ABSTRACT
Oil and gas are often produced together with water coming from a zone beneath the hydrocarbon zones. The produced formation water will usually contain dissolved salts. The operator may further add methanol or glycol to suppress hydrate formation (Chapter 13). The miscibility between water and oil is quite limited, whereas the water content in gas and gas condensate mixtures can be quite significant. The solubility of hydrocarbons in the aqueous phase is usually small but can nevertheless be quite important. In arctic and other environmentally sensitive regions, the hydrocarbon concentration in the water phase can, for example, decide the need for cleaning formation water before dumping it into the sea.
