A flexible pipe for subsea transportation of production fluids, a method of manufacturing flexible pipe body and a method of providing corrosion protection to armour wires of at least one tensile armour layer of a flexible pipe having a breached pipe annulus are disclosed. The flexible pipe comprises a fluid retaining layer, an outer sheath and at least one tensile armour layer comprising a plurality of helically wound monofilament armour wires of a first material, each having a non-circular cross section with an aspect ratio of greater than 1:2 disposed between the fluid retaining layer and the outer sheath. The tensile armour layer further comprises at least one helically wound elongate anode element substantially having a cross-section aspect ratio of 1:1 and comprising a further material, interposed between armour wires, the anode element cross section having an area that is 50% or less of a corresponding area of said non-circular cross section.

A method to reduce the total anode mass of a cathodic protection system by reducing or eliminating the total cathode area is disclosed, the system comprising: a metallic first-layer coating which being anodic to the component or substrate to be protected, bonded to the component or substrate and electrically conductive. A sacrificial anode in the form of a metallic second-layer coating is distributed over the first-layer coating. The second layer coating has an open circuit potential that is equal to the first-layer coating or being anodic to the first-layer coating and to the substrate, the second-layer coating electrically conductive, bonded to the first-layer coating and exposed to the surrounding environment.

An electric field gradient sensor is presented, having a sensor body having an outer surface; and a plurality of electrodes distributed over the outer surface, each electrode having an electrode surface facing outward from the surface. The plurality of electrodes are arranged forming a plurality of electrode pairs, each electrode pair formed by a first electrode and a second electrode located on opposite sides of the sensor body. This sensor enables three-dimensional measurements of the electric field gradient along structures located in an electrically conductive medium, such as subsea structures, for example for monitoring the cathodic protection of such structure.

Zinc ribbon anodes and methods of making the same are provided herein. In some embodiments, the zinc ribbon anode includes a hollow elongated zinc ribbon having a first end, a second end opposite the first end, an outer surface, and an inner surface defining a hollow space extending from the first end to the second end; and an elongated metal core disposed within the hollow space and in contact with the inner surface, wherein a cross-section of the hollow elongated zinc ribbon taken between the first end and the second end and perpendicular to the outer surface is polygonal in shape, and wherein the cross-section has an aspect ratio of at least 1.5:1.

The invention relates to a propeller arrangement in a cathodic protection system for a marine vessel with a marine propulsion system, which cathodic protection system comprises a direct current power source with a positive terminal. The propulsion system comprises at least one driveline housing at least partially submerged in water; a torque transmitting drive shaft extending out of the driveline housing; and at least one propeller mounted on the drive shaft. According to the invention, the at least one propeller is electrically isolated from its drive shaft. Each electrically isolated propeller is electrically connected to a slip ring connector, which slip ring connector is in electrical connection with the positive terminal. The invention further relates to a vessel provided with such a propeller arrangement.

A system provides impressed current cathodic protection (ICCP) of a marine structure (50) and powers a load in a load arrangement (100) arranged on the marine structure (50) and in contact with the water (10). The power source provides a supply current to generate an electrical potential of the marine structure. The load arrangement (100) has an electrode arranged (130) to extend from the load arrangement into the water for transferring the supply current via the water. The load (20) is coupled between the electrode (130) and a power node (120). The power source is connected to the marine structure and to the power node. The load arrangement is arranged to use the supply current to provide power to the load. Thereto the supply voltage may have an AC component at a high frequency. The load may be an UV-C LED for emitting anti-fouling light.

The invention discloses an offshore Tension Anode system and an installation method thereof. The system comprises a tension platform, a tension device, a composite cable integrated with auxiliary anodes and reference electrodes, and a gravity type foundation base, wherein the tension device is installed on the tension platform; the upper end of the composite cable is tensioned by the tension device, and the lower end of the composite cable sinks to a seabed along with the gravity type foundation base and is anchored by the gravity type foundation base; and the composite cable integrated with the auxiliary anodes and the reference electrodes is a main part of the system. The system is simple in structure and convenient to install and transport. The invention further discloses the installation method of the system, which can safely and reliably install the offshore tension anode system on an offshore platform. The installation method mainly comprises: (1) lifting the composite cable and the gravity type foundation base to an offshore platform; (2) installing the gravity type foundation base on a seabed; (3) installing the composite cable; (4) tension adjustment and lock fixation of composite cable.

An anti-fouling arrangement in a marine vessel with a marine propulsion system, the propulsion system comprising at least one driveline housing, a torque transmitting drive shaft extending out of the driveline housing, and at least one propeller mounted on the drive shaft. The at least one propeller is electrically isolated from its drive shaft, wherein each electrically isolated propeller is connected to a positive terminal of a direct current power source, and each metallic component to be protected against fouling is connected to a negative terminal of the direct current power source. A control unit is arranged to regulate the voltage and current output from the direct current power source.

A marine ICCP system includes an electrical circuit comprising a primary and a secondary circuit. The primary circuit comprises a first electrode connected to a positive terminal of a power source to act as an active anode; and a second electrode connected to a negative terminal of the power source. The secondary circuit comprises a passive electrode normally disconnected from the electrical circuit and arranged to act as back-up protection, wherein the second electrode connectable to the passive electrode. The passive electrode is arranged to be connected to the power source if a detected output voltage in the primary circuit reaches a maximum value and if a determined polarization potential for the cathode is insufficient. The control unit is operable to control the output voltage supplied to the primary and secondary circuits separately in order to supply an individual output voltage to each circuit.

A system and method for direct and/or active detection and monitoring of civil engineering or other infrastructural structures, and in a preferred embodiment, for hydrocarbon leakage in oil and gas pipelines, storage structures, and/or transportation structures. Particularly, the system and method relate to various nanocomposite sensor coating and data gathering systems. In one embodiment, the apparatus includes a single measurement sensor coating (thin film) sensor. Other embodiments relate to multiple measurement sensor coating systems. The sensor is comprised of either a discrete conductive filament layer, or a single or multiple mesh of interwoven filaments of conductive material in one direction and nonconductive material in a perpendicular direction, as a substrate coated with sensitive coating materials to form a sensor grid. Various embodiments of the sensor coating and their applications are also disclosed.