On the relationship between pore size distribution and wettability alteration of carbonate oil reservoir rock

Abstract

Pore size distribution (PSD) and wettability are critical factors in controlling the sweep efficiency of reservoir fluids, particularly crude oil. The alteration of wettability from oil-wet to water-wet is a key concern when injecting water into reservoirs. This study evaluates two rock samples from different formations, each with distinct characteristics. The cores were imaged under various wettability conditions—dry, water-wet, oil-wet, and post-injection of a sodium dodecyl sulfate surfactant—using a core scanner, and the PSD was analyzed through computer image analysis core photo analysis software. The results show that altering the wettability of the rock surface leads to changes in the pore size distribution. Furthermore, the relationship between wettability and PSD was investigated using the contact angle measurement method. It was observed that as the surfactant concentration increased, the surface wettability of cores with larger pore sizes shifted from oil-wet to water-wet to a greater extent than in cores with smaller pore sizes.

Keywords

contact angle, core image analysis, pore size distribution, wettability

Document Type

Journal Article

Date of Publication

1-1-2026

ISSN

1091028X

Volume

29

Issue

5

Publication Title

Journal of Porous Media

Publisher

Begell House

School

Centre for Sustainable Energy and Resources / School of Engineering

Copyright

subscription content

Content Type

Metadata only

First Page

21

Last Page

36

Recommended Citation

Manshad, A. K., Azadehfar, H., Asl, F. O., Mohammadi, A. H., Iglauer, S., & Keshavarz, A. (2025). On the relationship between pore size distribution and wettability alteration of carbonate oil reservoir rock. Journal of Porous Media, 29(5), 21–36. https://doi.org/10.1615/JPorMedia.2025055475

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Link to publisher version (DOI)

10.1615/JPorMedia.2025055475