Produced water describes water that is produced along with the oil and gas. Produced water originates from water that is trapped in permeable sedimentary rocks within the wellbore.

Produced water – any water produced to the surface from the wells along with the natural gas and condensates is called produced water. Produced water occurs because gas reservoirs are typically bounded by a lower layer of water below the gas-water contact. Water production from gas fields is usually of three types:

Condensed water – this is the water that is condensed at the surface facilities from the reservoir water-saturated gas phase.

Formation water – this is liquid water that is present in the reservoir above the gas water contact that is carried to the surface facilities with the gas phase during production.

Breakthrough water – this is water that is present at and below the GWC that rises as the reservoir pressure declines and enters the production tubing and arrives at the surface facilities.

Disposal of produced water can be problematic in environmental terms due to its highly saline nature. Produced water contains high levels of minerals, salts and other chemicals classified as non-hazardous.

There are certain schemes that treat produced water, by separating the oil from the water, selling the oil to refiners and treating the briny water by evaporation.