The mud is not abrasive. It is a lubricant, but at near 10,000 psi it will abrade slowly. The trick is to balance the gas/oil pressure with a column of heavy mud down the bore before the BOP and casings loose their integrity.
150 posted on 05/26/2010 8:11:58 PM PDT by DonnerT
(Those in power no longer fear the caliber of the ballot.)