Pipelines have been used as a channel for the transportation of resources for a significant time in industrial history. Pipelines transport food materials, coal, petroleum, chemicals, water, and many such resources at a large scale across distances, ensuring a steady flow of raw or finished materials, consistent outputs, reduced costs, and safer transport that reduces human contact with potentially hazardous materials or materials that may be easily contaminated.
Pipelines are utilized for a wide range of applications and are often categorized based on the material they carry or the stage of the industrial process that they are utilized for. Pipelines, when categorized based on the stage of the industrial process are called gathering pipelines, distribution pipelines, and transmission pipelines. The material used to construct these pipelines varies according to their application. However, steel is a common material used to construct gathering and transmission pipelines. Materials like copper, plastics, composite materials, and iron may also be used to construct pipelines.
Failure in the integrity of the pipeline may result in catastrophic consequences that may result in the release of the materials carried which may be hazardous and wasteful. Such accidents may cause severe harm to the environment, economy, and human health. These incidents may also be fatal to human and animal life and cause toxic leaks, fires, and explosions.
Pipeline meltdowns disrupt the supply of resources and affect the industries dependent on them. The efforts taken to clean up and rectify such incidents, along with potential legal expenses and revenue losses make pipeline meltdowns an important factor for most industries that utilize pipelines.
CAUSES FOR PIPELINE MELTDOWNS
The integrity of pipelines is of utmost importance and industries aim to evade or counter the failure by employing thorough analysis of the design, materials, and environment.
Pipeline meltdowns may be caused by reasons such as:
Exposure to the elements causes the degradation of the pipelines. The material carried by the pipeline may also lead to corrosion which eventually weakens the pipelines and causes the risk of leakages and rupture of the pipeline. Corrosion may include external and internal corrosion.
Equipment such as pumps, valves, fittings, etc may cause disruptions in the flow of material in pipelines and even failure of its structural integrity. Depletion, irresponsible maintenance, and manufacturing defects of the equipment are responsible for such failure. Other forms of mechanical failure may include stress corrosion cracking (SCC) and selective seam corrosion (SSC).
Inevitable natural phenomena:
Natural disasters like floods, earthquakes, sinkholes, etc. may cause damage or rupture in the pipeline. Pipelines are not designed to handle the force of such phenomena and fail to withstand the stress caused.
Construction errors and accidents:
Damage during maintenance procedures, construction, or excavation work may result in the failure of pipelines. Interaction of the pipeline with poorly operated machinery or tools may cause such damage.
External damage by force:
Tampering of the pipelines by vandals or destructive social elements may also lead to pipeline accidents.
The Shocking Reality of Pipeline Meltdowns Revealed
The term ‘pipeline meltdown’ is not generally used in industries to describe pipeline failure and the consequences arising from it. However, certain incidents in history were of such a large scale and caused significant damage to the point that they could rightfully be considered meltdowns.
Some significant pipeline meltdown disasters are:
Transmountain Pipeline Leak:
In 2007, in British Columbia, damage to a pipeline from the backhoe used by a contractor lead to a leak of around 59,000 gallons of crude oil into a locality.
Deepwater Horizon Oil Spill:
In the year 2010, the Deepwater Horizon offshore rig, in the Gulf of Mexico experienced a blowout that led to a release of 4.9 million barrels of oil into the ocean. This incident severely damaged the marine ecosystem and the fishing industry in the region.
Enbridge Pipeline Spill:
Another major spill in 2010, a pipeline carrying 843,000 gallons of crude oil ruptured and polluted the Kalamazoo River. This incident was caused by corrosion and lack of maintenance and detection of deterioration in the integrity of the pipeline. The reparation efforts took years to complete, and the ecosystem of the area was affected for a significant period.
Sissonville Gas Pipeline Explosion:
In 2012, an old transmission line, built in the 1960s exploded and lead to fires on an interstate. This led to a lot of destruction of property and pollution.
Exxon Pipeline Leak:
In 2013, a pipeline carrying oil leaked into the Yellowstone River. The pipeline became exposed due to damage from floods and leaked approximately 63,000 gallons of oil.
Colonial Pipeline Leak:
In 2016, the Colonial Pipeline, carrying the largest amount of refined products in the United States, experienced a leak. This caused the release of approximately 336,000 gallons of gasoline, which caused an explosion, followed by fires. This affected the fuel supply for many states in the USA and caused fuel shortages and economic losses arising from it.
Husky Energy Pipeline:
In July 2016, a pipeline failed in Saskatchewan, Canada, which led to the release of around 59,438 gallons of crude oil into a river. This polluted the river and affected the supply of drinking water, as well as poisoned the local wildlife and marine life.
Certain factors that may cause such incidents are inevitable and may be caused for a variety of reasons such as failure of equipment, human error, or inadequate maintenance. Thorough inquiries and investigations are carried out when such incidents occur, and stricter safety procedures and standards are employed to avoid any future incidents.
CHALLENGES FACED DURING INSPECTION OF PIPELINES
The sheer nature of pipelines, the location of their installation, and the availability of inspection techniques make their inspection extremely difficult. Some of the common challenges faced by industries during the inspection of pipelines are:
Pipelines usually span long distances and may be placed underground or in remote areas. Accessing these locations can be challenging for inspection as specialized inspection equipment will need to be utilized. Agreements with landowners and transport services are also important as inspection may interrupt regular activity on the land under which the pipelines are laid.
Pipeline radius and span:
Pipeline distribution systems are used in both short-range and long-range transmission applications. The diameter of pipelines can be vast and thorough inspection requires specific inspection technologies and apparatus.
