Gelation Performance and Microstructure Study of Chromium Gel and Phenolic Resin Gel in Bulk and Porous Media

Abstract

Polymer gel has been widely used to control excessive water production in many mature oilfields; however, there still exist some problems concerning the differences between gelation behavior in bulk and porous media. In this paper, the gelation time and microstructures of chromium gel and phenolic resin gel in bulk and porous media were studied. Results showed that for chromium gel, the initial gelation time in porous media was about 2.5–3.5 times of that in bulk and final gelation time in porous media was about 6.0–7.0 times of that in bulk. While for phenolic resin gel, the initial gelation time in porous media was about 1.0–1.5 times of that in bulk, and final gelation time in porous media was about 1.5–2.0 times of that in bulk. The morphology of chromium gel and phenolic resin gel in bulk were dendritic shape structure and 3D network structure, respectively. However, the morphology of chromium gel and phenolic resin gel in porous media were both dense gel membranes at low magnification. While at higher magnification, compared with the branchlike cluster structure of chromium gel in porous media, the network of phenolic resin gel was more developed. The experimental results can provide the basis for determining well shut off time and reveal the differences of gel microstructures between the chromium gel and phenolic gel in bulk and porous media.