Process control systems and methods for simultaneous crude oil dehydration, desalting, sweetening, and stabilization

A system for controlling desalting and dehydration of crude oil, the system comprising:

• a crude oil separation unit, the crude oil separation unit comprising a crude oil inlet, insulated electrostatic electrodes, a water outlet, an oil-water emulsion outlet, and a dried, desalted crude oil product outlet;
• a total dissolved solids (TDS) content monitor at the water outlet;
• a basic sediment and water (BS&W) content monitor at the dried, desalted crude oil product outlet;
• and
• a pounds per thousand barrels (PTB) salt content and volumetric water content controller in electronic communication with the TDS content monitor and the BS&W content monitor, wherein the PTB salt content and volumetric water content controller controls a process input to the system based on a comparison between the PTB salt content and volumetric water content of a dried, desalted processed crude oil stream at the dried, desalted crude oil product outlet versus a maximum set value for PTB salt content and volumetric water content of the dried, desalted processed crude oil stream, where the controlled process input is selected from the group consisting of chemical demulsifier injection rate;
• wash water injection rate;
• inlet crude oil heating;
• a pressure drop for mixing preceding the crude oil separation unit;
• current supply to the crude oil separation unit;
• inlet crude oil flow rate for processing;
• outlet crude oil flow rate of the dried, desalted crude oil product outlet;
• crude oil separation unit residence time;
• crude oil separation unit emulsion level;
• crude oil separation unit water level;
• and combinations thereof.