An automated microfluidic system for the investigation of asphaltene deposition and dissolution in porous media

Abstract

Design of an automated packed-bed microfluidic system with in situ Raman spectroscopy to better understand the self-assembly of asphaltenes in porous media.

Lab-on-a-Chip Systems in Asphaltene Characterization: A Review of Recent Advances

“…As an example, Chen et al studied the deposition and dissociation processes of asphaltene in porous media by integration of automated μPBRs with in situ Raman spectroscopy. 78 To conduct the experiments under an isothermal environment, the microfluidic device was attached to a thermoelectric heating source (see Figure 5a,b for a schematic diagram of the experimental setup and a photograph of the microreactors under in situ Raman spectroscopy). Herein, different syringe pumps were used to control the flow rates of n-heptane, asphaltenes in toluene solution, and xylene (for asphaltene dissolution) needed for deposition/dissolution studies.…”

“…The asphaltenes distribution in the packed-bed microchannels was determined by measuring the bed occupancy on the quartz surface. 78,79 Figure 5c summarizes the effect of temperature on the asphaltenes distribution and occupancy maps during deposition within a 20 min time frame. Based on the results, it can be inferred that, as the temperature increases from 25 to 65 °C, asphaltenes deposition occurs at a faster rate, as indicated by the high average occupancy (>0.8) even from the early time of deposition.…”

“…Nevertheless, the efficacy of xylene in dissolution of asphaltenes was deteriorated at higher temperatures due to the higher asphaltenes deposition and larger occupancy values, which, as a result, lowers the xylene distribution inside the microchannels. 78 Regarding the effect of surface wettability, Keshmiri et al fabricated glass micromodels to monitor asphaltene deposition dynamics as a function of solvent type and surface hydrophilicity/hydrophobicity. 48 The design of microporous media with parallel posts and a photograph of a microfluidic device filled with heated bitumen are presented in Figure 5d.…”

“…In addition to the effect of solvents on the deposition dynamics of asphaltenes, other experimental factors including temperature, microchannel hydrophilicity/hydrophobicity, and the presence of trace water in the system are shown to have significant effects on the asphaltene phase behavior. As an example, Chen et al studied the deposition and dissociation processes of asphaltene in porous media by integration of automated μPBRs with in situ Raman spectroscopy . To conduct the experiments under an isothermal environment, the microfluidic device was attached to a thermoelectric heating source (see Figure a,b for a schematic diagram of the experimental setup and a photograph of the microreactors under in situ Raman spectroscopy).…”

Screening High-Temperature Foams with Microfluidics for Thermal Recovery Processes

“…While the capital cost of microfluidic setup may be comparable to that of some conventional testing such as coreflood, the inherent speed and very low sample volume usage of microfluidic approaches derive their operational cost significantly lower than that of conventional methods. The precedent for microfluidic reservoir fluid analysis includes measurements of saturation point measurements, − solubility, , diffusivity, , solid deposition, − rheology, and nanoconfined fluid properties. − Microfluidics has also been extended to probe the pore-scale dynamics of various enhanced oil recovery processes for conventional and unconventional reservoirs. − Specifically for foam processes, a microfluidic device with different channel geometries (representative of SAGD reservoirs) was used to investigate the water–gas foam formation and fragmentation . The hysteresis of the foam generation and collapse has been evaluated and quantified as a function of gas/liquid volumetric ratio in a simple microfluidic channel .…”