The effects of steam on the combustion of oil on sand

This paper reports on a simultaneous differential thermal analysis (DTA)/evolved gas analysis (EGA) system developed to study in-situ oil-oxidation reactions. The oxidation of crude oil deposited on sand was studied, including catalysis by dissolved ionic compounds and reservoir sand materials and changes in the reaction mechanism caused by the presence of steam. The influence of steam was the most significant of these factors. In the presence of steam, the low-temperature-oxidation (LTO) exothermicity is similar to the dry case, but the oxygen consumption is dramatically reduced and, unlike the dry case, all consumed oxygen appears in the effluent carbon oxides. Participation of water and its radicals in the reaction mechanism is probably responsible for this change. These reactions should have a major influence on wet in-situ combustion.