Page 336 - Drilling Technology in Nontechnical Language

Chapter 13 – DRILLING PROBLEMS AND SOLUTIONS 327

with time, sticking forces will increase with time, and as more attempts
are made, the more the fish itself might become damaged or worn.

Fishing considerations for radioactive sources

If radioactive materials are contained in the fish, many governments
mandate that they must be recovered even if the cost is very high. In this

case, fishing can only be abandoned if certain rules are met (which will
change with the area and government involved), after having exhausted all

possibilities to recover the fish.
Some logging tools containing radioactive sources that are run on
drillpipe are designed so that the source itself can be recovered. A special
tool is run on wireline into the drillstring where it can latch onto the source
container and pull it back to the surface.

Summary

This chapter looked at some of the commonly encountered downhole

problems, such as lost circulation, stuck pipe, and fishing operations.
When these problems occur, the root causes plus the current status of the

well must be established before an effective strategy, specifically targeted
to solve the problem, can be formulated.

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