Hi,
there is a regular article at http://www.diveweb.com/commdive/features/mayjune2001.01.htm on corrosion from Dr. Harvey Hack. I think they link an email address for him, he would probably have some good information for you.
Regards,
Tim
there is a company called United Energy. THey make a compound which makes the oil sludge liquify, and can still be processed later. I think they have a website running now, but do not know the address. Might be worth looking into for your application.