Microfluidic Devices for Characterizing Pore-scale Event Processes in Porous Media for Oil Recovery Applications

Abstract

Microfluidic devices are versatile tools for studying transport processes at a microscopic scale. A demand exists for microfluidic devices that are resistant to low molecular-weight oil components, unlike traditional polydimethylsiloxane (PDMS) devices. Here, we demonstrate a facile method for making a device with this property, and we use the product of this protocol for examining the pore-scale mechanisms by which foam recovers crude oil. A pattern is first designed using computer-aided design (CAD) software and printed on a transparency with a high-resolution printer. This pattern is then transferred to a photoresist via a lithography procedure. PDMS is cast on the pattern, cured in an oven, and removed to obtain a mold. A thiol-ene crosslinking polymer, commonly used as an optical adhesive (OA), is then poured onto the mold and cured under UV light. The PDMS mold is peeled away from the optical adhesive cast. A glass substrate is then prepared, and the two halves of the device are bonded together. Optical adhesive-based devices are more robust than traditional PDMS microfluidic devices. The epoxy structure is resistant to swelling by many organic solvents, which opens new possibilities for experiments involving light organic liquids. Additionally, the surface wettability behavior of these devices is more stable than that of PDMS. The construction of optical adhesive microfluidic devices is simple, yet requires incrementally more effort than the making of PDMS-based devices. Also, though optical adhesive devices are stable in organic liquids, they may exhibit reduced bond-strength after a long time. Optical adhesive microfluidic devices can be made in geometries that act as 2-D micromodels for porous media. These devices are applied in the study of oil displacement to improve our understanding of the pore-scale mechanisms involved in enhanced oil recovery and aquifer remediation.

Microfluidic devices, materials, and recent progress for petroleum applications: A review

“…F I G U R E 1 Assembly of a laminated packed bed. Extracted with permission from Bowden et al [30] PDMS microdevices have been evaluated in several studies such as EOR, [16,[69][70][71][72] electrocoalescence of aqueous droplets in crude oil, [73] relative permeability in coal, [74] migration of fine particles in single-phase and multi-phase flows, [75] optical measurements of oil release from calcite, [62] influence of chemical additives on water-based heavy oil mobilization, [76] and others. These studies demonstrate the versatility and wide range of applications of PDMS microfluidic devices in the petroleum industry, allowing researchers to investigate various fluid behaviours and phenomena under controlled conditions.…”

Inhibiting Asphaltene Deposition Using Polymer-Functionalized Nanoparticles in Microfluidic Porous Media

“…Microfluidic Device Fabrication. The microfluidic devices were fabricated using NOA-81 material (Norland Optical Adhesive), a thiolene-based photocurable polymer, 30 according to the previously published procedures by Vavra et al 31,32 The microfluidic device in this study is a single-permeability porous media made up of round posts (Figure 1a), with a porosity of 91.6%. This microfluidic design can highlight asphaltene deposition from the complex fluid flow within the near-wellbore region.…”

Microscopic Particle Image Velocimetry Analysis of Multiphase Flow in a Porous Media Micromodel

“…Furthermore, with photolithography, a wide range of optically clear materials are available for micromodel fabrication, including polydimethylsiloxane (PDMS), 8 photoresist, 9 and Norland optical adhesive. 10 The optical transparency of micromodels fabricated using the materials described above enables the systematic study of flow characteristics inside the pore structures. For example, microscopic particle image velocimetry (μPIV) is a velocity measurement and flow visualization technique that serves as the basis for many porous media micromodel studies.…”