Primary Demulsifier is used for separation of water from crude oil. As crude oil is produced from a reservoir it tends to become mixed with either natural formation water or mixed formation and injection water. It enhances desalting performance and, in some cases, used as crude dehydration chemical for crude storage tanks. This formulation shows excellent result in removing solid particles and offers rapid break up of the emulsion water interface layer. The use of this chemical depends upon the severity of crude oil and water emulsion.