Investigating the Influence of Heavy Oil Recovery by In Situ Combustion during Air Injection as EOR Technique

Journal of Applied and Emerging Sciences Vol (10), Issue (01) [75] Abstract--Heavy oil is one of the most useful energy resources specially in the times of crises when other resources are not present in profusion. However, Occurrence of heavy oil in unconsolidated sands is one the most challenging factor to recover the heavy oil. Therefore, in this study the main focus is derived towards the extraction of heavy oil with optimistic procedure called air injection. For the research, a reactor assembly was developed for the experimental work on air (21% oxygen) injection into heavy oil (12.59 °API) reservoir. Total 13 kinetics runs were conducted on unconsolidated cores by varying the parameters involved system pressure, flow rate (air flux), oxidation temperature (heat input), and rock formation (sand matrix). It was found that the process is very dependent on operating conditions employed, as oxygen consumption rate was very dependent on air flux. Increase of air flux from 15.19 to 22.78 m/m-hr resulted in slightly increasing rates of oxygen consumption over the temperature range under investigation. The temperature difference also shows great effect on the high temperature oxidation. The pressure and porous media also have great impact on the combustion behavior. The influence of individual parameter was obtained from analysis of the inlet oxygen and composition of flue gases from the combustion cell. Indeed, the oxygen conversion was too less to evaluate the kinetic data at temperature less than 250 °C while for oxidation reactions, the oxygen statistics analyzed from temperature above than 350 °C. The experimental results reveal that the average maximum peak temperature was 440 °C, and the oxidation reaction process at high temperature was very effective in terms of produced carbon oxides with an average percentage of 9.5% CO2, 5.5% CO in flue gases. Oil displacement was observed from the analysis of flue gases, consequently; incremental oil recovery was achieved between 56%-80% under high temperature oxidation (HTO) conditions.