Oil and gas field wastewater is derived from the petroleum and natural gas exploration. The water quality and quantity is relative to the process, exploration procedure and operation management. It mainly includes oil and gas field produced water, fracturing outlet liquid, drilling wastewater and some comprehensive wastewater.
Oil-gas field wastewater contains very complex components, differing when exploration strata and mining process changes. But it has some common characteristics : as large amount of salt and gas dissolved in the wastewater, many kinds of chemicals are dosed into the wastewater, it contains oil, suspended solids, scaling ions, microorganisms.