Marine environments can be some of the harshest environments on the planet for corrosion of steel structures. Indeed, the earliest application of cathodic protection can be traced back to Sir Humphrey Davy and the British Navy’s investigation into corrosion on copper sheathed wooden vessels. This video demonstrates MATCOR’s impressed current sled anodes that are successfully being used to protect steel piles for jetties, docks and other similar steel structures in marine environments.
At 1:03 in the video, we demonstrate how the marine anode sled operates with a trade show model.
At 4:05 you see a MATCOR Sea-Bottom Marine Anode Sled being lowered into the water as part of the cathodic protection system protecting a steel jetty structure in Indonesia. The jetty is constructed with four interior rows of concrete piles and an exterior row of 247 bare metallic piles. The operator initially considered galvanic anodes to protect the jetty from corrosion – until they compared the cost, time and effort to install the required 374 aluminum anodes each weighing 200 each. Instead they opted for six marine anode sleds, taking only three days to install.
For assistance with near shore marine anode systems, please CONTACT US.
As the world’s leading manufacturer of linear anodes, and the only manufacturer of a linear anode specifically designed for use with horizontal directional drilling installations, we thought it would be appropriate to discuss various anode options for HDD installation.
Can any linear anode be used in conjunction with horizontal directional drilling?
An engineer’s favorite answer to any question is “It depends” and this is certainly the case with HDD installations. The important thing to note is that when attempting to pull a linear anode through a bore hole, there is a chance that the pulling forces on the anode will exceed the strength of the anode and cause the anode to break. Even if the anode does not break completely, stretching of the anode can weaken or damage the internal header cable or anode to cable connections.
There are a lot of variables that can impact the success of any linear anode HDD installation. The short answer is yes, with the right bore hole, any linear anode can be pulled successfully. Conversely, with the wrong bore hole, any linear anode can be pulled apart during installation.
What are the key factors to consider when planning an HDD linear anode installation?
The key factors include a site geotechnical investigation, terrain and route mapping, and bore planning.
Site Geotechnical Investigation
Any discussion about HDD installation planning starts with a site geotechnical investigation. Obtaining a geotechnical survey or as much geological information about the respective jobsite is very important. A great amount of record information is available through sources including:
United States Geological Society (USGS)
National Geological Map Database
Publications of the US Army Corps of Engineers
The National Soil Survey Center (NSSC) a division of the US Department of Agriculture
State Departments of Transportation
Original construction records
In addition to record information, site-specific investigations (soil bores and soil sampling) by trained geologists and geotechnical service companies can provide valuable detailed data on the planned bore area geology. The geotechnical analysis should identify several relevant items including:
Soil identification along the bore route to locate rock, rock inclusions, gravely soils, loose deposits, discontinuities and hardpan
Soil strength and stability characteristics
Local drillers with experience in the identified area can often provide valuable insight based on similar projects in the same area.
Terrain and HDD Route Mapping
Collecting accurate topographical information of the bore route is another critical component in the planning phase. Terrain and HDD mapping includes determining HDD bore hole entrance and exit locations, identifying and mapping elevation profile changes, ensuring that other utilities are appropriately identified and avoided, assessing the need for traffic control, evaluating any environmental considerations or limitations that might impact the use of drilling muds and hole conditioners.
Bore Planning Software
Several commercial bore planning software tools are available to assist in the planning phase. These programs utilize the soil and geotechnical data combined with the terrain and route mapping information to provide a graphic visualization of the job helping the driller more accurately “see” and perform the job from start to finish. These software tools help the contractor select the appropriate drill rig, drill bit type and back reamer based on the anticipated soil conditions and the total bore length. By choosing the drill stem and length, the desired bore path depth, desired minimum cover, diameter and bend radius of the product being pulled, the software plots a proposed bore pitch, calculates setback distances, figures point to point bore paths, estimates hole volumes and calculates pullback time. The software can also provide a fluid–mixing process map that shows how much mud should be used based on soil conditions, drill unit and tooling used.
If a bore planning software package is not used, field calculations should be performed to appropriately choose the correct drill rig, drill bit and back reamer tooling requirements, desired bore path and quantity and type of drilling fluids to be utilized.
