Cathodic protection monitoring

1. A method of monitoring cathodic protection of an item receiving cathodic protection located underwater at an underwater hydrocarbon extraction facility from a topside facility located onshore on a vessel or rig, the facility further including a subsea electronics control module, the method comprising the steps of:

providing a pair of first and second electrodes;

electrically connecting the first electrode to an item requiring cathodic potection located underwater at an underwater hydrocarbon extraction facility;

positioning the second electrode being in contact with water proximate the item;

producing an electrical signal indicative of a cathodic protection level of the item;

converting the signal into a communications format compatible with the subsea electronics control module;

passing the converted signal to the subsea electronics module;

transmitting the converted signal from the subsea electronics module to a surface location along a line within an umbilical cable; and

determining the cathodic protection level of the item responsive to the converted siginal.

2. A method according to claim 1 , wherein the communications format compatible with the subsea electronics module comprises CANbus.

3. A method according to claim 1 , wherein the communications format compatible with the subsea electronics module comprises profibus.

4. A method according to claim 1 , wherein the communications format compatible with the subsea electronics module comprises modbus.

5. A method according to claim 1 , wherein the pair of first and second electrodes comprises a first pair of first and econd electrodes wherein the item requiring cathodic protection is a first item requiring cathodic protection, the method further comprising the steps of:

providing a second pair of electrodes, a first electrode of the second pair of electrodes being electrically connected to a second item requiring cathodic protection positioned at a different location than the first item, and a second electrode of the second pair of electrodes being in contact with water proximate the second item;

producing an electrical signal indicative of the cathodic protection level of the second item;

converting the respective signal into a communications format compatible with the subsea electronics module;

passing the converted signal indicative of the cathodic protection level of the second item to the subsea electronics module; and

determining the cathodic protection level of the second item responsive to the potential between electrodes of the second pair of electrodes.

6. A method according to claim 5 , wherein the signal is passed to the subsea electronics module on a network bus.

7. A system for monitoring cathodic protection of an item receiving cathodic protection located underwater at an underwater hydrocarbon extraction facility from a topside facility located onshore or on a vessel or rig, the system comprising:

an underwater hydrocarbon extraction facility having an item requiring cathodic protection;

a pair of electrodes, a first electrode of the pair of electrodes being electrically connected to the item requiring cathodic protection and a second electrode being in contact with water proximate the item, the first and the second electrodes being operably positioned to produce a potential therebetween and an electrical signal indicative of a cathodic protection level;

a subsea electronics module;

a transducer for converting the signal into a communications format compatible with the subsea electronics module;

one or more cables operably coupled between the transducer and the subsea electronics module to pass the converted signal to the subsea electronics module;

an umbilical cord positioned to transmit the converted signal from the subsea electronics module to a surface location; and

a topside facility located at the surface location, configured to analyze the converted signal to thereby determine the cathodic protection level of the item requiring cathodic protection.

8. A system according to claim 7 , wherein the transducer converts the signal to a CANbus format.

9. A system according to claim 7 , wherein the transducer converts the signal to a profibus format.

10. A system according to claim 7 , wherein the transducer converts the signal to a modbus format.

11. A system according to claim 7 , wherein the pair of first and second electrodes is a first pair of first and second electrodes, the system comprising a second pair of electrodes, a first electrode of the second pair of electrodes being electrically connected to a second item requiring cathodic protection positioned at a different location than the first item, and a second electrode of the second pair of electrodes being in contact with water proximate the second item.

12. A system according to claim 11 , comprising a network bus connecting each electrode pair and the subsea electronics module.

13. A method of monitoring cathodic protection of an item receiving cathodic protection located underwater at an underwater hydrocarbon extraction facility from a topside facility located onshore or on a vessel or rig, the method comprising the steps of:

providing a pair of first and second electrodes;

electrically connecting the first electrode to an item requiring cathodic protection located underwater at an underwater hydrocarbon extraction facility;

positioning the second electrode in contact with water proximate the item;

producing an electrical signal indicative of a cathodic protection level of the item;

converting the signal into a communications format compatible with the subsea electronics control module, the step of converting performed by a transducer;

passing the converted signal from the transducer to the subsea electronics control module;

transmitting the converted signal from the subsea electronics control module to a topside facility positioned at surface location via a line within an umbilical cable; and

determining the cathodic protection level responsive to the converted signal, the step of determining performed at the topside facility.

14. A method as defined in claim 13 , wherein the topside facility is a master control station (MCS).