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US 11,078,577 B2Granted
Fiber optics to monitor pipeline cathodic protection systems
AssigneeSaudi Arabian Oil Company
InventorSaeed Omar Aljabri
Life of this patent
Estimating the term…
Abstract
A system implementing fiber optics to monitor pipeline cathodic protection systems includes a cathodic protection system coupled to a hydrocarbon pipeline and a fiber optic system connected to the cathodic protection system. The cathodic protection system passes a current through the hydrocarbon pipeline to control corrosion of the hydrocarbon pipeline. The fiber optic system measures the current flowing through the hydrocarbon pipeline over time and provides the measured current.
Claims20
A system comprising:
- a cathodic protection system coupled to an underground hydrocarbon pipeline, the underground hydrocarbon pipeline comprises a first portion and a second portion buried in aerated soil, and a third portion positioned between the first portion and the second portion, the third portion buried in non-aerated soil, the cathodic protection system configured to pass a current through the hydrocarbon pipeline to control corrosion of the hydrocarbon pipeline;
- a fiber optic system connected to the cathodic protection system, the fiber optic system comprising a fiber optic cable coiled around the underground hydrocarbon pipeline, wherein a first number of coils of the fiber optic cable around the first portion and the second portion is different from a second number of coils of the fiber optic cable around the third portion, wherein the first number of coils is based on a resistivity of soil in which the first portion and the second portion are buried, and the second number of coils is based on a resistivity of soil in which the third portion is buried, the fiber optic system configured to measure in real time the current flowing through the hydrocarbon pipeline over time and provide the measured current, and wherein the fiber optic system comprises a signal processor to determine a current density of the current and compare the current density to a current density threshold.
A method comprising:
- passing a specified quantity of current to an underground hydrocarbon pipeline to control external corrosion of the underground hydrocarbon pipeline, wherein a quantity of current flowing through the underground hydrocarbon pipeline is affected by the external corrosion of the underground hydrocarbon pipeline, wherein the underground hydrocarbon pipeline comprises a first portion, a second portion and a third portion positioned between the first portion and the second portion;
- monitoring reflected light passing through a fiber optic cable coiled around the underground hydrocarbon pipeline, wherein the reflected light is modulated by a magnetic field produced by the quantity of current flowing through the underground hydrocarbon pipeline, wherein the fiber optic cable is coiled around the underground hydrocarbon pipeline, wherein a first number of coils of the fiber optic cable around the first portion and the second portion is based on a resistivity of soil in which the first portion and the second portion are buried, and a second number of coils of the fiber optic cable around the third portion is based on a resistivity of soil in which the third portion is buried;
- determining, based on the monitored reflected light, the quantity of current flowing through the underground hydrocarbon pipeline;
- determining a current density of the current flowed through the underground hydrocarbon pipeline by the cathodic protection system;
- and
- comparing the determined current density with a threshold current density.
3 more elements
A method comprising:
- coiling a fiber optic cable around an underground hydrocarbon pipeline connected to a cathodic protection system configured to pass a specified quantity of current to the underground hydrocarbon pipeline to control external corrosion of the underground hydrocarbon pipeline, wherein a quantity of current flowing through the underground hydrocarbon pipeline is affected by the external corrosion of the underground hydrocarbon pipeline, wherein the underground hydrocarbon pipeline comprises a first portion and a second portion positioned in aerated soil, and a third portion positioned in non-aerated soil and between the first portion and the second portion, wherein a first number of coils of the fiber optic cable around the first portion and the second portion is different from a second number of coils of the fiber optic cable around the third portion, wherein the first number of coils is based on a resistivity of soil in which the first portion and the second portion are buried, and the second number of coils is based on a resistivity of soil in which the third portion is buried;
- passing light through the fiber optic cable;
- monitoring reflected light passing through a fiber optic cable in response to the light, wherein the reflected light is modulated by the quantity of current flowing through the underground hydrocarbon pipeline;
- determining in real time, based on the monitored reflected light, the quantity of current flowing through the underground hydrocarbon pipeline;
- determining a current density of the current;
- and
- comparing the current density with a threshold current density.
4 more elements
Dependencies are inferred from the claim text.