Abstract: Oil production and transportation via pipelines results in the formation of water-oil emulsions due to the presence of shear forces and pressure and may also contain hydrocarbons like asphaltenes, waxes, resins, solids from crude, and carboxylic acids which serve as natural emulsifiers. Several problems may arise from the co-production of water and crude oil. This may include the cost associated with the pumping or transportation of the water by tanker or via the pipeline, corrosion of production facilities (like pipes, pumps, and downstream distillation columns), poisoning of the downstream by industrial catalysts. Demulsification refers to the breaking down of emulsion into its component incompatible phases (ie. water and oil). It is an important process in the petroleum sector where emulsions are always encountered as deliberate or natural occurrences. In this work heavy oil from Western onshore, Gujarat, India was collected in order to examine the temperaturedosage optimization of chemical demulsification. This work will focus on the analysis of the effectiveness of various oil soluble demulsifiers on heavy crude oil and the importance of temperature-dosage optimization in demulsification process.Keywords: - Emulsion, demulsifier, demulsification