Activation of (Na, Ca)-bentonites with soda and MgO and their utilization as drilling mud

Abstract This study explores, as an alternative to sodium bentonite, the possibility of (Na, Ca)-bentonites to meet the required drilling mud properties. Activation of the bentonites was performed using the most popular (Na 2 CO 3 ) and also the most controversial additive (MgO) and their blends. Upgrading the (Na, Ca)-bentonites was elaborated on the basis of viscosity, swelling index, filtration loss and electrokinetic measurements. The combination of soda and MgO produced a significant synergy.