Microfluidic investigation of the deposition of asphaltenes in porous media

Chuntian Hu, and Ryan L. Hartman*

Department of Chemical and Biological Engineering, The University of Alabama, Tuscaloosa, Alabama 35487, United States, e-mail: rhartman@eng.ua.edu
The deposition of asphaltenes in porous media, an important problem in science and macromolecular engineering, was for the first time investigated in a transparent packed-bed microreactor with online analytics to generate high-throughput information. Residence time distributions of the packed-bed microreactor before and after loading with ~29μm quartz particles were measured using an inline UV-Vis setup. Stable packing of quartz particles with porosity of ~40% and permeability of ~500mD was obtained. The presence of the packing materials caused significant reduced dispersion under the same velocity via estimation of dispersion coefficients and the Bodenstein number. The damage of the packed-bed was more severe near the inlet, and as expected the flow rate was observed to influence the asphaltene deposition mechanism. At higher flow rates, hydrodynamic bridging resulted in significant pressure drops in shorter time scales and less asphaltenes being retained under the same dimensionless pressure drop. The innovation of packed-bed microfluidics for investigations on asphaltene deposition mechanisms bridges molecular, nano-, and micro-scale, mechanistic discoveries that could enhance the design of subterranean reservoirs for conventional and unconventional energy production.