Fishing a Crushed Mandrel

Evaluative Case Study

Retrieving downhole hardware is often achieved by engaging a mandrel with overshot or spear. If both techniques fail to retrieve a fish, the operator is left with quite a challenge. An impression block can be run, but this generally proves unreliable. The operator can proceed directly to milling, but this is time-consuming, costly and destructive.

Instead, the operator can run the VR90 X-ray diagnostic service to determine the cause of the failed fishing attempts.

The image (top right) obtained at Visuray’s test facilities shows a case where the mandrel has been crushed, and hence the spear tool would not fit inside nor the overshot around the mandrel. Additionally, the VR90’s dimensionally-accurate images allow the operator to design a custom fishing tool and quickly retrieve the hardware without destroying it.