation of State (EOS) modeling of PVT experiments has been utilised to history match the ISC pilot performance. The ISC model calibrated from the history match of the actual data of the pilot shall enable in simulating the ISC process in the semi-commercial and the commercial phase. It would help in optimization of air injection rates, placement of air injectors, propagation of the combustion front, performance prediction and finally the ultimate recovery. The successful history match of the ISC process in the Pilot area in terms of water cut, liquid rates has enabled better understanding of the process. It was possible to obtain a good agreement for the propagation of the combustion front and the temperature distribution. The study has indicated that the ISC simulation on thermal simulator using single equation can be used as significant stepping stone in modeling the process in more detail using multiple equations and incorporating larger area.