Flow loop provides new insights on viscosity of drilling fluid dispersions
Flow loop provides new insights on viscosity of drilling fluid dispersions lead image
One of the most important limiting factors for faster horizontal underground drilling is the pressure of drilling fluids used to remove soil and rock. Such processes create highly complex fluid dispersions with viscosities that are difficult to characterize. New work provides insights into how to model these fluids more accurately.
Yu et al. characterized the viscometric properties of a drill test and model drilling fluid dispersion in a custom-built flow loop. Reporting fluid viscosity in terms of power law parameters, the group’s study can be used to predict pressure drops in drilling conditions.
Such work provides a critical understanding of the pressures at which bore walls fail, as well as when pipes might become clogged with solids during tunneling.
“Measurements of viscosity in drilling fluids at such high concentrations of solids is unique,” said author Joseph Samaniuk. “We also identified a technique to predict when the solids that are suspended in the fluid will begin to settle in the pipe and form a bed.”
The loop allowed them to study the flows of mixtures where solids constitute up to 50 percent of the dispersion’s volume, while other approaches are generally limited to 30 percent volume due to high mixing torques and rapid solids settling.
The group found that even model drilling fluid dispersions prepared with geotechnical data from a drill site may have significantly different viscometric characteristics than those found in real-world scenarios.
They look to improve modeling of fluid flow as solids are removed from bore holes and apply their methods to counteract pipe jamming and clogging.
Source: “Characterizing the non-Newtonian viscosity of high-solids drilling fluid dispersions by flow loop,” by Jianger Yu, Benjamin A. Appleby, Michael A. Mooney, and Joseph R. Samaniuk, Physics of Fluids (2022). The article can be accessed at https://doi.org/10.1063/5.0083982 .
This paper is part of the Celebration of Robert Byron Bird (1924-2020) Collection, learn more here .
