An Experimental Investigation of Water Influence on Dry Forward In-situ Combustion

In-situ combustion (ISC), also known as fire flooding, is not a new thermal enhanced oil recovery (EOR) technique. It is a potential alternative for heavy oil production when other thermal EOR methods are not adequate in certain reservoir conditions. A number of successful ISC application examples have been amply covered in the literature; however, the technique is still not widely used. Additional research on the influence of heterogeneities on ISC performance is required to improve predictability of this promising EOR technique.

To investigate the influence of initial water saturation on ISC performance, seven combustion tube experiments were conducted. The experimental investigations were performed on a Canadian bitumen sample (7.5 oAPI) from the Peace River region. During the experimental runs, initial bitumen saturation varied between 31.23% and 54.86%. Initial water saturation varied between 0% and 36.87%.

Temperature distribution along the combustion tube and effluent gas composition were recorded for each run and further analyzed. ISC dynamics were also investigated in terms of liquid production and postmortem analysis. Combustion front dynamics were interpreted with a CT scanner and a numerical simulation was used to obtain a chemical reaction scheme for one of the experiments.

The results showed that initial water saturation is a critical parameter to determine the success of dry forward combustion.