Omar, A.E., Desouky, S.M. and Karama, B., 1991. Rheological characteristics of Saudi crude oil emulsions. J. Pet. Sc,. Eng., 6: 149-160. Rheological characteristics of Saudi crude oil emulsions were measured with a Brookfield viscometer at temperatures of 10 degrees, 20 degrees, 30 degrees and 40 degrees C. The Saudi field crude oils used in the present study were: heavy, medium, light and extra-light. The emulsion constituents were crude oil, brine, emulsifier (Triton X-100) and dilute hydrochloric acid. The measured data were first classified into two groups for Newtonian and non-Newtonian fluids. The results showed that the non-Newtonian emulsions exhibit pseudoplastic behavior and their rheological characteristics can be described by the power-law model. Then, the effect of dispersed phase (oil) concentration and temperature on the rheological behavior of the emulsions were thoroughly investigated using statistical analysis (t-test).