Okra as an Environment-Friendly Fluid Loss Control Additive for Drilling Fluids: Experimental & Modeling Studies

Abstract Okra (Hibiscus esculents) is widely used as a thickener and viscosifier in medical and food industries due to its low cost, availability, longer shelf life, and high thermal tolerance. It is also environment friendly and available in abundance, especially in tropical and subtropical regions. To the best of our knowledge, this is the first report on the application of the okra solution as a fluid loss control additive in drilling fluids. The okra powder was characterized by X-ray fluorescence, Fourier-transform infrared spectroscopy, and scanning electron microscopy. The thermal stability of okra was tested using thermal gravimetric analysis. The microstructure stability of the okra-based solution was analyzed using shear and loss modulus. The okra powder was used in different concentrations (0.25, 0.5, & 1) wt% in a clay free water-based drilling fluid formulation. The experimental study revealed that the addition of 1 wt.% okra solution could reduce 20% fluid loss. The okra showed comparable performance compared to the conventional fluid loss control additive, starch. The main advantage was that okra has less impact on rheological properties compared to starch. TGA analysis of okra powder showed that it has strong thermal stability. The pH test showed that okra powder could not affect the pH of the solution. The shear and loss modulus tests revealed that the water-based drilling fluid samples with higher okra powder concentrations could develop a more stable microstructure. Overall, the experimental results suggest that okra containing drilling fluids can be used as an alternate solution to starch in drilling fluids without compromising other drilling fluids' properties. A Machine Learning (ML)-based rheological model was also developed to predict the rheological properties of okra-based drilling fluid formulations. The proposed ML model can predict the rheological properties of Okra-based drilling fluids with high accuracy.