Ultrasonic In-Line Inspection Technology (InVista) and Fitness-For-Service Assessment (LifeQuest) for non-traditional pipeline inspection applications.
Proposed pipeline integrity regulations allow operators to assess non-traditional pipeline sections using “best available technology”. The oil, gas and chemical process industries now use ultrasonic in-line inspection technology “Furnace Tube Inspection System” (FTIS) for detection of corrosion, other metal loss defects and deformation and it has accepted it as a valid means of assessing the condition of pipes and pipelines where traditional inspection preparation or access is difficult or expensive. The (FTIS) technique has now been extensively used in the field for evaluating the condition of pipes and has performed well in identifying corrosion and deformation in pipes in a variety of situations including buried and aboveground pipeline sections as well as plant process piping.
The InVista ultrasonic tool is the pipeline hybrid of (FTIS) and is a fully self contained, free flowing In-Line Inspection tool, equipped with sensors equally distributed around the circumference of the tool. The presence of corrosion or other three dimensional anomalies disturbs the ultrasonic pulse sequence, and is picked up by the receiver and recorded onboard. Since every pipeline varies by age, construction method, product transported, type of line coating, soil condition and climate, pipeline operators are now using “best available technology”, a new generation of internal inspection tools offering case-specific sensitivity and through conduit capability.
Fitness-for-service assessment is a multi-disciplinary approach to evaluate structural components to determine, as the name suggests, if they are fit for continued service. The component of interest (Pipelines) may contain flaws or other damage, or it may be subject to more severe operating conditions that the original design anticipated. The typical outcome of a fitness-for-service assessment, using API 579 standards, is a go/no-go decision on continued operation. An evaluation of remaining life and/or inspection intervals may also be part of such an assessment.
Our introduction discusses the actual application of these advancements in In-Line Inspection tools for “unpiggable” pipelines and fitness-for-service assessments for a pipeline operator in North America, which allows that operator to maintain the pipeline’s immediate and long-term integrity.