Cathodic Protection

Most wells are constructed to extract groundwater, inject water, or monitor groundwater conditions. Other, less common types of wells include cathodic protection wells. Cathodic protection wells, sometimes called 'deep groundbeds,' house devices to minimize electrolytic corrosion of metallic pipelines, tanks, and other facilities in contact with the ground.

"Cathodic protection" is a term used for certain measures taken to prevent or minimize electrolytic corrosion of metallic equipment and structures. Cathodic protection devices redirect current to ow from a "sacricial" anode to the soils-water electrolyte, instead of from an anode area on a pipeline or other metallic structure to be protected. The protective anode's role is to corrode in place of the metallic object it is designed to protect, as shown in Figure . The protected facility is made to be a permanent cathode by use of cathodic protection devices. us, the facility is said to be "cathodically protected."

Protective or sacricial anodes can be placed close to ground surface or at signicant depth. Anodes have been placed at shallow depths in horizontal and vertical arrays for many years. Shallow arrays are oen not well suited for metropolitan areas because of land requirements, or suited for areas where electrical interference may be high.

Deep vertical anode installations, usually referred to as "cathodic protection wells," were rst developed and used during the 1940s. ey were developed in response to the constraints of shallow anode arrays.

Cathodic Protection Wells

Cathodic protection wells are widely installed to protect metallic objects in contact with the ground from electrolytic corrosion. Such objects include petroleum, natural gas, and water pipelines, and related storage facilities; power lines; telephone cables; and switchyards. Cathodic protection wells are sometimes used to control electrolytic corrosion in large water wells.

Many cathodic protection wells have been constructed to protect pipelines that transport natural gas or other "hazardous" materials. e Natural Gas Pipeline Safety Act, Public Law 90481- adopted by Congress in August 1968, provides requirements for cathodic protection of certain pipelines.

Most cathodic protection wells in uae are located in areas where underground pipelines or "conveyance" systems are numerous and must be protected.

"Cathodic protection" is a term used for certain measures taken to prevent or minimize electrolytic corrosion of metallic equipment and structures. Cathodic protection devices redirect current to ow from a "sacricial" anode to the soils-water electrolyte, instead of from an anode area on a pipeline or other metallic structure to be protected. e protective anode's role is to corrode in place of the metallic object it is designed to protect. e protected facility is made to be a permanent cathode by use of cathodic protection devices. us, the facility is said to be "cathodically protected."

Drilling a 6- to 12-inch diameter borehole to a desired depth. Cathodic protection wells normally range from 100 to 500 feet in total depth. A few wells have been constructed to depths of 800 feet.

Placing a string of anodes in the borehole within a designated interval, usually referred to as the "anode interval."

The protective anodes of a cathodic protection well usually corrode away with time. us a cathodic protection well's anodes determine the well's useful life. Anodes are usually designed to last 15 to 20 years.

There has been an increasing tendency to construct cathodic protection wells with large diameter vent pipe or casing so that anodes can be replaced through the casing. Anode replacement through casing eliminates the need to drill replacement wells when anodes have been expended.

Drilling & Installation Work for Cathodic Protection (CP)

Cathodic protection (CP) is a technique to control the corrosion of a metal surface by making that surface the cathode of an electrochemical cell. It is a method used to protect metal structures from corrosion. CP systems are most commonly used to protect steel pipelines and storage tanks, steel pier piles, ship hulls, offshore oil platforms and onshore oil well casings. Since first discovered in the early 19th century, CP has been proven an effective method for reducing corrosion and preventing stress corrosion cracking in large metal structures.

There are two types of CP: Sacrificial and Impressed CP. Sacrificial (or galvanic) CP protection uses anodes designed and selected to have a higher electrochemical potential than the metal of the structure to be protected. The potential of the structure’s surface is polarized, until the surface has a uniform potential, halting the corrosion process. Of course, the galvanic anode continues to corrode, consuming the anode material until eventually it must be replaced. This form of CP is not practical for large scale installation where long- term corrosion protection is required.

Impressed current cathodic protection (ICCP) involves the application of an external DC current through long-lasting anodes. Anodes are normally installed in grouped configurations in the electrolyte. These groupings (both horizontal and vertical) in an underground application are called groundbeds. The groundbeds are connected to the power by a positive cable to the power source. A negative cable connects the power source to the structure.

In field of Cathodic Protection Al Shallalat provides comprehensive and complete range of services including; system engineering &
design, manufacturing and/or supply of all the equipment and materials, installation, field supervision and assistance for commissioning meeting customers’ needs.

We are committed to provide efficient design and cost effective Cathodic Protection solutions to meet each customer’s specific requirements.

Corrosion protection is an essential component in the maintenance of all steel-based assets. Al Shallalat focuses in developing and utilizing leading edge data acquisition analysis and communication technologies. Where pipelines and underground storage tanks are involved, the application of appropriate corrosion management will ensure assets integrity vis-a-vis safe and reliable supply of products such as gas, oil and water.

Cathodic Protection Services:

1. Cathodic protection for Oil & Gas, Process Plants, Power Plants and other industries.
2. Cathodic protection for pipelines (including large diameter)
3. Cathodic protection for storage tanks Cathodic protection in hazardous environment
4. Cathodic protection of reinforced concrete structures.
5. Remote monitoring for CP systems