BACKGROUND

The accurate and reliable knowledge of drilling mud properties, especially the density and viscosity, at the drill bit is valuable. However, due to the lack of sensors close to the drill bit, it can be challenging to obtain the appropriate information in a timely manner. Because the fluid properties can typically only be measured or tested on the surface, there is a delay between the measurement and the current fluid property down-hole. In other words, most “real-time” measurements are on the fluids that have circulated back to the surface, which may have different properties from the fluids closer to the drill bit.

