1. n. [Drilling Fluids]

The shear stress measured at low shear rate after a mud has set quiescently for 10 minutes as per the standard API procedure.

See related terms: clay-water interaction,  deflocculant,  deflocculated mud,  direct-indicating viscometer,  drill solids,  flat gels,  funnel viscosity,  gel,  gel strength,  gelation,  gelled-up mud,  gels,  guar gum,  Herschel–Bulkley fluid,  hydrometer,  hydroxyethylcellulose,  Marsh funnel,  mixed-metal hydroxide,  progressive gels,  shear strength,  shear-strength measurement test,  ten-second gel strength,  thixotropy,  VG meter,  weighting material,  zero-zero gels