When crude oil is produced from an oil field well, it is generally accompanied with variable proportions of water, which makes the separation of water from crude oil commercially difficult. In this research it was found the best alternative demulsifier (belongs to the researchers) from the demulsifiers (unknown chemical formula) that is used in the wet oil treatment. Which is highly effective and less costly in economic terms of their counterparts. The crude oil that we made our research is taken from Jamboor field in Iraq. (Specific gravity = 0.6417) and the water quantity 0.18 ml, if we used organic component Benzene with demulsifier (special formula belongs to researchers), we will see that the quantity of water in crude 0il is (0.17 ml).