There are many physical and chemical properties of drilling fluids that are useful to know or even critical to determine. The physical properties of a drilling fluid, the density, and the rheological properties are examined continuously to optimize the rotary-drilling process. These properties contribute to preventing an influx of formation fluid, providing wellbore stability, providing hydraulic energy at the drilling bit, removing drilled solids (cuttings) from the well and suspending them during static periods, and permitting segregation of solids and gas at the surface. The chemical properties of a drilling fluid provide the chemical effects associated with formation damage, rheological-property changes, and cuttings-transport issues.
