The exigency for efficient drilling fluids (mud) in the oil and gas industry has prompted the development of novel additives to address challenges encountered in high-temperature wells. Copper oxide nanoparticles (CuO NPs) possess distinctive characteristics, including low toxicity and exceptional thermal stability. This study explored the synthesis of CuO NPs using a natural extract from Colocasia esculenta leaves. The extract is abundant in phytochemicals and serves as both reducing and capping agents. The potential of the biogenic CuO NPs to enhance the lubricity in mud has been explored for the first time. Their ability to form a continuous and thin lubricating film at the muddrill string interface is expected to reduce the frictional resistance between them significantly. Besides this, the filtration and rheological performance of the developed mud have also been investigated. The formulation exhibited significant enhancements in lubricity, with a 27% increase, and filtering performance, with a 48% increase. The rheological profile, which exhibited shearthinning behavior, demonstrated strong agreement with the Herschel−Bulkley model. Furthermore, the NPs showed the capability of reducing the negative effects of heat-induced deterioration on the characteristics of mud. This highlights their potential as advantageous substances for drilling operations conducted at high temperatures. The results emphasize the advancement of drilling fluid technologies that are both environmentally benign and economically feasible by utilizing the advantages of biogenic CuO NPs. This study aims to enhance green chemistry methodologies in the oil and gas sector by tackling issues related to both performance and sustainability.