Identifying a Well Obstruction

Client Case Study

In an offshore horizontal well, a North Sea operator encountered an unexpected restriction above the wireline entry guide. A series of lead impression block (LIB) runs failed to yield conclusive results in investigating the restriction, which was suspected to be a retrievable plug originally placed 200 meters further down the well which had been pushed upwards. 

In order to verify the operator's suspicion and decide on the most suitable fishing approach, the VR90 downhole X-ray diagnostic service was run.

The VR90 tool was tractored until it was held up at a depth of nearly 3000 meters. A first imaging sequence revealed a debris field very close to the bottom nose of the tool with a diameter which matched the inner diameter of the retrievable plug. The measured distance to the debris field and the plug dimensions were obtained, and it was determind that the tool was resting inside the plug's fishing profile.

A second imaging sequence was then performed just above the first position, outside the fishing profile. It indicated a curved unobstructed object eccentered in the well consistent with the top of the plug.

Based on the data obtained by the VR90 tool, it was deduced that the plug's fishing profile was free, filled with debris and eccentered in the well. This information allowed the operator to discard the LIB conclusions and to successfully retrieve the plug.
 
View Client Case Study PDF