An experimental investigation of forward combustion oil recovery

Abstract

Although the forward combustion oil recovery process has proved to be a successful method of obtaining oil production from predominantly heavy oil reservoirs, the process is not fully understood. The experimental data obtained on this process to date have been the result of numerous field tests and laboratory combustion tube experiments. The objective of this research, based on laboratory combustion tube experiments, was to evaluate the liquid and solid content of the pore space ahead of the maximum axial combustion tube temperature. Particular emphasis was directed to the region between the maximum axial combustion tube temperature and the downstream end of the steam plateau. During this investigation, 30 combustion tube experiments were performed utilizing a number of combustion tube sizes, of which the majority were 43-45 inches in length and 2-1/2 inches in diameter. Liquid saturations from the peak axial combustion tube temperature to the downstream end of the steam plateau were calculated for several runs on the basis of fluid production. Several runs were terminated after the burning front had advanced about one third of the length of the combustion tube. Then the combustion tube was cut open and selectively sampled. The samples recovered were analyzed to estimate saturation distributions, atomic hydrogen-carbon ratios and the hydrocarbon content of the sand matrix. Differential thermal analyses were run on samples taken from terminated combustion tube runs in an attempt to establish the properties of those materials in the region immediately downstream from the maximum axial temperature. Combustion calculations were performed for each of the successful tube runs. ...