Optimization of the demulsification of water in oil emulsion via non-ionic surfactant by the response surface methods

The most challenging issue faced by the petroleum industry in recent years was the water production during crude oil and gas extraction. This challenge has caused aggravated damages to treatment facilities by increasing the cost of production as water production increased over time. However, most of the water produced from oil and gas platforms is produced as water in oil emulsion. Treating emulsion has been experienced using techniques involve specific chemical methods. This study used the bottle test technique to investigate the performance of non-ionic demulsifiers, Propargyl Alcohol (PA) and Triethylene Glycol (TG), in breaking water in oil emulsion. Subsequently, a factorial design was applied for the characterisation of five variables, namely demulsifier dose, toluene concentration, pressure drop, temperature, and sitting time. Then, the significant factors were further analysed using Central Composite Design (CCD) based on the Response Surface Method (RSM). In particular, CCD was used to study the influence of demulsifier dose, toluene concentration, pressure drop, temperature, and sitting time on the response and to find the optimal condition to achieve maximum dehydration. Additionally, Analysis of Variance (ANOVA) was used to test the accuracy of the mathematical models established using CCD. The results show that demulsifier dose, temperature, and sitting time were the most significant parameters for breaking the emulsion, and that the optimal values for the input variables were successfully obtained using RSM.