What EMI tubing inspection finds

What the scan is looking for

EMI — electromagnetic induction — inspection uses magnetic principles to read the condition of the tubing wall without touching it. It works in flowing and sand-laden environments where contact methods struggle, and it produces a digital trace rather than a subjective opinion.

• Wall loss from general corrosion, including loss on the inside surface that no visual inspection would see.
• Rod wear — the localized grooving that develops where the rod string has been contacting the tubing.
• Pitting and localized corrosion, which matters more than average wall thickness because failure happens at the worst point.
• Manufacturing and handling defects present before the joint ever went in the hole.

Why average wall thickness is the wrong number

Tubing does not fail at its average condition. It fails at its worst point. A string that averages comfortably inside tolerance can still contain a single joint with deep localized wear, and that joint sets the service life of the whole string. Scanning identifies which joints those are, so they can be pulled and the rest put back to work.

The economics

The comparison is not scan cost against zero. It is scan cost against a downhole failure: the workover rig, the fishing job if it parts, the deferred production while the well is down, and the environmental exposure if the failure reaches surface. Against that, inspecting tubing that is already out of the hole is inexpensive.

There is a second benefit that is easy to overlook. Because each scan is a digital record, repeated inspections show a rate of change. Knowing how fast a string is degrading is what turns maintenance from reactive to scheduled.

What this costs if it is missed The cheapest moment to inspect tubing is while it is already on surface during a planned job. Deciding to scan after a failure means paying for the rig twice.

Operators and technology both matter

EMI produces a trace that has to be interpreted. The same data read by an experienced operator and an inexperienced one yields different decisions. Site Safe Solutions is the only provider in the Permian Basin with ACE-Making technology and the operators to go with it.