Rheological Modeling of Sustainable Drilling Fluid Optimized for Electromagnetic Geophysical Exploration

Abstract In borehole environments, the use of optimized imaging fluids is critical for enhancing Ground Penetrating Radar (GPR) data quality by mitigating the adverse electromagnetic effects caused by water. The novel imaging fluid developed at the Drilling Technology Laboratory (DTL) of Memorial University of Newfoundland offers a unique solution, utilizing optimized electromagnetic properties to significantly improve signal clarity during borehole electromagnetic surveys. Despite the promise of this fluid, there has been a notable gap in the detailed study of its rheological behavior, which is essential for effective application, particularly in fluid circulation and placement in borehole operations. This study addresses this gap by conducting an in-depth analysis of the rheological properties of this E-M compatible imaging fluid, formulated with weighting agents of different grain sizes. Results from experimental measurements were utilized to model the fluid’s behavior using several mathematical models, including Bingham Plastic, Power Law, Herschel-Bulkley, Casson, and Robertson-Stiff models. By comparing the experimental results with theoretical predictions using statistical techniques such as RMSE, absolute average percentage error (ϵAAP), and standard deviation of average percentage error (SDϵAAP), the Herschel–Bulkley and the Robertson and Stiff rheological models accurately predicts fluid rheology for API Barite and Micro Barite weighting agent fluids. This research not only fills the critical gap in understanding the rheology of the developed E-M compatible imaging fluids but also establishes a foundation for selecting the optimal rheological model for hydraulic calculations, improving the overall efficacy of electromagnetic surveying in borehole environments.