Polymer Suspensions - New Alternatives in Oilfield Chemistry

The different polymers are available as concentrated solutions, gels, crushed powders, beads, and partially pre-crosslinked solid microgels. Applying special dispensers and slicing units with sophisticated apparatus for filtering and relaxation storage, all solid polymers often cause serious formation damage due to their poor and slow solubility in water. Therefore, searching such formulations, which eliminate the mentioned drawbacks, may contribute significantly to improvement of polymer technologies. One of the possible options is the application of “liquid” polymer. The “liquid” polymer is a stabilized suspension of bead-like polymers in water-miscible solvent with active content of 40-45%. The polymer beads are monodispersed and have narrow size distribution (<1 mm). Usually tenside mixtures are used to stabilize these dispersions. The laboratory studies focused on laser particle sizing, dissolution kinetics, colloid chemical, rheological, and flow properties in porous media (sandstone). Based on the experimental findings, it was found that “liquid” polymers readily and rapidly dissolve in water (within less than 2 h), the solutions are free of microgels and mechanical entrapment was minimal even in low permeable (<25 mD) sandstone cores. In addition, they decrease the surface tension to 30-35 mN/m, the interfacial tension lowering was also min. one order of magnitude, and they proved to be compatible with other chemicals. It was also proved that the rheological and flow properties were identical or very similar to those data obtained by conventional solid polymers having similar structure. The extra beneficial properties of “liquid” polymers in all oilfield chemical applications may significantly contribute to improvement of polymer-based technologies; meanwhile the surface facilities can be simplified, or completely eliminated (e.g. the “liquid” polymer can be directly injected to the wellhead in “smart” water flooding). In addition, the chemical cost of commercial products is practically the same as of the solid polymers. Earlier the “liquid” polymer was successfully applied in water shutoff and conformance treatments in Oman using silicate/polymer gel, and recently for water shutoff treatments in Hungary using silicate/polymer solution with nanoparticle (silica) fillers. Based on the laboratory studies and successful filed pilots, the “liquid” polymers may open new vistas in all oilfield applications.