Combustion/oxidation behavior of athabasca oil sands bitumen

Oils that are potential candidates for in situ combustion recovery processe s are often screened by means of their oxidation characteristics: in partic ular, the kinetics of the ignition process and the transition from low-temp erature to high-temperature oxidation through what is known as the "negativ e temperature gradient region." These characteristics are readily studied i n ramped-temperature oxidation tests, which involve the controlled heating of recombined, oil-saturated cores in a one-dimensional plug flow reactor u nder a flowing stream of air (or oxygen-containing gas). The purpose of the se tests is to study the global oxidation behavior and reaction kinetics un der controlled conditions, with the end purpose of providing realistic data for incorporation into a numerical simulator which can be used to predict field performance. A ramped-temperature oxidation apparatus was used to conduct a detailed, tw o-year parametric study of the oxidation characteristics of Athabasca Oil S ands bitumen. The text matrix involved various levels of pressure, gas inje ction rate, oxygen content of the injected gas, and maximum ramp temperatur e. This paper dei tails the principal findings for the 45-test study; espec ially the need to maintain high reaction temperatures (>380 degrees C) in o rder to mobilize and produce heavy oils under conditions of dry in situ com bustion. Design considerations and operational guidelines for successful fi eld projects arising from the results of this study are also discussed.