What anode should be selected for HDD installation?
MATCOR manufactures two linear anode products (SPL-FBR™ Linear Anode and the Iron Gopher™) that are both, in the right circumstances, suitable for use in HDD installations. The installation contractor, along with the client, must carefully select the appropriate anode and the appropriate anode installation methodology. The two generally accepted methodologies are direct pulling of the anode through the properly conditioned borehole by attaching the anode to the backreamer after the initial pilot hole has been drilled. The second installation methodology involves pulling an HDPE pipe sleeve into the borehole, installing the anode inside the pipe, and then removing the HDPE sleeve. The tables that follow are intended to assist the installer in selecting the appropriate anode and installation methodology. The selection of the appropriate anode type and installation methodology is subjective based on a qualitative analysis.
TABLE 1 – Linear Anode Application Difficulty
• Less than 200 foot pulling length • Minimal changes in elevation • No environmental restrictions on use of drilling muds/hole conditioners • Installation costs and risks are low
• 200-500 foot pulling length • Moderate elevation change • No environmental restrictions on use of drilling muds/hole conditioners • Installation costs are modest and risks are low
• 500-1000 foot pulling length • Moderate elevation changes • Some environmental restriction on use of drilling muds/hole conditioners • Installation costs are higher and risks are moderate
• 500+ foot pulling length • Extreme or multiple elevation changes • Restrictive environmental limits on use of drilling muds/hole conditioners • Critical application with high costs and risks
TABLE 2 – Anode Selection Guidelines
Linear Anode Application Difficulty 1
SOIL TYPE 2
Gravel / Coble
*Anode is to be installed in HDPE sleeve that is then removed
NOTES 1Classifying the linear anode application difficulty using Table 1 is a qualitative analysis and may warrant taking into consideration other risk factors that may be appropriate. In general, the more difficult the application, the more costly the installation component, the greater the case to use the higher pulling strength Iron Gopher and the greater the incentive to use temporary HDPE sleeving to assure the lowest risk installation. 2Soil Types based on the US Department of Agriculture Soil textural classification guidelines. Earth Loams would include the broad range of Sandy Clay Loam, Loam, Silt Loam, and Clay Loam.
What contingency planning is warranted for an HDD installation?
Even with proper project planning and an experienced installation contractor, some consideration should be given to contingency plans if something unforeseen happens during the HDD boring and anode installation.
Are alternate bits available if needed to complete the pilot hole?
Is a larger boring machine available if needed?
If drilling is more challenging than anticipated, do we have ready access to HDPE pipe for sleeving if warranted?
Does the project warrant having one or more spare anode assemblies in the event of an anode breakage during installation?
While these risks can be greatly minimized with proper planning, asking these questions before mobilizing to the site can help solve problems more quickly, saving time and money.
For assistance with linear anode selection for HDD applications, MATCOR’s linear anode systems, project management or installation, please CONTACT US.
What is the best way to prevent damage to sled anode cable connections due to rough sea current and waves?
MATCOR marine sled anodes (Sea-Bottom™ Anodes) are designed with the cable connections routed inside a high density polyethylene (HDPE) protective pipe with holes to provide a level of mechanical protection. Then we use concrete weights to help secure the HDPE pipe (with the cable inside) to the sea bottom so that they are not subject to wave or tidal action.
The protective housing is pictured here and called out as item 4 on the drawing on page 3 of our Sea-Bottom Marine Anode Sled brochure. For the concrete weights, you can use a variety of methods from sacks of concrete to custom formed concrete cast weights. Below is a photo of the weights that were locally supplied to us for a recent project in Indonesia. These weights are installed by divers during the sled anode installation.
For assistance with impressed current anode system design, MATCOR’s Sea-Bottom Marine Anode Sleds, project management or installation, please contact us at the link below.
MMO anode technology has taken over the cathodic protection industry and MATCOR has been on the forefront for the last 20 years. Ted Huck, our VP of International Sales was interviewed at the recent NACE Corrosion Conference. In this video he discusses MMO anode technology for cathodic protection systems and the importance of reliable anode to cable connections.
