Oxidation of light crude oil in porous media

Experimental results on the oxidation reaction kinetics in the forward combustion oil recovery process are presented. A total of 20 runs were made where in a stationary thin layer of unconsolidated sand was burned at non isothermal condition with a ramp of 5 degree C per min from room temperature (40 degree C) to 500 degree C in the combustion cell. Individual runs were made by changing various sand pack properties to permit determination of the effect of matrix upon the oxidation reaction. An expression was obtained for the burning rate of carbon as a carbon concentration, combustion temperature with 21% oxygen concentration. The carbon-burning rate for four types of sand pack indicated in a first order reaction with respect to carbon concentration. The effect of combustion temperature on the reaction rate constant matched the Arrhenius equation. The activation energy was not similar for these four types of sand pack examined. The activation energy decreased for porous media containing fine sand. The rate of oxidation of crude oil at reservoir temperature was found to be significant. (author)