Drilling liquid from plant based oil using carbon based nanoparticles

•Non-food-grade vegetable oil as an alternative drilling liquid.•Synthesis of carbon-based nanoparticles from coconut shell and graphite.•Surface area of Graphene nanoparticles and coconut shell carbon nanoparticles.•Graphene nanoparticles enhance vegetable-based synthesized drilling mud.•The toxicity test shows that graphene-based nanomuds have no ecological effects. The risks of disposal associated with using mineral-based drilling liquids have prompted the search for alternatives. Despite their long-standing use in the industry, mineral-based liquids pose challenges due to their eco-toxicity, poor biodegradability, and low fire resistance. Recently, vegetable-based liquids have gained attention for their excellent environmental friendliness and high fire resistance. In this study, a green drilling liquid was developed from non-food grade vegetable oil. The base liquid was extracted and the oil underwent epoxidation to enhance the thermal stability. Two different carbon-based nanoparticles were synthesized from coconut shells and graphite. The graphene nanoparticles derived from graphite exhibited a higher surface area compared to those from coconut shells. The properties of the developed graphene nanomud, such as gel strength, thermal conductivity, specific gravity, mud viscosity, mud filtrate properties, cutting carrying index, electrical conductivity, and toxicity, were investigated and compared with diesel-based nanomud. Results showed that neem graphene nanomuds possess properties that are comparable to, and in some cases better than diesel-based oil mud. The addition of 0.25–2.0 wt.% of graphene nanoparticles increased the electrical conductivity of the fluid from 58.7 to 229.5 µS/cm at 25 °C, enabling the use of resistivity imaging techniques for wellhole geological studies. Additionally, the nanofluids demonstrated desirable thermal conductivity, ranging from 0.138 W/m·K to 0.267 W/m·K at 25 °C, making them suitable coolants. Furthermore, toxicity tests using bean plants demonstrated that graphene-based nanomuds are environmentally friendly and could offer a cleaner, more sustainable option for drilling operations.