MMO Anode Technology
MMO anodes, or mixed metal oxide anodes are the latest technology in the corrosion industry. Mixed metal oxide anodes are lightweight and durable with a very low consumption rate.
MMO anodes are a mix of metal oxide electrocatalysts. In the presence of a DC voltage source they cause an electrical reaction that generates cathodic protection current. Unlike conventional impressed current anodes that physically consume as part of the cathodic protection reaction (at rates measured in kg/amp-year), MMO anodes are dimensionally stable and do not consume. Instead, they have a long and predictable catalytic life. MMO anodes consist of a thin coating of the MMO catalyst over an inert lightweight titanium substrate and are available in a wide range of shapes and configurations.
Why Cathodic Protection Systems Fail
The most critical component to any cathodic protection anode system is the connection of the anode to the cable that runs back to the power supply. Because the cable is part of the anode system, if it has any nicks or defects or is not water tight, that cable can become part of the anode and will very quickly consume. When that happens, the anode fails. So, with cathodic protection systems it is imperative to have the highest quality connections.
Typically, when a cathodic protection anode system fails, it is not the anode that fails, it is the anode connection that fails. MATCOR has developed a proprietary technology for connecting wire anodes to cable, called Kynex®. Wire anodes are the heart of a lot of our products and this proprietary anode technology is a huge leap forward in the reliability of these connections.
At the end of the day, for our clients, it’s all about delivering value. It’s providing a cost effective solution that’s going to serve them for a very long time. As a designer and manufacturer of cathodic protection anode systems, we are able to specifically address client needs with customized corrosion prevention solutions that provide:
Great economic value
MATCOR Products and Services
MATCOR is one of the world’s leading cathodic protection companies. We design, manufacture, install and service cathodic protection systems for clients worldwide. MATCOR provides services to the pipeline, midstream and oil & gas industries, protecting assets such as pipelines, storage tanks, and compressor stations. We also do a lot of work in the power industries, petrochemical, and chemical industries. Anywhere where you have buried steel structures, we are there to stop corrosion. We encourage you to contact MATCORthrough our website where our corrosion specialists and engineers can provide a solution tailored to your needs.
Cathodic protection, when applied properly is an effective means to prevent corrosion. For many underground applications, such as pipelines, cathodic protection system design is relatively straightforward. Plant and facility environments, however, are not simple applications. Plants have congested underground piping systems in a tightly spaced footprint. The presence of copper grounding systems, foundations with reinforcing steel embedded in concrete, conduit, utility piping and structural pilings (either bare or concrete with reinforcing steel) can greatly complicate the task of designing a cathodic protection system.
For simple plant facilities, it is possible to isolate the piping and utilize a conventional galvanic corrosion prevention system. This works only if the plant piping is electrically isolated from other underground structures for the life of the facility. For most plant and facility applications, it is not practical to isolate the piping from the grounding system for the life of the facility. In these cases an impressed current anode system is the only alternative.
3 Cathodic Protection Methods for Underground Piping and Structures
There are three basic approaches to cathodically protect underground piping and structures using impressed current anodes.
One method is the deep anode in which high current capacity anodes are installed from the structure in a deep hole drilled vertically 150+ feet deep. This is analogous to lighting a football field with floodlights.
Shallow Anode or Distributed Anode Bed
Another method is to use a shallow ground bed anode design where many smaller capacity ground bed anodes are spaced near the intended structures – analogous to street lamps lighting a street.
The third method is to place a linear anode parallel to and in close proximity to the piping to be protected discharging current continuously along its length – similar to fiber optic lighting.
This technical bulletin details the advantages of using the linear anode approach for new plant construction projects to protect buried piping in a congested environment. This approach provides the most effective solution both technically and commercially.
