The rheological behavior of a pseudo-oil-based mud formulated with Hura crepitans plant oil as base fluid

Abstract

The need to prevent our environment from deterioration caused by toxic waste from drilling mud is a prime objective to the oil and gas industry. The exploration of non-edible plant oil for potential base oil in formulating drilling mud is progressing due to the environmentally friendly nature. This research work involves using a commercial synthetic oil from the oil industry and Hura crepitans oil. This oil samples were used as a base fluid in preparing the mud from which the rheological properties were analyzed. Chemical oil extraction method using soxhlet apparatus was used to extract the oil from H. crepitans seeds; it was then distilled to remove the solvent. The mud samples were formulated with 7 and 9 g concentrations of the viscosifier, and properties were measured at 113 and 158 °F. It was then aged for 16 h at 240 °F, and mud properties were measured before and after hot rolling for comparison. Different rheological models were used to describe the experimental data. The physical properties of the synthetic oil and H. crepitans oil reveal a flash point of 213.8 and 399.2 °F, fire point of 226.4 and 500 °F, viscosity index of 297 and 207, specific gravity/density of 805 and 907, respectively. The mud properties of the synthetic oil-based mud had a better emulsion stability, lower plastic viscosity, higher yield point values, and lower gel strength than the H. crepitans oil-based mud. The rheological properties of synthetic and H. crepitans oil-based mud increase and decrease, respectively, after hot rolling. The optimal concentration of viscosifier was 7 g to have maintained the API acceptable range for the rheological properties. Based on the R^{2} values, RMSE values, and the fitted plots, Herschel–Bulkley had a better description of the experimental data.