The present research has investigated the effect of microwave energy on improving the flow properties of heavy crude oil. The fragmentation of crude oil molecules was carried out with and without using 1 and 10 wt. % concentration of various types of H-donors like tetralin, cyclohexane, and naphtha.  Microwave power of 320, 385, and 540 W and radiation time 1-9 min, and temperature were studied. The kinematic viscosity and asphaltene content were measured for evaluation the improving of heavy crude oil.

   Results show that viscosity of crude oil decreased with increase H-donor concentration, a maximum percentage of viscosity reduction was10.63 % for tetralin at 6 min radiation time, while 8.67%, and 7.34% for cyclohexane and naphtha at 4 min respectively. The high H-donor polarity is the high viscosity reduction.

   The asphaltenes content of crude oil was decreased during microwave treatment process, a maximum percentage of reduction was 39.73% for tetralin at 6 min radiation time, while 34.40% and 46.29 % for cyclohexane and naphtha at 4 min respectively. The viscosity of crude oil was decreased with asphaltenes content decrease.

   The temperature of a crude oil was varied during the microwave treatment and it was depended on radiation time and radiation power and H-donor type.

   The best reduction of crude oil viscosity and asphaltenes content was achieved at a moderate radiation power385 W.