Cement cake properties in static filtration. Influence of polymeric additives on cement filter cake permeability
Résumé
During cementing operations on oil wells, fluid loss control additives are generally used to prevent water loss and to maintain a constant water-to-solid ratio in cement slurries. But their mechanism of action is not yet completely understood. An experimental procedure is described to discriminate between the two predominant phenomena which are the increase of interstitial water viscosity and the decrease of cement cake permeability. The influence of polymeric additives is studied and more particularly the efficiency of fluid loss control additives is related with a threshold concentration corresponding to the overlapping concentration of macromolecular chains in solution. © 1993.