Preparation of clay inhibitor based on pomegranate peel extract and its application in drilling fluids

The application of drilling fluids and additives plays an important role in drilling operations. Additionally, one of the most crucial ways to increase drilling efficiency since environmental rules were passed is by finding an inexpensive and ecologically acceptable drilling fluid additive. Pomegranate peel extract (PP) and PP modified by AlCl3(PPA) were created in this study. Their effects on inhibiting clay swelling were evaluated by linear swelling test, mud ball test, anti-swelling test and drilling fluid performance evaluation. The performance of the modified pomegranate peel extract on inhibiting clay swelling was compared with that of KCl. The swelling rate of bentonite was effectively reduced by 1.20% PP, which represented a substantial improvement above 4% KCl. The results of this study indicated that PPA has excellent performance in inhibiting clay swelling compared to known inhibitors. PP was modified by 0.06% AlCl3(named as PPA-1). The YP/PV remained basically stable after the addition of PPA-1 to the drilling fluid in the 100°C hot rolling experiment. Thus the drilling fluid showed good rheological properties. And the drilling fluid prepared with PPA-1 has a high shale recovery rate. Finally, the correlation between the molecular structure of PP and PPA-1 and its inhibition mechanism was assessed by XRD and IR. This study provides a pathway for converting low-cost agricultural by-products into high value-added industrial materials.