The emulsions are considered as most favourable drilling fluid to drill sensitive formations like shales. In this work, an attempt has been made to develop an emulsion using palm oil. The polymers and surfactant were added to the system to improve the emulsion mud characteristics. It was observed that these emulsions were showing favourable rheological properties and poor filtration control characteristics. But, poor filtration properties were further controlled by fly ash (2% wt/v). The stability of the developed emulsions has been well checked with zeta potential (-66.84 to -42.74 mV) measurements. The present study would provide useful information for the selection of eco-friendly palm oil-in water emulsion for drilling oil & gas wells. Keywords: Palm oil, Shale, Emulsion, Interfacial surface tension, Zeta potential
