Effect of natural Frankincense extract on clay swelling inhibition in water-based drilling fluids

The effect of Frankincense extract (FE) as an environmentally friendly additive on the swelling inhibition of sodium bentonite in aqueous solution is presented. The inhibition potential of FE was assessed through sodium bentonite (Na-BT) sedimentation tests, rheological investigations, and immersion test. The results indicated that the inhibition property of FE is dependent on its concentration and its performance at 5 wt.% is comparable to potassium chloride at 3 wt.% as a commonly used inhibitor. FE increased the loading of Na-BT in deionized water (DI water) from 7.5 to 17.5 wt.% at 5 wt.% FE concentration. Furthermore, FE reduced the dispersion of Na-BT, resulting in an increase in Na-BT particle size from 1034 nm in DI water to 4294 nm at a 1 wt.% FE concentration. X-ray diffraction test and thermal gravimetric analysis revealed that FE can insert itself into the interlayer space of clay minerals. FE reduced the zeta potential of Na-BT from -24.3 mV in DI water to -5.21 mV at a 5 wt.% FE concentration. Additionally, the compatibility test proved that FE could also decrease the drilling fluid filtration and act as a fluid loss control agent.