DRILLING

Drilling fluids play a critical role in the success of oil and gas drilling operations, yet the Nigerian petroleum industry relies heavily on imported bentonite and additives for drilling mud formulation, leading to high operational costs and foreign exchange losses. This study evaluates the suitability of selected locally sourced clays from Iyi-Ogene, Okuaghe, and Ikpoba deposits in Delta and Edo States, Nigeria, for use in water-based drilling mud formulation. Laboratory-scale drilling muds were prepared using raw and chemically activated clays, with sodium carbonate employed as the activating agent and carboxymethyl cellulose (CMC) used as a viscosifier and fluid-loss control additive. Standard American Petroleum Institute (API) procedures were adopted to determine key drilling mud properties, including density, rheological parameters (plastic viscosity, apparent viscosity, yield point, and gel strength), filtrate loss, and pH. The results show that untreated local clays exhibited poor rheological behavior and excessive fluid loss, making them unsuitable for direct drilling applications. However, significant improvements were observed after chemical activation and polymer treatment, with several formulated mud samples meeting acceptable API performance criteria. The study demonstrates that locally sourced clays, when properly activated and enhanced with suitable additives, can serve as viable alternatives to imported bentonite for water-based drilling mud formulation. The findings highlight the potential for cost reduction, improved local resource utilization, and increased sustainability in Nigeria’s drilling operations.