Document Type : Article
Department of Petroleum Engineering, Ahwaz Faculty of Petroleum Engineering, Petroleum University of Technology, Abadan, Iran.
Department of Chemical Engineering, Abadan Faculty of Petroleum Engineering, Petroleum University of Technology, Abadan, Iran
Drilling fluid is one of the most important and expensive aspects of any drilling process. Colloidal Gas Aphron (CGA) has been found eective in controlling the ltration rate by bridging the pores of the reservoir rock; hence, reducing the formation damage. This work aims to synthesize the CGA in water based drilling fluids to study the stability, rheology, ltration loss characteristics and formation damage properties of the resulting fluid. Besides, an investigation on type of polymer, surfactant, and their concentration eects on the characteristics of the fluid, as well as optimum ratios of polymers in drilling fluid was performed. Experimental results showed that Xanthan Gum (XG) provides more acceptable rheological properties (especially viscosity) in comparison to Guar Gum(GG) for preparing the base fluid. Moreover, the Sodium Dodecyl Sulfate (SDS) produces more stable micro-bubbles than Hexadecyl Trimethyl Ammonium Bromide (HTAB) as a surfactant. Bubble size measurement to observe the eect of polymer, surfactant type and concentration was performed. Through the experiments, the pH of the drilling fluid was monitored which proved the CGA introduced the best performance around a pH of 9. Furthermore, a XG/GG ratio of 3:1 is suggested to reduce the cost while maintaining the