Desalter Chemical Control System

A method comprising:

• obtaining a fluid sample from a crude oil desalter;
• measuring at least one of a density or a mass flow rate of the fluid sample;
• and
• adjusting a flow rate of a chemical additive into an inlet of the crude oil desalter based at least in part on the measured density and/or the measured mass flow rate, wherein the step of adjusting comprises generating a control signal from a PID flow controller and sending the control signal to a chemical additive pump, wherein the control signal causes the chemical additive pump to adjust the flow rate of a chemical additive, wherein the PID flow controller accepts a setpoint of at least one of minimum lower level of emulsion layer, maximum upper level of emulsion layer, minimum emulsion height, and maximum emulsion height, and wherein the PID flow controller outputs the control signal in based at least in part on the setpoint and the density, the mass flow rate, or both.

A method comprising:

• obtaining a fluid sample from a crude oil desalter;
• measuring at least one of a density or a mass flow rate of the fluid sample;
• adjusting a flow rate of a chemical additive to a location upstream of the crude oil desalter based at least in part on the measured density or mass flow rate;
• wherein the step of adjusting comprises generating a control signal from a flow controller and sending the control signal to a chemical additive pump, wherein the control signal causes the chemical additive pump to adjust the flow rate of the chemical additive, wherein the flow controller is a PID controller, wherein the PID controller accepts a setpoint of at least one of minimum lower level of emulsion layer, maximum upper level of emulsion layer, minimum emulsion height, and maximum emulsion height, and wherein the PID outputs the control signal in based at least in part on the setpoint and the density, the mass flow rate, or both.