Hydrophobically Modified Sulfonated Polyacrylamides for IOR: Correlations between Associative Behavior and Injectivity in the Diluted Regime Polyacrylamides sulfonés modifiés hydrophobes pour la RAH (IOR) : corrélations entre le caractère associatif et l’injectivité en régime dilué

We report new experimental correlations between the injectivity through polycarbonate membranes and associative properties of random Hydrophobically Modified Water Soluble Polymers (HMWSP) with sulfonated polyacrylamides (SPAM) backbones and variable compositions in hydrophobic units. The investigations are focused on both their associative behavior in the diluted and semi-diluted regime and their injectivity under frontal filtration conditions in the diluted regime. Results from viscosimetric and dynamic light scattering measurements indicate the existence of thresholds in terms of amount (≥ 0.5 mol%) and mass (≥ C12) of alkyl hydrophobic units above which interchain interactions arise. These interactions are evidenced by the presence of multichain aggregates in diluted solutions and by enhanced thickening abilities in semi- diluted solutions. The filtration study was performed with capillary pore membranes (track-etched) in the Darcy regime under constant -flow rate and high Jamming Ratio conditions. Results show that: injection of diluted solutions of HMWSP without interchaininteractions (i.e. with composition in hydrophobic units belowthe above mentioned thresholds) does not lead to significantmobility and permeability reductions as compared to theinjection of a reference Water Soluble Polymer (WSP); injection of diluted solutions of HMWSP with interchain interactions leads to significant mobility and permeability reductions; HMWSP-induced mobility and permeability reductions are essentially due to irreversible polymer adsorption on the pore walls and not to the formation of filter-cakes; HMWSP adsorbed layers thicknesses are limited by the effective stress applied by the solution’s flow in the pores. Nous présentons de nouvelles corrélations expérimentales entre l’injectivité dans des membranes de polycarbonate et le caractère associatif de Polymères Hydrosolubles Modifiés Hydrophobes (PHMH) ayant des squelettes de polyacrylamide sulfoné (PAMS) et des compositions variables en unités hydrophobes. Cette étude concerne, d’une part, la caractérisation du caractère associatif des polymères en régime dilué et semi- dilué et d’autre part, leur injectivité lors de filtrations frontales en régime dilué. Les résultats de viscosimétrie et de diffusion dynamique de la lumière révèlent l’existence de seuils en termes de quantité (≥ 0,5 mol%) et de masse (≥ C12) des unités hydrophobes alkyles, au-delà desquels des interactions intercha nes apparaissent. Ces interactions se traduisent par la présence d’agrégats dans les solutions diluées et par un pouvoir épaissi