Polymer:

A substance that consists of large molecules formed from smaller molecules in repeating structural units (monomers).

In oilfield operations, various types of polymers are used to thicken drilling mud, fracturing fluid, acid, water, and other liquids.

See micellar-polymer flooding, polymer mud.

In petroleum refining, heat and pressure are used to polymerize light hydrocarbons into larger molecules, such as those that make up high-octane gasoline.

In petrochemical production, polymer hydrocarbons are used as a feedstock for plastics.