Impact of grain roughness on residual nonwetting phase cluster size distribution in packed columns of uniform spheres

Abstract

We imaged the pore-scale distribution of air and water within packed columns of glass spheres of different textures using x-ray microcomputed tomography after primary drainage and after secondary imbibition. Postimbibition residual air saturation increases with roughness size. Clusters larger than a critical size of about 15 to 40 pores are distributed according to a power law, with exponents ranging from τ = 2.29 ± 0.04 to 3.00 ± 0.13 and displaying a weak negative correlation with roughness size. The largest cluster constitutes 7 to 20% of the total residual gas saturation, with no clear correlation with roughness size. These results imply that activities that enhance grain roughness by, e.g., creating acidic conditions in the subsurface, will promote capillary trapping of nonwetting phases under capillary-dominated conditions. Enhanced trapping, in turn, may be desirable in some engineering applications such as geological CO 2 storage, but detrimental to others such as groundwater remediation and hydrocarbon recovery.

Shale Wettability: Data Sets, Challenges, and Outlook

“…However, caution must be taken during contact angle measurements as surface contamination and surface cleaning methods can lead to a significant bias in reported data . Moreover, contact angle is not a bulk measurement …”

“…The experimental methodology used for contact angle measurements is based on sessile drop or captive bubble configurations; these two approaches are most common in the petroleum industry. ,, More recently, micromodels are also used for contact angle measurement-associated microscale images; this literally works as a “lab-on-a-chip”, , while X-ray μ-CT imaging allows real-time localized contact angle measurements at the millimeter scale. , These methods have the advantage that the fluids reside inside a porous medium; however, experiments are more difficult and costly.…”

“…87 Moreover, contact angle is not a bulk measurement. 88 The experimental methodology used for contact angle measurements is based on sessile drop or captive bubble configurations; these two approaches are most common in the petroleum industry. 56,86,89 More recently, micromodels are also used for contact angle measurement-associated microscale images; this literally works as a "lab-on-a-chip", 90,91 ray μ-CT imaging allows real-time localized contact angle measurements at the millimeter scale.…”

“…56,86,89 More recently, micromodels are also used for contact angle measurement-associated microscale images; this literally works as a "lab-on-a-chip", 90,91 ray μ-CT imaging allows real-time localized contact angle measurements at the millimeter scale. 88,92 These methods have the advantage that the fluids reside inside a porous medium; however, experiments are more difficult and costly. 56 with permission from Elsevier.…”

Cryogenic Liquid Nitrogen Fracking Effects on Petro-Physical and Morphological Characteristics of the Sembar Shale Gas Formation in the Lower Indus Basin, Pakistan

“…14,64 In addition, this assessment has significant implications for the multiphase flow of hydrocarbons within oil and gas reservoirs and the associated residual saturation. 65 The surface topography of the thin section of shale before LN 2 treatment is displayed in Figure 6a. The 3D images taken using the AFM technique illustrate that the root-mean-square (RMS) surface roughness increases after the sample is exposed to LN 2 treatment at time intervals from 30 to 90 min (Figure 6b−d).…”