The oil and gas industry has some of the most complex and high-maintenance infrastructure of any sector, with literally miles of pipeline that has to be kept in prime condition for maximum productivity. Performing line inspection visually is practically impossible, especially when you consider that corrosion and pitting can occur inside the pipeline as well as on the outside.
Fortunately, operators and inspectors can take advantage of magnetic flux leakage (MFL) technology to give them a fast and relatively easy way to detect any flaws or defects that may exist in the pipe. Through the use of MFL pigging technology, oil and gas companies can keep a watchful eye on some of their most important assets and prevent serious problems.
How Does MFL Pigging Work?
Pigging is the process of using a specialized tool called a pig that is inserted into the pipeline and carried along with the flow of fluid or gas. In many applications, this process is used for cleaning the interior of the pipe, but with the use of an intelligent pig it also can be used for non-destructive testing and pipeline inspection.
An MFL pig is equipped with powerful magnets that generate a magnetic field around the pipe as it travels through it. Sensors placed on the outside of the pipe are used to detect any anomalies in the field. Changes in the amount of magnetic flux leaking out of the metal as the MFL pig passes through the pipeline typically indicate areas where the condition of the metal has changed due to pitting, cracking, erosion or corrosion. The sensitivity of the equipment is such that operators can detect the precise dimensions of the anomalies to track the progression of any deterioration in the pipeline integrity.
Benefits of MFL Pigging in Pipeline Inspection
The use of MFL inspection for pipelines is widespread throughout the oil and gas sector, and for good reason. Using this technology to inspect pipes offers a wide range of benefits for operators, including:
- Less Downtime: Because the inspection tool can be introduced inside the pipeline while it is in use, there is no need to shut down production. Operators can continue on with business as usual while the MFL inspection is being performed.
- High Accuracy: Detecting magnetic flux leakage is an extremely accurate method of inspecting pipelines, thanks to the sensitivity of the technology employed. Advanced software analyzes the data to provide operators with detailed and precise measurements of the pipe's condition so they can make the most informed decisions about maintenance and repairs.
- Greater Efficiency: An MFL tool can run through a pipeline at high speeds without any loss of accuracy in the data it produces. What's more, the software is capable of providing immediate analysis of the results so there's no need to wait for a report to make any decisions.
- Exceptional Versatility: This technology can be deployed in liquid and gas pipelines with the same high level of performance. It also serves to detect metal loss in a wide range of pipelines, with no accommodations needed for varying diameters, medium speed or internal pressure.
- Integrations: Another crucial benefit of MFL pigging is that it can be combined with other inspection technologies without interference. This means operators can combine multiple processes into one operation and cut down on the number of tool runs they need to perform.
How MFL Pigging Stacks Up Against Other Inspection Techniques
Magnetic flux leakage is one of two main non-destructive testing methodologies a pipeline operator may employ. The other is ultrasonic testing (UT), which uses ultrasound waves to detect any changes in the thickness of the metal as a UT tool passes through the pipe. Each method has its strengths, such as UT pigging's enhanced ability to detect the overall thickness of the pipe walls. On the other hand, MFL technology generally can be used at higher flow rates and often does a better job of spotting small defects. Choosing the right method involves understanding the qualities of the specific pipeline and what the objective of the inspection is.
However, one of the key advantages of smart pigging is that multiple inspection technologies can be integrated at the same time. MFL testing and ultrasonic testing can be combined to be performed simultaneously, giving a pipeline operator the flexibility to choose the methodologies that make the most sense for the given infrastructure and assets. Utilizing a combination of testing methods at the same time means operators can compensate for each individual method's shortcomings without the need to perform multiple tests on an individual basis.
The Role of MFL Testing in Pipeline Maintenance and Safety
The relative ease and convenience of MFL pigging technology make it a critical tool for keeping pipelines working as efficiently and safely as possible. Its ability to scan for defects and anomalies so quickly and easily means potential problems with a pipe can be spotted and dealt with before they have an opportunity to develop into something more serious. This not only prevents costly downtime and the potential loss of production, but it also serves to enhance on-site safety. The use of MFL for inline inspection helps prevent unexpected pipeline breaches and other equipment failures that could put workers at risk and harm the environment. By conducting MFL testing on a regular basis, operators can ensure their assets will continue to remain in good working order for as long as they can.
MFL pigging has made the oil and gas sector's job that much easier, giving operators accurate, actionable insights into the health of their infrastructure without sacrificing efficiency or production. Thanks to its exceptional and cost-effective capabilities, there's every reason to believe MFL inspection will continue to be a cornerstone of the industry for the foreseeable future and beyond.