المجلة الدولية للعلوم والتقنية

API gravity is a measure of how heavy or light crude-oil is compared with water. The measurement is a positive number that is inversely correlated to crude-oil specific gravity (the lighter the crude-oil, the higher the API gravity). that is important for crude oil trading and pricing. In the current study, Five were prepared with different sample crude oils blends from a very light crude oil Al-Wafa (W) and a light crude oil Al-Feal (F) as follows: Blend1 (20%W , 80% F ); Blend2 (35% W , 65% F ) ; Blend3 (55% W , 45% F ); Blend4 (70% W , 30% F) and Blend5 (85% W , 15% F) at a temperature15.6 °C. to obtain the experimental API gravity; to develop the reliable mathematical expression for the most important API gravity using non-linear regression and to analyze the predictive model results using standard statistical techniques. The predicted API gravity results have been validated in comparison with the experimental data gathered in the laboratory. High precision results between the predicted and experimental values have been noticed with overall average absolute deviation (AAD%) of (0.68%). From the predicted results in this study, it can be concluded that the performance of the developed model are excellent.