1. n. [Formation Evaluation]
The volume close to the borehole wall in which all of the moveable fluids have been displaced by mud filtrate. The flushed zone contains filtrate and the remaining hydrocarbons, the percentage of the former being the flushed-zone water saturation, Sxo. In simple models, the flushed zone and the invaded zone are synonymous.
Synonyms: invaded zone
See: diameter of invasion, flushed-zone water saturation, formation water, hydrocarbon, invasion, water saturation