Synthesis of novel solid scale inhibitors based on silver tungstate loaded KIT-6 for scale removal from produced water: static and modeling evaluation

Abstract

Oilfield scaling is a major problem in the oil and gas industry. Scaling issues cost the industry millions of dollars in damage and lost production every year as scaling is one of the main causes of global production decline. In this study, solid scale inhibitors based on silver tungstate loaded KIT-6 were synthesized and evaluated using a static scale inhibition test. The synthesized materials were characterized using wide and low XRD, N₂ adsorption–desorption, TGA, and FTIR, SEM, and XPS analyses. Small-angle XRD patterns showed that KIT-6 had 3D-mesopore diffraction peaks with a cubic Ia3d space group. Wide-angle XRD patterns of silver tungstate loaded KIT-6 confirmed the crystallinity. The prepared catalysts are characterized by higher surface areas (394–918 m² g⁻¹), large pore volumes (0.63–0.98 cm³ g⁻¹), narrow pore size distributions (5.3 nm), and high thermal stability up to 1000 °C. The results of this study demonstrate that the inhibition efficiency of the scale inhibitor increases and that of the calcite scale inhibitor decreases with increasing pH (2 to 8). This proposes that the scale inhibitor is more effective under alkaline conditions. An inhibition efficiency of 99% on calcium carbonate can be achieved at an optimal dosage of 7.5 ppm at 55 °C, indicating that the scale inhibitor exhibits a relatively good inhibition performance on calcium carbonate. The use of these materials can potentially lead to more efficient and cost-effective solutions for scale inhibition in various industrial processes.