An intelligent system is provided for monitoring a subsea structure and delivering appropriate cathodic protection to desired areas of the subsea structure. According to an embodiment, the technique involves monitoring a cathodic protection potential level at an important location or locations of the subsea structure. Based on the data acquired via monitoring, a controller is able to apply voltage levels to the subsea structure so as to attain and modulate a desired cathodic protection level, e.g. a cathodic protection level within a range of about −800 mV to −950 mV (SCE). Consequently, undesirable overprotection and under protection are avoided and the subsea structure is adequately protected from corrosion while reducing undesirable production of hydrogen.

Assemblies and methods for monitoring the cathodic protection of underground or submerged structures may include a coupon assembly including a conductive test coupon and a reference electrode for determining the voltage potential difference of the protected structure without substantially interrupting surrounding current sources. The reference electrode may be at least partially covered with an electrolytic material in electrical contact with the surrounding environment via a plug including a porous material. A method of installation of the assembly may allow a single technician to install the coupon assembly using a probe rod without extensive on-site excavation. The coupon assembly may be configured to seat securely with the probe rod for stability during installation, and release from the probe rob when the probe rod is separated from the coupon assembly and withdrawn from the ground, leaving the coupon assembly at a preselected depth or preselected distance from the protected structure.

Assemblies and methods for monitoring the cathodic protection of underground or submerged structures may include a coupon assembly including a conductive test coupon and a reference electrode for determining the voltage potential difference of the protected structure without substantially interrupting surrounding current sources. The reference electrode may be at least partially covered with an electrolytic material in electrical contact with the surrounding environment via a plug including a porous material. A method of installation of the assembly may allow a single technician to install the coupon assembly using a probe rod without extensive on-site excavation. The coupon assembly may be configured to seat securely with the probe rod for stability during installation, and release from the probe rob when the probe rod is separated from the coupon assembly and withdrawn from the ground, leaving the coupon assembly at a preselected depth or preselected distance from the protected structure.

A system comprises a cathodic protection system having an anode and configured to protect a protected structure from corrosion. The system comprises a monitoring circuit operatively coupled to the cathodic protection system. The monitoring circuit comprises an electrical-to-optical transducer. The electrical-to-optical transducer is configured to generate a light signal in response to electrical current flowing between the protected structure and the anode of the cathodic protection system, the protected structure and a reference electrode, or the reference electrode and the anode.

A system comprises a cathodic protection system having an anode and configured to protect a protected structure from corrosion. The system comprises a monitoring circuit operatively coupled to the cathodic protection system. The monitoring circuit comprises an electrical-to-optical transducer. The electrical-to-optical transducer is configured to generate a light signal in response to electrical current flowing between the protected structure and the anode of the cathodic protection system, the protected structure and a reference electrode, or the reference electrode and the anode.

A remote terminal unit for use in monitoring a metallic pipeline can take an electrical measurement at the pipe and transmit the measurement in a modulated signal to a main measurement unit located along the pipe and distant from the remote terminal unit. The electrical measurement is taken at regular time intervals between a reference electrode electrically connected to the pipe and a coupon composed of a sacrificial corrosion material in order to monitor the pipe for possible corrosion. The electrical measurement is modulated with a low frequency carrier signal for transmission along the pipe, eliminating the need to take the measurements directly at physical locations along the pipe.

An apparatus is for detecting corrosion in an internal pipe bore in a pipeline. A tracer chamber containing a first tracer is formed in a portion of the pipeline and is bounded towards the internal pipe bore by a chamber wall having a first corrosion resistance and including at least one wall portion with a second corrosion resistance, the second corrosion resistance being smaller than the first corrosion resistance. A method is for detecting corrosion in an internal pipe bore in a pipeline.

An apparatus is for detecting corrosion in an internal pipe bore in a pipeline. A tracer chamber containing a first tracer is formed in a portion of the pipeline and is bounded towards the internal pipe bore by a chamber wall having a first corrosion resistance and including at least one wall portion with a second corrosion resistance, the second corrosion resistance being smaller than the first corrosion resistance. A method is for detecting corrosion in an internal pipe bore in a pipeline.

A method and system is disclosed for testing a cathodic protection system that protects a metallic structure with one or more DC power sources electrically connected to the metallic structure and an associated reference electrode. The metallic structure may be cathodically protected at multiple locations. A Cathodic Protection Waveform Monitoring Unit (CPWMU) operates independently from power cycling by the cathodic protection system to measure cathodic protection voltage levels by measuring, over one or more measurement time periods, a voltage differential between the metallic structure and its associated reference electrode, a plurality of times when power provided to the metallic structure is cycled on and off. The CPWMU includes digital storage to store values indicative of the measured voltage differentials over the measurement time period. A Cathodic Protection Waveform Reader (CPWR) that may be remotely located from any CPWMU communicates with a number of CPWMU's within communication range to obtain the values stored in the CPWMUs. The CPWR may be positioned in a variety of aircraft, vehicles or be hand carried.

A method and system is disclosed for testing a cathodic protection system that protects a metallic structure with one or more DC power sources electrically connected to the metallic structure and an associated reference electrode. The metallic structure may be cathodically protected at multiple locations. A Cathodic Protection Waveform Monitoring Unit (CPWMU) operates independently from power cycling by the cathodic protection system to measure cathodic protection voltage levels by measuring, over one or more measurement time periods, a voltage differential between the metallic structure and its associated reference electrode, a plurality of times when power provided to the metallic structure is cycled on and off. The CPWMU includes digital storage to store values indicative of the measured voltage differentials over the measurement time period. A Cathodic Protection Waveform Reader (CPWR) that may be remotely located from any CPWMU communicates with a number of CPWMU's within communication range to obtain the values stored in the CPWMUs. The CPWR may be positioned in a variety of aircraft, vehicles or be hand carried.