High-Pressure Ignition of Oil Sands Samples in Oxygen Atmospheres Containing Various Concentrations of Diluents

In-situ recovery of oil from oil sands deposits by combustion requires the injection of vast quantities of oxygen into the bed of deposits. Accordingly, there is a need to establish the ignition characteristics of high-grade Athabasca oil sands in environments containing pure oxygen at high-pressure and including the role of the presence of various diluents with the oxygen. A high-pressure constant volume bomb with a water calorimeter was employed as the test apparatus over the pressure range of 0.1 MPa to 4.0 MPa at ambient temperature. The role of the presence of the diluents, helium, nitrogen and carbon dioxide, with the oxygen, was also considered. Controlled ignition was achieved by employing electrically fusable nickel-chromium wire looped around the sample. Moreover, the presence of an ignition promotor such as benzoic acid was also considered. The paper presents the results of an experimental program that examined the effects of changes in the pressure, amounts of diluents and ignition energy on the ignition limits and subsequent combustion processes at ambient initial temperature. Moreover, the morphological changes to the samples at various stages of the process were also examined and discussed.