Russia has been building a shadow tanker fleet since the first warnings of an embargo were raised. They have been buying old tankers and using them to sell oil to Asia. Only takes a few voyages to payback their investment. See more on DW https://www.dw.com/en/russia-plans-to-sidestep-eu-oil-ban-with-shadow-fleet/video-63973242
At this time we think only about 10-20% of Russian production will be affected.

Russian Oil Embargo Already Defeated