1. n. [Formation Evaluation]
Formation water with low salinity. Water is considered fresh when its low conductivity makes the interpretation of resistivity logs difficult. The salinity at which this becomes important depends on temperature and clay content, among other factors, but is generally somewhere less than 10 ppk.
2. n. [Geology]
Water that is low in dissolved salt (< 2000 ppm).
See: brine, connate water, hydrostatic head, hydrostatic pressure, interstitial water