Among energy supply resources, crude oil has special importance as it supplies more than half of the world energy demands, today. In oil trade, transportation costs have significant effect on ultimate price like other commodities; therefore trade partners often try to select the nearest demand and supply resources. In the research reported herein, global oil trade flows were investigated during 2003 and role of distance as a transportation factor, in trade distribution was appraised. Accessible and relevant oil trade data for 115 countries were gathered. The study database consisted of 20 variables in four categories of trade, geographical, economical and political. Firstly, preliminary statistical analyses of the database were performed. Compared to other variables, country distances and gross domestic product showed higher correlation with national oil trade variables. Furthermore, simple modeling demonstrated that models in form of power had the best fit between oil trade variables, as dependent variables, and the others as independent variables. Moreover, multivariable oil trade models were developed and evaluated. Country distance, which is a geographic variable, was found as a significant decreasing factor in global oil trade. Gravity models for global oil trade were found as good descriptive models. The key variables of the models were gross domestic product of exporters and importers, and country distances which had positive and negative effect on growth of international trade. Finally, linear programming optimized oil trade and the results were compared with observed distribution. Comparison of observed and optimized distribution for the sea network showed possibility of improvements up to one third in total transportation cost.