Experimental study on a six-speed online measurement system for drilling fluid rheology

Abstract:

To address the issues of poor real-time performance and insufficient accuracy in traditional manual measurement of drilling fluid rheological parameters， this study developed a six-speed online drilling fluid measurement system. By deriving the shear rate based on the concentric cylinder flow model， parameter solutions were achieved by incorporating the Bingham model， power-law model， and Herschel-Bulkley rheological model. The end effect was analyzed through CFD numerical simulation， and a corresponding dynamic correction method was proposed. An experimental platform was established to compare the measurement results of the online module with those of a standard Fann 35 viscometer. The test results show that the system exhibits high consistency with the benchtop viscometer， with an average deviation of less than 5% between the readings. The fitting error of the HB model is below 2%， significantly outperforming the Bingham model. Temperature reduction markedly increases plastic viscosity and yield stress， enabling data standardization through temperature compensation. The system responds to step changes in rotational speed within approximately 2 s， demonstrating excellent dynamic performance. This system enables real-time， continuous， and high-precision measurement of rheological parameters， providing effective technical support for intelligent monitoring of drilling fluid performance and safe， efficient drilling operations.