Flow behaviors of polyacrylamide solution in brine through core.

In this paper, we studied the effects of the chemical structure and compositions of polymer and brine on the flow properties with the aim of mobility control. Five kinds of partially hydrolyzed polyacrylamides were used as polymer samples. We used brine which contained mono-valent (Na+, K+) or divalent (Mg2+, Ca2+) ions.We measured the flow properties of polymer solutions as apparent viscosity, screen factor, resistance factor and residual resistance factor and discussed the relation between each other. The results were as follows:(1) The resistance factor, residual resistance factor and screen factor, respectively, increased with a polymer molecular weight increase. From these results, it was confirmed that the resistance factors had a positive correlation with the screen factors.(2) The resistance factor and apparent viscosity decreased with a brine concentration increase. These behaviors become extremely remarkable in divalent ion solutions. However, the screen factors decreased relatively little and the residual resistance factors were almost constant in these brines.(3) The resistance factor increased at a frontal velocity of over 5ft/day, but there was a reverse tendency at a rate less than 5ft/day.