A significant role in creating safe drilling conditions is played by hydrodynamic pressures in the well, which are determined by the rheological properties of drilling fluids. Rheological properties of drilling fluids are studied from the position of classical mechanics. This approach does not require taking into account the discreteness of the fluid at the suspension level and the composition of the fluid itself, and does not take into account the influence of intermolecular forces acting inside the fluid. The paper considers the influence of the state of bonds in water on the rheological properties of drilling fluids.