Illuminating a Problem with Stuck Tubing

Client Case Study 

A large independent US operator was performing scheduled maintenance on downhole production equipment in a land well when they encountered a section of stuck tubing. After numerous remedial milling and cutting operations, the operator was still unable to pull a section or determine the cause of the sticking. A year after shutting the well, the operator cosidered bringing the well back online, but needed to diagnose the current condition of the fish and where it was located within the wellbore. 

Visuray ran the VR90 downhole X-ray diagnostic service to evaluate the condition of the tubing. As the well had been abandoned for more than a year, the opaque the debris-filled well fluid meant that X-ray diagnostics was the best solution.

The 2D X-ray image above showed that the outer diameter of the tubing had been reduced from the original 2.875 in to 2.68 in as a result of extensive concave milling. Furthermore, milling had squeezed the inner diameter to 1.78in, such that it was preventing the onsite fishing tools from passing into the tubing. 

The illustration on the right shows the tubing to be fairly centered in the casing, with no discernable angle of orientation, nor any pinching or collapsing of the surrounding casing that would hav prevented it from being latched with an overshot.

The VR90 X-ray diagnosis provided the operator with the precise size and location of the tubing top, which allowed them to confidently develop an appropriate intervention strategy.
 
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