oil recovery. The oscillatory shear and flow shear behaviors of Xanthan are important to oil flooding. The
oscillatory shear relates to molecular motions, while flow shear reflects flowing characterization. In oscilla-
tory shear mode, the storage modulus, loss modulus and tan
has been measured. Calculating relaxation spectra through storage modulus, we found that the peak of segments’ relaxation heads to smaller relaxation
time side. Also, the quantity of relaxation units increases as concentration increases. However, the relaxation
time spectra are less affected by salinity. In flow shear mode, the relationship between shear rate and viscos-
ity has been investigated. As concentration or salinity increases, the pseudoplastic of Xanthan solutions
becomes more obvious. Furthermore, primary normal stress differences of Xanthan semi-diluted solutions
lightly increase at first then sharply decrease as shear rate increases. This abnormal phenomenon may refer
to wall slip.