Plant and Facility Cathodic Protection Design Issues
Electrical Isolation in a Congested Plant Environment
Electrical isolation is a major concern when designing a CP system for any plant or facility application. Isolating a single cross country pipeline segment from point A to point B is achieved rather simply through the use of electrical isolation flanges/isolation joints that the pipeline operator maintains and tests regularly. The realities of power plant piping networks, on the other hand, significantly complicate electrical isolation. By code, everything above grade in a plant must be grounded, yet it is common to see cathodic protection systems designed based on isolation of the buried piping. Even if electrical isolation is achieved during the plant construction, maintaining electrical isolation over the life of the facility may not be realistic. Given the speed and complexity with which new plants are erected, achieving electrical isolation during construction is no simple task. Once installed, electrical isolation flange kits require regular monitoring and periodic replacement that often does not occur. Piping modifications and other plant maintenance activities can also result in an inadvertent loss of electrical isolation. Cathodic protection design that relies on electrical isolation should be avoided for plant applications.
Current Distribution – a Critical Issue in Cathodic Protection Design
Another critical issue that must be properly considered during the design of a CP system for plant applications is the highly congested underground environment and the challenges of achieving thorough current distribution. Buried piping is often located in congested underground areas in close proximity to grounding systems, foundations with reinforcing steel, pilings systems, metallic duct banks and other structures that can shield current from the piping systems that are the intended target of plant cathodic protection systems. It is virtually impossible to assess where current will go in a plant environment – the more remote the anode source, the more difficult it is to assure appropriate current distribution.
When discussing current distribution, it is also important to discuss the potential for stray current. For grounded systems, current that is picked up by other buried metallic structures is merely current that is wasted and not available to protect the intended buried piping structures. For isolated metallic structures, such as foreign pipelines, ductile iron piping systems, and nearby facilities or structures, stray current may be a significant concern. Stray current problems occur when current is picked up on an isolated structure and later discharges off that structure and back to a grounded structure. At the location where stray currents discharge, rapid corrosion may be inadvertently induced on the isolated structure.
The Case for Linear Anode Cathodic Protection System Design
The linear anode solution consists of long runs of linear anode installed parallel and in very close proximity to the piping being protected. The current output is kept very low and is generally consistent across the entire system. A linear anode is in effect a distributed system with an infinite number of anodes spaced continually. This system provides the best technical cathodic protection solution and minimizes the current output required as follows:
Does not require electrical isolation. Because the linear anode is closely located next to the piping being protected, electrical isolation is not a significant concern. The anode is “closely coupled” to the piping and operates with a very low anode gradient that minimizes any losses to nearby structures including grounding.
Assures good current distribution as the anode runs parallel to the piping being protected. The linear anode cathodic protection system design eliminates any requirement for supplemental anodes to address areas where remote anodes may be shielded after the CP system is commissioned. Wherever the piping goes, the linear anode follows in the same trench. This also makes it very easy to adapt the design during piping revisions that may change the piping system routing as the plant construction proceeds.
Eliminates risks of stray current. Close proximity to the piping being protected significantly limits current losses to other structures and virtually eliminates shielding and stray current concerns. This also significantly reduces the total current requirements for the system, reducing the rectifier requirements.
Access issues – the linear anode is installed in very close proximity to the piping that is to be protected. This minimizes the risk of third party damage and reduces trenching required for buried cable. If installed in conjunction with the piping, the anode can be placed in the same trench as the piping affording the anode protection by the piping itself from external damage. This is a very cost effective cathodic protection installation when installed concurrently with the piping.
Ease of installation – when installed alongside the piping as the piping is being installed, the installation is simply a matter of laying the anode cable in the trench.
Our experts are happy to answer your questions about your plant piping cathodic protection system design.
Iron Gopher® Impressed Current Linear Anode System designed for horizontal directional drilling (HDD) is installed beneath an above ground storage tank (AST)
Chalfont, PA (May 27, 2015) – MATCOR, Inc. the trusted full-service provider of proprietary cathodic protection products, systems, and corrosion engineering solutions recently released a video showing the installation of the company’s Iron Gopher impressed current linear anode system at the site of an above ground storage tank in Texas.
Trenching to install cathodic protection systems may not be feasible for applications such as cross country pipelines, congested industrial environments and under above ground storage tanks. For these horizontal directional drilling applications, a linear anode with superior mechanical strength is required. The Iron Gopher with Kynex® technology is the only impressed current linear anode designed specifically for cathodic protection in horizontal directional drilling applications.
