The Study of the Biopolymer- Surfactant Mixture Effect on Performance of Water Based Drilling Mud

In this study the effect of xanthan gum biopolymer and tallow-amin-poly-ethylene glycol surfactant on the properties of water based drilling mud has been studied. The effect of biopolymer or surfactant and mixtures of them with different ratios has been investigated on effective viscosity, shear stress and amount of filtration. The result shows that rheological and filtrate controlling properties of fluid with the polymer-surfactant mixture have better operational condition than fluids with only polymer or surfactant. The biopolymer-surfactant mixtures have also better linear curve on high shear rates. The cases, which consist of biopolymer-surfactant mixture have better filtrate controlling in comparison with samples which have only biopolymer. In the cases with only surfactant the amount of filtrate much higher than desirable amount with respect to polymeric and combinating cases. Filter press experimens was also carried out in high pressure and temperature. It is observed that the amount of filtrate increased with higher rate than low pressure and temperature.