Abstract:

The tests for the flow of a partially hydrolyzed polyacrylamide in three different sand packs have been conducted in this paper, The viscoelastic effect is found to exist not in compacted corundum sand cores sintered with aluminium phosphate but in quarts sand cores cemented by cement and epoxy resion, This phenomenon is believed to relate to the pore structure and permeability o} cores, For sand cores showing the viscoelastic effect，on the basis of Kelvin model，a mathematical model has been given for descibing the restoring deformation caused by polymer molecules rate fined in porous media. This model shows that pressure being stable，the change of flow rate with time accords with an exponential reaction when the cores are washed by the water until flow rate becomes constant and then the pressure is let to reduce. And the validity of this model is analyzed in this paper as well.

Key words: Viscoelasticity, Polymer, Mathematical model, Porous structure, Permeability