Vocabulary for pipeline inspection matching (runcoms)

(5 Min Read – Industry) I am a data analyst. I have not seen a set of terminology that is from this perspective. These are the terms I use. I wrote this to use as a glossary for papers that I write.

Help me improve this? What is confusing? What mistakes have I made? What have I overlooked? How are things different for pipes made from polymers?

Leave me a comment below. Thank you. 🙂

• anomaly – a feature that is a discrete contiguous region of an unidentifiable pipeline inspection signal. All pipe wall defects are anomalies, but not all anomalies are pipe wall defects. An anomaly may be an aberrant sensor signal caused by a glitch.
• construction feature – a feature that is a deliberate element of the pipeline. When a pipeline inspection detects a construction feature, it is often possible to identify the physical element that made the signal. Example construction features include welds, patches, and aboveground markers.
• environmental features – a feature near the pipeline that may be seen by an inspection. Example environmental features include road crossings, slope changes, and electrical lines.
• event – a location within an inspection where there is a deviant signal. Events are reported in units of position. (Examples: distance, time, GCS coordinate) All features are events. Not all events are features.
• feature – a contiguous region of signal deviation within an inspection. A feature is a single logical entity, like a corrosion pit or the leading edge of a valve. In inspections with multiple scan lines, a feature will often span multiple adjacent scan lines.
• inline inspection (ILI) – a pipe inspection that was taken from inside the pipe and was propelled passively by the fluids or the pressure of the operating pipeline. This implies that the inspection used no active propulsion.
• inspection– a dataset collected during a single examination of a pipe, which was collected over a single time interval as a single and discrete effort.
• internal inspection – any inspection taken from the inside of a pipe. In addition to inline inspections, it includes tethered and untethered actively propelled inspections taken from inside a pipe.
• moving set – The more recent inspection, which is matched to the reference set. I call this “Inspection (B).”
• odometry – a linear measurement of the distance traveled since the start of an internal inspection. It is similar to a timestamp in that it serves as an ordered index for the data in an inspection.
• reference point – Unique or unusual features, like valves and marker plates, that are easy to identify across inspection datasets.
• reference set – The older inspection or dataset to which the moving set is matched. I call this “Inspection (A).”
• scan line – the time or distance-indexed trace from a single sensor. An inspection may have multiple scan lines if there were multiple sensors or multiple passes.

• data correlation – matching an inline inspection to an in-ditch inspection. Example: relating a defect from an in-ditch detailed inspection to a corresponding corrosion cluster from an MFL inspection
• corresponding features – inspection features representing the same physical entity in two or more inspections
• data segmentation – compare a pipeline inspection to the pipeline’s environment. Example: labeling specific dents with the local backfill material
• feature matching – finding corresponding features in two or more inspections. Features, which are signals, correspond when they represent the same physical entity at the same physical location in two inspections.
• joint matching – identifying corresponding spools across two or more inspections.
• runcom – an inspection run comparison
• run comparison – matching two or more inline inspections. Also called an inspection “runcom.” Example: estimating defect-to-defect corrosion growth rates
• weld counting – A practical and common way of implementing a runcom. This method compares the joint index number and the joint length of two inspections.

• aboveground marker (AGM) – a temporary or permanent beacon that relates a location inside the pipe to a location outside the pipe. During an inspection, AGMs are used to track a pig’s progress. Inline inspections often “see” them, making them good reference points for comparing inspections.
• geographic coordinate system (GCS) – a grid system that is overlaid on the Earth to locate points on its surface. Sometimes called “GIS coordinates,” the term “GCS” is more general, since the coordinates retain meaning even outside the context of a geographic information system (GIS).
• girth weld (GW) – a circumferential weld that joins two construction features. Most pipe inspections can detect a girth weld, so they serve as useful proxies for the pipe spools between them.
• joint – in the context of oil and gas pipelines, the term “joint” can refer to both a “pipe spool” and the “connection between pipe spools”. This is ambiguous. The meaning: “a circumferential connection between lengths of pipe” is useful. This allows the term to include girth welds, flanged joints, sockets, and others. It should be defined when used in this way.
• multi-sensor inspection ball (MSIB) – a spherical inline inspection device for liquid pipes that is smaller than the pipe diameter. These are often used for leak and theft detection.
• pig – does NOT mean “pipeline inspection gauge.” Some smartypants made this up after they were already called “pigs”. Not everything is an acronym. (See Clarion’s 2003 “pipeline pigging handbook” )
• segment – a segment is a length of pipe, usually consisting of several spools, having an agreed-upon name. Often, a segment corresponds to a length of pipe that can be inline inspected.
• small inspection device (SID) – an inline inspection device which is small enough to be used without a launcher or receiver.
• spool – a prefabricated length of pipe sized appropriately for a particular mode of transport, such as a truck. Compare this with spiral-weld pipe, which is fabricated on-site from a continuous roll of steel. Spools from the same construction project often have a uniform length.
• weld – to keep everyone on their toes, this term will sometimes refer to any connection between pipe units, including flange and bell joints. It is like saying “I’ll have a coke,” with reply “What type?”