On-chip porous media: Porosity and permeability measurements

• Published in: Chemical engineering science 2013-08, Vol.99, p.274-283
• Main Authors: Joseph, Jerry, Siva Kumar Gunda, Naga, Mitra, Sushanta K.
• Format: Article
• Language: English
• Subjects: Chemical engineering; flow resistance; image analysis; IP (Internet Protocol); Media; Microfluidics; Networks; oil fields; oils; On-chip porous media; Permeability; Porosity; porous media; Pressure drop; Throats
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2013.05.065

In porous media, accurate determination of petrophysical properties such as effective porosity and permeability are important to understand the porosity–permeability relationships that help in improving the oil extraction mechanisms. Measuring porosity and permeability for on-chip porous media is difficult due to their small length scales. Hence in the present work, we conduct experiments to calculate the effective porosity and permeability of on-chip porous media containing different pore-networks. Four different types of on-chip porous media varying in number of pore bodies and pore throats are fabricated in this work. Porosity for each on-chip porous media is determined by using image analysis technique. Absolute permeability is estimated by measuring the pressure drop across the pore network and applying Darcy's law. The pore sizes of the networks range from 40μm to 70μm and the porosity of the on-chip porous media varies from 0.39 to 0.67. The flow resistance in the networks, measured by the quantity ΔP/Q, is found to decrease with the increase in Darcy number (K/h2). The permeability values range between 2.66±0.06 and 15.93±0.55 Darcy (2.625×10−12±0.059×10−12 and 15.72×10−12±0.542×10−12m2). It is found that as the number of pores and throats in on-chip porous media increases, the porosity increases as expected resulting in approximately one order of permeability increase. The results of this study would help in understanding the porosity and the permeability values in on-chip porous media that are miniaturized versions of oil reservoirs, which can be effective in understanding pore scale porosity–permeability relationships. [Display omitted] •Conducted experiments to calculate the effective porosity and permeability of on-chip porous media.•Effective porosity is determined by using image analysis technique.•Permeability is estimated by measuring the pressure drop across the pore network and applying Darcy's law.•The flow resistance in the networks is found to decrease with the increase in Darcy number.•Quantification of porosity and permeability would help in future studies of pore-scale transport in reservoir engineering.