Produced Water

Produced water is a term used in the oil industry to describe water that is produced as a byproduct during the extraction of oil and natural gas. Oil and gas reservoirs often have water as well as hydrocarbons, sometimes in a zone that lies under the hydrocarbons, and sometimes in the same zone with the oil and gas. Oil wells sometimes produce large volumes of water with the oil, while gas wells tend to produce water in smaller proportion.To achieve maximum oil recovery, waterflooding is often implemented, in which water is injected into the reservoirs to help force the oil to the production wells. The injected water eventually reaches the production wells, and so in the later stages of waterflooding, the produced water proportion ("cut") of the total production increases.