Investigating almond seed oil as potential biodiesel-based drilling mud

With increasing strict environmental laws, there is a need for operators to design a benign oil-based muds (OBMs). In this study, oil extracted from non-edible sweet almond seed (SASO) was used as the continuous phase to formulate biodiesel-based drilling mud (BBDM). Different properties of the BBDM including the economic viability were evaluated and compared with those of the diesel OBM to determine the applicability of these properties for drilling fluids and their level of toxicity to the environment. The results indicate that the rheology, filtration properties, electrical stability, thermal stability and shale swelling inhibition performance of the BBDM are comparable with those of the diesel OBM. The biodiesel has a significantly higher flash point of 169 °C than the diesel with 78 °C; demonstrating that it can supply better fire safety than the diesel. The data of the toxicity test indicate SASO to be safer and less harmful compared to diesel #2 type used. After the 28-day period of biodegradation tests, the BBDM and the diesel OBM showed 83% and 25.2% aerobic biodegradation with Penicillium sp., respectively. The low branching degree and absence of aromatic compounds in the BBDM contributes for its higher biodegradation. The economic evaluation of the BBDM indicates low cost of formulation and waste management. The general outcome of the tests illustrates that SASO has the potentials of being one of the technically and environmentally feasible substitutes for the diesel OBM.