Behind the Science - Try to guess what is the most important object in the picture (second part)

Some posts ago I published a picture asking what was the most important object in this picture that was taken on the rig floor after the casing. It has been a challenge for many persons even here in the ship. Are you ready for the answer?

Picture8 (FILEminimizer) 

The little cylinder showed in the picture is the go-devil and is going to be sent through the pipe string to allow the release of the pipe string from the casing system.

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Look at this video< to see what is going to happen right after the picture of the rig floor and if you want to know more about the casing give a look to the video "An explanation of deep sea coring" in the video collection< of the website.