A Method of Making Two-dimensional Glass Micromodels of Pore Systems

Abstract

Two-dimensional micromodels of pore systems can be made in glass by use of a photo-imaging technique followed by chemical etching of the glass. Th'e method is a modification of one usedfor making printed circuits in the electronics industry. Pore systems with many thousands of individualelements ofspecifiedgeometry and arrangement can be fabricated. Such models are useful for observing the ef-fects of pore and fluid variables on the trapping and subsequent mobilization of residualphases during secondary and ter-tiary recovery processes. Introduction This paper describes a method for mak-ing transparent, two-dimensional M. McKellar micromodels of pore systems in glass. The displacement of one fluid by ano-ther in a porous medium, say %A,ater displacing oil in a reservoir rock, is af-fected by the geometry and surface pro-perties of the pores in the medium, the properties of the fluids and their interac-tions with each other and the solid sur-faces, as well as on the forces acting on the system. . The complex interactions among i-nov-ing multiphase fluids and porous niedia can be observed conveniently in trans-parent, two-dimensional micromodels and this can provide a better underst@and-ing of the processes.The advantage of two-dimensional models over other idealized porous media, such as packs of glass beads, is that the geometry and topology of the Malcolm McKellar, P.Eng., is currently a . system can be specified precisely. A disadvantage is that three-dimensional networks have topologic properties not shared by two-dimensional networks.For example, bicontinua cannot exist in two dimensions(l). Attempts have been made in the past to mechanically scribe a pattern on wax-coated glass and to etch this pattern with hydrofluoric acid(2). However, 'such a process relies on the manual dexterity of the model maker and does not lend itself to making complex or repetitive patterns. Others have used mono-layer packs of glass beads successfully(3,4), but such systems do not allow precise control of pore geometry nor wide variability of pore geometry within a single system. Bonnet and Lenormand(5) and Mahers et ai. (6) (1981) produced micromodels in nylon film using a photo-etching pro-cedure similar to one commonly used for making printing plates. The advantage over previous methods is that large and complex models composed of many thou-sands of pores of specified geometry and arrangements can be photo-reduced to give pores of sizes approaching those commonly found in reservoir rocks.The technique described in this paper uses photo imaging followed by chemical etching in glass and has the limitation that pores less than about 20 /Am in radius are difficult to etch with precision. However, in the case of pores bounded by glass, the roughness and wettability are more easily controlled than in models with surfaces of nylon or resin.The method is similar to one used for making printed circuits in the electronics industry, but modification is necessary because the available photo resists cannot withstand exposure to hydrofluoric...

Experiments on transport of hydrophobic particles and gas bubbles in porous media

“…The experiments were conducted in glass models (McKellar and Wardlaw, 1982;Goldenberg et al, 1987) consisting of glass plates with etched channels and large voids. The channels have mean depths and widths of approximately 1 mm and intersect at 90 ~ with approximately 3 mm spacing.…”

Pore-Scale Monitoring of Wettability Alteration by Silica Nanoparticles During Polymer Flooding to Heavy Oil in a Five-Spot Glass Micromodel

“…This 2-D pattern from the thin section was drawn using Corel Draw software, and this pattern was etched onto the glass by utilizing acid etching technique (Mckellar and Wardlaw 1982;Dehghan et al 2010;Jamaloei and Kharrat 2010) to create a synthetic porous medium of desired morphology. The 2-D pattern of the sand stone thin section is shown in Fig.…”

Percolation as a Basic Concept for Macroscopic Capillarity

“…Extensive experimental and theoretical studies of this simple phenomenon exist (Avraam and Payatakes 1999;Gardescu 1930;Jamin 1860;McKellar and Wardlaw 1982;Øren et al 1992;Oxaal 1991;Oxaal et al 1991;Payatakes 1982). It is, therefore, surprising that the concept of hydraulic percolation has been neglected in the modeling of two phase flow until 10 years ago (Hilfer 1998).…”