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Why is water added to crude oil during the desalting process?

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Aerial view of an oil refinery complex near New Orleans, Louisiana, with storage tanks, industrial structures, and smoke rising from the facility, surrounded by open land. — petroleum refining Aerial view of an oil refinery near New Orleans.

In the petroleum refining process, fresh water is added to crude oil during the desalting stage to facilitate the removal of salt from the oil.1

If this salt were not removed, it would deposit on the tubes of the furnace as the oil is heated for further processing, leading to plugging and potential equipment failure. By introducing water and passing the mixture through an electric field, the salt is dissolved into a saltwater phase that can be effectively separated from the crude oil.1