Safety considerations are of utmost importance as pipelines may be hazardous and working with them, or in their vicinity may be hazardous. Strict-safety measures should be enforced for operators and inspectors to ensure the employees’ safety and safe handling of the pipeline and its mechanisms. Precautions should be taken for work in confined spaces, the presence of toxic or hazardous matter, high operating pressures, and the risk of possible failure or leaks.
Pipeline coating or insulating material:
Pipelines are usually coated with protective material to prevent corrosion and regulate temperature. Many inspection processes get hampered by the presence of coating material and the presence of a coating or insulation material may obstruct the testing apparatus and their ability to detect potential defects.
Certain factors like the weather, temperature, moisture, terrain, etc. can affect the inspection process. The ability of testing procedures to accurately detect damage to the pipeline may be affected and the inspection apparatus may either give errors or get damaged.
Inference and analysis of data:
The process of obtaining data on the structural integrity of pipelines is crucial but accuracy of interpretation and analysis is also important. The data obtained must be meticulously studied to prevent deformities, defects, and impending risks to the safety of the pipeline.
Each non-destructive testing procedure that is generally used to study pipelines, has its shortcomings. The nature of the material, environment, scale of the pipeline, and geometries play an important role in determining the eligibility of testing procedures. Sufficient research and knowledge of pipeline systems and testing procedures are required to determine the most appropriate testing method for a given situation.
Advancement in inspection methodologies, robots, remote sensing, and data analysis has enabled engineers, operators, and organizations to continuously improve and control the challenges faced in operating a pipeline transmission or distribution system. Adherence to industry standards and responsible operation ensure the integrity of pipelines.
TECHNOLOGY AVAILABLE FOR INSPECTION OF PIPELINES
Non-destructive methods are extensively used for the inspection and analysis of the integrity of pipelines without obstructing their operation and causing damage. The non-destructive testing methods generally used for the testing of pipelines include:
SafeRad Radiography: This is a method of radiographic inspection, patented in the UK, wherein radiation hazards are eliminated with the use of radiation attenuation material to block radiation and special containers to avoid radiation exposure. This method also channels the radiation beam to limit the area under radiation exposure to only the testing region.
In-Line Inspection: This method, also known as Smart Pigging, utilizes a device called a ‘smart pig’. This device is installed on the pipeline and travels through its length. The apparatus includes sensors to collect data on the status of the pipeline including the geometry, signs of corrosion, defects, and thickness of pipeline walls.
Modern and complex non-destructive testing methods combine multiple testing apparatus, sensors, and robots to easily access, assess and record data on the safety of the pipeline.
INDUSTRY STANDARDS FOR PIPELINE INSPECTION
Stringent industry codes and standards have been laid down by various organizations to ensure that devastating pipeline meltdowns do not reoccur. Apart from these failures, these industry standards ensure safety and work environment quality for the personnel involved in the construction, maintenance, and regular operation of such pipelines.
Some industry standards that ensure pipeline integrity are as follows:
American Petroleum Institute- API 1160: Managing System Integrity for Hazardous Liquid Pipelines.
American Petroleum Institute- API 570: Piping Inspection Code
American Petroleum Institute Recommended Practice 1173- Pipeline Safety Management Systems.
American Petroleum Institute Recommended Practice 1170- Pipeline Safety Management Systems.
American Society of Mechanical Engineers: B31.4 – Pipeline Transportation Systems for liquid hydrocarbons and other liquids
American Society of Mechanical Engineers: B31.8S- Gas Transmission and Distribution Piping Systems- Managing System Integrity of Gas Pipelines
National Association of Corrosion Engineers (NACE): 35100-SP0102-2017- In-line inspection of Pipelines
National Association of Corrosion Engineers (NACE): SP0502-2010- Pipeline External Corrosion Direct Assessment Methodology
National Association of Corrosion Engineers (NACE): SP0206-2016-Internal Corrosion Direct Assessment Methodology for Pipelines carrying normally Dry Natural Gas (DG-ICDA)
National Association of Corrosion Engineers (NACE): SP0204-2015-Stress Corrosion Cracking, Direct Assessment Methodology
Det Norske Veritas (DNV) GL-DT-F101- Submarine Pipeline Systems
International Organization of Standardization (ISO) 9001: Quality Management Systems
National Transportation Safety Board (NTSB) Recommendation P-12-17- Pipeline Safety Management Systems
NPRM- Pipeline Safety: Safety of Gas Transmission and Gathering Pipelines
These standards, along with local regulations and organization standards are followed by operators and administration to obtain accurate and efficient inspection data.
Pipeline meltdowns are rare incidents; however, the negative consequences far outweigh the rarity. Hence, proactive measures to ensure pipeline safety should be carried out and continuous improvement of the integrity of these pipelines and methods of testing and monitoring its physical state is imperative.
Incidents like pipeline meltdowns enforce the need for stringent safety measures, thorough and routine inspections, and improved emergency measures and technologies. The impact of pipeline meltdowns should be mitigated.
The Future of pipeline inspection techniques holds great potential and is driven by technological progress and research. The advancements in robotics and autonomous systems eliminate the need for human monitoring and decrease the probability of human error. Real-time monitoring and automated safety shutdown procedures are made possible using such technology.
Advancement in sensors enables efficient detection of defects as the range and accuracy of the sensors are progressively improved. Research and development have made this apparatus more compact, which may aid in eliminating issues arising from complex and bulky testing equipment.
Progress in data management and analysis has allowed for accurate inferences and better foresight into the integrity and behavior of the pipelines under inspection. Decision-making processes are hence made more efficient and predictive maintenance and risk assessment is made possible.
The integrity of pipelines is a complex and multifaceted issue and continuous improvements to safety standards and risk mitigation should be carried out by responsible industries, engineers, operators, and regulatory authorities.