“As another example, Colonial Pipeline installed several thousand feet of our Iron Gopher® linear anode at an HDD project in NE Georgia,” said Ted Huck, VP of Sales for MATCOR. “With its unique design and greatly increased strength, Iron Gopher is superior to anything seen in the market for cathodic protection in HDD applications.”
MATCOR to Present on Impressed Current Linear Anode Cathodic Protection at NACE UAE Corrosion Conference in Abu Dhabi
Chalfont, PA (April 27, 2015) – MATCOR, Inc. the trusted full-service provider of proprietary cathodic protection products, systems, and corrosion engineering solutions will present a paper exploring the use of flexible impressed current linear anodes to minimize current densities for a wide range of cathodic protection applications at the annual NACE UAE Corrosion Conference held at the St. Regis in Abu Dhabi, United Arab Emirates May 12-14, 2015.
The presentation explores flexible impressed current linear anode cathodic protection that extends the benefits of linear anodes for various CP applications. To minimize current distribution challenges, the linear anodes are designed utilizing multiple internal connections, which provides redundancy and protection against uneven anode consumption, minimizes current densities and allows placement in close proximity to the structure. The linear anode is simple to install, requiring only a small trench, and is ideal for congested areas and tight spaces. See below for the complete abstract.
ABOUT THE AUTHOR
Shailesh Javia serves as International Director for MATCOR and has over 22 years experience focused on corrosion engineering and cathodic protection. His diverse knowledge and experience includes designing cathodic protection systems, managing turnkey CP projects and conducting commissioning surveys for cross country and city gas pipelines, tanks and vessels, tank bottoms, and industrial facilities including fertilizer, petrochemical and power plants, and refineries. Mr. Javia is a certified NACE Cathodic Protection Technologist, has successfully completed the NACE Direct Assessment Course and has presented several papers at NACE and ASME conferences.
ABSTRACT: Applications of Impressed Current Linear Anodes in Cathodic Protection
Flexible impressed current linear anodes can extend the benefits of linear anodes to a wide range of cathodic protection applications. Tight spaces, high traffic areas, poorly coated pipelines, new construction tank bottom, tank bottom retrofits, reinforcing steel-in-concrete, sheet pile walls or inside large diameter pipes – are all good examples of linear anode cathodic protection applications.
Linear anodes handle current distribution challenges by minimizing current densities, in addition to placement in close proximity to the structure being protected from corrosion. Innovative design utilizing multiple internal connections provides redundancy, protects against uneven anode consumption and minimizes voltage drop.
Linear anodes can simply be laid alongside a new pipeline; cable plowed next to an existing pipeline, or installed utilizing horizontal directional drilling (HDD) under an existing structure. Linear anodes require only a small trench for installation, ideal for congested areas and minimizing landowner “right of way” issues.
If Warren Buffet’s investment strategy is any indication, pipeline efficiency is going to start playing a bigger role in moving crude oil and natural gas in the United States.
The Berkshire Hathaway luminary is spearheading a swap of about $1.4 billion in shares of Phillips 66 for full ownership of the energy company’s pipeline petroleum transport services business. The business unit’s focus is polymer-based additives that are used to move crude oil and natural gas through pipelines more efficiently by reducing drag.
The shift in Berkshire’s investment strategy comes amid a boom in U.S. crude oil and natural gas production. Since many liquids pipelines in the United States are operating at capacity, producers can use the pipeline petroleum transport additive to quickly increase capacity without immediately growing pipeline infrastructure.
Although future pipeline projects may be in the works to meet the sharp increase in demand, the process of gaining approval for new pipeline projects can be slowed by permitting.
A greater reliance on existing pipelines for transporting liquids means that producers and pipeline owners need to pay even more attention to cathodic protection management, according to Kevin Groll, project management director for MATCOR, a Pennsylvania-based company that specializes in cathodic protection products and services.
