In situ combustion in porous media: heterogeneities effects and upscaling of reactive systems. – INSICOMB

The study of combustion in porous media has a long history in the literature from the petroleum engineering perspective. With the decrease of resources in the past decade and a high rise of barrel prices, non conventional resources have encountered a higher interest because they now represent the main part of the existing resources. One of the significant difficulties in the application of experimental and theoretical results to natural and engineering systems is that the phenomenon of combustion is very difficult to upscale because of the non linearity of the reactive terms and also of the strong coupling existing at the local scale between heat and mass transport. Part of the difficulty in mechanistically representing the species transport at the field scale is the enormous disparity between the largest and the smallest length scales of interest from grain combustion to field phase displacement). One method to address the disparity of scales is to conduct some forms of upscaling process that seek to only maintain the important features of the physical or chemical processes expressed at the smallest scales of the problem when applied at the largest scales of interest. Previous studies developed by Debenest (2003) and Elayeb (2008) and by our research teams have led to the determination of thermochemical data bank that we can use at the larger scale but under certain simplifying assumptions (homogeneous materials, no variations of density, diluted species).We propose in this project to continue this approach from the grain scale to the scale of the porous medium itself by considering full kinetic model at the smallest scale and the coupling between fluid flow, solute transport and thermal transport, inherent to any in situ combustion scenario. Experimental studies of combustion in a model porous medium will be performed and will provide data which will be used to validate theoretical developments. The modelling step will be performed at several scales (grain, pore and darcy scale) in order to better understand phenomena involved and compare theory and experiment. Ultimately, a first attempt at comparing theoretical developments and field-scale data will be performed from Albi tube experiments.