Enhanced oil recovery (EOR) is drawing increased attention due to the sharp increase in demand. In order to improve EOR there is a need to understand the electrokinetic behaviors of polyelectrolytes in complex fluids as they penetrate throughout constrained and tortuous pathways. In our research, poly-diallyldimethylammonium chloride (poly-DADMAC) was used as a probe molecule to understand factors affecting penetration of polyelectrolyte into small pores. Dialysis was used to selectively remove relatively low-mass fractions of polyelectrolyte, in order to narrow the broad molecular mass range of poly-DADMAC samples. Streaming potential tests (Streaming Potential Jar) were used innovatively to help understand polymer diffusion and adsorption at various ionic strengths on external surface and in nanopore networks. Factors influencing the streaming potential and polyeletrolyte diffusion such as time, molecular mass, concentration, temperature, etc. will be discussed.