Silica mud - coating on DP

Hello,
we are using silica mud to achieve maximum shale inhibition in Switzerland for Nagra wells coring wireline from almost top to bottom with special coring DP. 
Unfortunately we got a glassy silicate film on all surfaces, which got in contact with the silica mud. Because the clearance between inner core barrel and DP ID is small, we want to remove the silica coating and perform an MPI inspection of the DP.  
Has anyone experience how to remove the silica coating? Is there a way to prevent build up of the coating apart from flushing with fresh water after use? Actual information is, that the coating needs to be removed mechanically, there is no way to remove it with chemicals.  So it is planned in the moment to use a 100 bar high pressure washer or pearl blasting. 

Thanks in advance

Peter-Joern Palten

2 Answer(s)

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