US Patent 9366099 Doping of drilling mud with a mineralogical compound

Presented are methods and systems for tracking and assessing drilling fluid flow and performance and, accordingly, detecting drilling mud return depth. The drilling mud is injected with a mineralogical dopant in an amount that does not affect the physical or chemical properties of the drilling mud. The doped drilling mud is injected into a known mud pulse and a detector identifies the mud pulse in which the mineralogical dopant emerges from the borehole, allowing calculation of the drilling mud return depth.