The placement of polymer gels in water producing reservoir layers is one of the chemical options to reduce or totally shutoff water production. A correct determination of the optimum placement depth of the polymer gel treatment requires understanding of gel strength behavior when it is subjected to a pressure difference during production.

This paper reports a study on the behavior of an organically crosslinked polymer system in porous media. The work includes experiments and a mathematical model. The experiments were performed using natural sandstone cores at temperatures ranging from 80°C to 120°C. The gel strength was determined under different conditions (gel composition, permeability, temperature and treatment volume). Also the behavior of the gel before and after gel failure was studied.

The data was successfully interpreted considering three main effects: (a) gel compressibility, (b) micro-flow through the porous gel and porous medium and (c) post-failure macroflow. The model takes into account the above three effects and is solved analytically to yield an expression of the evolution of the pressure, which is in excellent agreement with the experiments.

You can access this article if you purchase or spend a download.