1. n. [Drilling Fluids]

Ratio of the volume percent synthetic fluid to the volume percent brine in a synthetic mud, where each is expressed as a percent of the total liquid in the mud. The SBR is calculated in an analogous way to the oil/brine ratio using data from the retort test.

Alternate Form: SBR

See related terms: calcium test,  chloride test,  oil/water ratio,  syn,  synthetic-base mud,  water, oil, and solids test