“Any time you have pipeline you have to protect it from corrosion,” Groll said. “And that’s especially true when you increase the value of a pipeline by increasing its capacity. If that pipeline were to develop a corrosion problem you’d be facing a situation where your profitability could suffer significantly.”
“With pipeline owners using additives to push greater volumes of liquids it becomes imperative to use cathodic protection products such as impressed current anodes and cathodic protection rectifiers to protect the increased capacity and profitability of the pipeline infrastructure.”
Production from the Marcellus Shale natural gas reserves is expected to exceed 13 billion cubic feet per day this December, nearly seven times the 2 billion cubic feet per day it produced during the same period in 2010, according to a recent report.
The report on Marcellus Shale production data, by the U.S. Energy Information Administration, said the figure would equal about 18 percent of total U.S. natural gas production during the month.
One of the Marcellus Shale companies that’s taking advantage of the natural gas boom is Cabot Oil & Gas Co., based in Houston, which claimed 15 of the 20 highest-producing natural-gas wells in the area during the first half of the year.
According to Dan O. Dinges, Cabot’s chief executive officer, 10 wells from a single well pad in Auburn Township produced enough natural gas in 30 days to meet the average monthly demand of the entire city of Philadelphia.
Cabot plans to increase its Marcellus Shale drill rigs from six to seven in 2013, with each rig capable of drilling 20 wells during the course of the year.
The sharp rise in natural gas reserves production hints at the growing need for Marcellus Shale companies to incorporate pipeline corrosion control equipment like cathodic protection rectifiers into their gas delivery infrastructure, according to Chris Sheldon, who works as utilities practice lead for MATCOR, a Pennsylvania-based cathodic protection company.
“Marcellus Shale companies are experiencing a tremendous upswing in natural gas production and are building new drill rigs and digging new wells to take advantage of the vast natural resource at their feet,” Sheldon said. “That means a lot of new pipes are going to be laid. And more pipes means more opportunities for corrosion.”
“At MATCOR, we’re here to help Marcellus Shale companies, as well as other pipeline companies and natural gas producers, with a full line of advanced cathodic protection equipment, systems and services designed to help them meet their corrosion control needs.”
A proposed $3.5 billion natural gas pipeline took a leap forward last Thursday and by 2017 is expected to be providing fuel to run Florida Power and Light Co.’s plants.
Florida’s two pipelines, the Florida Gas Transmission pipeline, and Gulfstream pipeline deliver gas primarily from such offshore areas as the Gulf of Mexico.
The pipeline’s northern 465 miles is a joint venture of Houston-based Spectra Energy subsidiary Sabal Trail Transmission and a newly formed subsidiary of Florida Power and Light’s parent company, NextEra Energy Inc., called U.S. Southeastern Gas Infrastructure LLC. The southern 126 miles, known as Florida Southeast Connection, is a subsidiary of NextEra.
The pipeline will travel through four Alabama counties, eight Georgia counties and 13 Florida counties. It will end at Florida Power and Light’s Martin County plant near Indiantown. The new pipeline will connect to FPL’s new plants under construction in Riviera Beach and Hollywood.
Commissioner Eduardo Balbis said the pipeline will help mitigate supply interruptions and price fluctuations. It’s also a plus that the cost is $450 million below that of other options.
The project is projected to create more than 6,600 jobs.
Jeff Householder, president of Florida Public Utilities Co., said the additional gas supplies, especially the cheaper shale gas, are needed for the state’s growth and economic development. He expects his company and others will build lateral lines from the pipeline.
Florida Power and Light has signed agreements with the two entities that will own the new pipeline for an initial 400 million cubic feet per day beginning in 2017 with an option for an additional 200 million cubic feet in 2020 and later.
Florida Gas Transmission’s pipeline has a capacity of 3,100 million cubic feet per day, and Gulfstream’s pipeline has a capacity of 1,300 million cubic feet per day
The project approved Thursday differs from a proposal the PSC rejected in 2009 when Florida Power and Light sought to build the 280-mile Florida EnergySecure Line itself.
The pipeline must be approved by the Federal Energy Regulatory Commission and other federal and state agencies. It would give the state 25 percent more natural gas capacity.