(163a) Two Dimensional Acoustic Mapping of Fluid Transport in Porous Media – Oil Production Technology Development Applications

Two Dimensional acoustic mapping of fluid transport in porous media – oil production technology development applications

Marc Cassiede and John M. Shaw, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Canada

Abstract. Existing and proposed process concepts based on hydrocarbon and non-hydrocarbon injection into hydrocarbon reservoirs for enhancing production impose a need for better understanding of diffusive mass transfer phenomena in porous media at the pore scale. A clear understanding of active diffusion mechanisms [1] and accurate mutual diffusion rates [2] underlie the quality of reservoir management and hydrocarbon production models. For example, Athabasca bitumen and other high-mean-molar-mass and structured organic materials exhibit complex phase behaviors at the nano- and micro- meter length scales [3,4]. These fluids comprise well-dispersed nanoscale asphaltene-rich phase domains and maltene-rich phase domains that undergo phase transitions in a largely independent manner. The controlling diffusion mechanism in these fluids was recently shown to be composition dependent [1]. Both Fickian and Single File diffusion mechanisms are active. As these resources often arise within limestone or sandstone formations, the presence of micro and nano channels in these media is expected to impose additional constraints on the composition ranges where one or the other or both diffusion mechanisms are active and on observed diffusion rates. Detailed knowledge of transport processes in these porous media and diffusion between injected fluids and hydrocarbon resources in particular comprise crucial and needed process knowledge gaps. Real time measurement of local composition and flow in petroleum reservoir rocks is challenging. A high resolution acoustic technique based on phased array technology has been developed [5] where two multi-element acoustic sensors are used in transmission mode to record times of flight of acoustic waves that propagate through a medium placed between pairs of transmitter-receiver sensors located along the probes. Automated data acquisition and data processing procedures permit the generation of short time interval two-dimensional speed of sound maps. Illustrative near-pore-scale real-time imaging results showing imbibition front movement and mutual diffusion of light hydrocarbons and Athabasca bitumen in natural porous media are presented and discussed.

[1] M. Alizadehgiashi and J. M. Shaw, Fickian and non-Fickian diffusion in heavy oil + light hydrocarbon mixtures, Energy Fuels, 29 (4), 2177-2189 (2015).

[2] H. Fadaei, J. M. Shaw, D. Sinton, Bitumen-Toluene Mutual Diffusion Coefficients Using Microfluidics, Energy & Fuels, (27) 2042-2048 (2013). 

[3] A. Bazyleva, M. Becerra, D. Stratiychuk-Dear, J. M. Shaw, "Phase behavior of Safaniya vacuum residue", Fluid Phase Equilibria, Volume 380, 25, 28-38 (2014).

[4] S. Reza Bagheri,  A. Bazyleva,  M. R. Gray, W. C. McCaffrey, and J. M. Shaw, Observation of Liquid Crystals in Heavy Petroleum Fractions, Energy & Fuels, 24 (8) 4327–4332 (2010).

[5] M. Cassiède and J. M. Shaw, Non-intrusive, high-resolution, real-time, two-dimensional imaging of multiphase materials using acoustic array sensors, Rev. Sci. Instrum. 86, 044902 (2015).