Beneficiation Process of Locally Available Bentonitic Clay: An Efficient Utilization in Drilling Fluid Application in Akwa Ibom State

Abstract

This study investigates the enhancement of bentonitic clay obtained from Oron, Nigeria, through a systematic beneficiation process aimed at improving its swelling ability, viscosity, and rheological properties to meet the technical standards required for drilling fluid applications in the oil and gas industry. The beneficiation process includes mechanical purification, chemical treatment with sodium carbonate (soda ash), and ion exchange to activate the calcium-based nature of the clay to a sodium-based form, crucial for its drilling fluid performance. Mineralogical and chemical analyses, including X-ray diffraction (XRD) and scanning electron microscopy (SEM), were used to evaluate the structural changes following beneficiation. The UV-Visible spectra revealed that Eniongo Beach (EBC) absorbed at 430 nm, Usung Beach (UBC) at 544 nm, and Edek Okong Beach (EOBC) at 597 nm, with absorption increasing in the order EOBC > UBC > EBC, indicating variations in particle size and structural complexity. SEM imaging showed that the bentonitic clay samples had micro-sized particles of irregular shapes, and Energy-Dispersive X-ray Spectroscopy (EDS) revealed that the clay was rich in Al, Si, Ba, Mg, and Ca. XRD analysis confirmed the crystalline nature of the clays, with well-resolved peaks corresponding to various inorganic minerals. Rheological testing of the beneficiated clay indicated a significant improvement in its properties, with an apparent viscosity of 10 cP, plastic viscosity of 10.25 cP, yield point of 4, fluid loss of 18 mL, and gel strength of 2/4 lb/100 ft² at 10 sec/10 min. These results demonstrate a marked enhancement in the rheological properties of the clay, aligning with American Petroleum Institute (API) standards for drilling fluids, making the beneficiated Oron clay a viable option for high-performance drilling operations