In complement to physical or biological treatments, chemical-based technologies are used to process water to a safe, potable product or to mitigate the release of contaminants in receiving waterbodies along with wastewater discharges. Different chemical processes are used to remove targeted contaminants or to convert them into stable oxidized end products that can be safely disposed of to receiving water streams without any adverse ecological effects or risks to human health.

In the production process, some chemicals are required to aid the production, handling, or transportation of crude oil or treated produced water before being re-injected into the well.