Patent ID: 11913444
Assignee: SENSIA LLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F  E  H | IPC E  F  H

Claim 4:
5. An electrical submersible pump system, comprising:
an electrical submersible pump (ESP) comprising an electric motor;
drive circuitry electrically coupled to the ESP and configured to provide an electrical signal to power the ESP;
a current sensor configured to measure a current of the electrical signal;
a voltage sensor configured to measure a voltage of the electrical signal;
a processing circuit configured to:
calculate speed of a shaft of the electric motor based on a frequency induced by rotation of the electric motor detected in the current;
calculate a density of a fluid in the ESP based on the speed; and

an intake pressure sensor coupled to the ESP and configured to measure a pressure of the fluid at an intake of the ESP; and
a discharge pressure sensor coupled to the ESP and configured to measure a pressure of the fluid at an outlet of the ESP;
wherein the processing circuit is configured to:
determine a ratio of pressure-to-torque in the ESP based on the measured pressure of the fluid at the intake of the ESP, and the measured pressure of the fluid at the outlet of the ESP;
determine a value of flow of the ESP based on at least the pressure-to-torque ratio, wherein the density of the fluid in the ESP is further based on the value of flow; and
reduce the speed of the electric motor responsive to the density being lower than a predetermined threshold value.