Experimental study of rheological behavior of foam flow in capillary tubes

Studies of foam flow in highly permeable porous media are still limited due to foam's complex behavior and discrepancies research. Specifically, it is unclear how flows capillary tubes what the effects material tube diameter are. We have investigated rheology pre-generated tubes. Experiments were carried out using two types tubes: hydrophobic (PTFE – polytetrafluoroethylene; FEP fluorinated ethylene propylene) hydrophilic (GT glass tubes). The was previously formed sand-pack by co-injecting a surfactant solution nitrogen gas. effect size on versus gas fraction (for fixed rate) rate fraction). A three-parameter Herschel-Bulkley model used describe Pictures GT taken determine mean bubble area image analysis. estimated wall-slip velocity compared results with bulk-foam an analytical expression for volumetric through circular observed shear-thinning all (FEP, PTFE, GT), successfully fitted its behavior. PTFE behaved as yield-stress fluid, while yield stress not also found that transition quality depends type diameter. show apparent viscosity higher (FEP tubes) than This explained being because difference surface roughness. corrected without wall slip matches calculated measured bulk better. Therefore we conclude considering important when studying media.